use checkboxes to select items you wish to download

  

	In 1926, Haldane, in "The Origin of Life," wrote that "the cell consists of numerous half-living chemical molecules suspended in water and enclosed in an oily film.  When the whole sea was a vast chemical laboratory the conditions for the formation of such films must have been relatively favorable" (Haldane 1926:3).  [added 02/01/03]
	In 1926, James Batcheller Sumner crystallized urease (Sumner 1926).
	In 1926, Sturtevant found the first gene inversion in Drosophila.
	In 1926, Warburg discovered a carbon monoxide-sensitive iron porphyrin enzyme which catalyses cell respiration.
	In 1926, 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, Dirac solved the derivation of Planck's law and called Heisenberg's quantity symbols q-numbers and ordinary numbers c-numbers (Dirac 1926:561-569).
	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 mathematically the dual wave-particle nature of such things as electrons through their wave function, or eigenfunction, involving the coordinates of a particle in space, e.g., y(x,y,z).  This 'wave mechanics' predicted the positions of the electrons, vibrating as Bohr's standing 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 is related to the probable location of the flash.  While the mathematics itself is the deterministic 'classical' mathematics of classical waves, the results show complete mathematical equivalence to matrix mechanics.
	Later in 1926, Born, in "Quantenmechanik der Stossvorgînge," considering that the wave does not describe the exact behavior of any particle, interpreted the equation in terms of Bohr-Kramers-Slater probability.  This added the arrow of time to Schrödinger's classical, i.e., 'reversible,' mathematics, and 'quantum mechanics' was completed (Born 1926:52-55).
	Still later in 1926, Heisenberg, in "Über die Spektra von Atomsystemen mit zwei Elektronen," using the unified quantum mechanics, quickly calculated the spectrum of several states of the helium atom.
	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). Waves may have a corpuscular aspect and particles may have a wave aspect, depending on the properties of the model to be explained.  For example, photon particles can be described as concentrated packets of waves, called 'wave packets,' with zero mass energy and electric charge and without well-defined edges.
	In 1926, Oskar 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). He also suggested that "the origin of Planck's quantum may be sought just in this periodicity in the fifth dimension" (Klein 1926:516).
	In 1926, Klein and, independently, Walter Gordon developed an equation in relativistic quantum mechanics for spin-zero particles.
	In 1926, Gregor Wentzel, Kramers, and Leon Brillouin, each independently, invented the 'semiclassical, or WKB, approximation,' a technique in quantum mechanics, wherein "the wave function is written as an asymptomatic series with ascending powers of the Planck constant h, with the first term being purely classical" (Dictionary of Physics 2000:444).
	In 1926, Robert Alexander Watson-Watt proposed the name 'ionosphere' for the conducting atmospheric layer.
	In 1926, Eddington, in The Internal Constitution of the Stars, a summary of his work, said that all stars must maintain a temperature of at least forty million degrees in order to maintain their fuel supply.
	In 1926, Ralph Howard Fowler, in "On Dense Stars," using the statistical description of atoms published the previous year by Fermi, showed the correct relation of energy and temperature in a white dwarf, leading to the conclusion that they "do not shine by thermonuclear reactions and that their light must come from the slow leakage of heat contained in the nondegenerate nuclei" (Lang and Gingerich 1979:573).
	In 1926, Donald Howard Menzel, in "The Planetary Nebulae," raised the possibility that the Balmer emission lines, lines in the hydrogen spectrum created when electrons drop back to a lower energy level, are "the result of photoionization by ultraviolet star light, followed by recombination of free electrons and protons" (Lang and Gingerich 1979:573).
	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.
	In 1926, [?] Busch focused a beam of electrons with a magnetic lens, laying the foundations of electron optics.
	In 1926, Lorentz modelled the damming of the Zuiderzee as the head of a Dutch government committee (Cercignani 1998:202). [added 02/01/03]
	In 1926,  Jan-Christian Smuts coined 'holism in order to give a name to "the view that an intergrated or organic whole has a reality independent of and greater than the sum of its parts" (Webster's 1979:867).
