SCIENTIFIC DISCOVERY SINCE THE PHYSIOCRATS

In 1779, Jan Ingelhousz showed that plants use carbon dioxide and that light is required for oxygen production.

In 1780, Spallanzani demonstrated that contact between the sperm and egg is necessary for fertilization.

In 1780, Lavoisier and Pierre Simon Laplace published their conclusion that respiration is a form of combustion.

In 1781, Cavendish synthesized water by exploding hydrogen in oxygen.

In 1781, William Herschel discovered the planet Uranus.

In 1782, Peter Jacob Hjelm discovered molybdenum.

In 1783, John Michell pointed out that a star that was sufficiently massive and compact would have such a strong gravitational field that light could not escape.

In 1783, Spallanzani said that digestion is not merely chewing but is a chemical process.

In 1783, Jacques Alexandre César Charles became the first person to ascend in a hydrogen balloon.

In 1785, Laplace, in Théorie des attractions des sphéroides et la figure des planètes, published his coefficient and the potential function, two means of analyzing physical problems.

In 1785, Charles Augustin de Coulomb said that the electrostatic force between two charged bodies is proportional to the product of the amounts of charge on the bodies divided by the square of the distance between them.

In 1786, Luigi Galvani showed that the nerves transmitted electricity, and that it was possible to control the motor nerves of frogs using electrical currents.

In 1788, Jean Senebier demonstrated that it is light, not heat, from the sun that is effective in photosynthesis.

In 1788, Joseph Louis Lagrange, in Mécanique analytique, developed that part of mechanics which deals with particles and rigid bodies using procedures general enough that they were, and still are, applicable to all calculations. Newton's "dynamical theory contains truth but not method. Lagrange's Mécanique is a method. First, one looks to see whether the system under analysis has a symmetry of some kind.... Corresponding to any symmetry there is some dynamical quantity that remains constant." Thus, often the solution to an equation "follows at once from the existence of the symmetry" (Park 1990:248-249). This work is presented solely by algebra and calculus, with no diagrams and no geometry.

In 1789, Antoine Laurent de Jussieu, in Genera Plantarium, stressed the significance of the internal organization of organisms.

In 1789, Lavoisier proved that mass is conserved in chemical reactions. He also demonstrated that glucose itself could be fermented and was made up of ethanol and carbon dioxide.

In 1789, Jeremy Bentham reoriented semantics "whereby the primary vehicle of meaning came to be seen no longer in the term but in the statement, [that is,] as the unit accountable in the empiricist critique" (Quine 1953:39,42).

In 1790, Kant, in Kritik der Urtheilskraft, said that the analogy of animal forms implied a common original type and thus a common parent.

In 1790, Johann Wolfgang von Goethe, in Metamorphose de Pflanzen, sought to discover the 'primal plant,' and coined 'morphology.'

In 1791, Goethe published "Zur Optik," which led, in 1810, to the publication of Farbenlehre, a compendium of chromatic phenomena. He sought a personalized relation to a holistic continuity of inorganic and organic nature which he opposed to Newtonian reductionism's dependence on theoretical constructs.

In 1791, Pierre Prévost proposed the theory that when a body is not at the same temperature as its surroundings, heat will flow between them.

In 1792, Alessandro Volta discovered he could arrange metals in a series in such a way that chemical energy is converted into electrical energy; that is, two dissimilar metals are submerged in an electrolyte and connected by an circuit and thereby exchange electrons. By 1800, he had invented the so-called voltaic cell, a pile of such metals.

In 1792, Jeremias Benjamin Richter published his measurements of 'equivalent weight,' that is, how much of a given acid is required to neutralize a given base.

In 1794, Erasmus Darwin, Charles' grandfather, proposed that "warm-blooded animals have arisen from one living filament...possessing the faculty of continuing to improve by its own inherent activity, and of delivering those improvements by generation to its posterity." He also suggested that the conflict between males over which "should propagate the species" had the final cause that the species "become improved" (E. Darwin 1794:505,503).

In 1795, James Hutton, a proponent of the vast antiquity of geological formations, wrote Theory of the Earth, the earliest comprehensive treatise which can be considered a geologic synthesis. Confining his attention to the earth's dynamics, he deplored speculative attempts to account for the origin of processes which could be observed in current operation. James Hall succeeded in devising experiments which reproduced in miniature the processes which, according to Hutton, are responsible for the formation of rock strata under the conditions prevailing in the earth's crust.

In 1796, Edward Jenner investigated the folk tale that milk maids were immune to small pox, the virus variola major, and in a brief series of experiments confirmed that exposure to cow pox, the virus vaccinia, rendered immunity. The principle that a survivor of a disease such as smallpox or the plague was usually able to resist a second infection had long been observed. By the late eighteenth century, vaccination was understood and employed in Turkey for smallpox. The method involved the inoculation of children on the skin with 'matter' from the pustule of a mild case. In most instances, the child showed mild symptoms and was subsequently immune.

In 1796, Lagrange called dynamics a four-dimensional geometry.

In 1796, Laplace, in Exposition du système du monde, hypothesized that the solar system was created from a spinning cloud of gas. "Gravity pulled most of the gas to the center, thereby creating the sun. At the same time, some of the material, because of its spin, could not be absorbed by the young sun and instead settled into a disk. Eventually these dregs became the planets" (Ray 2000:43).

In 1796, Carl Friedrich Gauss discovered that the regular heptagon was inscribable in a circle, using only a compass and a straightedge--the first discovery in Euclidian construction in over 2000 years.

In 1798, Thomas Robert Malthus, in his Essay on the Principle of Population, contended that population increses by a geometric ratio whereas the means of subsistence increase by an arithmetic ratio.

In 1798, Cavendish constructed a torsion balance by which he measured the mean density of the Earth. [added 9/1/00]

In 1799, Joseph Louis Proust ennunciated the 'Law of definite proportions,' which he had arrived at by showing that copper carbonate contained definite proportions of copper, carbon, and oxygen, independent of the method of preparation.

In 1799, Laplacebegan the publication of Mécanique céleste, "an encyclopedia of calculations relating to the six known planets and their satellites, to the shapes of the rotating planets, and to the tides in the earth's oceans" (Park 1990:252).

In the beginning of the nineteenth century, Franz Joseph Gall speculated that the cerebral cortex represented the highest level of the brain and that its development characterized mammals. His aim was to localize cerebral functions by introspection, i.e., phrenology, and theorized that abstract mental functions, such as secrecy or mother love, occur in discrete areas of the cerebral cortex. He further believed that each mental function, that is, each bump on the cortex, would grow through use, on analogy to muscles.

In 1800, Karl Friedrich Burdach introduced the term 'biology,' which replaced 'natural history,' which traditionally had three components, zoology, botany, and mineralogy.

In 1800, Marie François Xavier Bichat published the first of several books dealing with the pathology of tissues.

In 1800, William Nicholson and Anthony Carlisle showed that chemical reactions could be produced by electricity by decomposing water into hydrogen and oxygen in a process which came to be known as 'electrolysis.'

In 1800, Herschel hypothesized the existence of infrared beyond the visible spectrum and of radiant heat.

In 1801, John Dalton stated that the total pressure exerted by a mixture of gases is equal to the sum of the partial pressure of the individual gases.

In 1801, Thomas Young , in "On the theory of light and colors," proposed that light striking the retina creates vibrations and the frequency of the vibrations excites a particular nerve filament, "one for each principle colour" (Young 1802:20). This trichromatic theory of vision is now known as the Young-Helmholz theory. At that time, Newton's particle theory was thought by most physicists to exclude the possibility of light moving in waves.

In 1801, Gauss's research into infinitesimal calculus and algebra culminated in the publication of Disquisitions arithmeticae. In the same year, Gauss employed his 'least squares' approximation method, which fits a regression line to a set of data, to calculate the orbit of Ceres. It was published in 1808.

In 1803, Dalton applied atomic theory to a table of atomic weights, postulating that atoms can neither be created nor destroyed and that all atoms of an element are identical. He showed how "the laws of chemical combination demanded the existence of atoms, [and is] generally regarded as the founder of the atomic hypothesis" (Glashow 1991:101).

In 1804, Nicholas-Theodore de Saussure published a description of the action of photosynthesis.

In 1805, Friedrich Sertürner isolated morphine from the poppy plant.

In 1805, Alexander von Humboldt noted that species had not arisen at a single place.

In 1805, Ludolf Christian Treviranus said that spermatozoa were analogous to pollen.

In 1806, Louis Nicolas Vauquelin and Pierre Jean Robiquet isolated the first amino acid, 'asparagine,' from asparagus.

In 1806, Adrien Marie Legendre invented, independent of Gauss, a least squares method.

In 1807, Humphrey Davy revealed that alkalies and, later, earths were metallic oxides. He also advanced the theory that hydrogen is generally present in acids, and classed chemical affinity as an electical phenomena. He also isolated potassium and sodium by electrolysis and proved that chlorine and iodine are elements.

In 1807, T. Young, in Lectures on Natural Philosophy and Mechanical Arts, coined the word 'energy,' for the fundamental quantity created by the heat which moved particles in D. Bernoulli's kinetic theory. Also, Young presented experiments which verified that color was created by the wave theory of light and described the eye defect, now called 'astigmatim.'

In 1807, Jean Baptiste Joseph Fourier published the formula for a Fourier series, by which any repeated event can be defined by its phase and its amplitude and represented as a set of simple wave forms.

In 1808, Joseph Louis Gay-Lussac ennunciated the 'Law of combining volumes,' which said that when gases combine they do so in small whole number ratios.

In 1809, Jean-Baptiste Monet de Lamarck, in Philosophy Zoologique, stated that heritable changes in 'habits,' or behavior, could be brought about by the environment, that acquired characters could be achieved by selective breeding, and that the use and disuse of parts could lead to the production of new organs and the modification of old ones. His knowledge was much broader than E. Darwin's and he was the first important proponent of evolution, that is, that species, including man, were mutable over generations and adaptible to changed environments.

In 1809, T. Young applied wave theory to refraction and dispersion phenomena which led to a description in terms of transverse vibrations. In turn, this led to raising questions about the nature of ether since it was assumed to be fluid-like: Fluids can't transmit transverse waves.

In 1810, William Hyde Wollaston isolated a second amino acid, 'cysteine,' from a bladderstone.

Beginning around 1810, Jöns Jacob Berzelius, in denying the generic and hierarchical classification of chemicals, showed that, as specific properties, acidity and basicity are composed of specific components, for example, a certain degree of electro-negativity or positivity. Similarly, in his theory of salts, the oxides of qualitatively opposed radicals lay on the same ontological plane. The specificity of the radicals, not the degree of oxidation, became the chief determinant between organic and inorganic, showing that in the former "a sufficiently large number of atoms entered...to permit the manifestation of apparent transitions occasioned by relatively small differences in composition" (Melhado 1981:123).

In 1811, Amedeo Avogadro proposed that equal volumes of gases at the same temperature and pressure contain the same number of molecules. He used 'integral molecules' and 'elementary molecules' to denote what were later called the molecules of a chemical compound and the atoms of the elements of which it was composed. Later physicists determined the number of atoms in a 'mole' to be 6.02552 x 1023, and called it Avogadro's number. The reality of molecules came to be accepted by organic chemists after about 1860, but in the early twentieth century physicists still doubted their reality.

In 1812, Georges Cuvier, in Discours sur les révolutions de la surface du globe, maintained the stratigraphic succession proved that fossils occur in the chronological order of creation: fish, amphibians, reptiles, and mammals. He applied the new Jussieu approach to animals, but read the paleontological evidence to justify a succession of cataclysms, each followed by creation of new flora and fauna. At this time paleotology was still a branch of geology. Cuvier supported the idea of the fixity of species and opposed Lamarck's conception.

In 1814, Joseph von Fraunhofer devised a primitive spectroscope by allowing light to pass through a narrow slit and then a prism, obtaining Newton's rainbow with numerous sharp, narrow dark lines in fixed positions.

About 1814, Augustin Jean Fresnel and François Arago discovered that perpendicular beams of polarized light do not interfere with each other, which led to the theory of transverse theory of light waves. Fresnel also obtained circularly polarized light.

In 1815, Konstantin Sigizmundovich Kirchhof reported that wheat glutin is capable of being converted to dextrin and sugar.

In 1815, William Prout proposed that the atomic weights of elements are multiples of that for hydrogen.

In 1817, Christian Heinrich Pander described three germ layers in chick embryos.

In 1818, Étienne Geoffrey Saint-Hilaire defined the concept of 'homologous,' that is, having the same evolutionary origin, e.g., a wing and an arm, although he didn't come up with the word until 1825. A friend of Lamarck's, he found numerous evidences of the environmentally-induced disuse of parts. He "tried to combine continuity of descent with discontinuity of form by the hypothesis that new species and higher categories start from the occasional appearance of monsters capable of flourishing in an appropriate environment" (Wright 1948:916).

In 1818, W. C. Wells enunciated the principle of natural selection amount human populations, suggesting that African populations are selected for their relative resistance to local diseases.

After 1818, Gauss was employed doing geodesic surveys where, aside from writing numerous papers on differential geometry, he invented the 'heliotrope,' a device used to measure distances by means of reflected sunlight. One of the papers had to do with 'potential theory,' and another with 'Gaussian curves.'

In 1819, Arthur Schopenhauer, in Welt als Wille und Vorstellung, called "the genital organs the focus of the will [adding that] indeed, one may say man is incarnate sexual instinct, since he owes his origin to copulation and the wish of his wishes is to copulate" (Schopenhauer 1819:314).

In 1819, Hans Christian Oersted initiated the study of electromagnetism by discovering that current in a wire produces a magnetic field that curls around the wire.

In 1820, Lamarck described the origin of living things as a process of gradual development from matter.

In 1820, Christian Friedrich Nasse said that while hemophilia occurs only in males, it is passed through the female line.

In 1820, J. B. Caventou and P. J. Pelletier isolated quinine from cinchona bark.

In 1821, Augustin-Louis Cauchy, in his Cours d'analyse, established the calculus on the formalism of his concept of analytic function, divorcing the idea from any reference to geometrical figures or magnitudes and unequivalently stating that the limit must be zero for higher order infinitesimals.

In 1821, Jean François Champollion, employing the Rosetta Stone, established the principles for deciphering Egyptian hieroglyphics. T. Young, also employing the Rosetta Stone, deciphered the demotic script.

Between 1822 and 1824, John Goss, Alexander Seton, and T. A. Knight, each independently, observed the segregation of a recessive trait in peas, but kept no records of later generations.

In 1822, André Marie Ampère published his conjecture that all magnetism can be attributed to electric currents.

In 1823, János Bolyai invented a non-Euclidean geometry by assuming that one could be constructed without the parallel postulate. It was published in 1832.

In 1824, Nicholas Léonard Sadi Carnot wrote a book on the relation between heat and mechanical energy. In a series of operations, known as Carnot's cycle, he showed that even under ideal conditions an engine cannot convert into mechanical energy all the heat energy supplied to it.

In 1825, Jean Baptiste Bouillard established the location of the language function, which in fact accorded with Gall's phrenology, in the anterior cortical lobe and that there could be paralysis of this function without paralysis of the limbs.

In 1825, Christian Leopold von Buch concluded that varieties may become species through being segregated.

In 1825, George Poulett Scrope, in Considerations on Volcanos, wrote that all lava formations could be accounted for by volcanic action of an intensity no greater than the present.

In 1825, Oersted isolated aluminum.

In 1825, Michael Faraday discovered benzene.

In 1826, Nikolai Ivanovich Lobachevsky announced the development of a system of hyperbolic geometry in which Euclid's fifth postulate was replaced by one allowing more than one parallel line through a fixed point.

About 1826, Robert Grant, August Schweigger, and Friedrich Tiedemann declared themselves in favor of a common origin for

both plants and animals.

In 1826, Heinrich Olbers expressed the paradox that if the universe was infinite, the night sky would be bright with stars.

In 1827, Georg Simon Ohm discovered that the ratio of the potential difference between the ends of a conductor and the current flowing through it is constant, and is the resistence of the conductor.

In 1827, Robert Brown noticed random movement of microscopic particles suspended in fluid. This is known as Brownian movement.

In 1828, Karl Ernst Ritter von Baer, having examined the fetal anatomy of numerous species, published the view that all animals have three germ layers and that that the ontogeny of embryos proceeds from initial homogeneity to heterogeneity by stages similar to other young animals, but not by the recapitulation of the adult forms of lower animals.

In 1828, Friedrich Wöhler synthesized urea by heating ammonium cyanate. This was the first synthesis of an organic compound from inorganic material, opening a new era in organic chemistry and isomerism.

In 1828, William Rowan Hamilton predicted the existence of conical refraction and developed general equations of motion in optics, including the principle of least action. "The classical Hamiltonian expresses the energy of a dynamical system in terms of coordinates q and momenta p, and therefore takes on a continuous set of values. It cannot lead to discrete energy levels. For this reason, the Hamiltonian H is replaced in quantum theory by the Hamiltonian operator Hop" (Prigogine 1996:133).

In 1829, Charles Lyell, in Principles of Geology, built a synthesis on the methodological limitation that the past could be studied only by analogy to what natural agencies, given enough time, could accomplish in the present. His opinion that there was uniformity in the causes of change--rather than catastrophic floods--"implied that they must forever produce an endless variety of effects, both in the animate and inanimate world" (Lyell, quoted in Hardy 1965:62). In Thomas Huxley's opinion, Lyell's work bore the primary responsibility for smoothing C. Darwin's path. Wallace credits Lyell's idea that the surface of the earth was in a continual state of slow modification for making obvious to him that life must be continually adjusting to these changed conditions.

In 1829, Johann Döbereiner began the rationalization of the chemical elements he observed triadic groups whose central member was the arithmetic mean of the two outer members.

In 1829, James Mill published the first volume of Analysis of the Phenomena of the Human Mind in which he said that resemblance can be reduced to co-occurrence, a special case of what he called synchronous order.

In 1830, Robiquet and others discovered the hydrolytic splitting of the glucoside, 'amygdalin.'

In 1830, Giovanni Battista Amici traced the growth of the pollen tube down through the 'style' and into the ovule of the flower.

In 1830, Macedonio Melloni invented the thermocouple, by which the transmission of heat by various substances can be measured.

In 1831, Brown discovered the cell nucleus.

In 1831, Faraday discovered electromagnetic induction, the generation of an electric field by a changing magnetic field, thereby inventing the electric motor.

In 1833, Johannes Peter Müller published his discovery that sensation is not controlled by the stimulus but rather is dependent on the particular sense organ involved: Each sensory nerve produces its own specific sensation, e.g., any stimulation of the optic nerve results in a sensation of light.

In 1833, Marshall Hall described the mechanism by which a stimulus can produce a response independent of both sensation and volition, and coined the term 'reflex.'

In 1833, Gauss invented the electric telegraph.

In 1834, Anselm Payen and Jean-François Persoz isolated 'diastase' from barley malt and postulated the importance of enzymes in biology.

In 1834, Faraday published the fundamental law concerning electrolysis: , the passage of electricity through ionic solutions: The number of moles of a substance produced at an electrode is directly proportional to the number of moles of electrons transferred to that electrode. Besides coining electrolysis, 'electrode,' and 'ion,' he named 'electrolyte,' 'anode,' the positive pole of an electrode, 'cathode,' the negative pole, and 'anions' and 'cations,' depending on whether the ions are travelling to the anode or the cathode.

In 1834, Charles Babbage developed a mechanical calculating machine, or 'analytical engine.'

In 1835, Berzelius published the first general theory of chemical catalysis and classified fermentation as a catalyzed reaction.

In 1836, Theodor Schwann reported the action of 'pepsin' and described its properties.

In 1837, Heinrich Gustav Magnus determined that carbon dioxide released in the lungs had been carried there by blood and that more oxygen and less carbon dioxide was contained in arterial than in venous blood.

In 1837, René Dutrochet observed that chlorophyll is necessary for photosynthesis.

Also in 1837, Hugo von Mohl described 'chloroplasts' as discrete bodies within the cells of green plants.

In 1837 and 1838, Schwann, Charles Cagniard de la Tour, and Friedrich Traugott Kützing, working independently, said that "yeast was a living organism which was responsible for fermentation. This began a lengthy debate over whether fermentation was a chemical or a vital process" (German Life Science Information Service 1993:6).

In 1837, Ralph Waldo Emerson observed, "The ancient precept, 'Know thyself,' and the modern precept, 'Study nature,' become at last one maxim" (Emerson 1837:56).

In 1838, Mattias Jakob Schleiden put forward the theory that plant tissues are composed of cells, and recognized the significance of the nucleus. Schwann made a similar claim for animal tissues.

In 1838, Purkinje found that nerve cells consist of two parts, later named axons and dendrites. About this time, he also coined the term 'protoplasm,' and, with Mohl, established that the protoplasm is the living contents of a cell.

In 1838, Carlo Matteucci recorded the production by a muscle of an electric current with a galvanometer (named after Galvani).

In 1838, Gerardus Johannes Mulder published Berzelius' term 'protein.'

In the late 1830s, Richard Owen distingushed between 'homology' and 'analogy:' A wing of a bird and a bat are analogous since for flight one has feathers and the other membrane, but the bones and musculature are homologous. He supported the fixity of species.

In 1839, Mohl described the appearance of the cell plate between the daughter cells during cell division, or 'mitosis.'

In 1839, Johann Schoenlein, using a microscope, discovered a microbial parasite of humans, Trichophyton schoenleinii, which causes ringworm of the scalp.

In 1839, Christian Swann discovered the existence of ozone.

In 1839, Louis Jacques Mandé Daguerre made public his invention of the first photographic process.

In 1839, George Boole developed analytic transformations, the basis of Boolean algebra, which is of fundamental importance in the study of the foundations of mathematics, logic, and computer simulation.

In 1840, T. L. Hünefeld reported his observation of crystals in the blood.

In 1840, William Whewell introduced the word 'scientist.' Until then, science had retained its medieval denotation, truth derived from first principles, or moral science, as opposed to natural philosophy.

In 1840, Louis Agassiz published a demonstration of the existence of a glacial epoch in the temperate zones.

In 1840, Christian Friedrich Schönbein isolated 'ozone,' naming it from the Greek word ozein, to smell.

In the 1840s, James Prescott Joule and Julius Robert Mayer, working independently, established the general relationship between heat and work, which is the first law of thermodynamics, a form of the law of conservation of energy, i.e., the form of energy can be changed, but it can neither be created nor destroyed. The idea of energy, a thing without weight which could neiter be seen nor felt and had a constant value through many transformations, was not quickly adopted.

In 1841, Albrecht von Kölliker showed that spermatozoa are sex cells which arise by a transformation of cells in the testes.

In 1842, Johann Japetus Steenstrup described the alternation of sexual and asexual generations in animals and plants. In some jellyfish, the 'medusoid' stage usually reproduces sexually, giving birth to the 'polyp,' or 'hydroid,' stage, which reproduces asexually. Ferns have a 'sporophyte' generation which produces spores which give rise to a 'gametophyte' generation which reproduces sexually (Hale and Margham 1991:26).

In 1842, Christian Doppler developed the theory that the frequency of energy in the form of waves changes depending on the motion of either the sender or the receiver.

In 1843, Justus von Liebig speculated that organic acids, such as malic, tartaric, and oxalic, are intermediates in a plant's production of carbohydrates.

In 1843, James Braid suggested changing the term 'animal magnetism' to 'hypnotism,' from the Greek hypnos, to sleep.

In 1844, Karl Friedrich Wilhelm Ludwig showed that waste products are passively filtered by the 'Malpighian corpuscle' in the kidney and then concentrated as they pass through the tubules.

In 1844, Robert Chambers, anonymous author of Vestiges of the Natural History of Creation, wrote that "mental action...passes at once into the category of natural things. Its old metaphysical character vanishes..., and the distinction usually taken between physical and moral is annulled" (Chambers, quoted in Gillispie 1951:157). Chambers developed his "evolutionary theory as a metaphorical extension of von Baer's principle" (Gould 1977:110). He was crucially influenced by Comte's positivism.

In 1844, C. Darwin wrote, but didn't publish, an essay presaging the theory of the origin of species.

In 1845, J. Dzierzon reported that among bees the drones hatch from unfertilized eggs while workers and queens are from fertilized eggs.

In 1845, Adolf Wilhelm Hermann Kolbe synthesized acetic acid.

In 1845, Jacques-Joseph Moreau maintained that mental illness with its delusions and hallucinations was not the reult of stimulation, but rather the result of "a diminution of intellectual function and a disproportionate development of vestigial psychic activities" (Ellenberger 1970:290).

In 1846, William Morton demonstrated the effective use of ether as an anesthesia.

In 1846, Carl Gustav Carus published Psyche, which begins, "The key to the knowledge of the nature of the soul's conscious life lies in the realm of the unconscious.... The first task of a science of the soul is to state how the spirit of Man is able to descend into these depths" (Carus, quoted in Ellenberger 1970:207).

In 1846, the planet Neptune was discovered where Urbain Jean Joseph Leverrier and, independently, John Couch Adams had predicted a planet would be found.

In 1846, Henry Creswicke Rawlinson published his deciphering of the cuneiform of the Behistun Inscriptions.

In 1847, K. B. Reichert saw under a microscope blood which consisted of tetrahedral crystals and went some way toward demonstrating that it is protein.

In 1847, W. Bergmann pointed out that populations of warm-blooded species living in cool climates tend to be larger on average than members of the same species living in warmer climates because the surface area to volume ratio in less and, therefore, heat loss is reduced.

In 1847, A. Derbés observed the progressive lifting of the vitelline membrane which begins at the point of sperm entry in the course of fertilization.

In 1847, James Esdaile made the first systematic use of hypnotism for anesthetizing surgical patients.

In 1847, Hermann Ludwig Ferdinand von Helmholtz formulated the conservation law mathematically. He was the first to suggest that the brain commands movement in dreaming and thus gives rise to sensory images. He often spoke of perception in terms of 'unconscious inference.'

In 1847, Lambert Babo said that the addition of a solute to liquid vapor decreases the vapor pressure proportional to the amount of the solute.

In 1848, Emil Du Bois-Reymond demonstrated that the signal propagated along a peripheral nerve was a wave with a negative electrical charge.

In 1848, Louis Pasteur discovered molecular dissymmetry, or chirality. Later, he coined the distinction between users and non-users of oxygen, 'aerobic' and 'anaerobic.'

In 1848, Claude Bernard discovered the glycogenic function of the liver.

In 1848, Müller showed that one of the biological mechanisms necessary for human speech is a superlaryngeal vocal tract.

In 1848, William Thompson proposed an absolute temperature scale, known as the 'Kelvin scale,' from the title he received from the British government.

In 1850, Franz von Leydig discovered interstitial cells in the connective tissue of the testes.

In 1850, Jean Baptiste Boussingnault demonstrated that plants need only nitrogen from the soil and obtain carbon from the atmosphere.

In 1850, Rudolph Julius Emanuel Clausius, generalizing Carnot's principle, introduced the concept of 'entropy,' a measure of disorder in a system. This, the second law of thermodynamics, states that entropy can never decrease in a closed system. Thus was introduced irreversibility, i.e., time's arrow, to classical physics.

In 1851, Jean Bernard Léon Foucault demonstrated that a pendulem's swing, seen relative to the Earth, would gradually precess. This is evidence of the the Earth's rotation.

In 1851, Samuel Schwabe announced his discovery of the 11-year sunspot cycle. [added 12/29/00]

In 1851, Bernhard Placidus Johann Nepomuk Bolzano's study of paradoxes was published, three years after his death. In this work, he gives examples of one to one correspondences between elements of a set and its subset.

In 1852, Franz Unger put forth his theory of the common descent of plants.

In 1852, Georges Newport observed the penetration of the vitelline membrane of a frog egg by sperm.

In 1852, Helmholz measured the speed of nervous impulses.

In 1853, Alexander Wood introduced the hypodermic syringe just in time to be used as a morphine delivery system in the America Civil War.

In 1853, L.Teichmann discovered and named 'heme,' the non-protein, iron-bearing part of blood.

In 1853, Florence Nightingale first recommended the regimen of cleanliness which dramatically reduced the death rate in hospitals.

In 1854, Rudolph Virchow published the idea that the mechanism of disease could only be found at the level of cellular chemistry.

In 1854, Helmholtz predicted the heat death of the universe on the basis of thermodynamic theory.

In 1854, Georg Friedrich Bernard Riemann, in Ueber die Hypothesen, welche der Geometrie zu Grunde liegen, proposed another substitute for Euclid's fifth postulate representing elliptic space.

