Three Scientific Revolutions: How They Transformed Our Conceptions of Reality

by Richard H. Schlagel

  3. The arrangement of the elements, or of groups of elements, in the order of their atomic weights, corresponds to their so-called valences [the combining power of an element] as well as, to some extent, to their distinctive chemical properties—as is apparent, among other series, in that of lithium, beryllium, barium, carbon, nitrogen, oxygen, and iron (brackets added).

  4. The elements which are the most widely diffused have small atomic weights.

  5. The magnitude of the atomic weight determines the character of the element, just as the magnitude of the molecule determines the character of a compound.

  6. We must expect the discovery of many yet unknown elements—for example, elements analogous to aluminum and silicon, whose atomic weight would be between 65 and 75.

  7. The atomic weight of an element may sometimes be amended by a knowledge of those of the contiguous elements. Thus, the atomic weight of tellurium must lie between 123 and 126, and cannot be 128.

  8. Certain characteristic properties of the elements can be foretold from their atomic weights.56

  This enabled Mendeleev in 1895 to present his Periodic Table consisting of two columns, one vertical and the other horizontal. Both columns listed the elements under the headings given by Berzelius, with the vertical column presenting them according to their atomic weights and chemical properties while the horizontal column listed them in increasing numerals according to their atomic numbers as determined by the number of protons in their nucleus, beginning with hydrogen as 1 since it contains 1 proton. As now written, it appears as H but in a water molecule as H2O (with the subscript 2) because it contains two elements of hydrogen.

  What a great progress had been made by chemists since Lavoisier’s explicit recognition of oxygen as the combustable gas and the resurrection of the ancient atomic theory of Democritus and Leucippus by Dalton culminating in Mendeleev’s Periodic Table. We now await the discovery of new elements and their molecular structure in compounds along with the interior structure of the atom.

  Chapter VI

  TRANSITION TO THE THIRD REALITY IN THE LATE NINETEENTH AND TWENTIETH CENTURIES

  We have just seen how long it had taken and how arduous the task was to replace the Aristotelian and religious worldviews (though religionists still do not accept the fact that there is no longer any plausibility to religious explanations) with the early modern scientific corpuscular-mechanistic explanation of the universe and physiological nature of human beings. Starting with Copernicus in the middle of the sixteenth century, it was not until the latter half of the nineteenth and mainly in the twentieth century that this earlier, more preliminary mechanistic conception of reality was replaced by the third major transition, along with the consequent technological advances.

  As American physicist Michio Kaku states in his latest book, “the time was right for the emergence of an Einstein. In 1905, the old physical world of Newton was crumbling in light of experiments that clearly suggested a new physics was about to be born, waiting for a genius to show the way.”57 Though a continuation of the earlier scientific discoveries and theoretical advances of the previous three centuries, it brought about a decisively greater understanding of the world and of human beings due to a much more realistic and extensive conception of the physical universe owing to greatly improved telescopic observations and spectroscopic evidence; deeper probing of the interior structure of the atom; the rejection of Newton’s deterministic-mechanistic universe of absolute space and time due to the uncertainty principle in quantum mechanics and Einstein’s view of space-time as a four-dimensional field in his general theory of relativity; paradoxes such as the wave-particle duality; and the replacement of “intelligent design” and “special creation” of humans with the confirmation of evolution, brain research (eliminating the soul), and the deciphering of the genetic code.

  Ernest Rutherford, the father of nuclear physics, “once said that the rapidity of advance during the years 1895–1915 has seldom, if ever, been equaled in the history of science.” Even if true at that time, Rutherford did not live to witness Hubble’s astonishing telescopic discoveries and evidence of the inflationary recession of the universe, Georges Lemaître’s anticipation of the Big Bang explanation of the origin of the universe, tunneling microscopes, nuclear fission and fusion, nuclear reactors and particle accelerators, computer technology, genetic decoding and engineering, along with the lunar landing and controlled interplanetary space flights. One can truthfully say there were more new advances in science in the twentieth century than in the entire past history of science that emended Newton’s deterministic, absolutistic, mechanistic worldview with a much more extensive and complex conception of reality.