	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, Heisenberg, in "Über den anschaulichen Inhalt der quantentheoretischen Kinematik und Mechanik," said electrons do not possess both a well-defined position and a well-defined momentum, simultaneously; i.e., "Even in principle we cannot know the present in all detail" (Heisenberg 1927:83).  This uncertainty has nothing to do with the limitations of human observers; it is intrinsic, and converts absolute certainties into relative probabilities.  Expressed as an inequality, one may say that the smaller the uncertainty about position, the greater the uncertainty about momentum, and vice-versa.  "Quantum uncertainty makes it impossible to define any set of conditions precisely for the atoms" (Gribben 1998:19), and thus refutes, in principle, any possibility of, say, a gas in a box reversing itself to its original position over any amount of time, in the manner of Poincaré's ideal 'cycle times.'  Quantum uncertainty also provides the loophole to the law of the conservation of energy through which the forces embodied in photons make their brief appearances. Born and Pasqual Jordan collaborated with Heisenberg setting up the matrix algebra to describe this 'uncertainty principle.'
	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 momentum, the 'complementarity principle' as he called it, is engendered by the measurement process in a specific experimental situation; i.e., measurement is inseparable from wave function reduction, or 'collapse.'  "Wave-packet collapse...is the only irreversible feature of quantum mechanics and the one extraneous to the basic equations of this theory, which are perfectly time-reversible" (Cercignani 1998:118).  Measurement is also 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).  The complementary principle itself implies closure: The microworld "part has no meaning except in relation to the [macroworld] whole, the total context....  What Bohr's philosophy suggests is that words like electron, photon, or atom should be regarded [like energy as a useful model that consolidates] in our imagination what is actually only a set of mathematical relations connecting observations" (Davies and Brown 1986:12,26).
	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, Clinton Joseph Davisson and Lester Halbert Germer measured the length of a de Broglie wave by observing the diffraction of electrons by single crystals of nickel.
	In 1927, Paul Ehrenfest proved the theorem that "the motion of a wave packet is in accord with the motion of the corresponding classical particle, if the potential energy change across the dimensions of the packet is very small" (Dictionary of Physics 2000:529).
	In 1927, Walter Heitler and Fritz London showed that chemical bonding, the force which holds atoms together, is electrical and a consequence of quantum mechanics.
	In 1927, Dirac described a method of quantizing the electromagnetic field (Dirac 1927:243-265, 710-728).
	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.
	In 1927, Georges Lemaître proposed, independently of Friedman, an expanding model of the universe from an initial singularity and consistent with Einstein's General Theory.  The main difference from Friedman was that Lemaître included both the redshift-distance relation and radiation pressure.  This enabled him to show the importance of the early stages of the expansion: When the "primeval atom" exploded outwards, "the expansion [had] been set up by the radiation itself," and "the receding velocities of extragalactic nebulae are a cosmical effect of the expansion of the universe" (Lemaître 1931:490).  One important implication is that the universe is not infinite, which incidently explains away Olbers' paradox.
	In 1927, Jan H. Oort, confirming Lindblad's hypothesis that the Milky Way is rotating, concluded the "stars closer to the galaxy's nucleus will generally revolve faster than the Sun, and hence those inner stars in the direction of the Sun's motion will be pulling away from the Sun, whereas those inner stars symmetrically opposite the direction to the nucleus will be catching up" (Lang and Gingerich 1979:555).
	In 1927, Menzel obtained accurate measurements of the surface temperatures of Mars and Mercury.
	In 1927, Vannevar Bush started construction on the 'Differential Analyzer,' an analog computer, which measured the rotation of various rods by mechanical means, in order to speed the solution of problems related to the electric power network.
	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 (Griffith 1928).
	In 1928, Linus Carl 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. Alpha decay is a 'tunnelling process.'  The tunnelling effect involves the waviness of an alpha particle, or any electron, which makes it finitely probable it will tunnel through what would have been an insurmountable obstacle if it were a classical particle.  Having tunnelled, the alpha particle is no longer held by the 'strong nuclear force' and is repelled or radiated away.  Gamow also pointed out that the edges of wave packets can interact over distances at which particles would be repelled, making nuclear fusion possible at temperatures that exist inside the Sun and other stars.