In 1855, Wallace published the principle that species are always in proximity to an allied species which precedes it in the fossil record. He deduced this from evidence in the Malay Archipelago, "which is traversed near Celebes by a space of deep ocean [which] separates two widely distinct mammalian faunas" (Darwin 1872:335).

In 1855, Bernard maintained that the constancy of a body's internal environment was aided by secretions from tissues in all organs.

In 1855, Thomas Addison described a syndrome associated with the degeneration of the adrenal cortex, subsequently known as 'Addison's Disease.'

In 1855, John Snow, investigating London's piped water supply, showed graphically that cholera could be transmitted by water from a particular pump.

In 1855, Julius Plücker drove an electric current through a vacuum tube, producing a glow of light.

In 1855, Herbert Spencer began publishing a projected ten volume work concerning the principles of synthetic philosophy, in which evolution was invoked as a universal principle that involved progress through stages toward greater complexity.

In 1856, fossils identified as an early variant of Homo sapiens were found in Neanderthal.

In 1856, Ludwig developed perfusion techniques which kept animal organs alive after their removal from the body.

In 1856, W. Thomson explained his notion "that electricity in motion is heat; and that a certain alignment of axes of revolution in this motion is magnetism" (Thomson, quoted in the Dictionary of Scientific Biography, XIII 1976:384).

In 1857, Bernard demonstrated the formation of glycogen by the liver.

In 1857, Pasteur demonstrated that lactic acid fermentation is carried out by living bacteria.

In 1858, Darwin's friends, including Lyell, arranged for the simultaneous announcement of Wallace's and Darwin's idea of natural selection.

In 1858, Friedrich August Kekulé von Stradonitz suggested that carbon atoms are formed in chains.

In 1858, August Ferdinand Möbius, while investigating the properties of one-sided surfaces, invented the so-called 'Möbius strip.'

In 1859, Darwin in On the Origin of Species by Means of Natural Selection or the Preservation of Favored Races in the Struggle for Life, asserted all life had a common ancestor and that the origin of species was natural selection acting on variants within a population and yielding differential reproduction of the most adapted, and that this was comparable to the artificial selection practiced by plant and animal breeders. Until Darwin, the conception of mutation was confused by its application to what Linnaeus identified as species, which were actually aggregates of species. Subsequently, leading anatomists, like Ernst Heinrich Haeckel, reoriented their work to the tracing of evolutionary relationships among animal groups. Darwin was an experienced geologist--in fact, he served as the secretary of the Geological Society from 1838 to 1841, and a large part of On the Origin of Species is devoted to describing geological evidence, from which he drew illustrations of "what was then a generally admitted proposition: that the forms of organic life which had succeeded each other on the earth were progressive in character.... But uniformitarianism as an attitude toward the course of nature could not be carried to its logical conclusion in a theory of organic evolution until a formulation sufficiently scientific to be compelling could attack the idea of a governing Providence in its last refuge, the creation of new species" (Gillispie 1951:217-218).

In 1859, cocaine was isolated.

In 1859, Kolbe synthesized salicylic acid.

In 1859, Riemann, in Beweis des Satzes, dass eine einwerthigemehr als 2nfach periodische Function von n Verónderlichen unmöglich ist, generalized to n dimensions Gauss's differential geometry. This created the tools for the mathematical expression of the general theory of relativity.

In 1860, Pierre Eugöne Marcelin Berthelot, in Chimie organique fondeé sur la synthöse, described the synthesis of several carbon compounds.

In 1860, Robert Wilhelm Bunsen and Gustav Robert Kirchhoff, in Chemische Analyse durch Spektralbeobachtungen, recounted their discovery of cesium and rubium and explained the Fraunhofer lines in the solar spectrum. Bunsen also explained the action of geysers and invented lab equipment. Kirchhoff formulated two laws concerning electricity: At any instant the sum of the voltages around any loop is zero and at any node the sum of the arriving and departing currents is equal.

Also in 1860, Gustav Theodur Fechner, in Elementen der Psychophysik, attempted to explain how the psychical and the physical are two aspects of one reality. He formulated the rule that, within limits, the intensity of a sensation increases as the logarithm of the stimulus. Sigmund "Freud took from Fechner the concept of mental energy, the 'topographical' concept of the mind, the principle of pleasure-unpleasure, the principle of constancy, and the principle of repetition" (Ellenberger 1970:218).

Also in 1860, Joseph Wilson Swan made an incandescent lamp using a carbon filament.

In 1860, James Clerk Maxwell, in "Illustrations of the dynamical theory of gases," showed that viscosity is independent of density.

By 1861, Paul Broca was able to further isolate the language function and showed that a lesion in the lt cortical lobe causes the loss of speech, or 'aphasia,' thus demonstrating an asymmetry that Gall had not suspected.

In 1861, Ignaz Philipp Semmelweis published his deduction that childbirth fever was transmitted on the hands of doctors during their examinations.

In 1862, Henry Walter Bates said that in 'lepidoptera,' a class of butterflies and moths, mimicry in appearance of unpalatable species by palatable species suggests that the mimics enjoy protection from predation.

In 1862, Pasteur published the germ theory: Infection is caused by self-replicating microorganisms, and that attenuated viral cultures granted immunity. These beneficent antigens he named 'vaccines' in honor of Jenner and his vaccinia virus.

[Pasteur was a proponent of 'vitalism,' which "accepted the word 'life' as a substitute for specific chemical information" (Kornberg 1989:34); hence, fermentation was "a physiological process, inseparably connected with the vital act of a microorganism known as the 'fungus offermentation'" (Sönderbaum 1929:1). According to the tenets of vitalism, there is, consequently, no reason that physics should illuminate the processes of life since they are essentially different and not reducible to one another.]

In 1862, Béguyer de Chancourtois proposed a pattern of twenty-four elements on a cylindrical table with periodicity of properties.

In 1862, Julius von Sachs produced experimental evidence that starch was a product of photosynthesis.

In 1864, Felix Hoppe-Seyler named the colorless, proteinaceous part of blood 'globin;' thus, haemoglobin. His spectroscopic reports led George Gabriel Stokes to describe, on the basis of more spectroscopic observations, the physiological function of blood as illusrated by its repeated reduction and oxidation.

In 1864, John Alexander Reina Newlands prepared the first two-dimensional periodic table of the elements. This was arranged in the order of atomic weights and remarked the 'law of octaves,' i.e., that every eighth element known at that time had similar properties. In the same year, William Odling published a chart with fifty-seven regions including some gaps. Still in the same year, Julius Lothar Meyer showed that the ability of elements to form compounds with one another varied periodically with atomic weight.

In 1865, O. F. C. Deiters proposed the image of the nerve cell which is accepted today: cell body with its nucleus, multiple, branching dendrites, and a single axon.

In 1865, Bernard observed, in Introduction à l'étude de la médecine expérimentale, that the internal environment was balanced or self-correcting, that disease states are often extreme manifestations of normal processes, and that, between living matter and the physical world, the difference is in the degree of complexity, which is greater in living systems (Bernard 1865:111-117). He was explicit in his attack on biological vitalism.

In 1865, Lister, using carbolic acid as antiseptic and sterilizing his instrument, proved the efficacy of antiseptic surgery.

In 1865, Stradonitz devised a ring model for the structure of benzene.

In 1865, Maxwell published his conclusion that the known electric, magnetic, and electromagnetic phenomena are explained by mathematical equations restating Coulomb's law, Ampère's conjecture, Faraday's law of induction, and with the addition of the inversion of Faraday's law, namely, that a magnetic field could be generated by a changing electric field.

In 1866, Gregor Mendel, in "Versuche über Pflantenhybriden," interpreted heredity in terms of a pairing of dominant and/or recessive unit characters; that is, ones that could in practice be treated as indivisible and independent particles. "What chiefly fascinated Mendel...was the nature of heredity which the vigour of grafts showed to be stronger than environment, that is, the stock on which they had been grafted. He...began to produce hybrids, not to improve the yields, but to follow the behavior of characters from generation to generation" (Jacob 1970:202-203).

In 1866, Edmund Vulpian noted that curare interrupts the communication between the nerve and the muscle fibers.

In 1866, Haeckel published his 'biogenetic law' wherein ontogeny is erroneously said to recapitulate phylogeny. However, in attempting to rationalize it, he invoked the mechanism of changes in developmental timing, coining the word 'heterochrony.' He also coined 'ecology,' 'ontogeny,' and 'phylogeny.' The recapitulation theory of development was widely held at the time, and earlier by Goethe, Johann Gottfried von Herder, and biologists associated with naturphilosophie. Haeckel's version of Darwinism persisted, e.g., in the ideas of the socialist Karl Kautsky, August Weismann, Freud, Carl Gustave Jung, and the Hitlerite Monist League (Gould 1977:115-116). Haeckel also published misleading illustrations in support of his theory.

In 1866, Max Schultze discovered two sorts of receptors in the retina.

In 1866, William Huggins made the first spectroscopic observations of a nova.

In 1867, Theodor Meynert showed that the laminated form of the cortex was due to the distribution in parallel layers of different categories of neurons.

In 1867, Helmholtz, in Handbuch de Physiologischen Optik, explained the mechanism of lens accomodation in the eye.

In 1867, Fleeming Jenkin, in a review of Origin of Species, pointed out that variation would be eliminated with an inheritance which was a blend of the parents. Blending inheritance is analogous to mixed paints. This criticism caused Darwin, in subsequent editions, to resurrect Lamarck's theory of acquired characters, which was not finally put aside until the rediscovery of Mendel and unit characters in 1900.

In 1867, Darwin, working on his theory of sexual selection and failing to understand why caterpillars are often brightly adorned, wrote Wallace, who explained his theory of warning coloration, which today is proven.

In 1867, Aleksander Onufriyevich Kovalevsky extended the germ layer concept to invertibrates.

In 1867, Wilhelm Griesinger published the second edition of his psychiatric textbook in which he said that mental diseases are brain diseases and that the onset of psychosis was experienced as an intrusion of a 'thou' on the 'I,' or ego.

In 1868, Helmholtz proposed the resonance theory of hearing.

In 1868, Maxwell published a paper on 'governors,' the first significant paper on feedback mechanisms.

In 1869, Dmitri Ivanovich Mendeléev and, independently, Julius Lother Meyer formulated the 'Periodic law.' Meyer showed that Newlands' 'Law of octaves' only holds for the first two periods. He also evolved the atomic volume curve which represented graphically the relation between the atomic weights and the volumes of the elements, expressed by dividing atomic weights by specific gravities. Mendeléev left gaps in his table where he predicted elements would be found, which, in due course, they were, removing any doubt as to the validity of the periodic table.

In 1869, Eduard von Hartmann published Philosophie des Unbewussten, in which the 'unbewussten' and the 'will' of Schopenhauer and others. Modern discussions of the unconscious are generally dated from this time.

In 1869, George M. Beard distinguished 'neurasthenia,' a nervous disease of men, from hysteria, a women's disease, as, in an earlier time, men's 'hypochondriasis' had been distinguished from women's ' vapeurs.' Subforms of neurasthenia came to be called phobias.

In 1869, Francis Galton, in Hereditary Genius, suggested a genetic basis for intelligence. He established that the science of heredity could be concerned with deviations measured in statistical units. His discovery of the standard deviation gave him the mathematical machinery to handle variability and to treat population as a unit of explanation.

In 1869, Georg Cantor published his proof of the apparent paradox which stated says that an infinite class has the unique property that the whole is no greater than some of its parts. The proof involves acknowledgement that the class of integers is infinite and countable and, then, establishing a one-to-one correspondence between the class of integers and its subset, the class of even numbers. This was the beginning of set theory.

In 1869, Charles Joseph Minard, in a graph showing Napoleon's march to Moscow and back, set a new standard for such representations plotting multivariate data: The size of the army, its location on a two-dimensional surface, its direction, and the temperature on various dates during the retreat.

In 1869, John Hyatt produced 'celluloid,' the first synthetic plastic to be put into wide use.

In 1870, Gustave Fritsch and Edward Hitzig demonstrated an inseparable link between electricity and cerebral function, but did not show where the electricity was produced.

In 1870, Camillo Golgi established that neurons in the brain sent information to the motor nerves and received it from the sensory nerves. He developed a silver impregnation method that allowed microscopic visualization of the anatomy of the whole neuron.

In 1870, Spencer, in The Principles of Psychology, suggested that learning was accompanied by an increased efficiency in the communication between neurons.

[The demonstrations of the 1870s and 1880s that the internal processes of cell division were fundamentally the same in plants and animals magnified the cell as a universal unit of structure.]

In 1871, St. George Mivart, in On the Genesis of Species, claimed that, contrary to Darwin, species arise suddenly with large-scale changes already intact: Inheritance by blending, as Darwin proposed, meant that variation would have to be sustained by an extremely high mutation rate.

In 1871, Darwin, in The Descent of Man, and Selection in Relation to Sex, suggested that there was no sharp discontinuity between the evolution of humans and animals, that "the difference was one of degree and not of kind" (Darwin 1871:127), and that, therefore, not only was the behavior of animals guided in part by primitive reasoning processes, but human behavior must also be guided in part by instincts.

In 1871, Johann Friedrich Miescher isolated a substance from the nuclei of white blood cells which is soluble in alkalis but not in acids. This substance came to be called 'nucleic acid.'

In 1872, John Thomas Gulick pointed out the inevitability of divergence among isolated groups even without environmental difference.

In 1872, Ludwig and Edward Pfünger showed that oxidation occurs in tissues, not in the blood.

In 1872, Ludwig Boltzmann, working on the kinetic theory of gases, argued that the second law of thermodynamics, and the spontaneous increase in entropy which it predicts, can only be understood in terms of large populations of particles, not individual trajectories, the primitive object of classical physics. Influenced by Darwin, he replaced the study of individual particles "with the study of populations, and showed that slight variations taking place over a long period of time can generate evolution at a collective level" (Prigogine 1996:20). By assuming that all microscopic states of a system have the same probability, he established that entropy was statistical; by the same token, he could not establish that long-term deviation from equilibrium was not impossible, even though very improbable. He proposed an equation which gives a mathematical description of a state and how it is changing.

In 1872, Felix Klein outlined his synthesis of geometric group transformations, in which he showed that there were three types of geometry: the Bolyai-Lobachevsky type where straight lines have two infinitely distant points, the Riemann type where the points are imaginary, and Euclid's type. The so-called 'Klein bottle,' with no inside, came out of these studies. The best known of his transformations is the so-called 'Klein four-group,' which was exploited by the Structuralists after the second world war.

In 1872, Claude Monet painted "Impression: Sunrise," which lent its name to Impressionism and may be used to mark the beginning of Modern Art.

In 1873, Anton Schneider described chromosomes during the process of mitosis during cell division.

In 1873, Moritz Wagner emphasized the effects of different environments on isolated groups of animals.

In 1873, Johannes Diderik van der Waals discovered the forces which were named after him.

In 1873, Maxwell, A Treatise on Electricity and Magnetism, wrote a summary of his equations in which he explained everything without mentioning ether, supposed by many physicists of the time to be the fundamental electromagnetic substance. Maxwell perceived that these equations had wave solutions and electromagnetic waves of all frequencies were generated by accelerating electric charges and travelled at the same speed. He proposed that these waves could be generated by creating a quickly oscillating current in the laboratory. He also proposed the idea that an intelligent being, i.e., 'Maxwell's demon,' could by simple inspection of molecules (i.e., without doing work) violate the second law.

In 1874, W. Betz extrapolated to the telencephalon the posterior-anterior sensorimotor dichotomy that prevails along the nerve axis, from the spinal cord to the brain.

In 1874, S. Bodkin published his observation that, in patients with leukemia, transcutaneous electrical stimulation of the enlarged spleen led to reduction in size and an increase in leukocyte count.

In 1874, Franz Brentano, in Psychologie vom empirischen Standpunkte, maintained that mental processes should be treated as intentional acts rather than passive processes. Among the auditors of classes which he taught were Edmund Husserl, Thomas Masaryk, Franz Kafka, Rudolf Steiner, and Freud.

In 1874, William Stanley Jevons, in Principles of Science, demonstrated a symbolic and logical method, intended to supplant Boole and John Venn, that involved permutations of ABC corresponding to the eight compartments of Venn's three-circle diagram. Jevons also designed labor-saving logic machines for exploiting his method, among them an 'abacus' similar to a primitive IBM punchcard machine.

In 1875, Richard Caton demonstrated that the brain's electricity originated in the cerebral cortex.

In 1875, Galton demonstrated "the usefulness of twin studies for elucidating the relative influence of nature (heredity) and nurture (environment) upon behavioral traits" (King and Stansfield 1997:382).

In the 1870s, Ernst Mach stated the principle that the inertia of a piece of matter is attributable to the interaction between that piece of matter and the rest of the universe.

Beginning in 1876 with anthrax, Robert Koch devised the method, which is still used, to isolate pure cultures of bacteria and showed the bacterial origin of many infectious diseases, including tuberculosis, cholera, bubonic plague, and sleeping sickness.

In 1876, Wallace published his special contribution to the study of evolution, The Geography of Animal Distribution.

In 1876, Carl Wernicke published a paper in which he described a new type of aphasia, involving an impairment of comprehension rather than execution, and located at a different locus from the aphasia described by Broca. According to Wernicke, interconnections between functional sites make more complex intellectual functions possible.

In 1876, Alexander Graham Bell invented the telephone.

In 1876, Nikolas August Otto designed the first four-stroke piston engine.

In 1877, Ernst Abbe published the first in a series of contributions to the theory of microscopic optics.

In 1878, F. Heinke published a study on herring, which climaxed the focus on animal studies.

In 1878, Wilhelm Wundt founded the first laboratory devoted to physiological psychology. He intuited that dreaming is the product of the simultaneous enhancement and impairment of different parts of the brain.

In 1879, Walther Flemming named 'chromatin' and 'mitosis,' made the first accurate counts of chromosome numbers,and discerned the longitudinal splitting of chromosomes.

In 1879, Jules-Henri Poincaré showed how automorphic functions can be used to express coordinates of any point in an algebraic curve as uniform functions of a single parameter.

In 1879, Max Karl Ernst Ludwig Planck, in Vorlesungen über Thermodynamik, opposed the idea that the validity of the second law depends upon the existence of an observer or his lack of information. The implication is that irreversibility is natural.

In 1879, Albert Abraham Michelson determined the speed of light to be 186,350 miles per second + or - 30 miles per second.

In 1879, Edwin Herbert Hall discovered a component of an electric field which when crossed with a magnetic field becomes perpendicular to the electric field. Known as 'Hall current,' or the 'Hall effect,' it was not explained until the advent of quantum theory.

In 1879, Gottlob Frege, in Begriffsschrift, proffered the first system of propositional calculus, also known as the calculus of sentential conjunctions.

In 1880, Sydney Ringer studied the use of body temperature in diagnosis and inorganic ions in heart contractions, making possible the analysis of heart metabolism.

In 1880, Hendrick Antoon Lorentz and, independently, Ludwig Valentin Lorenz devised equations relating the polarization of a molecule and the refractive index of a substance consisting of the same molecules.

In 1881, Wallace proposed to date the beginning of the Cambrian perd about 28 million years ago.

In 1881, Lucian Galard and John D. Gibbs obtained patents for systems of alternating electrical current.

In 1881, Venn, in Symbolic Logic, represented logical propositions diagrammatically.

In 1882, Eduard Strasburger coined the terms 'cytoplasm' and 'nucleoplasm.'

In 1882, Dmitri Iosefovich Ivanovsky demonstrated that tobacco mosaic disease is caused by "a self-replicating agent (or virus) that will pass through bacterial filters and can neither be seen with light microscope nor grown upon bacteriological media" (King and Stansfield 1997:382).

In 1883, Ilia Il'ich, also known as Élie, Metchnikoff identified the phagocyte as a purveyor of cellular defense, thereby raising questions of organismic identity, i.e., how do organisms protect themselves from their environment? He recognized that phagocytes, cells capable of engulfing particles, such as bacteria, define the 'self' constituents; that is, they devour tadpole tails as frogs metamorphosize into adults. Viewing the immune system as "self-referential, not antigen-driven," he saw inflammation as "self-directed 'immune' surveillance" (Tauber 1990:566). This biological line of investigation developed into 'humoral theory,' after the classic term for body fluids, and was driven by the need to understand what identified non-host elements. It may be noted that bloodletting did not go out of fashion until about this time.

In 1883, Edouard van Beneden, studying nuclear division associated with sexual reproduction, or 'meiosis,' in worms, discovered that, whereas the fertilized eg contains four chromosomes, the nucleus of the egg and the sperm each contain two. This finding implied that germ cells must undergo a special sort of nuclear division in which the chromosome complement is halved.

In 1883, Weismann stated that his 'germ-line theory,' namely, that the separation of the germ-line from the phenotype of the body, or soma, is final from the point in the egg's development when it is determined which cells will become the ovary or the testes--and potential immortal. In human beings, for example, this point occurs at the 59th day of gestation. This doctrine refuted Lamarck's theory that acquired characters can be inherited. It also made it possible to understand the genetics of animals (though not plants), and, hence, evolution without understanding development.

In 1883, Max Rubner said that a body's metabolic rate was proportional to its surface area.

In 1883, Oscar Hertwig described 'mesenchyme,' a term he coined for the protoplasmic network filled with a intercellular fluid which gives rise to connective and other tissue.

In 1883, Wilhelm Roux suggested that the filaments within the cell's nucleus carry the hereditary factors.

In 1883, Karl Georg Friedrich Rudolf Leuckart and A. P. Thomas, independently, working on the life cycle of sheep liver flukes, determined the snails were intermediate hosts.

In 1883, Galton advocated selective breeding of human beings, or 'eugenics,' which he coined from a Greek word meaning "hereditarily endowed with noble qualities" (Galton 1883:24). Eugenics was discredited through the uses to which it was put, especially during the 1930s and 1940s.

In 1883, George John Romanes published Mental Evolution in Animals, the first modern text comparing the psychology of humans and animals in objective terms.

In I883, Jean-Martin Charcot was able to obtain recognition of the neurological reality of hypnotism from the French Academy of Sciences. He thought only hysterics were susceptible to hypnosis, i.e., that hypnosis was itself a pathological condition.

In 1883, Pierre Curie discovered piezoelectricity, a form of electric polarity, in crystals.

In 1883, Mach, in Die Mechanik in ihrer Entwicklung, translated as The Science of Mechanics: A Critical and Historical Account of Its Development, attempted to eliminate metaphysics by reducing science to the sum of what appears to the senses, and, in particular, attacked Newton's assumption that absolute rotation is observable. "The object of science [is] to replace, or save experiences, by the reproduction and anticipation of facts in thought...; [but] we never reproduce the facts in full..., only that side of them which is important to us, moved directly or indirectly by practical interest" (Mach 1883:481-482). Concepts both compete for adherents and adapt to facts and to one another in order to survive. Mach also did work in the field of ballistics, where the 'Mach number' borrows his name.

In 1883, Osborne Reynolds introduced the 'Reynolds' number,' a dimensionless quantity associated with the smoothness of the flow of a fluid, which characterizes laminar and turbulent flow by relating kinetic to viscous forces.

In 1883, Gottlieb Daimler patented the gasoline combustion engine.

In 1884, A. Kossel isolated a protein from the nuclei of goose erythrocytes and called them 'histones.'

In 1884, Julius Kollman described the phenomena of 'neoteny' in his study of the axolotl form of Ambystoma tigrinum.

In 1884, J. Hughlings Jackson published his speculation that the neuropathological dissolution of function tends to roughly reverse the order of the acquisition of that function.

In 1884, Freud published a paper in which he found cocaine, an alkaloid in coca, effective against fatigue and neurasthenia.

In 1884, Jacobus Hendricus van't Hoff explained the principle of equilibrium in chemical dynamics and osmotic electrical conductivity.

In 1884, Edwin A. Abbott, in Flatland: A Romance of Many Dimensions, recounted the adventures of 'A. Square,' a character who inhabits a two-dimensional world populated by other geometrical figures--triangles, squares, pentagons, hexagons, etc. Toward the end of the story, on the first day of 2000, a spherical creature from 'Spaceland' carries A. Square off to show him the three-dimensional nature of the larger world. There A. Square speculates that Spaceland may itself exist as a subspace of a larger four-dimensional universe, an "infallible confirmation of the series [of end-points of a line, a square, a cube, etc.], 2, 4, 8, 16" (Abbott 1884:on line).

In 1884, Hilaire de Chardonnet invented the first artificial textile, which was made from cellulose. It was later named rayon.

By 1885, Oscar Hertwig and Strasburger developed the conception that the nucleus is the basis of heredity. Subsequently, Hertwig asserted that from the biological point of view sex merely the union of two cells.

In 1885, Roux, testing Weismann's idea of heredity and germ plasm, did one of the first experiments in what became experimental embryology when he showed that embryonic chick cells could be maintained alive in a saline solution.

In 1885, Friedrich Wilhelm Nietzsche completed Also sprach Zarathustra in which he created the term 'id,' meaning the resevoir of human instinctual drives. Other psychological terms employed frequently in his writings include sublimation and inhibition.

In 1886, Hippolyte Bernheim published his argument that hypnotism was a special case of general human suggestibility; i.e., anyone could be hypnotized.

[In the course of the nineteenth century, the practice of hypnotism brought with it greater popular, as well as medical, awareness of the split between conscious and unconscious behavior, as may be seen in the stories of E. T. A. Hoffman, E. A. Poe, Honoré de Balzac, Alexander Dumas, Victor Hugo, R. L. Stevenson, Fyodor Dostoevsky, and others (Ellenberger 1970:158-170). Greater experience with hypnotism also brought disillusion with its limitations, e.g., sensitized patients confirming their doctor's unspoken expectations, etc.].

In 1886, Pierre Janet, in L'Automatisme Psychologique, introduced the term 'subconscious' in the context of patients' fixed ideas.

In 1886, Richard von Krafft-Ebing, in Psychopathia Sexualis, included among his classifications the terms 'sadism' (after Donatien de Sade) and 'masochism' (after Leopold Sacher-Masoch).

In 1887, Wilhelm His discovered that in the early stages of development the nervous system is made up of independent, closely packed cells without axons.

In 1887, Auguste Forel showed that certain degenerative effects remained limited to the cell body and its dendrites.

In 1887, Svante August Arrhenius announced the theory of electrolytic dissociation which says that in aqueous solution the molecules of all acids, bases, and salts are split into ions. This theory depends on van't Hoff's equilibrium principle.

In 1887, Albert Abraham Michelson and E. W. Morley refuted the atmospheric 'aether' hypothesis which had predicted the presence of aether, or something lighter than air, through which light waves would move, on analogy to sound waves moving through air. It is now established that light waves are nothing but waving electric and magnetic fields.

In 1887, Heinrich Rudolf Hertz produced Maxwellian electromagnetic waves, the first radio waves. He demonstrated that they travel at the velocity of light and can be reflected, refracted, and polarized like light. The unit of frequency was named in his honor.

In 1888, Roux removed from a frog's egg one of the two cells existing after the first cleavage and obtained a half embryo.

In 1888, Santiago Ramón y Cajal, employing Golgi's staining technique, launched attacks on the 'nerve-net hypothesis' by demonstrating, the anatomical independence of the axon from its target cell, i.e., that neurons are juxtaposed, not continuous. At the time it was not realized that nerve cells do not interact through cell bodies,but through their axons and dendrites. This permitted two hypotheses: that of the nerve-net or continuous network and that of the neuron or contiguous, but independent cells. This question was not settled until the increased resolving power of electron microscopy after 1950.

In 1888, George Henry Falkiner Nuttall showed the blood serum contained bactericidal substances, from which he concluded that phagocytes were merely accessory to the protection offered by serum.

In 1888, Heinrich Wilhelm Gottfried Waldeyer named Roux's filaments 'chromosomes.'

In 1888, Theodore Boveri described the 'centriole' which in animals and most plants lies just outside a cell's nucleus.

In 1888, Nicola Tesla patented his invention of alternating electric current.

In the late 1880s, Louis Lewin and Arthur Heffter isolated the peyote alkaloid, mezcal.

In 1889, Wallace published his book on natural selection, which he called Darwinism.

In 1889, George FitzGerald suggested that the results of the Michelson-Morley experiment could be explained by the shrinkage of a body due to motion at speeds close to that of light.

In 1889, Giuseppe Peano postulated five properties of natural numbers in attempting to be as rigorous with numbers as Euclid had been with geometry.

In 1890, Boveri and Jean Louis Guignand established the numerical equality of paternal and maternal chromosomes at fertilization.