  As Einstein and Infeld wrote in 1951:

  During the second half of the nineteenth century new and revolutionary ideas were introduced into physics; they opened the way to a new philosophical view, differing from the mechanical one. The results of the work of Faraday, Maxwell, and Hertz led to the development of modern physics, to the creation of new concepts, forming a new picture of reality.58

  As we have seen, some of the major changes in physics involved the detection of diffraction patterns supporting the wave theory of light to complement Newton’s corpuscular theory; the replacement of the independence of electricity and magnetism with the concept of an electromagnetic field and the recognition that light, too, is an electromagnetic phenomenon; Einstein’s introduction of a variable four-dimensional space-time field to replace Newton’s conception of gravity as a mutually attractive force between objects; the rejection of indivisible solid atoms for a largely space filled atom conceived in terms of an inner solar structure of subatomic particles with electrical charges that determine the atoms’ properties and interactions.

  This also included the later discovery that whether light reacts as waves or corpuscles depends on the experimental conditions, thus introducing the wave-particle duality of light; the rejection of the ether as a necessary medium for the transmission of light and gravity; the fact that spatial or temporal measurements are not absolute but relative to the velocity of the measurer and its effect on the measuring device; the discovery of quanta of energy and the uncertainty of the measurements and existence of subatomic particles due to the indeterminate nature of their properties until measured; the red-shift in the light waves from outer space indicative of the recession of the light source and of an expanding universe, along with evidence that at least our universe began with a big bang about 13.7 billion years ago; string theory to replace all other theories although as yet there is no evidence to support it; and the possibility of a pluralistic universe with different laws of which ours is only a miniscule extension. It seems there is no end to the future discoveries facing science.

  While it is said that “the eighteenth century is the century of Newton,” it is equally true that it was in that century that scientists began the critical task of questioning and testing the fundamental concepts of the Newtonian scientific framework, a crucial function of science that accounts for its success and advancement. For unlike the followers of Aristotle (but not Aristotle himself) who claimed that all knowledge could be found in his works, and religionists who still claim that divinely revealed scripture as interpreted by church authorities contains the ultimate, eternal truth and thus scientific knowledge has only an instrumental value, the obvious advances of science and the tremendous changes in our conception and relation to the world that it has brought about belie this. The task now is to describe these later developments as clearly and simply as possible.

  Among the first challenges to Newton’s system was his conception of the corpuscular theory of light based on his prismatic discovery of the rays of light and the sharp boundaries of shadows. At the time there was considerable controversy over whether light consisted of waves or of corpuscles and whether it had a finite velocity or was propagated instantaneously. Most continental natural philosophers, such as Hooke and Huygens, defended the wave theory. It was Newton and Ola
us Roemer who first succeeded calculating the time for light to reach the earth from the sun to be about eight minutes. Hooke had proposed that light is a form of wave motion in a medium that was supported by Huygens in a lengthy article published in 1690 titled Traité de la lumière où sont expliquées les causes de ce qui arrive dans la réflexion et dans la réfraction. Et particulièrement dans l’étrange réfraction du cristal d’Islande (Treatise on light explaining the cause of reflection and refraction. And particularly in the strange refraction of Island crystal). But while Huygens’s extensive research was extremely influential on the continent, Newton’s prestige in the British Commonwealth was such that his corpuscular interpretation of light was dominate there until it was finally contested in the beginning of the nineteenth century.