	In 1928, Gamow devised the 'liquid drop model' of the atomic nucleus, implying that it is held together by something like surface tension.  "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" (Issacs 2000:271).
	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" (Szilard, quoted in Telegdi 2000:26).
	In 1928, Chandrasekhara Raman observed weak, inelastic scattering of light from liquids.  This effect, known as 'Raman scattering,' arises from vibrating molecules.
	In 1928, Albrecht Unsöld, using a spectroscope, investigated light from the Sun and "interpreted the strength of the hydrogen lines an implying that there are roughly a million times as many hydrogen atoms as anything else" (Gribbin and Gribbin 2000:94).
	In 1928, Weyl, in Gruppentheorie und Quantenmechanik, 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 (Weyl 1928).
	In 1928, John von Neumann conceived 'game theory.'
	In 1928, London revived Weyl's work on symmetry but showed that local gauge symmetry applies not to space but to the electromagnetic field which enforces the conservation of electric charge between local areas.
	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. He also pointed out that ultraviolet radiation could have been the spark which animated the "hot, dilute soup" (Haldane 1933:149).
	As early as 1929, Frank MacFarland Burnet 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; Burnet 1930).
	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, David Keilin, having discovered 'cytochromes,' proteins that function as electron-carriers, four years earlier, formulated the "fundamental idea of aerobic energy systems: the concept of the respiratory chain" (Mitchell 1978; Keilin 1929). [added 02/01/03]
	In 1929, K. Lohmann, Cyrus Hartwell Fiske, and Y. Subbarow, in muscle extracts, isolated 'adenosine triphosphate' (ATP), the phosphate bonds of which, when hydrolysed, release energy, and 'phosphocreatine,' from which some of the phosphorus in ATP in obtained.
	In 1929, Adolf Friedrich Johann Butenandt and, independently, 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-green-red-gold, etc., and taking them to be archetypal ideas.
	In 1929, Robert Jemison van de Graaf developed an electrostatic particle accelerator.
	In 1929, Szilard, in "Über die Entropieverminderung in einem thermodynamischen System bei Eingriffen intelligenter Wesen, "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 (Szilard 1929:539-541).
	In 1929, Dirac published his 'relativistic wave equation' which describes the electron's spin and led to the prediction of the electron's antiparticle, the 'positron.'. This more or less completed quantum field theory which combined quantum mechanics with Einstein's special relativity: "Just as photons were particles--the quanta--associated with the electromagnetic field, so the electron was associated with an electron field and the proton with a proton field.  Every kind of particle was intimately intertwined with a field, and every kind of field with a particle.  Since there were gravitational fields, [the prediction was made that] there must be particles called gravitons....  In the picture provided by quantum field theory, the particles influence each other by bouncing photons back and forth" (Johnson 1999:61-62).
	In 1929, Nevill F. Mott, in "The Wave Mechanics of a-Ray Tracks," analyzed the "wave functions [of the tracks] in the multispace formed by the co-ordinates both of the a-particle and of every atom" on a photographic plate in a cloud chamber..., [with the nuclei] considered effectively at rest" (Mott 1929:79-80), that is, stationary.  The equation he used is similar to Born's first probability equation which is time-independent.
	In 1929, Hubble, in "A Relation between Distance and Radial Velocity among Extra-Galactic Nebulae," observed that all galaxies are moving away from each other. Correlating the distance of a particular galaxy and the speed with which it is receding by an analysis of the light spectra, he noted a persistent cosmological redshift, and explained this in terms of the Doppler effect: The light is receding and the farther away the larger the 'gravitational redshift.'  It is the product of the stretching of the color wavelength by gravity; i.e., when an object has a very strong gravitational pull, what starts out relatively short wave (blue) will become relatively long wave (red).