In 1890, Hans Driesch separated two cells of a fertized sea urchin egg by shaking with very different results than Roux: From a single cell arose an entire sea urchin. Roux's frog experiment was repeated and by merely turning the cell over it developed into a whole frog. Thus, a cell's competence to develop fully was established. Roux was not deterred by this result and continued to maintain, against Weismann's germ-line theory, that the mechanics of development were distributed throughout the cytoplasm and triggered by each prior stage.

In 1890, Richard Altmann reported the presence within cells of organisms which live as intracellular symbionts, and were later named 'mitochondria.'

In 1890, Emil Adoph von Behring and Shibasaburo Kitasato showed that antitoxins, that is, antibodies, could be produced--without any knowledge of their chemical nature--which neutralized the soluble toxins, classically, diptheria, tetanus, and botulism.

In 1890, Theobold Smith demonstrated the transmission of disease by an 'arthropod vector,' a tick.

In 1890, William James, in Principles of Psychology, accepted the idea that all behavior derives from the nervous system. He also suggested that learning is accompanied by an increase in neuronal efficiency, and that primary memory, or short-term memory, is memory of the immediate past still in consciousness where it is the object of selective attention.

In 1890, Eugen Bleuler declared that 'dementia praecox' was curable.

Before 1890, Herman Hollerith invented a punch card tabulator which was used in the United States Census of I890. [added 11/25/00]

In 1891, Marie Eugene Dubois discovered 'Javaman,' now known as Homo erectus.

In 1891, Waldeyer named nerve cells 'neurons.'.

In 1891, George Redmayne Murray successfully treated hypothyroid patients with a preparation of sheep thyroid.

In 1892, Poincaré published the first of three volumes on celestial mechanics in which he made fundamental mathematical discoveries, such as his demonstration that dynamical systems are non-integrable, i.e., they are neither static nor deterministic. He also identified the reason for this, which is the existence of resonances between the degrees of freedom of, e.g., harmonic oscillators. His memoirs on 'analysis situs,' as it was then called, marked the beginning of modern topology.

In 1892, Lorentz, in the course of updating Maxwell's equations, proposed that light waves are the result of oscillations of an electric charge in the atom.

In 1893, Andreas Franz Wilhelm Schimper proposed the idea that the photosynthetic parts of plant cells came from cyanobacteria.

In 1893, Freud and Josef Breuer published *Fber den Psychischen Mechanismus Hysterischer, marking the beginning of psychoanalysis. They claimed that "hysterics suffer mainly from reminescences" (Breuer and Freud 1893:7).

In 1893, Michaelson completed the measurement of the standard meter in terms of the wave length of the red line of the cadmium spectrum, providing an absolute and reproducible standard.

In 1894, William Bateson, in Materials for the Study of Variation, emphasized the importance of discontinuous variations and described and named homeotic mutations.

In 1894, H. J. H. Fenton discovered a reaction, to which he lent his name, now considered to be one of the most important mechanisms of oxidative damage in living cells.

In 1894, Ramón y Cajal, combining and extending the ideas of E. Tanzi and E. Lugaro, proposed the plastic, or functional, change hypothesis for neuronal growth, according to which synapses on associative pathways are able to strengthen through use and to make new associations through learning.

In 1894, George Oliver and Eduard Albert Sharpey-Schaeffer demonstrated the effect of an extract of the adrenal gland, that is to say, a hormone, which contracted blood vessels and muscles and raised blood pressure.

In 1894, Emil Fischer suggested that a cell contains a chemically active substance whose geometrical configuration is complementary to that of another substance, fitting it like a key in a lock. These studies still form the basis of our notions of enzyme specificity.

[["From the time of Carnot on, when it was discovered that the new science of thermodynamics did not require any sort of picture or model to explain the nature of heat, there had been a widespread hostile attitude among Continental physicists [Mach is one example] to any form of hypothetical model in science. By [the time of Boltzmann, Planck, and Hertz], however, new developments in physics were requiring fresh patterns of explanation, and these warranted complex mechanical hypotheses" (Janik and Toulmin 1973:143)]].

In 1894, Hertz, in Principien der Mechanik, having studied Maxwell's theory which was entirely equations, noted that mathematical formulas could confer a logical structure on physical reality, creating 'possible sequences' of observed events.

In 1894, John William Strutt and William Ramsay discovered argon. [added 9/11/00]

In 1894, Oliver Joseph Lodge invented the 'coherer,' a detector used in early radio receivers.

In 1895, Richard F. J. Pfeiffer presented the theory that bactericidal substances in the blood, or "Antikörper," were "highly active" and "were formed 'under the influence' of the body's cells and were consumed in the process of destroying bacteria" (Keating and Ousman 1991:248).

In 1895, Smith produced a blood deficiency disease in guinea pigs by depriving them of leafy vegetables.

In 1895, Johannes Eugenius Bülow Warming, in Plantesamfund (which was translated as The Ecology of Plants in 1909), plotted the distribution of plants against temperature and moisture.

In 1895, Wilhelm Conrad Röntgen observed a new form of penetrating radiation, which he named X-rays.

In 1895, Guglielmo Marconi sent longwave wireless telegraphic, or radio, signals over a distance of more than a mile.

In 1896, Romanes promulgated the notion that behavior is species-dependent and phyletic, or inherited. He also coined the term 'Neo-Darwinism' in order to differentiate pre- and post-Weismannian concepts of evolution.

In 1896, Conwy Lloyd Morgan, James Mark Baldwin, and Henry Fairfield Osborn, each independently, proposed a theory of how acquired characters could be inherited. Lloyd Morgan concluded that evolutionary changes in anatomy can give rise to new behavior patterns. Baldwin named his version 'Organic Selection' "since it required the direct cooperation of the organism itself." The idea behind this so-called 'Baldwin effect' is that learning creates habituation which, in turn, provides the adaptive occasion for selection, or "overproduction with survival of the fittest" (Baldwin 1896:546,548-549).

In 1896, Ferdinand Isidore Widal introduced serological diagnosis through his discovery that typhoid patients agglutinate typhoid bacilli.

In 1896, Eduard Buchner discovered a chemical in yeast, which he called zymase. He noted that the crushed yeast, that is, cell-free yeast, fermented sugar. This observation opened the era of modern biochemistry.

In 1896, Freud suggested analyzing childhood conflicts in the study of neuroses. He also devised a psychoanalytic technique called 'free association' which allows emotionally-charged, repressed material to be consciously recognized. Over the next few years, Freud expanded his interpretive repertoire to include "dreams..., slips of the tongue, bungled actions, the forgetting of names, and what he called 'screen memories' (vivid but essentially counterfeit recollections from childhood)" (Kerr 1993:76).

In 1896, Pieter Zeeman discovered that a single spectral line splits into a group of closely spaced lines when the substance producing the line is subjected to a uniform magnetic field. This is known as the 'Zeeman effect.'

In 1896, Antoine Henri Becquerel discovered radioactivity in uranium.

In 1897, Paul Ehrlich determined that a toxin was toxic because it had a chemical, i.e., molecular, structure complementary to the molecular structure of the susceptible cell. If there were no matching receptors, this meant there was no disease. If there were some matches, but the cell did not have enough receptors to deal with all the toxins, the cell would produce more and release them into the blood. This was the first selective theory of antibody formation. By 1900, he had revised this theory to mintain that antibodies were continuously formed under normal conditions.

In 1897, Charles Sherrington named the junction between the neurons, a 'synapse.'

In 1897, Christiaan Eijkman proved that in a rice diet only rice with hulls intact would prevent 'beriberi.'

In 1897, Gabriel Bertrand designated certain inorganic substances co-enzymes because they were necessary to activate certain enzymes.

In 1897, Felix Hoffman synthesized a form of acetysalicylic acid that enabled the mass production of aspirin two years later.

In 1897, Jean Henri Fabre observed a series of stereotypic sequences in insect behavior, later named fixed-action patterns' by Konrad Lorenz.

In 1897, Joseph John Thomson demonstrated that cathode rays consisted of units of electrical current made up of negatively charged particles of subatomic size. Believing them to be integral to all matter, he hypothesized a model of atomic structure in which negatively charged particles, or electrons, were embedded in a sphere of positive electricity.

In 1897, Wilhelm Fliess suggested that all organisms were fundamentally bisexual, with the implication that adolescence is as much a time of sexual repression as of sexual flowering.

In 1897, Peirce attempted to publish a topographical system of symbolic logic which he belived could give geometric expression to any conceivable assertion or logical argument. "Once a formal structure had been adequately graphed, it could then be experimented upon in a manner similar to the way a scientist experiments with a structure in nature" (Gardner 1982:56).

In 1898, Osborne enunciated the evolutionary concept of 'adaptive radiation,' the descent from an ancestral form of related species occupying and exploiting different types of available habitats.

In 1898, Stokes suggested that X-rays were pulses of radiation emitted when electrons, ejected from a cathode, hit a target.

In 1898, Edward L. Thorndike devised the first reliable technigues for measuring learning in animals.

In 1898, Marie Sklodowska Curie and P. Curie discovered and isolated radium and polonium.

In 1898, J. Thomson showed that neon gas consisted of two types of ions, each with a different charge, or mass, or both. This raised the possibility that varieties of a single element might exist with the same atomic number but differ in mass.

In 1898, Wilhelm Carl Werner Otto Fritz Franz Wien, while studying streams of ionized gas, identified a positive particle equal in mass to the hydrogen atom, which later was named the 'proton.'

In 1898, Ramsey and Morris Travers discovered neon, krypton, and xenon.

In 1898, James Dewar liquified hydrogen.

In 1899, Charles O. Whitman , working with pidgeons, and Oskar Heinroth, working with ducks, independently discovered that the stereotypic responses of birds could be used as a taxonomic criteria for phylogenetic classification.

In 1899, the sixth edition of Emil Kraepelin's textbook, Psychiatrie, codified a diagnostic distinction, based on outcome statistics, by adding dementia praecox to 'manic-depression' and 'paranoia.'

In 1899, Ernest Rutherford characterized the radiation from radium as being quite complex, easily absorbed, and stopped by a few centimeters of air. These he named 'alpha rays.' He also characterized uranium radiation as far more penetrating. These he named 'beta rays.'

In 1899, Becquerel showed that radioactivity in uranium consists in charged particles that are deflected by a magnetic field.

["Up to the end of the nineteenth century, the minimum estimates of geologists were far in excess of the maximum which the physicists would allow for the age of the solar system on the basis of known sources of energy radiated by the sun. When the enormously greater energy from conversion of mass became known, there was no difficulty in reconciling estimates. It became possible indeed to determine the age of certain deposits from knowledge of the rate of transformation of uranium into lead with much more confidence than from estimates of rates of deposition.... [Thus] the apparent lack of evolutionary change in the last 6000 years [was] seen to be of no significance" (Wright 1948:920).]

In 1900, Julius Bernstein suggested that nerve impulse is produced by the temporary collapse of the cell membrane.

In 1900, the significance of Mendel's work was realized when there were three independent accounts of it by Hugo Marie de Vries, Carl Erich Correns, and Erich von Tschermak von Seysegegg.

In 1900, Karl Pearson developed the chi-square, or c2, test, a statistical procedure that enables the determination of how closely an experimental set of values conforms to theoretical expectation.

In 1900, Planck introduced the Quantum Theory, the hypothesis that oscillating atoms absorb and emit energy, or light, only in discrete bundles, or 'quanta,' rather than continuously, as classical physics would have it. Quanta are now known as photons.

In 1901, de Vries devoted his book, in Die Mutationstheorie, promulgated the principle characters, or genes, and the speculation that that made possible, namely, evolution of species by discontinuities, or 'saltations,' rather than by imperceptible gradations. This led to Darwin's eclipse for some years, at least, for those biologists who believed with de Vries that mutation superceded selection as the cause of evolution.

In 1901, Richard Bucke proposed the possibility of man's evolution from self-consciousness to 'cosmic consciousness.'

In 1901, Josiah Royce contended that "the distinction between Self and the not-Self had a predominently social origin" (Royce 1901:245).

In 1901, Planck discovered the first indications of the granular structure of electromagnetic radiation while working on the spectrum of blackbody radiation.

In 1901, Oliver Heaviside and, independently, Arthur E. Kennelly predicted the existence of an atmospheric layer, later named the ionosphere, that would reflect radio waves. This encouraged Marconi, the following year, to make a successful attempt to send radio signals across the Atlantic ocean. [revised 12/29/00]

In 1902, W. Bateson, in Mendel's Principles of Heredity: A Defense, in which he demonstrated that Mendel's principles apply also to animals. In the same year, he coined 'allomorph,' and, before 1909, also 'genetics,' 'homozygote,' 'heterozygote,' and 'epistatic.'

By 1902, Karl Landsteiner found that human blood could be divided into one of four groups, A, B, A-B, and O, thus making transfusions safe.

In 1902, E. Overton supported Bernstein's idea with evidence that exogamous sodium ions were responsible for the impulse.

In 1902, Ivan Pavlov combined associative learning with reflex acts, postulating the existence of associated stimuli, or 'conditioned responses.' Later, he also described two non-associated behavioral modifications, 'habituation' and 'sensitization.'

In 1902, Lucien Claude Cuénot proposed that a gene plus two enzymes controlled hair color in mice; if both enzymes were present, it was grey, or if only one, it was black.

In 1902, Josiah Willard Gibbs introduced population dynamics into physics by using an ensemble of points described by a probability distribution, or function. This function has a simple physical interpretation which is the probability of finding at a certain time t a point in the small region of phase space around the point q at momentum p. Gibbs also formulated the conception of chemical potential.

In 1902, Bertrand Arthur William Russell found the 'ultimate paradox:' If the set of all sets which do not contain themselves nonetheless contains itself, then it cannot belong to the set of all sets which do not contain themselves. If it does not contain itself, then it must belong to the set of all sets which do not contain themselves.

In 1903, the beginning of cytogenetics occurred when, in independent accounts, Bovari and Walter Stanborough Sutton pointed out that chromosomes permutated themselves in cell division, halved their complement in germ cell formation, and paired again in fertilization, in a "physical dance that kept perfect step with Mendel's abstract algebra" (Judson 1979:206).

In 1903, Willem Einthoven invented a string galvanometer which enabled him to produce the first electrocardiogram, or graphic record of the action of the heart.

In 1903, Richard Kraus distinquished natural, or normal, antibodies from acquired immune antibodies according to their 'avidity,' or strength. Both Ehrlich and Landsteiner, in contrast, were intent on reducing the difference to one of quantity.

In 1903, Metchnikoff, in Études sur la nature humaine, translated as The Rhythm of Life, argued that death from old age was only to be feared because of the accompanying pain and that, as science advanced and old age became less onerous, a natural wish to die would manifest itself.

In 1903, Orville Wright and Wilbur Wright achieved flight in a manned, gasoline power-driven, heavier-than-air flying machine.

["The emergence of genetics coincided with the redefinition of the term heredity to refer exclusively to transmission: what had previously been seen as two aspects of a single subject (transmission and development) came to be regarded as distinct concerns. By the early decades of the twentieth century, the study of transmission had become the province of genetics, whereas that of development--now split off from genetics--continued as the province of embryology" (Keller 1995:4-5). At the same time as thinking about evolution turned from Haeckelian comparative anatomy and Weismannian speculation to the laboratory, embryologists shifted Haeckelian phylogenetic recapitulation and Weismannian concentration on heredity to a concern for experiment and developmental mechanics, specifically to His's immediate causes of morphologies and Roux's Entwicklungsmechnik, or developmental mechanics. Unlike many cytologists, and later geneticists, who centered their investigations on the chromosomes, embryologists centered theirs on the cytoplasm of the egg. The geneticists were essentially reductionist; the embryologists integrative or holistic. Genetic methods were designed to look for differences through interbreeding; embryological methods, for commonality.]

In 1904, Nuttall, using precipitin tests of blood serum proteins, inferred the close phylogenetic relationship between humans and apes.

In 1904, T. R. Elliott recognized that chemical agents, and specifically adrenaline, acted as neurotransmitters in peripheral nerves, helping the nerve signal across the synapse.

In 1904 and 1905, Arthur Harden discovered that the presence of phosphate was essential to the enzymes which ferment sugar.

In 1904, Lorentz formulated the so-called 'Lorentz transformation,' which describes the increase in mass, the shortening of length, and the time dilation of a body moving at speeds close to that of light, by which the space-time coordinates of a moving system can be correlated with those of any other system.

In 1904, Hantaro Nagaoka proposed a 'Saturn model' of the atom with a nucleus and many electrons in a ring around it.

In 1904, Ramsey discovered radon.

In 1904, L. P. Teisserenc de Bort published the results of 581 free balloon ascents in which instruments measures the temperatures and pressures in the atmosphere to a height of about 14 km. [added 11/25/00]

In 1905, Metchnikoff introduced the theory that white blood cells are able to engulf and kill bacteria.

In 1905, Nuttall demonstrated the importance of bacteria for digestion.

In 1905, John Newport Langley discovered acetycholine, but it was not recognized in the brain until F. McIntosh did so in 1941.

In 1905, F. Knoop deduced the beta-oxidation of fatty acids.

In 1905, Edmund Beecher Wilson, author of Cell Biology in Development and Heredity (published in 1896 and numerous later editions and others), discovered that the X chromosome is linked to the sex of the bearer.

In 1905, Freud, in Drei Abhandlungen zur Sexualtheorie, redrew the line between normality and mental illness: "Not some mysterious hereditary degeneration read back into infancy, but an otherwise normal childhood experience that would bear a resemblance to the adult behavior (or in the case of neurosis, to adult repressed fantasy)" (Kerr 1993:93). In the same year, in a postscript to another paper, Freud argued that patients sought to reexperience old erotic situations by transferring them to their physician.

In 1905, Albert Einstein evolved the 'special theory of relativity' by working out the consequences of two postulates: The laws of nature are the same for all frames of reference in uniform relative motion and light is propagated at a constant velocity which is independent of the movement of the emitting body and the observer. In other words, observers in motion with respect to one another will disagree about length and time in the other's system. This theory "led to the discovery that time is associated as a fourth coordinate on an equal footing with the three coordinates of space, and that the scene of material events, the world, is therefore a four-dimensional, metrical continuum" (Weyl 1918:201). It also resulted in mathematical equations which confirmed the 'Lorentz transformations' and contained not only the velocity of a moving body relative to the observer, but c, the velocity of light. [added 11/25/00]

In 1905, Einstein sought an explanation for the photoelectric effect, the anomaly that electrons are emitted from the surface of a metal only if the incident light is of sufficiently short wave length. Einstein determined that a quanta of light, which he called a 'photon, in order to break the attractive forces holding the electrons in the metal, would have to impart the required energy, which, according to Planck's radiation law is Planck's constant times the light's frequency. "This elegantly quantified reversion to Newton's corpuscular theory of light by Einstein was one of the milestones if the development of quantum mechanics" (Dictionary of Physics 1997:387-388). [added 11/25/00]

In 1905, Einstein, by inverting Boltzmann's statistical formula for the distribution of gas molecules, derived the probability of a macroscopic state in terms of the entropy associated with it.

In 1906, W. Bateson and Reginald Crundall Punnett reported less-than-independent assortment, or 'linkage,' in gene alleles on the same chromosome in sweet peas.

In 1906, Sherrington showed, in his book The Integrative Action of the Nervous System, that those cells which send their fibers and impulses directly to the limb muscles can be influenced to fire by excitation or not to fire by inhibition.

In 1906, Frederick Gowland Hopkins noticed that 'accessory food factors,' later called vitamins, were essential to the growth of rats.

In 1906, Poincaré published a paper on the dynamics of the electron in which he obtained, independently of Einstein, many of the results of the special theory of relativity. In fact, in 1904 or earlier, it was he who gave the name the 'principle of relativity' to the proposition that, since the universe contains no standard of absolute rest, anything is moving only in respect to something else. However, he postulated nonelectric forces, or 'stresses,' to give stability to an electron; these were rendered irrelevant by quantum theory. [revised 11/25/00]

In 1906, Andrei Andreyevich Markov described sequences of randomly linked probability variables in which the future variable is determined by the present variable, but is independent of the way in which the present variable arose from its predecessors. These 'Markov chains' launched the theory of stochastic processes.

Beginning in 1906, Ferdinand de Saussure lectured on the structural principles of general linguistics, including the reciprocity of phonemes and the opposition of diachrony and synchrony.

In 1907, Ross Granville Harrison cultivated amphibian spinal cord, demonstrating that axons are extensions of single nerve cells. In so doing, he invented tissue culture.

In 1907, Alois Alzheimer characterized the senile degeneration to which he loaned his name.

In 1907, Arrhenius coined the term 'immunochemistry.'

In 1907, Hermann Minkowski coupled space and time into a four-dimensional continuum, providing a framework for all later mathematical work in relativity. "Henceforth space by itself, and time by itself, are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality" (Minkowski 1908:75).

In 1907, Luitzen Egbertus Jan Brouwer completed his doctoral dissertation on the logical foundations of mathematics which marked the beginning of the Intuitionist School.

In 1908, Archibald Edward Garrod, in Inborn Errors of Metabolism, recognized that gene products are proteins and showed that certain rare, inherited disorders were caused by the absence of specific enzymes. W. Bateson, in 1902, had suggested to him the probability that an inherited disorder was due to a recessive gene.

In 1908, Godfrey Harold Hardy worked out the equilibrium formula for a population heterogenous for a single pair of alleles: Assuming the truth of Mendel's laws (and generalizing them), the resulting combinations will expand into the binomial distribution, or p2(AA) + 2pq(Aa) + q2(aa), where p is the initial frequency of the dominant A in a population and q the initial frequency of the recessive a. This formula was derived independently by Wilhelm Weinberg, and is thus known as the Hardy-Weinberg equilibrium formula. It provided the first baseline for assessing the effects of mutation.

In 1908, William McDougall, in An Introduction to Social Psychology, postulated that human beings have as many as a dozen different basic instincts, e.g., curiosity, pugnacity, self-abasement, etc.

In 1908, J. A. Millikan determined the probable minimum unit of an electrical charge, that is, of an electron.

In 1908, Planck, attacking Mach's position that physical theories were based solely on sense data, held that "the physicist creates the system of the physical world by imposing form upon it..., creat[ing] the mathematical structures which organize empirical facts" (Janik and Toulmin 1973:138).

In 1908, Ernst Zermelo founded axiomatic set theory.

In 1909, Charles D. Walcott discovered the Cambrian Burgess Shale fossils.

In 1909, Andrija Mohorovicic observed a discontinuity within the Earth that marks the junction between the crust and the mantle.

In 1909, reports by Correns and Erwin Baur described the non-Mendelian inheritance of a factor influencing chloroplast development, thus beginning the recognition of extra-nuclear or cytoplasmic genetics.

In 1909, F. Meves proposed that mitochondria originate from preexisting structures of the same kind and carry their own heredity.

In 1909, Wilhelm Johannsen published Elemente der exakten Erblichkeitslehre which was concerned with how to grow pure lines of beans in view of the fact that natural selection can influence change only if there is genetic variability. To this end he distinquished between 'genotype' and 'phenotype,' the one being variant due to heredity and the other being due to environment. Naming Mendel's algebraic units 'genes,' Johannsen understood that to mean that each gene underlies a single trait.

In 1909, W. Bateson, in a much expanded new edition of Mendel's Principles of Heredity, echoed Mivart's idea that what was selected was born fit. Bateson believed that the variation giving rise to new species was saltational, but present fromthe beginning of life and waiting for disinhibition and expression. He coined the term 'genetics,' but abjured theorizing: Heredity, the Mendelian variations which he encountered in experiments, failed to explain big changes. By contrast, Pearson assumed that selection brought about stable varieties or species based on the small, incremental differences or gene frequencies in individuals belonging to groups of vast size.

In 1909, Kørbinian Brodmann published a map of the cortex with 52 areas, each with a function. This map is still in use.

In 1909, Edward Tyson Reichert conceived the ambition to plot the evolutionary relationships among species by the divergences between their hemoglobin molecules. To this end he published six hundred micrographs of hemoglobin crystals.

In 1909, Charles Jules Henri Nicolle showed that typhoid fever is caused by body lice.

In 1909, Hans Geiger and E. Marsden, under Rutherford's direction, scattered alpha particles with thin films of heavy metals, providing evidence that atoms possessed a discrete nucleus.

In about 1909, David Hilbert's work on integral equations established the basis for his subsequent work on infinite-dimensional space, which came to be called 'Hilbert space.'

In 1910, Francis Peyton Rous induced a tumor using a filtered extract of chicken tumor cells.

In 1910, Konstantin S. Mereschovsky published an essentially modern view of the bacterial origin of what later came to be called eukaryotic cells.

In 1910, Thomas Hunt Morgan discovered the white-eye sex linkage in Drosophila, relating it to Mendel's recessive traits, and thus initiating fruit fly genetics. His insistence that genes were not just logical constructs from Mendelian ratios developed into the general theory of linkage within a chromosome, according to which the strength of the linkage is inversely proportional to the likelihood that a crossover will occur during meiosis. Later, he maintained that cytoplasm could be ignored in studying genetics.

In 1910, P. Boysen-Jensen proved the existence of 'auxins' which are chemicals instrumental in the the growth of higher plants.

In 1910, Alfred North Whitehead and Russell, in Principia Mathematica, put forth the theory that there is a discontinuity between a class and its members and attempted to overcome certain logical paradoxes by the formal device of branding them meaningless.

In 1911, Alfred Henry Sturtevant, an undergraduate student of Morgan's, constructed the first rudimentary map of the fruit fly chromosome, establishing the genes are real. By 1917, the map was sufficiently continuous to be published.

In 1911, Casimir Funk isolated a crystal, which came to be known as B-complex, and coined the name 'vitamine.'

In 1911, Bleuler renamed dementia praecox 'schizophrenia.'

In 1911, Rutherford described the atom as a small, heavy nucleus, surrounded by electrons.

In 1911, Charles Thomson Rees Wilson developed the 'cloud chamber,' a device in which the paths of particles of ionizing radiation are made visible. The excess moisture in supersaturated vapor is deposited on the tracks of the ions.

In 1912, Alfred Lothar Wegener proposed a unified theory of continental drift.

In 1912, J. F. Gudernatsch, working with frogs, found that removing the thyroid gland prevents metamorphosis and that feeding thyroid extracts induces precocious metamorphosis.

In 1912, John Broadus Watson launched his polemic favoring the objective study of psychology as physicochemically-based behavior and reputiating introspection as unscientific. He denied the value of studying either consciousness or instinct, suggesting one could never be certain that a given behavior is free of learning.

In 1912, Jung conceptualized and named 'introvert' and 'extrovert,' and suggested the study of current conflicts for insights into the triggering of repressed, infantile contents.

In 1912, Max Theodor Felix von Laue obtained the first diffraction effects by letting X-rays fall on a crystal. Almost immediately, William Lawrence Bragg proposed a simple relationship between an X-ray diffraction pattern, or characteristic interference pattern, and the arrangement of atoms in a crystal that produced the pattern, thereby inventing X-ray crystallography.

In 1912, Louis Carl Heinrich Paschen and Ernest E. A. Back discovered that atomic line spectra have a splitting pattern in a very strong magnetic field.

In 1913, Lawrence Joseph Henderson proposed that the concept of fitness, which in animals is the relative ability to transmit its genes to the next generation, be extended to the environment. This has ramifications for the origin of life.

In 1913, Shiro Tashiro discerned slight increases in carbon dioxide production by stimulated nerves.

In 1913, C. Fabry and M. Buisson reported the existence of ozone, a gas created by a photochemical reaction between sunlight and oxygen. [added 11/25/00]

In 1913, Henry Gwyn-Jeffreys Moseley bombarded the atoms of various elements with X-rays and found that the wavelength decreased in proportion to the increase in the atomic weight of the element emitting the rays. From observing the wavelength, he discovered that the inner stucture responded in a characteristic group of lines, enabling the assignment of 'atomic numbers.' The periodic table turned out to coincide with these numbers rather than, as had been supposed, the atomic weight.

In 1913, Niels Bohr, applying the Planck quantum hypothesis to Rutherford's atomic model and postulating stable states and single frequencies, was able to calculate closely the frequencies of the spectrum of atomic hydrogen. This supported his proposal that electrons moved around the nucleus in restricted orbits and his explanation of the manner in which the atom absorbs and emits energy, and was the first theory of quantum mechanics.

In 1913, Frederick Soddy discovered that different forms of the same element were, in fact, groups of elements with the same chemical character, but varying in their masses. To express this new found complexity of matter, the term isotopic element, or isotope, was used.

In 1914, Nicholas Vaschide published his hypothesis that sleep is not just the absence of being awake, but is a vital instinctual, i.e., biological, process.

In 1914, Arthur Stanley Eddington hypothesized that spiral nebula were actually distant galaxies.