  As we now know, Thomas Young was among the first to challenge the corpuscular theory in a paper entitled “Outlines of Experiments and Inquiries Respecting Sound and Light” published in the Philosophical Transactions of the Royal Society in 1800. Impressed by the similarity of light and sound, he favored the theory that light is transmitted by waves. Along with additional criticisms of the corpuscular theory, his major objection was based on experiments showing that light radiated through small apertures produced diffraction patterns, which offered clear evidence of waves. In a paper titled “On the Theory of Light and Colours” in 1802, he described the light and dark bands in the diffraction patterns in terms now known respectively as constructive (in phase) and destructive (out of phase).59

  Despite the nearly incontrovertible evidence, the respect for Newton was so strong that the reaction in England was hostile rather than approving. However, that changed when a gifted French engineer named Augustine Jean Fresnel, having had doubts about the corpuscular theory and impressed by the results of Young’s experiments, decided to test whether Newton’s generally accepted explanation was true. His explanation was that the wave bands were produced by the attractive or repelling effects of the shapes and thickness of the apertures on the light corpuscles as they passed through. But when Fresnel, based on experiments that varied the shapes and thickness of the tiny openings, found they had no effect on the diffraction patterns that depended solely on the size of the aperture, even the English were converted. When he presented the results of his experiments in a “Memoir on the Diffraction of Light” to the Paris Academy in 1819, he was awarded a prize.

  It was Fresnel’s ability to quantify his results and predict additional testable consequences that was particularly convincing. As an example, rejecting Newton’s peculiar explanation of the polarization of light rays emerging from Iceland spar by attributing it to different sides of the corpuscles constituting the light rays, he concluded that the wave theory could provide a simpler and more plausible explanation if one accepted that the light waves were transverse, produced by the perpendicular vibrations upward and downward of the undulations emitted from the apertures. Thus Fresnel’s explanation proved to be a final vindication of Hooke’s and Huygens’s advocacy of the wave conception of light.

  Then Jean Léon Foucault, in addition to demonstrating the rotation of the earth by hanging a huge pendulum from the roof of the Panthéon in Paris in 1851 and inventing the gyroscope, in what is often referred to as an experimentum crucis, by exacting experiments begun in 1850 and confirmed in 1862, he demonstrated that light travels more slowly in denser media, thereby disproving Newton’s prediction that it would travel faster due to the greater attractive force of the more dense media on the corpuscles. This was the final blow to the corpuscular theory because nothing is more fatal to a theory than a definite disconfirmation of a crucial prediction.

  Furthermore, based on Foucault’s experiments, Hippolyte Louis Fizeau determined the velocity of light to be 300,000 kilometers per second, thus settling the dispute as to whether light was transmitted instantaneously, as many had believed, or with a finite velocity. So by mid-century, owing to these ingenious experiments confirming the properties of light, most scientists accepted the wave theory over Newton’s corpuscular theory. One would have to await Einstein’s 1905 paper explaining the photoelectric effect in terms of discrete quanta of light before the particulate properties of light would again be accepted.

  There is a further aspect to the discussion, the existence of the aether. Unlike the transmission of corpuscles, waves being a configuration of a medium required the existence of a medium that later was called “aether.” Although in Newton’s corpuscular theory light did not require a medium for its transmission, in the long quote in the previous chapter on Newton he did predict that in the future a unified theory would be developed to explain all the various astronomical, physical, chemical, optical, and even neurological phenomena in one integrated theoretical framework.

  Yet nothing illustrates more clearly the difficulty that such transitions present than the fact that even someone of Newton’s genius could not make a complete break with the older tradition. He continued to describe the underlying unifying force as due to the “vibrations” of an “a certain most subtle spirit”60 that conflicted with his criticism of “feigned hypotheses” and astute definition of the correct scientific method. Nevertheless, the concept of an electric spirit required for the transmission of electricity and possessing the vibratory elasticity needed for the transmission of light waves would soon be replaced by an all pervasive subtle medium called the “aether,” that in turn would be replaced later by Einstein’s concept of a space-time field. Such are the contingent fortunes of scientific theories owing to the continuous experimental testing of past theories. But despite the almost universal acceptance of the aether theory, the discovery of electromagnetism, radiation, and the invariant velocity of light, the explanatory value of the aether became nil and was discarded after the Michelson-Morely experiments and Einstein’s Special Theory of Relativity proved the invariant velocity of light.