	In 1929, Robert d'Escourt Atkinson and Franz Houtermans, inspired by Gamow's work, published calculations of how the tunnel effect might operate in stars and showed that even with the tunnel effect only the fastest-moving particles with the smallest positive charge, i.e., protons from hydrogen nuclei, could penetrate the barriers.  Their conclusion, and Unsöld's and Menzel's, regarding the preponderance of hydrogen on the Sun was ignored by most astronomers who preferred to believe that heavy elements prepondered, as on the Earth.
	In 1929, Frank Whittle, combining the concepts of rocket propulsion and gas turbines, invented jet propulsion.  Independently, Hans von Ohain put together the same combination in 1933.
	In 1930, Friedrich Breinl and Felix Haurowitz published a proposal for a template theory of antibody production (Breinl and Haurowitz 1930).
	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; Levene and Bass 1931).
	In 1930, Léon Rosenfeld, in "Zur Quantelung der Wellenfelder," applied quantum field theory to the gravitational field and was able to compute the gravitational self-energy of a photon, but obtained a quadratically divergent result.
	In 1930, Dirac, in the first edition of his textbook The Principles of Quantum Mechanics, defined the 'superposition' of states by saying that a "state A may be formed by the superposition of states B and C when, if any observation is made on the system in state A leading to any result, there is a finite probability for the same result being obtained when the same observation is made on the system in one (at least) of the two states B and C. The Principle of Superposition says that when any two states B and C may be superposed in accordance with this definition to form a state A and indeed an infinite number of different states A may be formed by superposing B and C in different ways" (Dirac 1930:15-16).  Dirac went on to say that this principle forms the foundation of quantum mechanics, and is completely opposed to classical mechanics since this principle requires indeterminacy in the results of observations.  On the other hand, superposition is thought to only occur at the unobservable microscopic level; it theoretically could but "does not happen in the world we know," the macroscopic world (Park 1990:426).
	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. This permitted acceleration of atoms to high speeds and the creation of nuclear reactions.
	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 1930, Menzel, using Stoney's argument, inferred the presence of hydrogen on the giant planets.
	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.
	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' respectable).  This study of innate and learned responses and the interaction between them is called ethology.
	In the 1930s, Rupert Wildt, building on Very's suggestion that Venus's atmosphere is mainly carbon dioxide, proposed that since that is highly opaque to surface radiation a considerable greenhouse effect would be produced.
	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.' (Creighton and McClintock 1931).
	In 1931, Sewall Wright concluded that 'random drift,' or chance fluctuation of allelic populations, was a significant factor in evolution.  This opposed 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 and the Structure of Molecules and Crystals, detailing the rules of covalent bonding.
	IIn 1931, John Howard Northrop and Moses Kunitz, applying the phase rule solubility test for the homogeneity of dissolved solids, corroborated J. B. Sumner's belief that enzymes are proteins.[added 02/01/03]
	In 1931, Ernst August Friedrich Ruska and colleagues invented the prototype of the transmission electron microscope.[added 02/01/03]
	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, in order to solve the question of where the energy went in beta decay, predicted the existence of a 'little neutral thing,' 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 that the aims of Frege , Hilbert, and B. Russell could never have been achieved.
	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 1931, Atkinson suggested that "the abundance of elements [in stars] might be explained by the synthesis of heavy nuclei from hydrogen and helium by successive proton captures, [which protons] would be absorbed by nuclei until they become unstable and ejected alpha particles" (Lang and Gingerich 1979:303).
	In 1931, Bernhard V. Schmidt invented a new type of telescopic optical system which made possible sharp photographs of wide areas of the sky.
	In 1932, Haldane introduced the term 'altruist.'
	In 1932, A. Bethe conceptualized 'pheromones,' chemicals secreted by animals and insects for communication.
	In 1932, Hans Adolf Krebs and Kurt 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.[added 02/01/03]
	In 1932, Axel Hugo Teodor Theorell isolated myoglobin and therefore was able to show its oxygen absorption and carrying capacities.[added 02/01/03]
	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, Frits Zernike invented the phase-contrast telescope (Zernike 1934). By 1935, he was applying the same principles to microscopes, but was unable to get them produced commercially until 1941. This development allowed unstained living cells to to be seen in detail for the first time. [added 02/01/03]
	Early in 1932, Irène Curie and Frédéric Joliot bombarded nonradioactive beryllium with alpha particles, transmuting it briefly into a radioactive element.