In 1915, Jacques Loeb, in The Organism as a Whole, maintained that a complicated organism was unimaginable without a prestructure in the egg which he characterized in colloidal chemistry terms. He also maintained that behavior consisted in stereotypic movements, directly elicited and controlled by sensory stimuli.

In 1915, Morgan, Sturtevant, Calvin Blackman Bridges, and Hermann Joseph Muller published The Mechanism of Mendelian Inheritance.

In 1915, Bridges discovered the first homeotic mutation in Drosophila, 'bithorax.'

In 1916, Gilbert Newton Lewis said that the chemical bond consists of two electrons held jointly by two atoms.

In 1916, Einstein completed the mathematical generalization of the theory of relativity. This included gravity as a determinant in the curvature of the space-time continuum, i.e., "a ray of light will experience a curvature of its path when passing through a gravitational field, this curvature being similar to that experienced by the path of a body which is projected through a gravitational field" (Einstein 1916:127). This theory replaced the Kepler-Newton theory of planetary motion, which was based on the assumption of an absolute space, with one which is able to account for the slow rotation, in the direction of motion, which the orbital ellipse of a planet undergoes. Employing Riemann's non-Euclidean geometry and equations which are highly non-linear, Einstein was able to predict radically new phenomena: the bending of starlight by the sun, the precession of the perihelion of Mercury, and the gravitational collapse of stars into 'black-hole.'.

In 1916, Karl Schwarzschild showed that, by the general theory of relativity, a star collapsing under its own gravitational force would cease to radiate energy beyond a certain parameter. This parameter is known as the the 'Schwarzschild radius' and passing it creates black-holes.

In 1916, Arnold Sommerfield modified Bohr's atomic model by specifying elliptical orbits for the electrons.

In 1916, Irving Langmuir concluded that adsorption, the condensation of gas on a surface, is a single molecular layer thick and chemically bonded to the surface. It is not, as most thought, analogous to the physical attraction which holds the earth's atmosphere.

In 1917, J. Schmidt demonstrated that the differences between individuals in a population were genetic. Richard Benedict Goldschmidt, in 1920, and Francis Bertody Sumner, in 1924, demonstrated it in other populations. Their findings caused the downfall of the mutationalist and Lamarckian theories of de Vries and Bateson and "permitted a selectionist interpretation of slight differences among local populations that were obviously caused by differences in the environment" (Mayr 1959:4).

In 1917, D'Arcy Thompson, in Growth and Form, took basic body plans and changed the size and position of the parts relative to one another in geometric ways, showing how evolution might have proceeded. His thesis was that form "is determined by its rate of growth in various directions, hence rate of growth deserves to be studied as a necessary preliminary to the theoretical study of form" (Thompson 1917:51).

In 1917, Landsteiner found that antibodies could be produced which reacted with synthetic haptens, that is to say, with incomplete antigens which are unable to induce antibody formation. This finding seemed for a long time to support a template model of antibody formation.

In 1917, James Hopwood Jeans submitted an essay in which he described a general theory of the configuration of equilibrium of compressible and non-homogeneous masses of astronomical matter, enabling him to explain the behavior of certain nebulae and describe the evolution of gaseous stars.

In 1918, Ronald Aylmer Fisher wrote the initial paper, "The correlation of relatives under the supposition of Mendelian inheritance," of what came to be known as population genetics, the joining of Mendelian experiments with a statistical approach to large populations.

As early as 1918, Paul Portier became convinced that mitochondria were direct descendents of bacteria.

In 1918, Bridges, working with Drosophila, suggested that gene duplications promote the evolution of organisms toward greater complexity.

In 1918, Hermann Klaus Hugo Weyl produced the first unified field theory in which the electromagnetic and gravitational fields appeared as a property of space-time.

In 1918, Ludwig Wittgenstein, in Tractatus Logico-Philosophicus, pointed out that "what can be said at all can be said clearly; and whereof one cannot speak thereof one must be silent" and "the sense of the world must lie outside the world" (Wittgenstein 1918:27,183).

In 1919, Harry Steenbock demonstrated the relationship between the plant pigment 'carotene' and vitamin A.

In 1919, Ernst Spath produced a synthetic version of peyote's psychoactive alkaloid, which he called 'mescaline.'

In 1919, Pierre Janet pointed out that the hypnotic condition must be learned by the subject: If the subject has never heard of hypnotism, it is unlikely that he can be hypnotized.

In 1919, E. Rutherford discovered the proton and published the first evidence of artificially-produced splitting of atomic nuclei; that is, he produced hydrogen through the bombardment of nitrogen with alpha radiation.

In 1919, Francis William Aston designed the mass spectograph and discovered neon isotopes with it, enabling him to explain nonintegral atomic weights. This revealed that the helium atom was less massive than four hydrogen atoms, pointing to the transmutation of the first two elements. [revised 12/29/00]

In 1919, Eddington led a team of astronomers who measured the bending of starlight by the gravitational pull of the sun, thus confirming Einstein's general theory of relativity.

In 1920, Hermann Staudinger began to work on macromolecules, such as proteins, which had hitherto been thought by many to be aggragates. Others questioned the strength of the atomic forces.

In 1920, Otto Loewi showed that the terminal branches of nerve fibers release stimulating and inhibiting chemicals.

In 1920, Friedrich A. von Hayak, in The Sensory Order, postulated that all perception is a product of memory and an act of classification of the qualities of objects and events performed by maps of cortical cells. These interconnections are reinforced by the experience of prior contact. This essay was not published until 1952.

In 1920, Jung, in Psychologische Typen, first used the term 'anima,' a word borrowed from Plato, who used it to represent the soul of the individual. Jung used it to represent the archtype of the mediator between consciousness and the collective unconscious (for men; for women, he used 'animus'). Ignoring these mediators meant the failure to acknowledge all parts of a cognitive whole with the consequence that the hidden part would be dominant.

In 1920, E. Rutherford postulated the existence of the neutron.

In the early 1920s, it was ascertained that there were two sorts of nucleic acid, deoxyribonucleic acid and ribonucleic acid.

In the early 1920s, Victor Jollos hypothesized that the disappearance of environmentally-induced acquired traits even after hundreds of generations indicated that there acquisition should be assigned to the cytoplasm rather than the nucleus.

In 1921, Frederick Grant Banting and Charles Herbert Best isolated insulin while working on pancreatic secretions.

In 1921, Felix d'Hérelle discovered bacterial viruses which he named 'bacteriophage.'

In 1921, Langley described the autonomic nervous system and its functions.

In 1921, Hopkins isolated gluthione.

In 1921, Theodor Kaluza wrote down Einstein's field equations in five dimensions. This reproduced the usual four-dimensional gravitational equations plus Maxwell's equations for the electromagnetic field. In other words, according to this hypothesis, electromagnetism is not a separate force, but an aspect of gravity in a higher dimension.

In 1922, Muller raised the question of the relationship of genes to viruses, or 'naked genes.'

In 1922, Herbert Spencer Gasser and Joseph Erlanger, working together, and Edgar Douglas Adrian found that the electric pulses within neurons caused chemicals to be released and that their rate of conduction was proportional to the thickness of their sheaths.

In 1922, Walter Garstang showed that phylogeny is not the cause but the product of different ontogenies.

In 1922, Elmer Verner McCollum led a team which showed that rickets is caused by a lack of a new food factor, vitamin D.

In 1922, Alexander Friedmann proposed a realistic model of an expanding universe which was consistent with Edwin Hubble's observations of red-shifts and Einstein's general theory of relativity. This model assumed that the universe was relatively uniform and predicted the the beginning and the end of time occur for dynamical reasons.

In 1923, Oswald Avery demonstrated that different types of pneumococci had different and specific exterior capsules and that bacteria are of distinct, heritable varieties.

In 1923, Bridges discovered chromosomal translocation in Drosophila.

In 1923, Otto Heinrich Warburg reached the conclusion that "cancer cells differ from non-cancer cells, including growing embryonic cells, by their failure to suppress glycolysis in the presence of oxygen" (Krebs 1981:20). Today, it is realized that this only one of many ways cancer cells differ; it is a symptom and not the primary cause.

In 1923, Robert Feulgen discovered a selective staining technique for DNA localization, which is still in use.

In 1923, Lloyd Morgan, in his book Emergent Evolution, used the word 'emergent' to show that higher orders are not mere resultants of what went before, but were qualitatively new.

In 1923, Thorsten Ludvig Thunberg characterized photosynthesis as an oxidation-reduction reaction in which carbon dioxide is reduced and water is oxidized.

In 1923, Johannes Nicolaus Brönsted' published his theory of the acid-base phenomena according to which any group of atoms that gives up a proton is called an acid, etc. In the same year, Lewis published his theory that neutralization accounts for the coordinate covalent bond between the acid and the base. His theory incorporated Brönsted proton theory as a special case.

In 1923, Jean Piaget, in Le Langage et la pensée chez l'enfant, maintained that child development proceeds in the same sequence of genetically determined stages.

In 1923, Eddington published The Mathematical Theory of Relativity, considered by Einstein the finest presentation of the subject in any language.

In 1923, Arthur Holly Compton demonstrated an increase in the wave lengths of X-rays and gamma rays when they collide with loosely bound electrons. This verified the quantum theory since the effect requires the rays be treated as particles rather than waves.

In 1923, Vladimir Zworykin invented the iconoscope television camera-tube.

In 1924, Aleksander Ivanovitch Oparin published his speculation that life, that is to say, metabolism + self-reproductivity (but not replication) + mutability, is preceded by the formation of mixed colloidal units, called coacervates, and is the inevitable result of chemical self-organization.

In 1924, John Burdon Sanderson Haldane began a series of papers in which gene frequency substitutions in a population were treated systematically.

In 1924, Alfred Lotka, in Elements of Physical Biology, compared the global eco-system to "a great world engine" in which "plants and animals act as coupled transformers of energy" in "the mill-wheel" that is driven by "solar energy" (Lotka 1924:331-335). Lotka gave analytical substance to the vision intuitively adopted by field biologists. Population ecologists took the 'logistical equation' for population growth, which is in fact based on an analogy with autocatalytic chemical reactions, from his book.

In 1924, Satyendranath Bose derived Planck's black box radiation law from photon statistics, that is, independent of classical electrodynamics.

In 1924, Louis Victor de Broglie hypothesized that a moving electron has wave-like properties.

In 1924, Eddington derived the various mass-luminosity relations of stars. [added 11/25/00]

In 1925, Raymond Arthur Dart published his discovery of a skull of a new species, Australopithecus africanus.

In 1925, Gilbert Adair published his determination of the correct size of the hemoglobin molecule and subsequently wrote the equation for hemoglobin's cooperativity.

In 1925, George Richard Minot and William Parry Murphy noticed that feeding raw liver aids in the treatment of 'pernicious anemia.' Their discovery led to the isolation of vitamin B12.

In 1925, Vannevar Bush designed the differential analyzer, predecessor of the analog computer.

In 1925, Theodor Svedberg designed the ultracentrifuge.

In 1925, S. A. Goudsmit and George Eugene Uhlenbeck assigned angular momentum to electrons and established that they have the quantum mechanical property of 'spin,' which is to say that "spin always comes in fixed discrete units that are integer multiples of one-half times Planck's constant h divided by 2p. (Davis and Brown 1988:21-22). Planck's constant has a value of 6.63 x 10-34 J-sec.

In 1925, Wolfgang Pauli perceived the principle that no two electrons in the atom can be in the same quantum state; in other words, two electrons must have opposite spin, thus cancelling each other, and there can be no more than two in the same orbital. This is known as the 'Pauli exclusion principle.'

In 1925, E. Ising published a one-dimensional model of ferromagnetism in an attempt to explore the problem of atoms in a solid, each with a magnetic moment and a spin. This model demonstrated that the energy of the system is taken to be proportional to the amount of magnetism and that at any temperature above absolute zero there would be no spontaneous magnetism. One- and two-dimensional models have applications for phase transitions and interfaces in semiconductor technology.

In 1925, Gustaf Ising published a proposal for a 'linear accelerator.' [added 12/29/00]

In 1925, Pierre Auger discovered that the ejection of an electron without the emission of a X- or gamma-ray photon is the result of the de-excitation of an excited electron within the atom.

In 1926, James Batcheller Sumner crystallized urease.

In 1926, Sturtevant found the first gene inversion in Drosophila.

In 1926, Warburg discovered a CO-sensitive iron porphyrin enzyme which catalyses cell respiration.

In 1926, Vito Volterra published his deduction of the nonlinear differential equation which describes the fluctuating balance of prey/predator populations: If prey increase, predators will also until prey decrease. As the predators starve, the prey increase. The two populations fluctuate out of phase with each other due to the length of the gestation period delaying the population peaks; i.e., the predator population is still growing after the prey population has begun to decline. This equation is similar to Lotka's logistic growth equation, although based on classical mechanics and W. R. Hamilton's principle of least growth. It is sometimes called the Lotka-Volterra equation.

In 1926, Werner Heisenberg proved that it is impossible to determine with perfect accuracy both the position and the velocity of a subatomic particle, such as an electron, thus converting absolute certainties into relative probabilities. Expressed as an inequality, one may say the smaller the uncertainty about position, the greater the uncertainty about velocity, and vice-versa. Max Born and Pasqual Jordan collaborated with Heisenberg in setting up the matrix algebra to adequately describe it.

Later in 1926, Erwin Rudolf Josef Alexander Schrödinger initiated the development of the final quantum theory by describing wave mechanics, which predicted the positions of the electrons, vibrating as Bohr's standing waves. The mathematics itself is the deterministic 'classical' mathematics of classical waves. It in no way acknowledges the actual phenomena, a minute flash which propagates the wave, or indeterminism, which enters when the intensity of the wave of related to the probable location of the flash. Born's interpretation of the mathematics is fundamental.

In 1926, de Broglie attempted to obviate the quantum mechanical conundrum 'wave or particle' by maintaining instead that it is 'wave and particle,' reasoning that "quantum phenomena do not exclude a uniform description of the micro and macro worlds..., system and apparatus" (Bell 1987:175).

In 1926, Oscar Klein, attempting to explain what happened to Kaluza's fifth dimension, proposed that we do not notice it because it is "'rolled up' to a very small size [and that] what we normally think of as a point in three-dimensional space is in reality a tiny circle going round the fourth dimension" (Davies and Brown 1988:49).

In 1926, R. Watson-Watt proposed the name 'ionosphere' for the conducting atmospheric layer. [added 12/29/00]

In 1926, Gregory Breit and Merle Tuve measured the distance to the ionosphere by measuring the time needed for a radio signal to bounce back. [added 12/29/00]

In 1926, [?] Busch focused a beam of electrons with a magnetic lense, laying the foundations of electron optics.

In 1926, Jan-Christian Smuts coined 'holism.'

In 1927, Muller demonstrated that the X-irradiation of sex cells in Drosophila causes an increased number of mutations, enabling mutations to be created experimentally.

In 1927, Landsteiner discovered the M and N blood groups.

In 1927, Martin Heidegger published Sein und Zeit, an original analysis of human existence. Unnoticed at the time in psychiatric circles, it later became the basis for 'existential analysis.'

In 1927, Bohr, after discussions with Heisenberg, took the position, which came to be known as the Copenhagen interpretation, that the impossibility of simultaneously measuring a particle's position and its velocity, the 'complementarity principle' as he called it, is engendered by the measurement process. Measurement is a means of communication, and communication requires a common time. "Every atomic phenomena is closed in the sense that its observation is based on a recording...with irreversible functions" (Bohr, quoted in Prigogine 1996:156).

In 1927, Born and Julius Robert Oppenheimer devised an adiabatic approximation in which "the motion of atomic nuclei is taken to be so much slower than the motion of the electrons that, when calculating the motions of electrons, the nuclei can be taken to be fixed positions" (Dictionary of Physics 2000:47). An adiabatic approximation occurs when the time dependence of parameters are slowly varying.

In 1927, George Paget Thomson diffracted electrons by passing them in a vacuum through a thin foil, thus verifying de Broglie's wave hypothesis.

In 1927, Einstein and Leo Szilard applied for a patent on a pump for liquid metals using a magnetic field to induce a ponderomotive force on a closed current loop in the fluid conductor. These pumps are used to circulate liquid sodium coolant in nuclear reactors. [added 12/29/00]

In 1927, Georges Lemaître proposed the 'big-bang' theory of the origin of the universe. One important implication is that the universe is not infinite, which incidently explains away Olbers' paradox.

In 1927, Richard Buckminster Fuller began the exploration of geodesics, "the most economical relationship between two events" (Fuller 1975:373), such as spherical great circles. This led to the development of geodesic domes, in the early 1940s, and the dymaxion map, patented in 1946.

In 1928, Albert Szent-Györgi showed that hexuronic acid was vitamin C and proposed the name L-ascorbic acid.

In 1928, Heinrich Otto Wieland and Adolf Otto Reinhold Windaus determined the structure of the cholesterol molecule.

In 1928, Lewis Stadler induced mutations in maize using ultraviolet light.

In 1928, Alexander Fleming discovered penicillin, a relatively innocuous antibiotic because it interfered with the synthesis of cells walls, a process specific to bacteria, rather than with metabolism.

In 1928, Frederick Griffith discovered that live pneumococci could acquire genetic traits from other, dead pneumococci.

In 1928, Linus Pauling, in "The Shared Electron Chemical Bond," wrote that "in the case of two hydrogen atoms in the normal state brought near each other, the eigenfunction...corresponds to a potential [that] causes the two atoms to combine to form a molecule. This potential [involves] an interchange of position of the two electrons forming the bond, so that each electron is partially associated with one nucleus and partially with the other. [This] leads to the result that the number of shared bonds possible for an atom of the first row is not greater than four, and for hydrogen not greater than one" (Pauling 1928:359-360). An eigenfunction is a function of an operator which yields a state that when acted on by that operator yields the same state multiplied by a number.

In 1928, George Gamow explained the lifetimes of alpha radiation using the Schrödinger equation.

In 1928, Rolf Wideröe and, independently, Szilard invented linear accelerators of a more advanced design than the one G. Ising had proposed. In his patent application, Szilard said, "The electric field can be conceived of as a combination of an electric field in accelerated motion from left to right and an electric field of decelerated motion from right to left. The device is operated in such a way that the velocity of the accelerated ion equals, at each point, the local velocity of the field moving from left to right" (Telegdi 2000:26). [added 12/29/00]

In 1928, Weyl created a matrix theory of continuous groups and discovered many of the regularities of quantum phenomena could best be understood by means of group theory.

In 1928, John von Neumann conceived 'game theory.'

In the late 1920s, it was found that deoxyribonucleic acid (DNA) was located exclusively in the chromosomes, whereas ribonucleic acid (RNA) was located mainly outside the nucleus.

In 1929, Haldane showed that the development of organic compounds took place before the first living things.

As early as 1929, Frank MacFarland Burnett came to believe that "resistant [to viruses] bacterial variants are produced by mutation in the culture prior to the addition of virus [and that] the virus merely brings the variants into prominence by eliminating all sensitive bacteria" (Luria and Delbrück 1943:491-492). "Where the mutational change to resistence is correlated to a change of phase, from smooth to rough or vice-versa, the change of the [antigenic make-up of the cellular] surface must be a direct result of the mutation" (Luria and Delbrück 1943:510).

In 1929, Fisher, in The Genetical Theory of Natural Selection, provided a mathematical analysis of how the distribution of genes in a population will change as a result of natural selection, and maintained that once a species' fitness is at a maximum, any mutation will lower it.

In 1929, K. Lohmann, Cyrus Hartwell Fiske, and Y. Subbarow isolated 'adenosine triphosphate' (ATP) and 'phosphocreatine' from muscle extracts.

In 1929, Adolf Friedrich Johann Butenandt and Edward Adelbert Doisy isolated 'estrone,' a sex hormone, from urine.

In 1929, Jung, in a commentary on Das Geheimnis der goldenen Blüte, translated as The Secret of the Golden Flower, began an exploration of the significance of alchemical symbolism in depth psychology for the resolution of conflicts of opposites. Over the following 25 years, he expanded the study of mandorlas, noticing analogies between quadripartite schemes, e.g., father-son-spirit-mother, black-red-green-gold, etc., and taking them to be archetypal ideas.

In 1929, Robert Jemison van de Graaf developed an electrostatic particle accelerator.

In 1929, Szilard disputed Maxwell, showing that 'inspection,' or information, is inevitably associated with a decrease in entropy; that is, the energy gained by the discriminations of the Demon will be wholly offset by the energy spent in acquiring the information on which the discriminations are based.

In 1929, Hubble observed that all galaxies are moving away from each other. Analyzing their light spectra, he noted a persistent redshift, and explained this in terms of the Doppler effect: The light is receding because the farther away it is the greater the redshift.

In 1929, Paul Adrien Maurice Dirac published his quantum mechanical equation which describes the electron in interaction with the photons of the electromagnetic field.

In 1930, Friedrich Breinl and Felix Haurowitz published a proposal for a template theory of antibody production.

In 1930, Gavin de Beer formalized the morphological modes in which ontogenetic acceleration and retardation could produce evolution.

In 1930, Fisher discussed stable, or equilibrium, states of the sex ratio in terms which later came to be called game theory. Taking random fluctuation of allelic populations into account and treating the processes of gene frequency as stochastic processes, he concluded that chance effects were negligible.

By 1930, Phoebus Aaron Levene had "elucidated the structure of mononucleotides and [shown them to be] the building blocks of nucleic acids. He also isolated the carbohydrate portion of nucleic acids and distinquished deoxyribose from ribose" (German Life Science Information Service 1993:14).

In 1930, Ernest Orlando Lawrence published the principle of the cyclotron which is using a magnetic field to curl up the particle trajectory of a linear accelerator into into a spiral. [revised 12/29/00]

In 1930, Subrahmanyan Chandrasekhar calculated that "white dwarfs more massive than 1.4 suns would collapse under their own weight, paving the way for the theoretical prediction of neutron stars and black-holes" (Begelman and Rees 1996:30).

In the early 1930s, the Theoretical Biology Club, at Cambridge University, adopted the process philosophy of Whitehead, in which the metaphysics of static substances is replaced by an ontology in which 'things' are actually emerging processes (Depew and Weber 1995:416). John Desmond Bernal, Joseph Needham, and Conrad Hal Waddington were members.

In the 1930s, Hans Spemann insisted that cell differentiation was the outcome of an orderly sequence of specific stimuli, namely, chemical inductive agents, which were predominantly cytoplasmic in operation.

In the 1930s, André Lwoff established that bacteria were biochemical systems generally comparable to the cells of higher organisms. Using them as experimental creatures, Lwoff determined that vitamins were either coenzymes or precursors.

Beginning in the 1930s, Boris Ephrussi's primary interest was genic action, the chain of reactions connecting a gene with a character, which bears on the general problem of differentiation. Using yeast, he concluded that hereditary variations arose not from the selection of pre-existing mutations but were induced by the environment.

Beginning in the 1930s, K. Lorenz, Nikos Tinbergen, and Irenäus Eibl-Eibesfeldt investigated natural, as opposed to contrived, animal behavior, and were able, by using comparative analysis of closely related species, to discern stereotyped natural behavior structures or episodes (thus making the notion of 'instinct' respectible). This study of innate and learned responses and the interaction between them is called ethology.

In 1931, Harriet B. Creighton and Barbara McClintock, working with maize, and Curt Stern, working with Drosophila, provided the first visual confirmation of genetic 'crossing-over.'

In 1931, Sewall Wright concluded that 'random drift,' or chance fluctuation of allelic populations, was a significant factor in evolution. This was opposite to Fisher's opinion. (It should be noted that at this period the assumptions necessary in order to quantify genes resulted in much over-simplification).

In 1931, Ulf Svante von Euler isolated the peptide 'substance P.'

In 1931, Pauling published "The Nature of the Chemical Bond," detailing the rules of covalent bonding.

In 1931, Harold Clayton Urey discovered deuterium, or heavy oxygen. Subsequently, he isolated isotopes of heavy oxygen, nitrogen, carbon, and sulphur.

In 1931, Hans Albrecht Bethe provided a solution to the one-dimensional Ising model on which most subsequent solutions to the two-dimensional model depend.

In 1931, Pauli predicted the existence of the 'neutrino.'

In 1931, Kurt Gödel published his proof that the axiomatic method has inherent limitations, namely, because the consistency of a set of axioms cannot be derived from itself, it is incomplete, thus showing the aims of Frege , Hilbert, and Russell could never have been achieved.

In 1931, Karl Jansky discovered naturally occurring radio emissions from outer space.

In 1931, Herbert Butterfield characterized the 'Whig interpretation of history' as "the tendency in many historians to write on the side of the Protestants and Whigs, to praise revolutions provided they have been successful, to emphasize certain principles of progress in the past and to produce a story which is the ratification if not the glorification of the the present" (Butterfield 1931:v).

In 1932, Haldane introduced the term 'altruist.'

In 1932, A. Bethe conceptualized 'pheromones,' chemicals secreted by animals and insects for communication.

In 1932, M. Knoll and Ernst August Friedrich Ruska invented the prototype of the electron microscope.

In 1932, Franz Moewus initiated studies on sexuality in a flagellated protozoa, the green algae Chlamydomonas, and subsequently demonstrated that unicellular organisms possessed genes that behave in the classical Mendelian way.

In 1932, Walter Cannon, in The Wisdom of the Body, maintained that the body's steady state is regulated by negative feedback mediated by the autonomic nervous system through the sympathetic and parasympathetic divisions of the hypothalamus.

In 1932, James Chadwick discovered the neutron.

In 1932, Carl Anderson discovered the positron, or positive electron, fulfilling Dirac's prediction, while studying cosmic rays.

In 1932, Heisenberg proposed a model of the atom in which protons and neutrons exchange electrons to achieve stability. [added 9/1/00]

In 1932, John Douglas Cockcroft and Ernest T. S. Walton built the first linear accelerator with which they bombarded lithium with protons, producing helium and achieving the first artificial nuclear reaction. [added 9/1/00]

In 1932, von Neumann, in Mathematische Grundlagen der Quanten Mechanik, dealt with the dualistic paradox by emphasizing the role of the observer, saying that it is we, and our consciousness, who produce the collapse of the wave function, not 'hidden variables.'

[The dualistic paradox may be thought of on analogy to the field anthropologist's problem: After meeting the anthropologist, 'primitive' people are changed by the encounter; or, as Bohr thought, analogous to the partition between subject and object, the movability of which enables us to talk about ourselves (Petersen 1968:3-4). However, in practice the distinction between wave and particle, between classical and quantum, makes very little difference. The distinction is made for a particular application depending on how much accuracy or completeness is desired. "It is the toleration of such an ambiguity, not merely provisionally but permanently, and at the most fundamental level, that is the real break with the classical ideal.... Indeed good taste and discretion, born of experience, allow us largely to forget, in most calculations, the instruments of observation" (Bell 1987:188-189)].

In 1932, Bernhard Schmidt invented a new type of telescope which made possible sharp photographs of wide areas of the sky.

In 1932, George Kingsley Zipf published the scaling relationships which are now known as Zipf's law, namely, that ordered quantities are apt to be inversely proportional to their rank, that is, proportional to 1, 1/2, 1/3, 1/4, etc.

In 1933, Arne W. K. Tiselius invented an electrophoresis apparatus which permitted the separation of charged molecules.

In 1933, Goldschmidt concluded that evolution was the result of sudden changes by successful mutations that act on early embryological processes.

In 1933, John Howard Northrop crystallized 'pepsin' and 'trypsin.'

In 1933, Hans Adolf Krebs and K. Henseleit discovered the 'urea cycle,' a circular pathway in liver cells in which excess ammonia, produced by the breakdown of amino acids, and carbon dioxide react together creating urea, which is filtered by the kidneys and excreted.

In 1933, M. Goldblatt and von Euler discovered 'prostaglandins.'

In 1934, Bernal began the structural analysis of proteins and, later, William Thomas Astbury established that the orderliness of cells was a structural, or crystalline, orderliness. This conception was revolutionary, marking the disappearance of the 'colloidal' conception of vital organization, itself a sophisticated variant of the older doctrine of 'protoplasm.'

In 1934, Warburg discovered the coenzyme nicotinamide and, the following year, that it was a constituent of cells.

In 1934, Henrik Dam and Doisy isolated and identified vitamin K.

In 1934, de Beer and Julian Sorell Huxley published The Elements of Experimental Embryology in which the central concept was that of a dominant region in relation to which other regions were specified.

In 1934, Pavel Alekseyevich Cherenkov discovered that when charged gamma ray particles pass through a transparent medium at a speed greater than the speed of light they emit light at certain angles. This is known as Cherenkov (sometimes Cerenkov) radiation.