  Turning now to another scientific revolution that would contest Newton’s mechanistic worldview, though it had been previously suspected that electricity and magnetism were not independent, it was Hans Christian Oersted in 1807 who demonstrated their interconnectedness. Investigating the effects of an electric current on the deflection of a magnetic needle, he discovered that a changing current induced a magnetic field and announced his discovery in an article titled Experimenta circa effectum conflictus electrici in acum maneticam in 1820.

  Describing it as “the conflict of electricity,” he wrote that the magnetic field produced by the electric wire occupied a curved space surrounding the magnet, whose direction was dependent upon whether the wire was above or below the needle along with the direction of the current. The French academician François Arago, upon learning of Oersted’s experiments, devised his own experiment in 1820 showing that when a current is passed though a circular copper wire it attracts unmagnetized iron filings that remain attracted to the wire as long as it is electrified, but immediately fall off when the current ceases. Then in 1824 he reported that a rotated copper disk produced a similar rotation of a magnetic needle supported above it.

  Another major contributor, Andre Marie Ampère, shortly after Oersted’s publications, proposed the laws governing the electric current’s deflection of the magnetic needle, along with the reciprocal attractions and repulsions of electric currents. His outstanding achievements are memorialized in the “well-known ‘Ampère’s Rule’, formulated by him for determining the deflection of a magnet by an electric current, and in the ampere, the practical unit of electric current, which is named after him.”61

  Next in the succession of contributors is Michael Faraday, referred to by British historian of science Charles A. Singer as “one of the greatest of scientific geniuses,” introduced the concept of a “field of force” to describe the magnetic aura created by a current from an electrified wire. Just as Ampère had demonstrated that a spherical coil of wire produces a magnetic attraction when a current is passed through it, Faraday in a series of experiments demonstrated the converse—that
moving magnets could “induce” an electric current. Realizing that “the essential factor in the production of the magneto-electric effects was change, movement of the magnet or of the coil, or making and breaking of the current or the contact,” he concluded that they are what produce the “fields of force” (p. 363). This discovery of electro-magnetic induction resulted in the invention of the dynamo and the production of electricity on such a large scale that it transformed civilization. We have become so dependent upon readily available electricity that whenever there is a loss of electricity in the Western world due to some natural disaster or snow storm life becomes chaotic.

  While Faraday’s great contribution was the experimental discovery of what generated the magneto-electric currents, it was James Clerk Maxwell who, by his equations describing the structure and changes of the “electromagnetic field,” fully developed the theory of electromagnetism that had been confirmed by Heinrich Hertz at the end of the nineteenth century. In his work On a Dynamical Theory of the Electro-magnetic Field, published in 1864, Maxwell declared that since the electromagnetic waves were transverse analogous to light and had the same velocity as light, the latter must also be a form of electromagnetism. It was this that led Einstein and Infeld to declare that the “theoretical discovery of an electromagnetic wave spreading with the speed of light is one of the greatest achievements in the history of science.”

  The next advance was the experimental attempt to discover the interior structure of the atom. In our previous discussion of atomism it was pointed out how the recognition of oxygen’s role in combustion by Lavoisier led to the development of chemistry and the identification of additional elements such as hydrogen and nitrogen, followed by Dalton’s and Berzelius’s determination, based on their atomic weights, of the ratios of the elements constituting the molecular structure of substances such as air and water. This culminated in Meyer’s and Mendeleev’s organization of the elements into the Periodic Table based on the periodicity of their properties according to their atomic weights. At the time, the assumption was that the monatomic elements were internally compact and therefore indivisible as was believed by Leucippus and Democritus, the originators of atomism. Their observable properties were explained by their sizes, shapes, mass, weight, and motion.