	In 1932, James Chadwick described the helium alpha particles which created the Curie-Joliet effect as consisting of two protons and two neutrons, thus isolating the neutron, the first particle discovered with zero electrical charge.  It has almost the same mass as a proton.  Atoms with identical chemical properties but different numbers of neutrons, and thus different masses, are called isotopes.
	In 1932, Harold Clayton Urey along with his teacher G. N. Lewis and colleagues demonstrated the existence of deuterium, or heavy hydrogen, spectroscopically.  Subsequently, he isolated isotopes of heavy oxygen, nitrogen, carbon, and sulphur.
	In 1932, Fermi succeeded in intensifying the Curie-Joliet effect by using the newly discovered and very massive neutrons in beta rays instead of alpha rays.
	In 1932, Carl David Anderson, using a cloud chamber in the study of cosmic rays, discovered the positron, or positive electron, fulfilling Dirac's prediction.
	In 1932, Heisenberg proposed a model of the atom in which protons and neutrons exchange electrons to achieve stability.
	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.
	In 1932, Peter Joseph Wilhelm Debye and others independently observed the diffraction of light by ultrasonic waves.
	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 to the experimenter.  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, Einstein and de Sitter put forth a revised cosmological model, which was a solution to the Friedman equations, took account of Hubble's proof of the expansion of the Universe, and tentatively implied an initial singularity.
	In 1932, Shapley published the first edition of the Shapley-Ames Catalogue of galaxies.
	In 1932, Edward H. Land invented polarizing film.
	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, Goldschmidt concluded that evolution was the result of sudden changes by successful mutations that act on early embryological processes (Goldschmidt 1933) .
	In 1933, John Howard Northrop isolated and crystallized the protein-splitting enzymes pepsin, trypsin, and chymotrypsin (Northrop 1935).[revised 02/01/03]
	In 1933, M. Goldblatt and von Euler discovered 'prostaglandins.'
	In 1933, Theorell isolated the 'yellow enzyme,' separated it into a catalytic coenzyme and apoenzyme, and found the main ingredient to be albumin. This led to Theorell's discovery of the chemical chain reaction known as 'cellular respiration' in which food is translated into energy. [added 02/01/03]
	In 1933, I. Curie and Joliet, using polonium plus beryllium in a cloud chamber, proved that "hard gamma rays...produce electron-positron pairs by materialization....  They also noted single positrons in addition to pairs" (Segrè 1976:193).
	In 1933, Fermi developed a theory of decay and weak interactions in which a neutron changed into a proton, emitting a neutron and a neutrino.  The following year, Heisenberg and others extended it in terms of the strong nuclear force.
	In 1933, Karl Jansky, in the course of investigating atmospheric static which was interfering with radio communications, established that the radio source he had been hearing since the previous year came from outside the solar system.
	In 1933, Fritz Zwicky discerned that a "considerable fraction of the mass had been missed" in measuring the velocities of certain galaxies (Peebles 1993:419).  What was first known as 'missing mass' became known as 'dark matter,' and today is discerned mainly through its gravitational effects.  "The nature of this dark matter is unknown....  Exotic [i.e., undetected] particles such as axions, massive neutrinos or other weakly interacting massive particles (collectively known as WIMPs) have been proposed....  A less exotic alternative is normal matter in the form of bodies with masses ranging from that of a large planet to a few solar masses.  Such objects, known collectively as massive compact halo objects (MACHOs), might be brown dwarfs...(bodies too small to produce their own energy through fusion), neutron stars, old white dwarfs or black holes" (Alcock et al. 1993:621).
	In 1934, Bernal and Dorethy Crowfoot began the structural analysis of proteins (Bernal and Crowfoot 1934) 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 is a constituent of cells.
	In 1934, Butenandt and colleagues isolated the hormone progesterone.[added 02/01/03]
	In 1934, U.v. Euler discovered a fatty acid which he called 'prostaglandin,' in the mistaken belief that it was produced by the prostate gland.