In 1934, Szilard filed the first patent application for the idea of a neutron chain reaction. The following year, in order to keep the patent a secret, he assigned it to the British Admiralty. [added 12/29/00]

In 1934, Enrico Fermi developed a theory of b decay. Heisenberg and others extended it in terms of the strong nuclear force. [added 11/25/00]

In the five years subsequent to 1934, Glenn Seaborg and Jack Livingood discovered or characterized the radioisotopes iodine-131, cobalt-60, and several others.

In 1934, Gaston Bachelard, in Le Nouvel Esprit Scientifique, declared that "one may imagine the spin of an isolated electron, for example, but one does not think it. Thinking...depends on mathematical relations.... Objects have a reality only in their relations" (Bachelard 1934:132). All else is imagination.

In 1934, Karl R. Popper, in Logik der Forschung, advanced the theory that the test of an empirical system is its 'falsifiability' and not its 'verifiability,' his aim being "to select the one which is by comparison the fittest, by exposing them all to the fiercest struggle for survival" (Popper 1934:42).

In 1935, Wendell Stanley crystallized the tobacco-mosaic virus.

In 1935, Max Delbrück wrote a paper entitled "On the nature of gene mutation and gene structure," which Schrödinger popularized ten years later. Delbrück sought the origin of life in bacteriophages.

By 1935, John Tileston Edsall and A. von Muralt isolated 'myosin' from muscle.

In 1935, William Cumming Rose recognized the essential amino acid 'threonine.'

In 1935, Szent-Györgi demonstrated the catalytic effect of dicarboxylic acids on respiration.

In 1935, H. Davson and James Frederick Danielli proposed a 'protein-lipid sandwich' model for the structure of cell membranes.

In 1935, Gerhard Domagk discovered the efficacy of prontosil, the forerunner of sulfa drugs, in the course of treating streptococcal infections.

In 1935, Hideki Yukawa attempted to model the fundamental 'strong' nuclear force by analogy with quantum electrodynamics. This led to the prediction of the existence of the 'pion,' or 'pi-meson.'

In 1935, Einstein, B. Podolsky, and N. Rosen proposed "a Gedanken-Experiment designed to show that the physical system had simultaneous properties that quantum theory could not determine, thereby demonstrating that the theory was 'incomplete,'" which allowed Einstein, et. al., to continue to adhere to the classical framework (Folse 1985:143). The implication of being incomplete is the need for additional, or hidden, variables.

In 1935, International Business Machines, or IBM, introduced a punch card machine with an arithmetic unit based on relays which could do multiplication. [added 11/25/00]

In 1936, Pauling and Charles Coryell reported that hemoglobin undergoes a profound structural change when it combines with oxygen.

In 1936, Edward Calvin Kendall and Phillip Showalter Hench discovered 'cortisone.'

In 1936, Egas Moniz designed the first prefrontal leucotomy to treat anxiety and agitation accompanying psychiatric conditions in humans.

Beginning in 1936, Fritz Zwicky, using a Schmidt telescope, discovered twenty supernovas and identified the two main types. Supernovas are violent events, and only at this time did the peaceful, harmonius, Aristotelian view of the stars begin to change.

In 1936, Alan M. Turing published "On Computable Numbers," in which he developed the Turing machine, the abstact precursor of the computer. A Turing machine consists of a finite set of logical and mathematical rules and a tape of infinite length.

In 1936, Alonzo Church proved the thesis that any mental process, such as the brain or a computer, which divides numbers into two sorts can be described by some general recursive function. It is sometimes called the Church-Turing thesis.

In 1937, Krebs discovered the citrus acid cycle, also known as the tricarboxylic acid cycle and the Krebs cycle. The citric acid cycle accounts for about two-thirds of the total oxidation of carbon compounds in most cells. Its end products are CO2 and high energy electrons which pass via NADH and FADH2 to the respiratory chain.

In 1937, James Papez proposed that the group of neurons that made up the anatomical substrate of the emotions was located in the limbic system.

In 1937, Landsteiner put forth the view that when a foreign substance entered the body it was taken up by phagocytic cells where it served as a template against which globulin molecules could be synthesized. This theory was later falsified, but was appealing at the time because it explained away the paradox that a finite number of genes could generate a comparably vast diversity of antibodies.

In 1937, Tracy Morton Sonneborn worked out how to mate different strands of Paramecium, a ciliated protozoa, and detailed the interaction of the cytoplasm and the nucleus. By this time, hybridization techniques made the study of microorganisms accessible. Since they reproduced rapidly and did not undergo the complexity of tissue differentiation, they were superior subjects for the study of the chemistry of the organism.

In 1937, Haldane, influenced by Landsteiner's ABO blood groups, developed the 'one-gene, one-antigen' hypothesis, which entailed that distinctions between antigens could be traced to the encoding by specific genes of different allelles.

In 1937, Theodosius Dobzhansky's book, Genetics and the Origin of Species, detailed Wright's position on genetic drift, and echoed Sergei Chetverikov's position, from the 1920s, that nature uses heterozygotes to 'soak up' and preserve variation. Dobzhansky held that the unit of evolution was the population and that this fact greatly reduced the time required to respond to environmental changes.

In 1937, Warburg demonstrated how the formation of ATP is coupled with the removal of hydrogen atoms from glyceraldehyde 3-phosphate.

In 1937, E. Chatton pointed out the differences between organisms such as bacteria and blue-green algae, which he named 'prokaryotes,' and all other organisms, which he called 'eukaryotes.'

In 1937, Eugen Werle and colleagues discovered 'kinins.'

In 1937, P. A. Gorer discovered the first 'histocompatibility' antigens in lab mice.

In 1937, George William Marshall Findley and F. O. MacCullum discovered 'interferon.'

In 1937, investigations into the properties of petrochemical polyamides by Wallace Hume Carothers resulted in the production of nylon fibers. His employer, DuPont, allied with the pulp wood industry, orchestrated a campaign to suppress competition from hemp fibers in the United States, under the guise of suppressing Cannabis sativa, and succeeded in making it illegal to grow that same year.

In 1937, Ivan Matveevich Vinogradov, in "Some theorems concerning the theory of prime numbers," proved that every sufficiently large integer can be expressed as the sum of three odd primes.

In 1937, George Stibitz demonstrated a one-bit binary adding machine. [added 11/25/00]

In 1938, McClintock described the bridge-breakage-fusion-bridge cycle in maize and predicted special structures on the ends of broken chromosomes, called telomeres.

In 1938, Jean Louis Brachet demonstrated that ribonucleic acids are accumulated in regions of high morphogenetic development.

In 1938, Warren Weaver coined the term 'molecular biology.'

In 1938, Otto Hahn, Fritz Strassman, and Lise Meitner bombarded the uranium nucleus with slow speed neutrons, interpreted the results to be nuclear fission, and calculated that vast amounts of energy would be released by a sustained chain reaction.

In 1938, H. Bethe and C. Weiszäcker proposed the existence of two chains of reaction by which the celestial conversion of hydrogen to helium is effected. These are the proton-proton cycle in less massive and luminous stars, and the carbon-nitrogen-oxygen cycle, in the most brilliant stars, where a minute amount of carbon act as a catalyst. After either of these processes has converted most of the star's hydrogen to helium, 'helium-burning' is initiated, and by the addition of helium the heavier elements are built up (through iron-56 and ultimately beyond that through bismuth-209 and the radioactive elements).

In 1938, Compton demonstrated that cosmic radiation consists of charged particles.

In 1939, J. Huxley introduced the notion to evolutionary studies of gradual change in a character, say size or color, over a geographic or ecological area. He termed this a 'cline.'

In 1939, Ernest Everett Just, in The Biology of the Cell Surface, emphasized the changes in the ectoplasm during and after fertilization.

In 1939, C. Anderson discovered the mu-meson, or muon.

In 1939, Bohr proposed a 'liquid drop' model of the atom, based on the fact that the density of a nucleus is independent of its size, thus suggesting the analogy with a liquid drop. "The success of the model has been associated with the fact that the binding forces in both the nucleus and the liquid drop are essentially short-ranged" (Isaacs 2000:271).

In 1939, Szilard and Eugene Paul Wigner visited Einstein to discuss methods of averting a German atomic bomb which led to Einstein's letter to the President of the United States. [added 12/29/00]

In 1939, Szilard proposed stacking alternative layers of graphite and uranium in a lattice, the geometry of which would define neutron scattering and subsequent fission events. [added 12/29/00]

In 1939, Tiselius and Elvin A. Kabat isolated immunoglobulin, or gamma globulin, as it was called at that time, from immune sera by electrophoresis. Until this time the chemical diversity of antibodies was not suspected.

In 1939, Nikolai Sergei Trubetzkoy's Grundzüge der Phonologie, which contains his theory of distinctive phonemic oppositions, was published posthumously.

In 1939, John Atanasoff and Clifford Berry built a proto-type 16-bit adding machine which used vacuum tubes. [added 11/25/00]

In 1940, Pauling suggested, in support of the immunochemical template theory, that the specificity of an antibody is the result of complementariness between its structure and a portion of the surface of the homologous antigen. In other words, this complementariness is induced by the antigen into the variable folding patterns and noncovalent bonds of the antibody after protein systhesis has already taken place.

In 1940, Herman Moritz Kalckar and Vladimir Aleksandrovitch Belitser discovered oxidative phosphorylation.

In 1940, Ernst Boris Chain and Howard Walter Florey extracted and purified penicillin and demonstrated its therapeutic utility.

About 1940, Carl Ferdinand Cori and Theresa Gerti Radnitz Cori described the catalytic process by which the body converts surplus sugar into storable glucogen.

From the work of Torbjörn Caspersson, published in 1940 and 1941, and Brachet, published in 1942, the association of RNA with cell growth was established.

In 1940, Landsteiner and colleagues found the Rhesus factor, a variant on the surface of red blood cells of most human beings, i.e., those that are Rh+.

In 1940, de Beer wrote Embryos and Ancestors, a refutation of Haeckel's biogenetic law.

In 1940, Fermi discovered the first transuranium element 'neptunium,' a byproduct of uranium decay.

In 1940, Urey became director of the United States government program to separate uranium isotopes. In the course of this, he developed statistical methods of isotope separation which permitted large scale production of uranium235.

Beginning about 1940 [?], Roman Jakobson propounded the theory that the sounds of all human languages are composed of atomic units, which he called 'features,' that all human beings innately possess the biological bases of these features, and individual languages are subsets of them. Language acquisition involves the "activation of the particular features that a given language uses; as people mature, they lose the unused ones" (Lieberman 1991:37).

In the 1940s, Wilhelm Reich proposed that cancer results from repressed emotions, especially those related to sexual desires.

In 1941, Haldane speculated that the self-reproduction of the gene could be demonstrated by labelling the gene and then seeing if the copy gene contained the label while the original did not.

In 1941, Fritz Albert Lipmann, using a bacterium that clots milk, proposed that adenosine triphosphate takes energy out of the metabolic flow and conducts it to reactions where needed. This was a radical sharpening of the idea of specificity.

In 1941, Astbury established the DNA had a crystalline structure.

In 1941, George Wells Beadle and Edward Lawrie Tatum, using the bread mold Neurospora crassa, published the assertion that genes control cells by controlling the specificity of enzymes, i.e., one gene controls one enzyme so a mutation in a gene will change the enzymes available, causing the blockage of a metabolic step. A major advantage of Neurospora over Paramecium is that the former can be grown on defined, preferably, synthetic medium, e.g., manufactured vitamins and amino acids, whereas the latter must have bacteria.

In 1941, Burnett, reviving ideas of Metchnikoff, focused on two experimental facts incompatible with the template hypothesis: "the continued production of antibody in the absence of antigen, and the presence of the secondary response, in which a second inoculation with an antigen elicits a host response qualitatively more rapid than that which followed the first inoculation" (Podolsky and Tauber 1997:27).

In 1941, Bush became director of the United States Office of Scientific Research and Development where he directed such programs as the mass production of sulfa drugs and penicillin, the development of the atomic bomb, and the perfection of radar. As part of the latter effort, Karl Lark-Horowitz, Seymour Benzer, and others developed germanium crystal rectifiers, the semiconducter later used in transisters.

In 1941, Seaborg and Livingood discovered plutonium, a fissionable isotope employed in the bomb dropped on Nagasaki.

Beginning in 1941, Lev Davidovic Landau constructed a complete theory of the quantum liquids at very low temperatures.

In 1942, Waddington described 'canalization,' the capacity to respond to an external stimulus by some developmental reaction, such as the formation of an ostrich's calloses, which are under genetic control. "Once a developmental response to an environmental stimulus has become canalized, it should not be too difficult to switch development into that track...by the internal mechanism of a genetic factor...; the same considerations which render the canalization advantageous will favor the supercession of the environmental stimulus by a genetic one. By such a series of steps, then, it is possible that an adaptive response can be fixed without waiting for the occurrence of a mutation which...mimics the response well enough to enjoy a selective advantage" (Waddington 1942:565).

In 1942, J. Huxley wrote Evolution, The Modern Synthesis, which lent its name to the 'modern synthesis' of evolutionary studies created by Fisher, Haldane, and Wright. It received its name because it "gathered under one theory--with population genetics--at its core--the events in many sub-fields that had previously been explained by special theories unique to that discipline. Such an occurrence marks scientific 'progress' in its truest sense--the replacement of special explanations carrying little power in prediction or extension with general theories, rich in implications and capable of unifying a diverse set of phenomena that had seemed unrelated" (Eldredge and Gould 1971:108).

In 1942, Ernst Mayr, in writing Systematics and the Origin of Species against the 'typological' species concept, did for systematics what Dobzhansky had done for genetics. Later, he came to deny the likelihood of any gene remaining selectively neutral, i.e., available for random drift, for any length of time.

In 1942, Szent-Györgi and colleagues showed that myosin was not the sole structural protein in muscle, but shared that role with 'actin,' the complex of the two being named actomyosin. They also showed that threads of actomyosin, in the presence of magnesium and potassium ions, contracted with the addition of adenosine triphosphate (ATP).

In 1942, J. Weiss discovered ionic 'charge transfer.'

In 1942, Fermi created the first controlled, self-sustaining nuclear chain reaction from 'piles,' Szilard's lattice, of uranium and graphite.

In 1943, bacterial genetics was born with the publication of the paper by Salvatore Luria and Delbrück, the core of the so-called 'phage group,' reporting evidence that mutation, not adaption, was how bacteria acquired resistance to phage and that mutation was revealed through its selection: "When a pure bacterial culture is attacked by a bacterial virus, the culture will clear after a few hours due to destruction of the sensitive cells by the virus. However, after further incubation for a few hours, or sometimes days, the culture will often become turbid again, due to the growth of a bacterial variant which is resistent to the action of the virus" (Luria and Delbrück 1943:491). Nine months later Jacques Monod and Alice Audureau demonstrated similar results which were published at the end of the war. Many people believed the resistance of bacteria to antibiotics was the result of some sort of adaption induced by the antibiotic, which implied that acquired characteristics could be inherited.

In 1943, Sonneborn discovered the cytoplasmic factor Kappa, which he was able to control through effecting the environment.

In 1943, Albert Hofmann injested the ergotomine molecule, lysergic acid 25 (LSD-25), which he had synthesized in 1938.

In 1943, Warren S. McCulloch and Walter H. Pitts published "A Logical Calculus of the Ideas Immanent in Nervous Activity," where they claimed that the brain could be modelled as a network of logical operators on a Turing machine. This initiated discussions which led to the use of computational metaphors and Boolean functions in the study of cognition.

In 1943, a team led by Howard Aiken built a huge programmable calculator, the 'Harvard Mark I.' [added 11/25/00]

[In the early, mid-1940s, there were two distinct approaches to understanding the nature of life, functional and structural. The proponents of a functional description were biochemists--Avery and Erwin Chargaff--and geneticists--Luria, Delbrück, Alfred Hershey, and Monod. The chief proponents of the structural approach, that is, characterizing the chemical sequences of the large, long-chain protein molecules and, stereochemically, reconstructing their three-dimensional architecture, were Bragg, Pauling, Astbury, and Bernal].

In 1944, through the experiments of Oswald T. Avery, Colin MacLeod, and Maclyn McCarty, it was established that the material of heredity, specifically in Griffith's dead pneumococci, was deoxyribonucleic acid. In other words, even though they were dead, the cells could transfer their genes as long as their DNA remained intact. Up to this time, most biologists thought genes were probably protein and nucleic acid was some sort of skeletal material for the chromosomes.

In 1944, Peter B. Medawar proved the immunological nature of graft-rejection.

In 1944, George Gaylord Simpson, in Tempo and Mode in Evolution, argued that no observations in the fossil record required 'inherent forces,' or orthogenesis, toward 'desired ends,' e.g., large size.

In 1944, Selman Waksman discovered streptomycin.

In 1944, L. Onsager published a complete solution for the two-dimensional Ising model.

In 1944, Szilard proposed the term 'breeder' to describe a reactor able to generate more fuel than it consumed. [added 12/29/00]

In about 1944, Stanislaw Marcin Ulam and Edward Teller suggested a two-stage radiation implosion design, employing both fusion and fission, permitting the detonation of thermonuclear weapons.

In 1945, Schrödinger, in What is Life?, asked questions about replication, structure, aperiodicity, and metabolism which set biology's agenda for 30 years.

In 1945, Ray Owen demonstrated that identical cattle twins, i.e., who had shared an in utero circulatory system, were unable, in adulthood, to mount an immune response to antigens produced by the twin. This was the first demonstration of immune tolerance.

In 1945, Michael James Denham White published Animal Cytology and Evolution, the first monograph on the subject.

In 1945, Wright devised the 'Coefficient of Relationship,' which represents in numerical form the genetic probabilities for related members of a population to carry replica genes. There are just three possible conditions of this in an individual, namely, that both, one only, and neither of his genes, at a given locus, are identical by descent, or c2+c1+c0=1. The relationship is completely specified by any two of them, e.g., 2c2+c1. One-half of this number, c2+1/2c1, may therefore be called the expected fraction of genes identical by descent in a relative.

In 1945, Maurice Merleau-Ponty, in the Phénoménologie de la Perception, asserted that the foundations of science entail the primacy of perception as against the older 'retinal image + judgement = perception as hypothesis.'

In 1945, John Mauchly and John Presper Eckert, working for the United States War Department, finished ENIAC, or Electronic Numerical Integrator and Computer, in order to more quickly ascertain artillery shell trajectories. [added 11/25/00]

In 1946, Joshua Lederberg and Tatum discovered that the bacteria Escherichia coli sometimes exchange genes.

In 1946, L. Michaelis proposed that free radicals were obligate intermediaries in metabolic pathways in living cells.

In 1946, Landau postulated an attenuation, or 'damping,' of wave motion when the velocity of a wave is comparable to the velocity of electrons in plasmas.

In 1946, Willard Frank Libby developed radioactive carbon-14 dating, employing the known rate of decay, measured by its half-life, and relative proportion of its decay products.

In 1946, von Neumann, Arthur Burks, and Herman Goldstine, in "Preliminary Discussion of the Logical Design of an Electronic Computing Instrument," defined the concept of a program and showed how a computer could execute such a program by obeying instructions and storing them in memory. This 'von Neumann architecture' is the basis for almost all computers today.

In 1947, Paul Weiss published his concept of 'molecular ecology,' which involves the functional roll of the cell surface and 'fields' of chemical and physical conditions: "Let the number of [molecules] keep on increasing..., and all of a sudden a critical stage arises at which some of the [molecules] find themselves...cut off completely from contact with their former vital environment by an outer layer of their fellows.... Thus would ensue a train of sequelae of ever-mounting, self-ordering complexity.... The fate of a given unit would be determined by its response to the specific conditions..., [which vary] locally as functions of the total configuration of the system--its 'field pattern,' for short" (Weiss 1967:819-820).

In 1947, John Tyler Bonner published a study of chemotaxis in slime mold, demonstrating that the interaction of chemical messages and receptors produces their aggregation in a complex organization.

In 1947, John Bardeen, Walter H. Brattain, and William Schockley invented the point-contact transistor amplifier, a voltage and current amplifier, which, in contrast to the vacuum tube it replaced, is an arrangement of semiconductor materials sharing common physical boundaries. A semiconductor is a solid material, e.g., silicon, in which certain induced impurities enhance its conductive properties.

In 1947, Langmuir proposed that non-linearities in weather phenomena made them unstable when subjected to small changes in their energy cycles. [added 11/25/00]

In 1948, Burnett and Frank Fenner hypothesized that the immune system discriminated between 'self' and 'nonself.'

In 1948 and continuing into 1949, Richard Feynman published numerous papers in which he completed the mathematics of the theory of quantum thermodynamics (QED), Dirac's equation of 1929. It is applicable, for example, in chemistry "to those problems in which heavy nuclei can be approximated as fixed point particles carrying an electric charge" (Gell-Mann 1994:110). In the late 1960s, Feynman's mathematics proved essential in quantizing gauge theories.

In 1948, Marie Goeppert-Meyer and, independently, Hans Jensen proposed the 'shell' structure of the nucleus in which the nucleons are assumed to move in shells analogous to atomic electron shells, or levels.

In 1948, Gamow and Ralph Alpher predicted that a 'big-bang' would have produced a background of microwave radiation. Along with H. Bethe, they developed the theory of the big-bang. The 'steady-state' theory of the universe, i.e., no beginning, failed to account for background microwaves.

In 1948, von Neumann observed that replication and metabolism are logically separable, and, in fact, are analogous processes to software (nucleic acid) and hardware (protein).

In 1948, Claude Shannon, in A Mathematical Theory of Communication, proposed a linear schematic model of communications, defining the fundamental problem of communication as the task of reproducing at one point in space a message created at another point. He worked out how such a message could be reliably sent, the theoretical limit of the amount of information it could contain, and contributed the notion of negentropy as a measure of information, thereby creating 'information theory.'. [revised 11/25/00]

In 1948, Norbert Wiener, in Cybernetics, which dealt with general communications problems, said, "Living organisms are metastable Maxwell demons whose stable state is to be dead" (Weiner 1948: ).

In 1949, Ivan Ivanovich Schmalhausen's Factors of Evolution: The Theory of Stabilizing Selection was translated into English by Dobzhansky and so associated with the 'modern synthesis.' He offered two versions of stabilizing selection. The first, which the modern synthesis adopted, built up "the mean or average form by selecting against the extremes at both ends of the distribution" (Gottlieb 1992:133). The second saw evolution as a process where, in the course of severe environmental pruning and breeding among the survivors, the traits which enabled survival, the 'adaptibilities,' might be assimilated genetically. This is similar to the Baldwin effect and Waddington's 'genetic assimilation.'

In 1949, Sven Furberg drew a model of DNA, setting sugar at right angles to base, with the correct three-dimensional configuration of the individual nucleotide.

In 1949, Frederick Sanger made the claim that proteins are uniquely specified, the implication being that, as there is no general law for their assembly, a code was necessary.

In 1949, Szent-Györgyi showed the isolated myofibrils from muscle cells contract upon the addition of ATP.

In 1949, Donald Hebb suggested in Organization of Behavior that selective reinforcement of neural connecions accounts for learning and memory. Moreover, this reinforcement causes the brain to organize itself into 'cell assemblages,' the building blocks of information. Since any given neuron would belong to several such assemblages, the activation of one assemblage would activate others, creating larger concepts and more complex behaviors.

In 1949, Jerzy Konorski suggested that memory is the result of functional transformations, or plastic changes, in neurons.

In 1949, Leon Brillouin proposed an information theoretical refutation of Maxwell.

In 1949, Freeman Dyson, in several papers, unified Feynman's and Julian Schwinger's radiation theories, emphasizing the so-called 'scattering matrix,' which contained the different routes from the initial state to a given end-point.

In 1949, Victor Negus and Arthur Keith reconstructed the supralaryngeal airways of a Neanderthal fossil and concluded that its tongue was closer to a chimpanzee's than a human's and that it lacked a pharynx, or soft palate.

In 1949, Gilbert Ryle, in Concept of Mind, held that the mind is part of the body's activity, not a separate and theoretically equivalent counterpart to the body, not "a ghost in a machine" (Ryle 1949:15).

In 1950, Chargaff showed that the tetranucleotide theory was wrong, in other words, that DNA did not consist of a monotonous succession of nucleotides (in a fixed order in sets of four), and that the molecule to molecule "ratio of total purines to total pyrimidines, and also of adenine to thymine and of quanine to cytosine, were not far from 1" (Chargaff 1950:13). The collapse of the tetranucleotide theory made it highly likely that nucleic acids were also sequentially specific.

In 1950, Cyril Hinshelwood published his derivation of the biological activity of a three-dimensional protein strictly from its one-dimensional sequence.

In papers of 1950 and 1951, McClintock, working in the genetics of maize, reported finding control elements, providing the first evidence that genetic regulation might be universal. She found evidence that some genes move from place to place and often affect nearby genes. In the mid-1970s, these genes were isolated and named transposons.

In 1950, George Ledyard Stebbins wrote Variation and Evolution in Plants.

In 1950, Lwoff published a book on kinetosomes, insisting that their development was primarily cytoplasmic.

About 1950, Boris Belousov discovered serendipitously a non-living chemical oscillator which came to be known as the Belousov-Zhabotinsky reaction.

In 1950, Karl von Frisch discerned the code which is conveyed by the dance of bees.

In 1950, Leo Rainwater combined the liquid drop and shell models of the atomic nucleus.

In 1950, Ernst L. Wynder and Evarts A. Graham published, in the Journal of the American Medical Association, a survey indicating a strong correlation between having lung cancer and smoking tobacco.

In the early 1950s, Bernal discussed the development of asymmetry in organic substances and the possibility of their being absorbed on particles of clay.

In the early 1950s, George H. Herbig and, independently, Guillermo Haro reported finding faint gas clouds within the constellation Orion. These are now known as Herbig-Haro objects.

In the 1950s, John Robinson distinquished between gracile and robust Australopithecus in functional terms, which he suggested are somewhat analogous to the differences between chimpanzees and gorillas, and suggested that the gracile type was ancestral to hominids.

In 1951, Pauling discovered by crystallography that an alpha helix, a twisted polypeptide chain, is the basic structure of many proteins. Successive turns of the helix are linked by hydrogen bonds.

In 1951, Lederberg and Norton Zinder announced that in order to become lysogenic bacteria need not wait for a mutation to arise if they can pick up a gene for resistence from another strain, a phenomena they called 'transduction.' In the same year, Esther Lederberg proved that lysogeny could be transmitted in bacterial crosses like any other genes.

Later in 1951, Monod and Melvin Cohn, with an array of artificial b-galactosides, learned to decouple the production of the enzyme from its natural stimulus and from the natural substrate, lactose, and called the process 'induced enzyme synthesis,' or just 'induction.' Subsequent work established that enzyme induction consists in the actual synthesis from amino acids of the entire enzyme molecule, and that this protein is stable, not 'dynamic,' as many thought.

In 1951, Carl Djerassi synthesized 19-nor-17a-ethynyltesterone, or norethindrone, an inhibitor of ovulation when taken orally.

In 1951, Erwin Mueller invented the field-ionization microscope.

In 1951, Otto Struve suggested the transit method of planet detection: In stars with a fortuitous alignment with the Earth, when a planet transits, or eclipses, the star, it will dim slightly.

In 1951, Willard Van Orman Quine, in "Two Dogmas of Empiricism," said the distinction between 'analytic' and 'synthetic,' roughly that between ideas and fact, and 'reductionism,' which holds that logical constructs are meaningful if they refer to immediate experience, are each ill-founded dogmas. The real "unit of empirical significance is the whole of science" (Quine 1953:42).

In 1952, Alan Hodgkin and Andrew F. Huxley demonstrated the ionic workings of nerve impuses employing a squid's gigantic axon.

In 1952, Alexander R. Stokes worked out the mathematics of helical diffraction, important in interpreting X-ray crystallographs.

In 1952, Lederberg and Luca Cavelli-Sforza and William Hayes, working independently, announced that bacteria differentiated into genetic donors and recipients. Hayes said further that when the doner passed a copy of its genes to the recipient, it could also pass the genetic ability to be a donor.

In 1952, Alexander Dounce said that the order of amino acids in each specific protein derives from the order of nucleotides in the corresponding RNA molecules which were templated by the DNA molecules.

In 1952, Guido Pontocorvo assembled evidence that the gene as the minimum unit of heritable physiological function had considerable length along the chromosome. The gene as the minimum unit in which mutations can be induced is much smaller. Therefore, mutations could occur at different points along a single physiological gene.

In 1952, Hershey and Martha Chase showed that when a phage particle infects its bacterial host cell, only the DNA from the phage enters the cell and the protein of the phage remains outside. Combining Chargaff's result with that of the Hershey-Chase experiment meant that the repeating elements of Schrödinger's codescript could be identified as the nucleotides carrying adenine, quanine, thymine, or cytosine.

By 1952, Turing had noticed that patterns are formed by the rates at which interacting chemicals diffuse and react. This "theory can, in principle, account for the specification of most (possibly of all) biological patterns, although the mathematical obstacles are often formidable" (Harold 1990:415). The mathematics involves "the bifurcation properties of the solutions of differential equations. Applied mathematicians had been aware for many years that when a parameter of a system passes through a certain critical value there can be a qualitative change in behavior as a previously stable state becomes unstable. The archetypal example, first studied by Euler more than two centuries earlier, is the sudden buckling of a beam when it is overloaded" (Saunders 1992:xiv). This theory accounts for certain organizational features in plants (e.g., the frequency of five petals and the scarcity of seven petals), but it is also compatible with physiological genetics.

In 1952, Humphrey Osmond and John Smythies theorized that schizophrenia was the result of a chemical chain reaction, the cycle of which could only be broken by a retreat from 'reality.' Osmond later coined the term 'psychodelic.'

In 1952, Jay Haley and Gregory Bateson recognized that the symptoms of schizophrenia are suggestive of an inability to discriminate logical types and described it in terms of a double-bind hypothesis.

In 1952, R. S. Mulliken worked out and systemized the quantum mechanics of 'charge transfer.'

In 1952, David Bohm extended and completed de Broglie's ideas concerning a unified description of quantum mechanics; that is to say, by making certain assumptions, e.g., that the field was objectively real, and, by hiding certain variables, he gave a plausible account of how to eliminate the indeterminism of having more than one point of view.

In 1952, Michael Ventris deciphered so-called 'Linear B,' an extremely archaic form of Greek.

In 1953, James Dewey Watson and Francis Harry Compton Crick built a model of DNA showing that the structure was two paired, complementary strands, helical and anti-parallel, associated by secondary, noncovalent bonds. This discovery made apparent the mechanism of replication. Their effort brought together the functional and the structural approaches to the study of life: Watson's background was with the phage group and Crick was a physicist learning X-ray crystallography. The two approaches combined to become, as Crick called it in 1947, "the chemical physics of biology" (quoted in Judson 1979:110) and, finally, molecular biology. Maurice H. F. Wilkens' and Rosalind Franklin's X-ray crystallographs of DNA supported the discovery of the structure.

[In 1953, in working out the structure of the double helix, Watson and Crick had "for the first time introduced genetic reasoning into structural determination by demanding that the evidently highly regular structure of DNA must be able to accomodate the informational element" (Stent 1980:xvii). In other words, "the basis of heredity switched from one based on location to one based on information encoded in the structure of macromolecules" (Sapp 1987:193). Watson and Crick employed 'information,' the recently popularized cybernetic term, differently than cyberneticists: Genetic information is functional whereas cybernetic information is defined as the mathematical converse of entropy].

In 1953, Szilard and Aaron Novick proposed that a cell's synthesis of some enzymes was not stimulated by the presence of an inducer, but by the absence of the enzyme's end product, a classic example of feedback control.

In 1953, Gamow began the attempts to explain the coding problem, that is, how the sequential structure of DNA could directly, physically order the sequential structure of proteins. In Gamow's scheme, several different base sequences could code for one amino acid.

In 1953, Stanley L. Miller, in Urey's lab, bombarded a mixture of ammonia, water vapor, hydrogen, and methane with an electrical discharge and produced the amino acids alanine and glycine.

In 1953, Medawar, L. Brent, and R. E. Billingham established in principle that immunological tolerance could be acquired by injecting hemopoietic cells from a genetically different donor into rodents in utero or at birth. Not having evolved the immunolgical equipment to reject them, the engrafted cells perpetuated themselves, and endowed the recipient with the donor immune system.

In 1953 and 1954, Vincent du Vigneaud synthesized the peptide hormones oxytocin and vasopressin.

In 1953, Eugene Aserinsky and Nathaniel Kleitman noticed regularly occurring periods of rapid eye movement (REM) during sleep and correlated this with when dreams are particularly vivid and emotionally charged. This opened a new era of research in the relation of brain to mind.

In 1953, von Neumann and Oscar Morgenstern published their formulation of game theory in reference to human economic behavior. A central assumption is that the players will behave rationally, and according to some criterion of their self-interest. About the same time, von Neumann applied game theory to United States nuclear strategy, which led to him being characterized, along with Teller, as Dr. Strangelove in Stanley Kubrick's movie.

In 1953, An Wang invented the magnetic core computer memory.

In 1953, Wittgenstein published his Philosophical Investigations in which he held, among other things, that the mind categorizes on the basis of 'family resemblances:' "How is the concept of a game bounded? What still counts as a game and what no longer does?... We do not know the boundaries because none have been drawn" (Wittgenstein 1953:I, 68-69).

In 1954, Marthe Vogt recognized that noradrenaline was present in the hypothalmus.

In 1954, Rita Levi-Montalcini and associates showed that nerve growth factor stimulated the growth of axons in tissue culture.

In 1954, Paul Zamecnik, working with rat liver, developed and refined the cell-free system, a biochemical cocktail, for protein synthesis. The basic constituents are molecules of RNA containing amino acids, enzymes, ATP, and microsomal particles, or ribozymes.

In 1954, Benzer, working with mutant rII viruses in bacteria, proved that mutations occurred within genes and devised a technique by which one could locate mutations at the scale of a single nucleotide. This enabled him to sequence, or map, the parts of the gene, the amino acids, that is to say, the 200,000 letters of the phage virus genetic code.

In 1954, Hugh E. Huxley and Jean Hanson and, independently, A. Huxley and R. Niedergerke observed in X-ray crystallographs that, when muscles contract, the areas built exclusively of actin filaments are comparatively narrow. To explain this, they hypothesized that bridges occur between the actin, or thin, filaments and the thick, or myosin, filaments and that these bridges pull thin filaments past the thick filaments in a racheting action. It is known as the 'sliding filament, moving cross-bridge model.'

In 1954, Anthony C. Allison provided evidence that individuals heterozygous for the sickle-cell gene are protected against malaria.

In 1954, Jean Dausset observed that some recipients of blood transfusions formed antibodies. These antibodies defined the first human leukocyte antigens (HLA) and led to the definition of human histocompatibility.

In 1954, Andrei N. Kolmogorov outlined a theorem, subsequently proved by Vladimir Igorevich Arnold and Jürgen Kurt Moser, and known as KAM theory, which dealt with the influence of Poincaré resonances on trajectories, showed their frequencies to depend on the values of dynamic variables, and provided the stating point for understanding the appearance of chaos in Hamiltonian systems.

In 1954, Chen Ning Yang and Richard Mills and others proposed that if there were as many as eight different electromagnetic fields which interacted with each other and with electrons proposed to be of three types of charge, then the charges would be able to change in different places and times.

In 1954, Charles Hard Townes developed the theory of the maser, or 'microwave amplification by stimulated emission of radiation,' which led to the development of optical masers, or lasers. The maser is an oscillator in which the basic frequency control arises from atomic resonance rather than a resonant electric circuit. The waves are coherent; that is, they're all the same frequency, in the same direction, and the same phase relationship. The following year, Nikolai Gennediyevitch Basov, independently, also developed a maser.

In 1954, at the time of his death, von Neumann was writing Theory of Self-Reproducing Automata, where he proved, in theory, that a 'cellular automaton' could reproduce itself provided it exceeds a certain threshold of complexity. This formalism was suggested to him by Ulam: Each cell in a lattice would be occupied by an automaton in one of a finite number of states. At each tick of a cosmic clock, the automaton would change to a new state, determined by its current state and the states of its neighbors. Automata theory is known as recursion theory among logicians. The book, edited by Burks, was published in 1966.

In 1954, Needham published the seven volumes of Science and Civilization in China.

In 1955, Walter Sampson Vincent announced experiments which suggested that a small fractional portion of RNA transfers nuclear information to the cytoplasm. This fraction was later given the name transfer RNA, or tRNA. Later that year, Crick hypothesized the existence of an intermediate nuclear product which he called an 'adaptor,' and ultimately came to be recognized as tRNA.

In 1955, Sanger completed the determination of the sequence of the amino acid bases in bovine insulin, the first protein to be so analyzed, revealing that there was a sequence unique to bovine insulin, that it was not a repetitive series, and thus confirming that a code would be required for protein synthesis.

In 1955, Neils Kaj Jerne suggested a natural selection theory of immunity in which cells, while still in the embryo, produce a wide variety of antibodies. Any antibodies which made contact with the embryo's own antigens would be permanently lost. "The early removal of a specific fraction of molecules [would] lead to the permanent disappearance of this type of specificity.... The absent specificities would include, beside auto-antibodies, natural antibody against antigens implanted in the animal during embryonic life" (Jerne 1955:853-854). Later, foreign antigens would select the best fit among the remaining antibodies, bind to them, and be delivered up for dissociation and elimination. The formation of this complex also stimulated the production, i.e., cloning, of more of the selected antibody, which is then capable of a more rapid secondary response.

In 1955, Élie Wollman and François Jacob found that, by agitating a bacterial culture, mating could be stopped when only part of the genes had been piped across, permitting the manipulation of a few genes at a time.

In 1955, Arthur Pardee and Rose Littman reported that 5-bromouracil, an analogue of the base thymine, causes a high proportion of mutants in phage.

In 1955, Severo Ochoa and Marianne Grunberg-Manago isolated the first enzyme involved in the synthesis of a nucleic acid, an RNA-like molecule in a cell-free system.

In 1955, Christian de Duve and colleagues proposed the existence of a new subcellular particle, which they named lysosome to emphasize the hydrolytic, or water-releasing, properties of its enzymes. This led to their discovery of another subcellular particle, which they named peroxisome.

In 1955, Kazuhiko Nishijima and, independently, Murray Gell-Mann identified puzzling high-energy tracks in a cloud chamber as an additive quantum number, which Gell-Mann called 'strangeness.' [added 11/25/00]

In 1955, after Oliver Smithies used starch gels to separate allelic protein by electrophoresis. Only then were extensive studies of wild species was possible.

In 1955, Leo Hurvich and Dorethea Jameson formulated the opponent-process color theory: There are three color 'channels' in the visual system, one channel is achromatic and signals differences in brightness; the other two are chromatic and signal differences in hue. Also, in the retina there are three mosaics of cone cells, the so-called long-wave (L), the middle-wave (M), and the short-wave (S) receptors. The difference between the the signals from the L and M receptors generates the red-green channel, and the difference between the sum of the signals from the L and M receptors and the signals from the S receptors generates the blue-yellow channel.

In 1955[?], Martin Ryle built the first radio telescope, employing the crystallographer's principles of interferometer, but on a different scale, and invented the technique of 'aperture synthesis' by which an array of smaller interferometers can simulate a very large one. This led to the discovery of quasars, pulsars, and neutron stars.

In 1956, Waddington demonstrated with Drosophila that selection for the ability to acquire a trait that appears in response to an environmental stimulus may, if it is selectively advantageous, become genetically assimilated after a certain number of generations.

In 1956, Heinz Fraenkel-Conrat and Gerhard Schramm, independently, demonstrated that tobacco-mosaic virus RNA is self-replicating and alone gives the disease.

In 1956, Wollman and F. Jacob published a first, rudimentary genetic map of the E. coli chromosome, and established that when the donor's chromosome entered the recipient, the recipient became endowed with two sets of genes for several hours until resuming cell division.

In 1956, Vernon Ingram, using electrophoresis and chromatography, showed that human normal and sickle-cell hemoglobins have different 'fingerprints,' i.e., their amino acids differed due to a mutated gene.

In 1956, Paul Berg noticed that the enzyme specific to an amino acid required something more to permit the enzyme to recycle and determined it was tRNA. At about the same time Zamecnik, Mahlon Hoagland, and Robert Holley made the same determination. Berg led the way to the enumeration of separate enzymes and species of tRNA for all twenty amino acids. Zamecnik and Hoagland discovered that tRNA carried, at one end, the three nucleotide sequence cytosine-cytosine-adenine where the amino acid hooked on. Holley sequenced tRNA, the first for any nucleic acid.

In 1956, Elliot Volkin and Lazarus Astrachan published data which suggested that cells possess a high-turnover RNA, which later proved to be messenger RNA (mRNA).

In 1956, Christian Boehmer Anfinsen concluded that the three-dimensional conformation of a protein is dictated by its amino acid sequence.

In 1956, Al Hubbard developed the rule in the therapeutic use of LSD-25 that it was contingent on the mindset of the person taking the drug and the setting in which the experience occurred.

In 1956, Steven Szara synthesized dimethyltryptamine, or DMT.

In 1956, Tsung Dao Lee and Yang published the suggestion that the law of parity conservation is violated by the 'weak' force, one of the four fundamental forces. Chien-Shiung Wu then performed an experiment which showed that parity is not conserved in beta decay, and thus there can be physically lawful asymmetry, or preferred handedness.

In 1956, Clyde Cowan and Frederick Reines confirmed the existence of the neutrino.

In 1956, Leon Cooper showed that in superconductivity the current is carried in bound pairs of electrons, or 'Cooper pairs.'

In 1956, Beno Gutenberg and Charles Richter pointed out that earthquake tremors follow a power law: In any given area in a year, the number of earthquakes that release a certain amount of energy is inversely proportional to that energy.

In 1956, George A. Miller published the paper, "The Magical Number Seven, plus or minus Two: Some Limits on Our Capacity for Processing Information."

In 1956, John McCarthy invented the term 'artificial intelligence.'

In 1956, Nathaniel Rochester and John H. Holland published computer programs which simulated neural networks.

In 1957, Matthew Meselson and Franklin Stahl developed density-gradient centrifugation for separating nucleic acids in order to confirm that DNA reproduces itself in the manner predicted by the Watson-Crick model.

In 1957, Arthur Kornberg discovered DNA polymerase, the first of a group of three enzymes responsible for DNA synthesis, that is, the attachment of nucleotides onto the unzipped DNA molecule during DNA replication, and, of the three, the one which repairs damaged DNA. It is the enzyme now used to make DNA probes.

In 1957, Melvin Calvin first observed unpaired electron spins, i.e., free radicals, induced by light in photo-synthetic systems.

In 1957, E. W. Sutherland and T. W. Rall isolated cyclic adenosine 5'-monophosphate, or cAMP.

In 1957, David Talmadge modified Jerne's hypothesis, giving it a cellular orientation, so that lymphocytes, that is, receptor-carrying cells, rather than serum, served as the source of immunological memory and selection. Independently, Burnett seems to have arrived at the same revision, which was subsequently included in his "Concept of Clonal Selection." The essence of this theory is fourfold: Each clone is produced somatically by genetic hypermutation; each clone produces antibodies which have the ability to react immunologically with a very small number of chemical configurations on the surface of an antigen; the immune system is able to distinquish self from non-self; and self-tolerance is set up early in life by the elimination of self-reactive lymphocytes.

In 1957, Feynman and Murray Gell-Mann proposed a law tying together the weak interactions at work in strange-particle decay and in beta decay which were permitted by the previous year's Lee-Yang-Wu proof. The particle transformations involved were particular types of spin-and-parity, known as 'vector' and 'axial vector'. Robert Marshak and E. C. G. Sudarshan drew similar conclusions at about the same time (Gleick 1992:335-338).

In 1957, Bardeen, Cooper, and John Schreiffer formulated the 'BCS theory' of superconductivity according to which a pair of negatively-charged electrons moving through a positively-charged elastic crystal lattice as a result of Coulomb forces.

In 1957, Herbert Kroemer showed theoretically that heterostructural transistors, made by laying down thin layers of semiconductors such as gallium arsenide, should be superior to conventional transitors built from specially modified pieces of a single material such as silicon. [added 12/29/00]

In 1957, Kees Boeke, in Cosmic View: The Universe in Forty Jumps, a book intended for children, illustrated what one would see by adding a zero, or power, to the scale of a square picture of two people on a picnic blanket, moving in and out twenty times.

In 1957, the United States government formed the Advanced Research Agency, or ARPA, in response to the Soviet Union's Sputnik, the first artificial satellite.

By 1958, David L. Nanney, working with ciliated protozoa, Tetrahymena, recognized the existence of two systems: genes and epigenetic mechanisms which regulate gene expression.

In 1958, Albert H. Coons showed experimentally that one cell made only one antibody. Later that year, Gustave J. V. Nossal and Lederberg, working together in Burnett's lab, verified the clonal selection theory's requirement that there could only be one antibody type produced by any given lymphocyte; this came to be known as 'allelic exclusion.' The same year, Lederberg recognized that, in the context of random drift, it was necessary to postulate the continuation throughout life of the diversification of antibody-producing cells. Lederberg also postulated that two signals initiated by a single interaction but separated in time were necessary to distinquish between inactivation of self and activation of nonself. Further, he introduced the rhetorical dichotomy between the terms 'selective' and 'instructive,' representing respectively the clonal and template models. Until Jerne's theory, all immunologists were agreed that the antigen impressed its mark on, or instructed, the antibody producing cells.

In 1958, F. Jacob and Wollman named and described 'episomes,' which are "circular, extrachromosomal sequences of DNA that possess the capacity to integrate into, as well as dissociate from, the chromosome of a cell. They can replicate either autonomously or while inserted within the chromosome" (Podolsky and Tauber 1997:392n24).

In 1958, Hofman isolated the active ingredient of the mushroom Psilocybe and synthesized psilocybin, which he noted had a marked similarity to serotonin.

In 1958, Jack St. Clair Kilby built the first integrated circuit.

In 1958, Phillip W. Anderson showed that the effect in a metal of strong 'disorder,' or irregularity, perhaps arising from a high concentration of atomic impurities, would localize all the electron wave functions; i.e., each quantum state would be confined to a certain region, falling off exponentially with the distance outside that region.

In 1958, Eugene Parker proposed the 'solar wind' theory: There is a flow of atomic particles from the Sun's corona which carries with it magnetic field lines that form into a spiral pattern as the Sun rotates. [added 12/29/00]

In 1958, Michael Polanyi, in Personal Knowledge, asserted that there is an interpretative ingredient in scientific knowledge.

In 1959, Noel L. Warner and Aleksander Szenberg performed the experiments which led to the concept of T (for thymus) cells and B (for bursa in birds, but produced in the bone marrow of adult mammals) cells.

In 1959, Pardee, F. Jacob, and Monod published an experiment establishing a generalized model of the synthesis of enzymes. That this occurs in the absence of genetically determined repressors is due to exogamous induction; that is, the immunity of lysogenic cells corresponds exactly to inductibility and, if regulation occurs at the gene and not later in the process, then regulation is completed at the level of the ribosome.

In 1959, Edmond H. Fischer and Edwin G. Krebs isolated and purified the first protein kinase.

In 1959, Rodney R. Porter showed that the antibody molecule could be cut into three pieces by utilizing an enzyme which cuts bonds within the peptide chain. Of the three pieces, two would still combine with antigen. These he named antigen-binding fragment, or Fab, and the third piece, crystallizable fragment, or Fc. The Fc region corresponds to different types of effector function. Also, he showed that the whole antibody could be divided into different functional classes, i.e., IgA, IgD, etc.

In 1959, Gerald M. Edelman demonstrated, by using reducing agents to split sulphide bonds between the peptide chains, that the immunoglobulin gamma G, or IgG, molecule, the most prevalent class in mammals, was a multi-chain structure. This showed that the chains were a reasonable size for determination of their amino acid sequence. Edelman also showed that antibodies are constructed in a modular fashion from domains, with the light chain composed of a variable and a constant domain and the heavy chain composed of four domains, three variable and one constant. Furthermore, he showed that the variable domains share homologous regions as do the constant domains.

In 1959, Bengt Samuelsson and Sune Bergström isolated prostaglandins.

In 1959, Albert Bruce Sabin developed a live-virus vaccine against poliomyelitus.

In 1959, H. Sherwood Lawrence proposed that infectious agents complex with transplantation antigens (self + x) and triggered lymphocytes to produce a soluble, specific receptor for this complex.

In 1959, Konstantin Gringauz, employing Soviet Luniks Satellites, observed the first signs of the solar wind. [added 12/29/00]

In 1960, Crick, Sydney Brenner, and F. Jacob predicted the existence of messenger RNA, the substance that gets repressed. The latter two and Meselson soon isolated it.

In 1960, Monod and F. Jacob developed the 'operon model,' which showed that "the discovery of regulator and operator genes, and of repressive regulation of the activity of structural genes, reveal that the genome contains...a coordinated program of protein synthesis and the means of controlling its execution" (Jacob and Monod 1961:354). The rate of information transfer from genes to proteins could be controlled by oscillation, that is, turned 'on' and 'off' at a specific speed. The exogamous inducer was almost invariably the end-product so this model did much to popularize the notion of feedback among molecular biologists.

In 1960, Jerne introduced the terms 'epitope' and 'paratope' to represent antigenic determinants and antibody-combining sites, respectively.

In 1960, Julius Marmur and Paul Doty reported that denatured, that is, unfolded, polypeptides could be renatured, regaining their original structure, provided that the two single strands were perfectly complementary.

In 1960, Max Perutz and John Kendrew worked out the crystallographic structure of the oxygen-carrying proteins, hemoglobin and myoglobin, a labor that Perutz had begun 23 years previously.

In 1960, Eugene Merle Shoemaker proved that an asteroid created the 1.2-mile diameter crater near Flagstaff, AR, and theorized that the moon's craters had a similar origin. This was confirmed by Apollo 17 in 1972. [added 11/25/00]

In 1960, Quine suggested a strategy for discussing disparate conceptual schemes by a 'semantic ascent,' arguing that "words, or their inscriptions, unlike points, miles, classes, and the rest, are tangible objects of the size so popular in the marketplace, where men of unlike conceptual schemes communicate at their best" (Quine 1960:272); i.e., don't talk about things, talk about the way we talk about things.

In the early 1960s, Gabriele Veneziano proposed a model to explain the systematic relationship between the spin and the mass of certain short-lived hadrons, which turned out to be the quantized motion not of a particle or a point, but of a 'string.'

In the early 1960s, Roger Penrose introduced new mathematical techniques to solve Einstein's equations where exact answers were unavailable because of asymmetry.

Beginning in the 1960s, Elias J. Corey developed the concept of retrosynthetic analyses. The most important syntheses were the eicosanid, e.g., prostaglandins, prostacyclins, and leucotrienes.

In the 1960s, Robert MacArthur and his colleagues invented simple holistic ecological models. His program in population ecology was aimed at bringing community ecology, e.g., the study of ant colonies, into the modern synthesis.

In the 1960s, Ilya Prigogine theorized that the first cells were thermodynamic 'dissipative structures,' that is, they organized themselves, and with the influx of energy (in the form of food or sunlight), became more instead of less organized.

In 1961, Benjamin D. Hall and Sol Spiegelman, working with phage, published proof that messinger RNA carries a specific message, confirming Volkin's and Astrachan's results.

In 1961, Marshall Warren Nirenberg and Heinrich Matthaei deciphered the first code group, a sequence of nucleotides that specified the amino acid phenylalanine. This they accomplished by adding artificial RNA, in this case, polytidylic acid, to a cell-free system in which the ribosomes would bind with the tRNA molecule complementary to the codon carrying the specific amino acid called for by the one-word message. Their announcement set off a race to decipher the rest of the code by Brenner, Ochoa, Crick, and others.

In 1961, Peter Mitchell, in the context of oxidative and photosynthetic phosphorylation, postulated energy coupling by an ion gradient, which is known as the chemiosmotic hypothesis. Mitchell proposed that electron transport and phosphorylation are not chemically linked, but rather coupled only by a transmembrane current of protons.

In 1961, Wigner published a proposal that self-replication is probable in terms of quantum mechanics, assuming that living states exist (which is to say that the formation of a single protein molecule by random means is infinitely improbable).

In 1961, David Hubel and Torsten Wiesel published results which showed that an anesthetized cat's visual cortex showed activity even though its brain waves showed it more asleep than awake. Later, they determined that, in the physiology of vision, neurons respond first to dark edges, rather than a spot of light.

In 1961, Roger W. Sperry published results of his studies of lateralization in animal brains in which disconnected cerebral hemispheres could be taught in such a way that one hemisphere learned one response while the other hemisphere learned a different response.

In 1961, Richard C. Lewontin was the first to explicitly apply game theory to evolutionary biology, pitting species against nature and seeking survival strategies.

In 1961, Holland circulated a technical report entitled "A Logical Theory of Adaptive Systems Informally Described," in which he propounded a general theory of adaption, i.e., if an agent is going to be adaptive, it requires feedback.

In 1961, Gell-Mann and Yuval Ne'eman invented a periodic table according to a system they called the 'eightfold way.' Consisting of triangles and hexagons, it predicted the existence of new, undiscovered particles.

In 1962, Hans Ris noticed the similarity in appearance of the DNA in chloroplasts to that of cyanobacteria.

In 1962, Werner Arber predicted the existence of restriction endonuclease enzymes, which are bacterial enzymes capable of cleaving DNA at points where specific nucleotide sequences occur.

Between 1962 and 1964, Edelman, Baruj Benacerraf, Joseph Gally, and colleagues confirmed that antibodies of different specificities had different primary structures, i.e., amino acid sequences. They proposed, and Christian Anfinsen, Edgar Haber, and colleagues confirmed, that antibodies also had different three-dimensional structures, i.e., they fold differently. That antibodies could be denatured and then be allowed to reform in the absence of antigen was the final disproof of the template hypothesis. Extending these proposals, Smithies pointed out that "for the combination of H [for heavy] and L [for light] chains to hold implications for antibody diversity..., they would have to be able to combine randomly" (Podolsky and Tauber 1997:65).

In 1962, John. B. Gurdon demonstrated totipotency, that is, that a fully differentiated cell still contains the genetic information to direct development of the cells in the entire animal. He accomplished this by removing the nuclei from fertilized frogs' egg and replacing them with a cell from a single tadpole's intestine. The frogs grown in this way had identical genetic constitutions, that is, they were clones.

In 1962, S. Cohen isolated epidermal growth factor.

In 1962, Michel Jouvet showed that REM sleep was controlled by the pontine brain stem.

In 1962, Rachel Louise Carson published Silent Spring, which concerned the dangers of pesticides.

In 1962, Paul Baran described 'packet switching,' the breaking down of data into labelled packets, and how this would be crucial for the realization of a computer network.

In 1962, Thomas S. Kuhn, in The Structure of Scientific Revolutions, wrote that "discovery commences with the awareness of anomaly, i.e., with the recognition that nature has somehow violated the paradigm-induced expectations that govern normal science" (Kuhn 1962:52-53). Indeed, a new paradigm is formed because it is incommensurable in any of several possible ways to the old theory and retained because it is useful, not because it is real.

In 1962, a rocket flown by a group led by Riccardo Giacconi found the first source of X-rays outside the Solar System, known as Scorpius X-1, and also the more general X-ray background.

In 1963, Monod, Jean-Pierre Changeux, and F. Jacob concluded that the inhibition of an enzyme by the end product of its pathway required a second active site on the molecule; they named the structural movement between these sites an 'allosteric transition.'

In 1963, Jerne invented the hemolytic plaque technique for screening large numbers of cells and capable of finding rare antibody producers. It proved critical to the development of monoclonal antibodies.

In 1963, Murray Gell-Mann and, independently, George Zweig, discovered and named the 'quark,' the fundamental component of neutrons and protons. Quarks probably come in six 'flavors,' of which there are three 'colors,' or charges, of each. Most physicists believe that quarks and 'leptons' represent the simplest level of structure.

In 1963, Roy Patrick Kerr described the anticipated properties of a rapidly rotating black-hole: it is elliptical; its surface area is less than that of a static black-hole of equivalent mass; if its rotation is sufficiently rapid, the area of the event horizon is reduced to zero; the area around the rotating hole rotates as well; and "a new, inner event horizon forms, and it becomes possible to travel through the black-hole, and emerge into a new universe or perhaps another part of our Universe" (Ridpath 1997:255).

In 1963, Edward Lorenz found what was probably the first example of a 'strange attractor,' a flow in phase space in which orbits converge to an object which is neither a fixed point nor a limit cycle.

In 1963 and 1964, Imre Lakatos, in Proofs and Refutations, suggested that mathematics develops by a process of conjecture, followed by attempts to prove it, that is, reduce it to other conjectures.

In 1964, Louis Leaky identified and named Homo habilis.

In 1964, Nirenberg and Phillip Leder found that lengths of artificial RNA as short as three bases were sufficient to make the ribosomes bind with the kind of transfer-RNA complementary to one codon.

In 1964, Har Gobind Khorana perfected the biochemistry needed to make long strands of RNA with known, simple repeating sequences.

In 1964, Charles Yanofsky established the co-linearity of the gene and the enzyme for making tryptophan in E. coli.

In 1964, William D. Hamilton contributed to the theory of evolution the notion of 'inclusive fitness,' i.e., that fitness--high fitness meaning high selectibility--should include the survival and reproduction of kin. The formula by which this is ascertained states that a gene will increase in frequency in a population if b, the benefit to the recipient, divided by c, the cost to the actor, both measured as changes in the expected number of offspring resulting from the act, is equivalent to k where k is greater than 1 divided by r, the relatedness of the actor to the recipient, or "the coefficients of relationship appropriate to the neighbors whom he affects: unity for clonal individuals, one-half for sibs, one-quarter for half-sibs, one-eighth for cousins, [etc.] and finally whose relationship can be considered negligibly small" (Hamilton 1964:8).

In 1964, John S. Bell, in "On the Einstein-Podolsky-Rosen Paradox," showed that no local hidden-variables theory can make predictions consistent with quantum mechanics; i.e., "the deterministic constraint about the values of identical observables for the two electrons and the statistical constraint about the values of different observables for the two electrons [are not] mathematically consistent with one another" (Albert 1992:68). [added 11/25/00]

By the mid-1960s, Ruth Sager reported numerous incidences of non-chromosomal mutation in a green algae, Chlamydomonas, all of which demonstrated the same pattern of maternal transmission.

About the mid-1960s, Sonneborn, still working with Paramecium, confirmed by grafting tests that the genetic basis for its morphology is contained in its cortex.

Beginning in 1965, Eric R. Kandel published reports on the synaptic facilitation of memory in Aplasia californica, a marine mollusk with a remarkably simple nervous system, and proved that biochemical change at the receptor level is the molecular basis of memory.

In 1965, a team headed by Brenner deduced that the codons UAG and UAA signal the termination of a growing polypeptide.

In 1965, Norbert Hilschmann sequenced Bence-Jones proteins, which are light chains of myeloma globulins found in the urine of myeloma patients, and determined that they possessed different amino acid sequences in their 'variable' and 'common' regions.

Later in 1965, William Dreyer and J. Claude Bennett proposed that within each Bence-Jones cell the variable region existed as an episome which would pair with the single common gene at a specific base sequence. Today, this is known as 'V-C translocation,' although at the time their theory was most noted for its hypothesis that the genetic material was in the germline.

In 1965, R. Bruce Merrifield and J. Stewart invented solid-phase peptide synthesis in which one end of a growing peptide is attached to a tiny plastic bead and amino acids are added individually.

In 1965, Arno Penzias and Robert Wilson confirmed the theory that the universe began with an explosion when they received in their astronomical radio antenna excess microwave noise, coming from all directions and with no obvious source. The implication is that intergalactic space is above absolute zero. This 'cosmic background,' together with the extant amount of helium, is corroborated by extrapolation to when the universe was a few seconds old and hot enough for nuclear reactions to occur.

In 1965, Orhan Berktay, building on earlier work by sonar researchers, discovered that ultrasound signals are distorted in water in a mathematically predictable way. [added 11/25/00]

In 1965, Roger Brown, in Social Psychology, wrote that categorization, or naming, for a child, begins at the level of distinctive action: you smell flowers and you pet cats and you throw balls. Further categorization moves in either an abstract or a concrete direction: upward to superordinate categories (like plant and animal) and downward to subordinate categories (like jonquil and Siamese).

In 1966, David Phillips solved the three-dimensional structure of an enzyme, lysozyme.

In 1966, Walter Gilbert and Benno Müller-Hill were the first to isolate a repressor molecule. Shortly thereafter, Mark Ptashne also isolated a repressor and confirmed it was DNA.

In 1966, Terje Lømo observed that a brief high-frequency train of stimuli to the hippocampus produces an increase in the excitory synaptic potential in the post-synaptic neurons which can be long lasting. This is known as 'long-term potentiation (LTP).'

From 1966 until the 1980s, Kwang W. Jeon observed amoeba being infected by bacteria and then the few survivors losing their disease but not the bacterial 'germs' which had become indispensible, i.e., symbiotic, to the lives of the amoebae.

In 1966, Jacques Oudin chose the term 'ideotype' to denote the class of antigenic determinants peculiar to a particular antibody from a specific individual. This may contrasted with 'allotypes,' a term coined earlier by Oudin, which are protein products of different alleles of the same gene.

In 1966, Brenner and Cesar Milstein devised a hypermutation model of antibody diversity in which they postulated an error-prone polymerase.

By 1966, through the use of Nirenberg's and Khorana's techniques, all twenty amino acids were decoded, including a number of 'degenerate' variations. "Degeneracy is different from strict redundancy but can include redundancy as a specific case.... Degenerate groups are isofunctional but nonisomorphic" (Edelman 1978:59).

In 1966, Lewontin and J. L. Hubby, surveying gene-controlled protein variants, demonstrated that between eight and fifteen percent of the loci in the Drosophila pseudoobscura genome are heterozygous.

In 1966, George C. Williams, in Adaption and Natural Selection, supported genic selection, defining a gene "as any hereditary information for which there is a favorable or unfavorable selection bias equal to several or many times its rate of endogenous change" (Williams 1966:25).

In 1966, Yakov Zel'dovich and Igor Novikov proposed that neutron stars and black-holes would be found in close binary systems.

In 1967, Edwin Lennox and M. Cohn revised the Brenner-Milstein model, characterized it as a 'somatic' model, as opposed to a 'germline' model, and named the nucleotide, where the error-prone polymerase operated, the 'generator of diversity,' or GOD.

In 1967, Colin C. F. Blake and colleaques published the three-dimensional structure of lysozyme at sufficiently fine resolution that it was possible to see how an enzyme accomodated its substate.

In 1967, Kornberg, Mehran Goulian, and Robert L. Sinsheimer synthesized a biologically active viral DNA, using as a template a single-stranded DNA chain from fX174 which requires no protein coat to infect bacteria.

In 1967, Reiji Okazaki showed that newly synthesized DNA requires a DNA fragment as a starter. These fragments are replicated discontinuously and then spiced together.

In 1967, Judah Folkman began the development of his theory that cancerous tumors could be stopped by inhibiting the first growth of blood vessels to them. Earlier, he had developed the first implantable drug-delivery system, later called Norplant.

In 1967, Gurdon, by transplanting somatic material into frog's eggs, discovered that the synthesis of RNA and DNA changes to the kind of synthesis characteristic of the host cell nucleus.

In 1967, Aaron Klug concluded that viruses had a geodesic and crystalline structure.

In 1967, Donald Mosier established experimentally that, in order to generate an immune system antibody response, lymphocytes must interact with non-lymphoidal cells, such as macrophage.

[In 1967, Jerne, facetiously imposing molecular terminology on immunologists, labelled those favoring the cellular point of view, such as Metchnikoff, Burnett, and M. Cohn, 'cis-immunologists' and those favoring the molecular point of view, such as Edelman and Porter, 'trans-immunologists.' These attitudes fell roughly from the traditional disagreement between the 'globalists,' or holists, and the reductionists. At the time and in the sense which Jerne intended the distinction, it referred to where the respective disciplines were coming from: "The trans-immunologists...start at the end, with the structure of antibody molecules, hoping to work their way backwards, and the cis-immunologists...start at the beginning, and with the effects of antigenic exposure, hoping to work their way forwards" (Jerne 1967:591).

In 1967, Steven Weinberg and, independently the following year, Abdus Salam completed the somewhat earlier observation of Sheldon Lee Glashow that the weak and electromagnetic forces share a number of common features: If the main difference between them is mass verses massless, "the spontaneous breaking of the underlying gauge symmetry" by a minute violation of parity in a weak neutral interaction permits the mass of the weak force to be treated as "a secondary phenomena, leaving the gauge symmetry of the dynamics itself intact" (Davies and Brown 1988:54-55). In other words, they reformulated the theory of the weak force integrating it into a theory of 'electroweak force,' reminescent of Maxwell's demonstration that electricity and magnetism were part of a more embracing scheme. The theory predicts the existence of the 'Z boson' and the 'W boson,' both confirmed in 1983/1984, and a heavy particle with spin 0, the 'Higgs boson.' [revised 11/25/00]

In 1967, Anthony Hewish and Jocelyn Bell determined that the highly regular pulses of a radio source from outer space originate in rapidly spinning neutron stars, which they called 'pulsars.' [added 12/29/00]

In 1967, Arthur Samuels finished building a computerized checkers player which could model the opponent's options, recognize its tactics, and make predictions on that basis.

In 1968, Norman Geschwind and Walter Levitsky showed that in male and female humans there are characteristic anatomical differences, e.g., the size of the planum temporale in the hemispheres of the brain.

In 1968, Donald Roy Forsdyke proposed that, within the immune system, "two separable and distinquishable signals [were] required to separate inactivation by self from activation by nonself" (Cohn 1994:30).

In 1968, Lionel F. Jaffe, working with Fucus eggs, published a description of the role of ionic current in developmental patterning.

In 1968, Motoo Kimura formulated the neutral theory of evolution which holds that almost all evolution at the molecular level is due to random drift, in contrast to neo-Darwinians who hold that natural selection plays the more prominent role. Subsequently, the discovery of various 'silent' genes, invisible to natural selection, have lent support to the concept of evolution by neutral genes. Neutral theory offers a baseline for evaluating the significance of selection and adaptive change.

In 1968, Christian Barnard performed the first human heart transplant.

In 1968, Jurgen Habermas pointed out that "psychoanalysis consists of the hermeneutic interpretation of the complex text that is provided to the analyst by his subject," not the physics of the mind, as Freud supposed (Stent 1985:217).

In 1968, ARPA contracted to build ARPANET, the prototype of the computer internet.

In 1969, Calvin published Chemical Evolution in which he gave several autocatalytic scenarios for the origin of life.

In 1969, Glashow, John Iliopoulos, and Luciano Maiani introduced a fourth quark, named 'charm.' [added 11/25/00]

In 1969, Marcian Ted Hoff designed the first microprocessor, an integrated circuit semiconductor chip which was able to receive instructions and send data.

In 1969, Brent Berliner and Paul Kay published Basic Color Terms: Their Universality and Evolution, in which they concluded that "there appears to be a fixed sequence of evolutionary stages through which a language must pass as its basic color vocabulary increases" (Berliner and Kay 1969:14); i.e., first, black and white encompass the entire spectrum, then red is added, then green or yellow, then blue, then brown, then many categories.

In 1969, Penrose discovered a process for extracting energy from a rotating black-hole: if when sending a mass, against the direction of the spin, into the ergosphere, the area immediately outside a black-hole, the mass were to split, one part entering the black-hole and another escaping, the emerging fragment may have greater energy than its entirety had to begin with. This extra energy is surrendered by the black-hole which must slow its rotation slightly.

In the late 1960s, Ralph Lewin discovered a microbe which he named Prochloron, a missing link in the history of symbiosis, combining the physiology of a plant with the structure of a bacterium.

In 1970, Lynn Margulis established that the main internal structures of eukaryotic cells had originated as independent living creatures.

In 1970, Mort Mandel demonstrated that placing E. coli cells in a cold calcium chloride solution rendered them permeable to nucleic acid fragments. This manuver is virtually indispensible in genetic engineering operations.

In 1970, Peter Bretscher and M. Cohn published a two-signal theory of self-nonself discrimination. Signal one occurs when a lymphocyte's antigen-specific receptor, that is, either B-cell antibody or T-cell receptor, contacts the appropriate antigen. If the lymphocyte receives no other signal, it is inactivated irreversibly, i.e., killed. This is the tolerance pathway. The second or activation signal was at that time thought to have been supplied only by helper T-cells, which are antigen-specific, thus maintaining tolerance. Their theory was based on its analogy to neural associative learning, i.e., plasma cells learned to respond to or tolerate a signalling antigen by virtue of its associated signal from a carrier-antibody cell.

In 1970, Susumu Ohno published Evolution by Gene Duplication in which he described gene duplication as an escape from the pressure of natural selection. "By duplication, a redundant copy of a locus is created. Natural selection often ignores such a redundant copy, and, while being ignored, it accumulates...mutations and is born a new gene locus with a hitherto non-existent function. Thus, gene duplication emerges as a major force of evolution. [Also], when the metabolic requirement of an organism dictates the presence of an enormous amount of a particular gene product, the incorporation of multiple copies of a gene locus by the genome often fulfills that requirement" (Ohno 1970:59-60).

In 1970, Lewontin took the position that the synthetic theory of evolution ought to be expanded to include multiple units of selection, e.g., cell organelles, haploid organisms, and gametes, as well as individual organisms. This is widely known as the anti-adaptionist position and is less reductive than the adaptionist position in which genes are the sole unit of selection. The latter position was explicit in the ideas of Williams and W. D. Hamilton. The issue seems to be the assumption which adaptionists make that selection strives for optimality which their opponents, e.g., Stephen Jay Gould and Lewontin, ridicule as 'Panglossian' (Gould and Lewontin 1978). Hamilton, along with John Maynard Smith and Richard Dawkins, developed game theory where they substituted population dynamics and stability for rationality and fitness for self-interest. In both cases, they were concerned with 'optimization' models, the proper role for which "is to provide the means for creating short-term evolution in the imagination" (Oster and Wilson 1978:312). Since optimization is based on the assumption that populations strive to be adapted to the contemporary environment, maladaptive traits and the fact of continuous evolutionary change are obstacles to testing optimization theories.

In 1970, Stephen Hawking and Penrose proved that the universe must have had a beginning in time, on the basis of Einstein's theory of General Relativity. The implication of this is that near the beginning of time, when the universe was sufficiently small, the laws of quantum mechanics would have applied. Earlier, Penrose had shown that black-holes produce 'singularities,' mathematical points where certain physical quantities attain infinite values. Hawking now showed that the big-bang must have arisen from a singularity.

In 1970, Stephen Hawking and Penrose proved that the universe must have had a beginning in time, on the basis of Einstein's general theory of relativity. The implication of this is that near the beginning of time, when the universe was sufficiently small, the laws of quantum mechanics would have applied.

In 1970, John Schwarz and André Neveu discovered a second string theory that described 'fermions,' the name given to particles of matter with spin equal to an odd multiple of the fundamental unit of spin. The following year, together with Pierre Ramond, they revised this model, reducing the dimensions to ten. This model came to be called the superstring Theory of Everything. "In the case of a superstring, the different harmonics correspond [not to different sounds, but] to different elementary particles" (Whitten 1988:93). String theory includes gravitons and super symmetry. It should be noted that it is not possible to experimentally test a theory of everything.

In 1970, John Conway developed the Game of Life, a computer program which began with randomly arranged white, or alive, squares and black, or dead, squares. These squares live or die according to a few simple rules centered on the density of the population, and, in the meantime, arrange themselves into all manner of coherent structures in inexhaustable variety.

In the 1970s, Manfred Eigen sought the origin of life in ribonucleic acid, the apparatus of replication. He was able to make RNA using an enzyme but no template. Leslie Orgel made RNA using a template but only zinc ions for a catalyst.

In 1971, Howard Temin and Satoshi Mizutani, working with Rous sarcoma virus which has RNA as its genetic material, proved that the RNA had a DNA intermediate; that is, the virus has an enzyme by which the RNA directs the behavior of the DNA. The same month, David Baltimore, working with the virus that gives mice leukemia, made the same claim. The enzyme is now known as 'reverse trascriptase.' By this process biologists can make DNA copies of active genes, or messenger RNA.

In 1971, Ronald J. Konopka, working in Benzer's lab, published his discovery in Drosophila of the first gene known to control a biological clock. On the X chromosome there are three alleles of a locus, which he named the period locus, that shape a fly's sense of time.

In 1971, Susan Leeman determined the eleven amino acid structure of the peptide, Substance P.

In 1971, Robert Trivers extended the notion of reciprocity to the explanation of altruism.

In 1971, Gould and Niles Eldredge published their conclusion that the fossil record is, indeed, accurate and evolution proceeds over time by 'punctuated equilibrium.'

In 1971, Kenneth G. Wilson demonstrated the ubiquity, or 'universality,' of critical point phenomena, such as phase transitions, using a technique which he called the 'renormalization group.' In the phase transition from liquid to vapor, for example, configurations are formed by the microscopic degrees of freedom near the critical point, that is, the point where the difference in the densities of the two phases vanishes and at which it is susceptible to renormalization group transformation.

In 1971, Gerhard 'tHooft proved that theories like the Yang-Mills theory could be described in the language of quantum mechanics and that theories with massive particles, like those postulated by Glashow, Weinberg, and Salam, were sensible so long as the masses come from spontaneous symmetry breaking. With Martinus J. G. Veltman, 'tHooft developed a dimensional-regularization method, involving temporarily modifying the number of space dimensions in a calculation. [revised 11/25/00]

By early 1972, through the collaborative efforts of Peter Lobban, Paul Berg, Herbert Boyer, Stanley N. Cohen, John Morrow, Janet Mertz, and Ronald Davis, animal genes were being placed in the plasmid of bacterial cells at places which readily rejoined even foreign DNA; thus was recombinant cloning begun, which, for once, answered more questions than it raised. For example, it permitted the identification of those genomic components which have no effect on development.

In 1972, Changeux isolated a receptor for the first time in a lab. The receptor was for acetylcholine and was from as eel.

In 1972, computerized axial tomography, or CAT scanning, was introduced.

In 1972, René Thom , in Stabilité Structurelle et Morphogénèse: Essai d'une thérie général des modèles, pointed out that structures, e.g., cells, have boundaries and a boundary implies a discontinuity. Moreover, "all creation or destruction of forms, or morphogenesis, can be described by the disappearance of the attractors representing the initial forms, and their replacement by capture by the attractors representing the final forms. This process [is] called 'catastrophe'" (Thom 1972:320). His description is similar to Thompson's, but much more sophisticated mathematically.

In 1972, Ray Tomlinson created the first electronic mail program.

In 1973, Jerne propounded a cognitive theory of immune ideotypic networks, envisaged as an autonomous, homeostatic system, with self-knowledge preceding the first antigenic encounter. In the course of this, he proposed the study of the brain from the point of view of epigenetic selection. Changeux took up his suggestion that same year.

In 1973, Solomon H. Snyder and Candace B. Pert identified specific opiate receptors in the brain.

In 1973, Timothy V. P. Bliss and Lømo demonstrated that a brief high-frequency train of stimuli to the hippocampus produces an increase in the excitory synaptic potential in the post-synaptic hippocampal neurons, which slowly dissipated back to the base rate. They called this long-lasting potentiation.

In 1973, R. M. Steinmann and Z. A. Cohn observed dendritic cells in the spleen and lymphoid organs of mice.

In 1973, Vinton Cerf and Bob Kahn began development of a protocol, later called TCP/IP, which allows diverse computer networks to interconnect and communicate with each other.

In 1974, Brenner described methods for inducing, isolating, and mapping mutations in a nematode, or worm, Caenorhabditis elegans.

In 1974, Peter Milner proposed the necessity of correlated, or simultaneous, firing by neural assemblies. He also argued that early cortical areas would have to be involved in visual awareness and suggested the mechanism for this would be backprojection from the higher cortical areas.

In 1974, Rolf Zinkernagel and Peter Doherty proved that immunization results when antigen-specific T-cells and the major histocompatibility complex (MHC) are the same haplotype, or haploid genotype, which is the configuration of alleles of the MHC on one chromosome of a specific individual. They also established that MHC-restriction occurs during the generation phase as well as during the effector phase.

In 1974, R. W. Hedges and A. E. Jacob discovered in E. coli a mobile DNA sequence, which they named a 'transposon.'

In 1974, William G. Quinn, working in Benzer's lab, established that flies can learn, i.e., they can remember, some for twenty-four hours, which is the equivalent of six years of a human life.

In 1974, Hawking postulated the existence of small black-holes and predicted that, in the gravitational field around a black 'minihole,' pairs of 'virtual' particles may last long enough for one particle to be drawn into the black-hole and the other to become 'real.' When this happens, the black-hole will appear to be emitting radiation and when this "'Hawking radiation' exceeds the amount of matter and energy entering the black-hole, [the hole] will start to evaporate" (Ridpath 1997:208). "The 'miniholes' are especially interesting to physicists because they may yield fundamental insights into how gravity links to other forces of nature" (Begelman and Rees 1996:223).

In 1974, Joseph H. Taylor and Russl A. Hulse, using a radiotelescope, discerned that a pulsar was emitting radio waves in a regular pattern of alternately speeding up and slowing down. They realized that this pulsar must be part of a binary system and that the alternation must be caused by gravitational waves, predicted to exist by Einstein's general theory of relativity. [added 12/29/00]

In 1975, Sanger and A. R. Coulson devised the 'plus and minus' method for determining the sequences of bases on a strand of DNA. Until then, genetic map-makers had relied on the relative position of changes, i.e., mutations, in the genes.

In 1975, Milstein and Georg Köhler devised a method to fuse myeloma cells with normal B-cells, in bulk, that would grow just the hybrids which produce monoclonal antibodies.

In 1975, Kevin Lafferty and A. J. Cunningham proposed a model of immune system activation in which the second signal, or 'co-stimulation,' comes from an antigen-presenting cell (APC) which need not display specificity for antigen.

In 1975, Viktor Hamburger confirmed that the neuronal system is regressive, i.e., adults have far fewer axons and synapses than newborn infants but more order.

In 1975, Hans W. Kosterlitz and John Hughes identified and named 'enkephalins,' which are pentapeptides with opiate-like activity, rather like endogenous morphine, or endorphins.

In 1975, Edward O. Wilson, in Sociobiology: The New Synthesis, analyzed the social instincts that bring together colonies of ants and bees, herds of antelope, and tribes of chimpanzee and human beings. His inclusion of the last of these was controversial: His opponents argued that the human animal was not enslaved by instincts, but rather was ruled by culture. Along with MacArthur and Trivers, Wilson led the emergence of a new paradigm, sociobiology.

In 1975, Richard D. Schwartz reckoned that Herbig-Haro objects are heated gases flowing away from a star. Subsequently, by extrapolating backward in time, other astronomers deduced the the source was "invariably...a star only a few hundred thousand years old" (Ray 2000:45).

Since 1975, a screen for environmental chemicals, devised by Bruce Ames and colleagues, has been in wide use. The test "uses histidine-requiring mutant strains of Samonella typhimurium and measures the frequency of back mutations that no longer require histidine supplements" (Hale and Margham 1991:28).

In 1975, Robert W. McCarley and J. Allan Hobson designed the reciprocal-interaction model of sleep cycle control in which waking occurs at the expense of REM sleep and vice-versa. McCarley recognized that this relation could be described by the equations of Lotka and Volterra.

In 1975, Mitchell Feigenbaum created the theory of universality in the rate of bifurcations.

In 1975, David Blackstock and Mary Beth Bennett determined that air, like water, propagates audible ultrasound in a nonlinear way. [added 11/25/00]

In 1975, Holland, in Adaption in Natural and Artificial Systems, propounded the 'schema' theorem, a genetic algorithm to the effect that any compact population of genes, a schema, that offers above average fitness will grow exponentially in the presence of reproduction, crossover, and mutation.

In 1976, Susumu Tonegawa proved that about 1,000 pieces of genetic material in the variable portion of the B-cell can be shuffled (or translocated or recombined) in different sequences. This permits the production of antibodies specific for over a billion different antigens, and occurs somatically, i.e., by mutation in the adult organism, not in the germline. This model is "a paradigm for the generation of maximum information storage from a minimal apparatus" (Podolsky and Tauber 1997:95).

In 1976, Dawkins, in The Selfish Gene, coined 'meme,' for bits of information which are replicated, like genes, in selected variants. [added 11/25/00]

In 1976, Robert Swanson and Boyer founded Genentech on the premise that patents could replace business secrecy, attracting academic scientists who could still publish.

In 1976, Mircea Steriade showed that in non-REM sleep the transmission of information is inhibited, i.e., certain brain cells are at rest, whereas in REM sleep they are reactivated.

In 1976, Julian Jaynes, in The Rise of Consciousness in the Breakdown of the Bicameral Mind, wrote that, before consciousness, the stress of making a decision would instigate an auditory hallucination of a voice which had to be obeyed. After a certain point in history, perhaps the introduction of writing, what had been innate affects interplay with newly conscious emotions: Shame generates guilt, fear produces anxiety, mating sex, anger hatred, etc. The behavioral world supplies by metaphor and analogy the referents for mental events: Problems are 'approached' and must be 'grappled with' and solutions are 'clear,' 'obscure,' etc. We speak of the conscious mind as 'quick' or 'slow,' or somebody as 'strong-' or 'weak-minded' and 'broad-' or 'narrow-minded.'

In 1976, Kenneth Appel and Wolfgang Haken announced that they had solved the four-color mapping problem by establishing by trial-and-error that there is an unavoidable set of 1,936 graphs of reducible configurations, and then confirming their conclusion by computer.

In 1977, Elso S. Barghoorn excavated fossil bacteria embedded in 3.4 billion year old rock.

In 1977, Gilbert induced bacteria to produce the non-bacterial proteins insulin and interferon. With Allan M. Maxam, Gilbert also published the 'chemical method' of gene sequencing.

In 1977, groups led by R. J. Roberts and Phillip A. Sharp discovered split genes in adenovirus 2. R-loop mapping by L. Chow and S. Berget showed the position of intron loops. Subsequently, Pierre Champbon described intervening sequences in chicken ovalbumin genes.

In 1977, Ferid Murad discovered that nitric oxide is a vasodilator, and thus controls blood pressure by relaxing the smooth muscle cells in the veins.

In 1977, Alfred G. Gilman and E. M. Ross showed that adenylcyclase is regulated by a protein that binds guanosine triphosphate, or GTP. Guanine nucleotide-binding regulators, or G-proteins, are activated in the presence of GTP. Activated G-proteins dissociate from their receptors and activate effector proteins, such as adenylcyclase, which control the level of 'second messengers.' Second messengers are small molecules or ions generated in response to the binding of a signal molecule to its receptor on the outer surface of the cell membrane.

In 1977, Christiane Nüsslein-Volhard, working with the development of Drosophila eggs, discovered that cell differentiation begins before fertilization at oogenesis with the accumulation of mRNA at the head end of the egg.

In 1977, Hideki Shirakawa, Alan G. MacDiarmid, and Alan J. Heeger announced that they had modified polyacetylene, by blasting it with iodine vapor, and increased its conductivity by a factor of 10 million. This was accomplished by adding (or subtracting) electrons from the polymer's chain of alternating double and single carbon bonds, in effect, bumping the charge and creating a current. [added 12/29/00]

In 1977, Benoit B. Mandelbrot published The Fractel Geometry of Nature in which complex curves are reduced to straight lines, or fractels, and undergo invariant scaling. He modified and generalized Zipf's law, demonstrating that fractels and scaling laws are closely related to the chaos of nonlinear dynamics.

In 1977, television signals were transmitted on optical fibers.

In 1978, Mary Leaky announced the discovery of fossilized human footprints from about 3.5 million years ago.

In 1978, Gilbert coined the terms 'intron' and 'exon' in the course of arguing that information for new and potentially useful proteins can be quickly and reversibly assembled from parts, already proven useful, of old proteins. He called this 'exon shuffling.'

In 1978, Edward B. Lewis announced that genes in the 'bithorax complex' in Drosophila are arranged in the same order along the chromosome as the parts of the body they affect and, during development, turn on in anatomical order, beginning at the head and ending at the anus. In a sense, therefore, a fly's body is a map of its genes.

In 1978, D. J. Finnegan, G. M. Rubin, Michael W. Young, and D. S. Hogness made detailed analyses of dispersed, repetitive DNAs in Drosophila, which vastly increased the understanding of mutability, transposition, hybrid dysgenesis, and retroviruses in eukaryotes.

In 1978, Vernon B. Mountcastle described a cortical model in terms of its columns being elementary functional units.

In 1978, Edelman published a study in which inherently variable neuronal groups constitute the units of of epigenetic selection. Stimuli themselves make the selection, reinforcing or ignoring the connectivity. Thus genetically identical brains will form different connections as they are exposed to different experiences. Redundance is created by the formation of a secondary repertoire of connections which respond to signals similar to those which formed them.

In 1978, Tonegawa's group revealed the existence of J sequences in light chains of immunoglobin, but only later that year was their role in V-J shuffling appreciated by Martin Weigart.

In 1978, in a joint article by the groups of Weigart and Hood, the somatic mechanism of 'combinatorial joining,' or association, of any class of heavy chain with molecules from any type of light chain was added to the model of antibody diversity.

In 1978, Octavio Pompeiano demonstrated that, during REM sleep, sensory nerve terminals are depolarized by signals from the brain stem, thereby reducing the amount of neurotransmitter reaching them and reducing external information. Moreover, he established that while internal motor commands are generated, inhibitory signals prevent their external activation.

In 1978, Martin Perl discovered the existence of the 'tau' lepton, or 'tauon.' [added 11/25/00]

In 1978, Lotfi A. Zadeh published an article on PRUF, or Possibilistic Relational Universal Fuzzy, a logical language where variables represent the degree to which a set is a fuzzy set. Near a boundary in a fuzzy set, one cannot be sure which side an element is on.

In 1978, Holland published a computer program utilizing bottom-up, learned control with feedback reinforcement or weakening, as appropriate, of the rules, or 'classifiers.' Relying on this program, 'agents' offer bids for message space in an auction-type market. The classifiers are treated like business firms who had to repay their suppliers, that is, other classifiers, thus transferring some of their reinforcement.

In 1978, Eleanor Rosch observed that categories, in general, have best examples which she called 'prototypes,' or better, degrees of prototypicality: e.g., substituting Paris for the fashion world or Wall Street for the business world.

["In the late 1970s, elementary particle physicists began speaking of the 'Standard Model' as the basic theory of matter" (Brown et al. 1997:3). It contains two kinds of particles, 'fermions,' which a particles of matter, with spin 1/2, and 'bosons,' which are particles involved in the transmission of forces. Fermions are either leptons, including electrons, muons, and tauons, and their neutrino counterparts, or quarks, including up, charm, and top and their charge complements, down, strange, and bottom. Leptons and quarks interact by exchanging generalized quanta, particles of spin 1. Bosons include 'gluons,' which carry the strong force that binds quarks together. Thus bound together, the quarks form 'hadrons.' The proton and the neutron which combine to make atomic nuclei are hadrons. Bosons also include photons, which carry the weakly interacting electromagnetic force, known in the Standard Model as the electroweak force, and attract electrons to orbit the nuclei. Other weak interactions are carried by the ' W -,' ' W+,' and ' Z' particles. Additional forces are carried by 'gravitons' and 'Higgs particles,' neither of which have ever been observed, but are required by the theory of General Relativity. Gravitons carry the force of gravity and Higgs particles drag on the movement of quarks and electrons, producing inertia, the essence of mass.] [added 11/25/00]

In the late 1970s, Sidney W. Fox converted amino acids into protonoids by heating them. They showed a wide variety of catalytic ability, albeit extremely weakly.

In 1979, Michael Potter, Stuart Rudikoff, and D. Narayana Rao used protein sequencing to predict the presence of heavy chain J regions and their role in the diversity of immunoglobin.

In 1979, David Marr's Vision was published posthumously. It described the theory of a computational process by which internal representations are thought of as a mapping from one representation to another by way of a 'primal sketch.' The idea underlying the primal sketch is the pre-understanding of the shapes of objects, which in turn depends on the variation in the light intensities.

In 1979, Anatol Rapoport, after years of considering the logical conundrum called the 'prisoner's dilemma,' established that the best game theoretical strategy in iterated encounters was the simplest, 'tit-for-tat:' Cooperate in the beginning and then do whatever the other player had done in the previous round.

In 1980, Temin hypothesized that retroviruses originated from retrotransposons.

In 1980 [?], Jerome Karle and Herbert Hauptman devised the appropriate constraints mathematically to enable small molecules to be read of an X-ray crystallograph.

In 1980, Jesse Roth and Derek Le Roith and others discovered insulin-like material in single-celled organisms, establishing that the peptide hormone could be produced outside the pancreatic beta cells.

In 1980, Nüsslein-Volhard and Eric F. Wieschaus characterized zygotic segmentation mutations in Drosophila melanoster.

In 1980, Hood, Phillip Early, Mark Davis, and others uncovered the D segment in the heavy chains of immunoglobin, and thus V-D-J shuffling.

In 1980, Baltimore and Fredrick W. Alt proposed a model in which following the completion of a light chain, no further rearrangement is possible, and therefore any one B-lymphoid clone will make one type of light chain. This eventually obviated the allelic exclusion controversies.

In 1980, Prigogine, in From Being to Becoming: Time and Complexity in the Physical Sciences, suggested that oscillations "near bifurcations play a crucial role because there the fluctuation drives the average" (Prigogine 1980:132). "The best understood example of metabolic oscillation is that which occurs in the glycolytic cycle.... The catalytic effects responsible for the oscillations...lead to a phase shift" (Ibid. 122-123).

In 1980, Klaus von Klitzing, G. Dorda, and M. Pepper found that variation of gate voltage in a silicon metal-oxide-semiconductor (MOS) in a strong magnetic field "gave regions in which the current was accurately perpendicular to the electric field, and the entire ratio of current to field [is] constant" (Thouless 1989:232-233). It also conforms to the 'quantum Hall effect;' that is, the current is a multiple of e2/h, where e is the electron charge and h is Planck's constant.

In 1980, Alan Guth proposed an 'inflationary' theory of the early universe in which, after the big-bang, it expanded exponentially. This hypothesis solves the problems of the universe's homogeneity and its flatness. It is an open question whether the big-bang proceeded from a black-hole in another universe.

In 1980, Heinrich Rohrer and Gerd Binnig developed the scanning tunnelling

microscope which enables images to be made of atoms embedded in surfaces.

In the early 1980s, Marvin Carruthers devised a way to synthesize strands of DNA of any desired base sequence.

In the early 1980s, Peter E. Wheeler argued that, with the shift to bipedalism, whole body cooling (retaining only head hair and developing sweat glands) released a physiological constraint on brain size in Homo.

In 1981, Thomas R. Cech, working with Tetrahymena, discovered a catalytic RNA molecules with the sophisticated reactivity previously known only in proteins: It could catalyze the cutting and splicing that leads to removal of part of its own length. An implication is that if RNA can catalyse as well as carry information, it may have evolutionarily proceeded protein and DNA.

In 1981, Harold E. Varmus and J. Michael Bishop demonstrated that the tumor generating properties of the Rous sarcoma virus are due to a protein encoded by the v-src gene.

In 1981, Stanley B. Prusiner isolated the infectious protein which causes scrapie in sheep and goats and spongiform encephopathies or Creutzfeldt-Jakob disease in people, each transmissible and heritable degenerative diseases of the nervous system. He called this particle a 'prion' and, noting its small size, determined that it had not a single gene.

In 1981, Derek Bickerton published Roots of Language in which he argued that, in Hawaii, "the first creole generation produced rules for which there was no evidence in the previous generation's speech" (Bickerton 1981:60). The implication of this is that the children made up these rules out of their genetic endowment.

In 1981, James Lovelock built a computerized simulation, Daisyworld, in which the biological and physical worlds are tightly coupled such that the biota ensures optimal physical conditions for itself. Using only conventional evolutionary rules and by increasing solar radiation a few degrees, a pattern of equilibrium is punctuated by a rapid proliferation of species.

In 1981, Robert Axelrod and Stephanie Forrest confirmed in a computer simulation via the genetic algorithm that a population of coevolving individuals could discover the tit-for-tat strategy which would spread quickly through the community.

In 1981, programmers at Microsoft Corporation developed a computer disk operating system, MS-DOS.

In 1982, Alt and Baltimore proposed that terminal deoxynucleotidyl transferase, or TdT, could insert the N region, as they chose to call the unencoded, inserted nucleotides, at immunoglobin junction sites.

In 1982, J. Edwin Blalock discovered interaction between the endocrine and immune systems in which the immune system produces the opoid peptide endorphin and adrenocorticotropic hormone (ANTH). These in turn modulate the behavior of the major types of immune cell.

In 1982, Leder calculated the potential combinatorial antibody diversification at 18 billion according to the formula sm(f1[VxJ]xf2[VxDxJ]), with VxJ and VxDxJ representing the combinatorial diversification achieved by the light and heavy gene segments, f1 representing the factor of light chain flexible joining, f2 representing the combined factors of heavy chain flexible joining and N insertion, and sm representing the factor of somatic point mutation (Leder 1982:111).

In 1982, Kandel and James H. Schwartz established that long-term facilitation, that is, the consolidation of short-term memory into long-term, requires cyclic AMP-responsive element-binding (CREB) genes.

In 1982, John Hopfield proposed a simple computer network which operated along Hebbian lines. Each of its units could have only two outputs, inhibition or excitation, but numerous inputs. Moreover, it faintly resembled human memory since any appreciable part of the input pattern acted as an address.

In 1982, Richard Rorty distinguished between 'truth,' as a property "of sentences or actions and situations," and 'Truth,' as "goals or standards..., objects of ultimate concern" (Rorty 1982:xiv).

In 1983, A. Roche-Lecours indicated that humans are probably born with two language areas, but the left area is innately able to soon dominate.

In 1983, Arthur L. Koch published his surface stress theory of microbial morphogenesis.

In 1983, Sidney Altman discovered an enzyme, ribonuclease P, which is intertwined with RNA, and that the RNA alone could weakly catalyse.

In 1983, Arthur T. Winfree published predictions on inducing and halting heart fibrillation based on non-linear dynamics and topology.

In 1983, Reinhard Mundt and Josef Fried made the first astronomical observations with a 'charge-coupled device,' a semiconductor offering greater sensitivity and contrast than traditional photographic plates. What they observed were jets from young stars, verifying the extrapolation from Schwartz' reckoning.

In 1983, David Goldberg built a genetic algorithm, classifier system computer program which learned to simulate central control of a gas pipeline, and from which a default hierarchy emerged, i.e., whenever the strong 'leak' message appeared, the default, or weak 'no leak,' disappeared.

In 1983, William Brian Arthur and others published a description of increasing-returns, or positive feedback, that is, "how chance events work to select one equilibrium point from many possible in random processes [permitting economists to] see mathematically how different sets of historical accidents could cause radically different outcomes to emerge" (Arthur, quoted in Waldrop 1992:46).

In 1984, Richard Leaky and Alan Walker excavated a Homo erectus skeleton, dated 1.6 million years ago.

In 1984, Jeremy Thorner and colleagues, using yeast cells, discovered the prototype prohormone processing enzyme, Kex2 endopeptidase (Julius et al. 1984:1075-1089). Closely related enzymes were later found to be responsible for processing the precursors of all peptide hormones and neuropeptides in mammalian cells. [added 11/25/00]

In 1984, W. McGinnis, C. P. Hart, W. J. Gehring, and F. H. Ruddle demonstrated that the homeobox gene sequence in Drosophila also exists in the mouse. This close similarity suggests an essential role in animal development.

In 1984, Yasutomi Nishizuka, having earlier discovered protein kinase C, published a paper in which he showed that it not only had a role in signal transduction but also one in tumor production.

In 1984, Jeffrey C. Hall, Michael Rosbash, and, independently, M. Young identified and cloned period, the gene controlling a fruit fly's biological clock.

In 1984, Francis O. Schmitt coined the term 'information substances' to include not only neurotransmitters and steroid hormones but peptide hormones, neuropeptides, and growth factors and their receptors.

In 1984, Stephen Wolfram, pointing out that cellular automata are similar to non-linear dynamics, contended that all cellular automata fell in one of four 'universality classes.' The first two classes are either static or orderly, the third is chaotic, and the fourth is complex, like Conway's Game of Life.

In 1985, Kary Mullis and co-workers invented the polymerase chain reaction which multiplies DNA sequences in vitro, making it possible to clone specific DNA sequences rapidly without the need of a living cell.

In 1985, Kandel, in Principles of Neural Science, recognized that psychotherapy, that is, the repetition of a 'new' story, changes and reinforces the functional connections between neurons: "Insofar as social intervention, such as psychotherapy or counseling, works, it must work by acting on the brain, and quite lightly on the connections between nerve cells (Kandel 1985:831).

In 1985, Robert Gallo and Luc Montagnier, independently, published identical genetic sequences of the AIDS virus.

In 1985, Richard E. Smalley and Harold W. Kroto discovered 'fullerenes,' or 'buckyballs,' molecules of 60 carbon atoms.

In 1985, Binning invented the atomic force microscope.

In 1985, Christopher G. Langton deduced the critical lambda (l) value at the exact edge of chaos, and reasoned that Wolfram's cellular automata Class IV, complexity, the phase transition between solid and fluid, and Turing's 'undecidability theorem' are all analogous.

Later in 1985, Stuart A. Kauffman, Norman H. Packard, and J. Doyne Farmer built a computer simulation in which simple polymers could "catalyze the formation of each other, generating autocatalytic sets that evolve in time to create complex chemical species whose properties are tuned for effective collaboration with each other. The system thus bootstraps itself from a simple initial state to a sophisticated autocatalytic set, which might be regarded as a precurser life form" (Farmer et als 1985:51). This is based on Kauffman's earlier searches for the origin of order, in which he used an iterating, parallel-processing model of random, self-organizing Boolean networks: Small changes in initial conditions unleashed bifurcating avalanches of changes from which appear the 'attractors' of chaos theory. Boolean networks are sufficiently similar to cellular automata to permit their assimilation.

In 1986, Dean Falk published data supporting the co-evolution in hominids of brain size and emissary foramina, small holes in the skull which contain blood veins.

In 1986, Howard Cooke hypothesized that the general erosion of telomeric DNA forecats senescence in humans.

In 1986, M. Young's lab determined the complete sequence of letters in the period gene's code. This means that mutant behavior can be isolated to a single letter; e.g., "at nucleotide 1390, counting from the start of the coding sequence, [if] the letter C is changed to a T, [this] transforms the three-letter word CAG (which means 'glutamate') into the three-letter word TAG (which means 'stop')" (Weiner 1999:173). Thus the manufacture of period's RNA ceases at this point.

In 1986, Colin Masters proposed that Alzheimer's disease is caused by oxidative stress. [added 11/25/00]

In 1986, Hood's lab introduced an automated DNA fluorescence sequencer.

In 1986, Per Bak, Chao Tang, and Kurt Weisenfeld, in the course of studying charge-density waves, discovered that self-organized criticality manifests itself like a pile of sand on a plate which is added to in a steady drizzle: Variously sized avalanches spill from the plate according to its power-law, i.e., the average frequency of a given size of avalanch is inversely proportional to some power of its size, e.g., 22 or 24.

In 1986, Johannes Georg Bednorz and Karl Alexander Müller found a new class of layers materials which semiconduct at much higher temperatures than any which had been found previously. In a pure state these materials insulate; with impurities they conduct.

In 1986, David Rumelhart, James McClelland, and others, in their book Parallel Distributed Processing, produced the algorithm known as 'the backpropagation of errors,' in which the error is graded, not binary, that is, it differentiates into a non-linear curve, and the network, as a whole, is always adjusted to reduce its errors.

In 1987, Rebecca L. Cann, M. Stoneking, and A. C. Wilson erected a genealogical tree which suggested that all human mitochondrial DNA can be traced back to a common African maternal ancestor.

In 1987, Nüsslein-Volhard and others show that a small group of maternal effect genes determine the polarized pattern in Drosophila embryo development.

In 1987, Hood's lab introduced an automated DNA synthesizer.

In 1987, Hans Reichenbach and Gerhard Hofle separated out of the Sorangian cellulosum strain of myxobacteria, which they had isolated two years earlier, a cell-killing chemical which they named 'epothilone.'

In 1987, James van House and Arthur Rich invented the positron microscope.

In 1987, Ahmed H. Zewail and colleagues, using lasers capable of pulsing in femtoseconds, observed the dissociation of cyanogen iodine (ICN). [added 11/25/00]

In 1987, George Lakoff, in Women, Fire, and Dangerous Things, made a case for embodiment as the basis for meaning and mind: "Truth is very much a bootstrapping operation, grounded in direct links to preconceptually and distinctly structured [personal, physical] experience and the concepts that accord with such experience" (Lakoff 1987:297); that is, image schemas are metaphorically mapped on to the corresponding abstract configuration, e.g., categories are understood in terms of container schemas, hierarchical structure is understood in terms of part-whole and up-down schemas, relational structure is understood in terms of link schemas, radial structure in terms of center-peripheral schemas, foreground-background structure in terms of front-back scemas, and linear quantity scales in terms of up-down and linear order scemas. Mark Johnson, who, in the same year, published The Body in the Mind, made a similar case.

In 1988, W. A. Devane discovered a cannabinoid receptor, CB1, which is the most abundant member of the brain's G-protein-coupled family and even approaches the glutamate receptor in quantity.

In 1988, Corey isolated and synthesized the active substance in an extract from the ginkgo tree, ginkgolid B, which interferes with platelet activating factor.

In 1988, Packard published "Adaption to the Edge of Chaos," and Kauffman, acknowledging that at the border between order and chaos lies complexity, i.e., life and its constraints, added selection to his computer model. Life without selection, describable in Kauffman's model, provides a 'null hypothesis,' or a baseline, which can "be used to detect the perturbing effects of selection or other 'agents' of evolutionary change" (Burian and Richardson 1991:269).

In 1989, John L. Hall, Z. Ramanis, and David J. L. Luck published their discovery of centriole-kinetosome DNA, which travels in mitosis, packaged as its own 'motility' chromosome.

In 1989, Folkman proposed the theory that tumors contain both stimulators and inhibitors of angiogenesis to explain tumor metastases after the tumor is removed.

In 1989, John Byl devised a self-reproducing automata so small, twelve cells in six states with fifty-seven transition rules, that it undermines "von Neumann's 'complexity threshold' separating trivial from non-trivial self-replication" (Sigmund 1993:24).

In 1989, Richard Palmer and Arthur built a computer simulation of the stock market in which agents taught themselves a sort of primitive technical analysis which led to bubbles and crashes.

In 1989, Holland built the ECHO artificial life simulation, a complex adaptive system, which provided "a distinction between phenotype and genotype, so that the fitness of a genotype depends on interactions of the phenotype with other agents and the local environment," complete exogamy, and analogs of "sophisticated ecological processes, such as biological arms races and speciation" (Holland 1995:48-49).

In 1990, W. French Anderson performed the first gene transplant on a human being, injecting engineered genes into a four-year-old to repair her faulty immune system.

In 1990, J. Milicki, K. Schughart, and W. McGinnis introduced a mouse gene into a Drosophila embryo, establishing that, in animals that have been evolving independently for hundreds of millions of years, genes will generate products that function interchangeably.

In 1990, teams led by Robin Lovell-Badge and Robin Goodfellow isolated the testis-determining factor gene, the master switch for mammalian sex determination. This they named SRY, for sex-determining region, Y chromosome. When introduced into newly fertized mouse eggs, it caused genetic females to develop into males.

In 1990, Jan Sapp, in Where the Truth Lies: Franz Moewus and the Origins of Molecular Biology, reflects on partisan representations of scientific roots, bias in gathering and interpreting data, the social negotiation of standards, especially for new paradigms,the technique problem in the replication of experiments, and the 'experimentalist-statistician paradox,' where data can be good to be true.' Far from being purely deductive, it is scientists' "anticipation of results that informs them of what experiments to perform...and what data to report.... 'The scientific paper' is...rhetoric" (Sapp 1990:116), and the science student's "version of 'truth' is closely associated with getting an 'A'" (Sapp 1990:306). The scientist decontextualizes knowledge, and the historian recontextualizes it (Sapp 1990:301).

In 1990, Tim Berners-Lee and CERN, The European Organization for Nuclear Research, implemented a hypertext system for information access for physicists.

In 1990, Walter Fontana built a computer simulation which he called algorithmic chemistry, or 'alchemy.' In it he exploited the fact that computer code is both a program and a data string: Program A reads program B as input data and interpretes it as program C. From the random interaction of a vast accumulation of these program strings emerges a variety of catalytic responses.

Beginning in 1990, Fred Wendorf and colleagues uncovered on the Nabta Playa, Egypt, the earliest-known megalithic astronomical calendar site.

In 1991, D. R. Knighton and colleagues determined the three-dimensional structure of the catalytic core of protein kinase.

In 1991, J. C. Hall, Charalambos P. Kyriacou, Rosbash, and colleagues cloned the period gene of Drosophila simulans, injected it into the egg of a Drosophila melanogaster, with the result that the rhythmic 'song' behavior of simulans was performed by melanogaster.

In 1992, a team led by Raphael Mechoulam discovered the first endogenous cannabinoid neurotransmitter, anandamide, an arachidonic acid derivative.

In 1992, Robert D'Amato deduced that the mechanism by which thalidomide operates is angiogenic inhibition.

In 1992, Ephraim Fuchs, by increasing the ratio of dendritic cells to B-cells, was able to show experimentally that neonatal mice would respond to foreign antigen. This disproved Medawar's theory that immunological tolerance existed at birth.

In 1992, the United States' COBE, or 'Cosmic Background Explorer,' astronomical satellite detected very small variations, or ripples, in the background cosmic radiation which are thought to be imprints of quantum fluctuations from the early universe.

In 1992, CERN released to the public their hypertext for physicists, naming [?] it the World Wide Web.

In 1993, J. William Schopf announced the discovery of fossilized bacteria in 3.5 billion-year-old rocks from Western Australia.

In 1993, Dean H. Hamer and colleagues produced evidence employing polymerase chain reaction that male homosexuality is preferentially transmitted through the maternal side and is genetically linked to chromosomal region Xq28, which is thought to contain several hundred genes.

In 1993, C. Robert Dell and collaborators, using the Hubble space telescope, saw swirling disks of gas and dust, such as Laplace had predicted, within the constellation Orion.

In 1993, Marc Andreeson and others developed a graphical user interface for the World Wide Web, called 'Mosaic X.'

In 1994, W. C. Orr and R. S. Sohal constructed transgenic lines of Drosophila having extra copies of the genes for the antioxident enzymes catalase and super oxide dismutase, which slowed the aging process.

In 1994, Polly Matzinger, following Fuchs' lead, hypothesized that what the immune system recognizes is danger to the organism, rather than making a distinction between the self and nonself. In her reanalysis, she found that antigen presenting cells (APCs) make the distinction between dangerous and harmless. With the benefit of an alarm signal, APCs are able to deliver the second signal in the two signal model to T-cells. B-cells receive the second signal from activated helper T-cells.

In 1994, Jerry Yin cloned a Drosophila gene which makes cyclic-AMP responsive element-binding (CREB) protein. This protein is a toggle swithch, activating or deactivating memory genes. Yin, Tim Tully, Quinn and a few colleagues proved this by injecting Drosophila with a second CREB gene, switching it on, and testing the flies' long-term memory, which was now extraordinary.

In 1994, Arturo Alvarez-Buylla, Chang-Ying Ling, Wen Shan Yu, and, independently, Anat Barnea and Fernando Nottebohm established the neurogenesis, including both new neurons and the replacement of old ones, occurs in adult song birds.

In 1994, Penrose, in Shadows of the Mind, maintained that consciousness is not computable and probably resides in the microtubules.

In 1994, Gerard Foschini proposed modifying Shannon's information theory so that, instead of points, spatial volumes could be linked by means of multiplying transmitters and receivers. A set of high-speed processors "look at the signals from all the receiver antennas simultaneously, [extracting] the strongest signal from the jumble, then [working] through the weaker signals one by one" (Mullins 2000:36). [added 11/25/00]

In 1995, J. Craig Ventner and many colleagues published the first complete nucleotide sequence of a free-living organism, Haemophilus influenzae.

In 1995, R. Sherrington, Peter H. St. George-Hyslop, and G. D. Shellenberg and many colleagues isolated and characterized two genes responsible for early-onset, familial Alzheimer's disease.

In 1995, Michel Mayor and Didier Queloz detected the first extra-solar planet using the 'wobble technique:' Inferring the orbit and minimum mass of a planet by periodic Doppler shifts as a star is pulled by the force of a planet's gravity. The planet circles the star 51 Pegasi in the constellation Pegasus.

In 1996, Folkman found angiostatin, a molecule that inhibits angiogenesis more powerfully than thalidomide.

In 1996, Leland H. Hartwell led a team from the Seattle Project in deciphering the genome of Saccharomyces cerevisiae, or baker's yeast. This was the first organism with a nucleus to have its genome deciphered. 38 percent of yeast proteins are similar to known mammalian proteins.

In 1997, the Fermi National Accelerator Laboratory, or Fermilab, conducted an experiment which provided the first direct evidence of the existence of the 'tau neutrino.' [added 11/25/00]

In 1998, Robert Waterston and John Sulston and numerous colleagues reported the mapping of the entire genome of Caenorhabditis elegans. About 33 percent of this worm's proteins are similar to those found in mammals.

In 1998, vascular endothelial growth factor genes were therapeutically inserted in a human heart and formed new blood vessels.

In 1998, Richard S. Stephens and colleagues mapped the 900 genes in the genome of Chlamydia trachomatis.

In 1998, A. G. Bodnar confirmed Cooke's hypothesis that the erosion of telomers forecasts senescence.

In 1998, Alan Sokal and Jean Bricmont distinguished between "knowledge (understood, roughly, as justified true belief) and mere belief," and added that, if one does not "take into account empirical aspects, then scientific discourse indeed becomes nothing more than a 'myth' or 'narration'" (Sokal and Bricmont 1998:195,197).

In 1999, Jochen J. Brocks and colleagues published their discovery of fossil molecular lipids which push back the horizon for eukaryotes to around 2.5 billion years ago.

In 1999, Paul A. Moore and numerous colleagues discovered and characterized B-Lymphocyte Stimulator (BLyS), a monocyte-produced growth factor molecule which causes B-cells to produce antibodies.

In 1999, Ian Dunham and 129 colleagues from the Human Genome Project announced the sequencing of the euchromatic part of human chromosome 22.

In 1999, Angelo Vescovi showed that mouse brain stem cells could produce blood cells. [added 11/25/00]

In 2000, teams led by Martin Schwab and Stephen Strittmatter published their identificaton of a gene, dubbed nogo, which codes for a protein, found in the protective sheaths of nerve cells, that blocks the regrowth of nerve cells in the brain and spine.

In 2000, Ventner led a team which sequenced Drosophila melanogaster's genome. 60 percent of known human disease genes have equivalents in this fruit fly, including p53, the so-called tumor suppressor gene which when mutated permits rampant cell division. About 50 percent of fly proteins are similar to mammalian proteins.

In 2000, Hervé Tettelin, Ventner, and numerous colleagues sequenced the genome of Neisseria meningitidic Serogoup B strain MC58, a bacterial agent which causes meningitis and septicemia, especially in infants.

In 2000, Masahira Hattori, Asao Fujiyama, Yoshiyuki Sataki and 59 colleagues from the Human Genome Project mapped the sequence of human chromosome 21, the smallest chromosome. An extra of this chromosome or additional genes from it produces Down syndrome.

In 2000, Thomas A. Steitz, Nenad Ban, Poul Nissen, and colleagues resolved the atomic structure of the large subunit of a ribosome of a bacteria, Haloarcula marismortui, using X-ray crystallography. As proteins "are largely absent from the regions of the subunit that are of primary functional significance to protein syntheses" (Ban et al. 2000:905), the view that RNA preceded proteins at the origin of life is supported. [added 11/25/00]

In 2000, Yoshiyuki Sakaki and colleagues sequenced the bacterium Buchnera's single chromosome and established its symbiosis with its host, Aphid cells: Of Buchnera's 583 genes, 54 code for enzymes dedicated to making the Aphid's essential amino acids. In return, since Buchnera lacks most of the genes essential to the construction of its cell membrane, the Aphid cells provide them (Shigenobu et al. 2000:81-86). [added 11/25/00]

In 2000, Karl Gebhardt, John Kormendy, Douglas Richstone, and, independently, Laura Ferrarese and David Merritt determined that the mass of a black hole correlates with the average velocity of the stars within its ellipsoidal host. This supports theories that quasars are growing black holes. [added 11/25/00]

In 2000, Vescovi's team demonstrated that mouse brain stem cells could turn into muscle cells after coming into physical contact with those cells. [added 12/29/00]

In 2000, Cornelia M. Weyand and colleagues found that rheumatoid arthritis patients had age-inappropriate deterioration of telomeres in T-cells, rather than overactive immune systems as had previously been thought (Koetz 2000:9203). [added 12/29/00]

In 2000, Peter J. Oefner and an international team erected a phylogenetic tree, based on binary polymorphisms associated with the non-combining region of the human Y-chromosome, which indicated the most recent common male ancestor lived 40,000-140,000 years ago and migrated out of Africa 35,000-89,000 years ago (Underhill 2000:358-361). [added 12/29/00]