Big Business Searches the Infinitesimal
I
FARADAY, describing his experiment which established a fundamental law of electrical science, — the induction of electric currents, — was asked, ‘What use is it?’ To which he gave the classic rejoinder, ‘Of what use is a newborn babe?’
Since Faraday and the discovery of his infant law — or rather since his statement of a relationship as old as matter and time — his idea has grown into a giant mighty in labor. This giant helps to turn alike the wheels of mammoth factories and domestic washingmachines, carries trivial and worldshaping messages through wastes of ocean and ether, drills tunnels through solid rock, and browns the family toast. An amiable giant, he has lately been impressed into entertaining the masses through the radio. Upon these services has been reared a mighty structure of finance, with billions invested in steam and hydroelectric power plants, and other billions invested in the distribution and use of the tremendous energy so generated.
A paramount lesson of history, stated by Spencer and simplified by Leavenworth, is this: ‘Discoveries in the realms of knowledge or art produce civilization. Defects in human nature or the inadequacy of environment are causes of its decline.’ To which might be added, with some optimism, ‘Discoveries may offset enough of the defects of human nature and reclaim sufficient resources from a supposedly exhausted environment to stave off decline indefinitely.’ The future of civilization, therefore, depends upon the outcome of the race between the science-and-art team and the defectand-want team. Clearly this race today proceeds at headlong pace. The World War resulted from defects in human nature and levied cruelly upon natural resources; but on the other hand we see art struggling to express sentiments nobler than the bellicose, and science seeking to repair war losses.
Faraday’s baby, a child of pure science, was slow to mature and get to work. That was in the nature of things. Those who had him in charge, the inventors, were mostly of small means though great faith, and often they had to go begging at Dives’ door that their child might satisfy his growing appetite. And the rich men, interested in sugar or ships or what not, seldom could see that here was something — this intangible called electricity — that had more in it financially and materially than anything else under the sun; that it had all things in it, and in due time would be doing the world’s work more efficiently than it ever had been done before. So the electrical industry languished for support in its youth. How changed our world might be to-day if the hundreds of laboratory workers who contributed to its early struggle for existence had possessed the means to set up all the apparatus and conduct all the researches they desired, and if capital always had been eager to bring the results to market in quantity!
The academic quarrel between pure science and applied science is not entirely ended; witness the recent exchange between the editor of the Scientific American and Professor Fessenden over the encouragement, or lack of encouragement, given to inventors by industry. No doubt there is much still to be done toward fair play for isolated laboratory workers, not only in the way of giving them adequate and deserved rewards, but also in the way of getting such of their findings as have practical value into use promptly. Nevertheless the factory and the laboratory are unmistakably drawing together. Successful industrialists of scientific bent, like Rockefeller and Eastman, are endowing research institutions. These donors, as practical men, are not troubled by caste distinctions in science; they know that, while years may be required to work out a research problem, soon or late the fruits of knowledge come to possess utility. And we also see great industrial corporations maintaining laboratories and staffs which laboriously conduct expensive investigations in pure science, even though the directors know that years must pass before the researches will return dividends — if ever.
An example of these farsighted efforts, perhaps the best example in America, is the General Electric Company’s researches into the infinitesimal and indivisible. Here is a corporation that on its material side marches to the tune of bigness. It has an army of employees, occupies enormous factories, sells vast quantities of intricate goods; and yet there is vision enough in the enterprise to perceive that the hidden basis for the whole structure is the smallest thing yet identified — the electron. The more the corporation knows about electrons, the more economically its goods can be made and sold, and the more secure is its future. While it is ready to learn about electrons from anyone, the General Electric Company is not willing to leave its future to chance. So it daily and systematically studies the riddle of the electron, just as daily and systematically it pushes the sales of articles through which, in their mysterious ways, electrons work for the owners of those mechanisms. Through the whole realm of the unseen, which no eye can pierce even with the aid of the strongest lens, through crystals, molecules, and atoms, this corporation’s scientists continue a search every whit as determined as any other corporation policy. And whatever of sale value they find on the way to the ultimate can be promptly applied to production and marketed. In this case the contact between science and capital is immediate, and General Electric descendants of the Faraday baby idea need not languish for opportunities to prove their utility to the world.
II
Considering that the infinitesimal escapes direct application of the senses, we know surprisingly much of its makeup and habits. Indeed, it is man’s knowledge of the infinitesimal that most fully exhibits both the persistence and the reasoning powers of the human species. That claim is sometimes made for astronomy, for the realm of infinite distances and vast bodies. Truly our accumulated body of such knowledge is a credit to human intelligence; yet of the two the pursuit of the infinitesimal seems to me the more difficult. The speed of the chase after the elemental little is relatively much faster than that after the elemental great. Man has been conning the stars since first he lifted his eyes, and computing their distances no doubt since ever he invented figures; but it was not until 1803 that Dalton gave the atomic theory quantitative form, and thereby cleared the way for physicists and chemists to think their way through the infinitesimal toward the inside of the atom.
The mind staggers before astronomical distances, yet calculations of the infinitesimal produce figures even more unnerving to the layman. If a drop of water were enlarged until it assumed the size of the planet Earth, each of its H2O molecules would be the size of a baseball, and the electrons would be no larger than pinheads. Yet, in spite of the extreme minuteness of these divisions of matter, their properties have been measured. The weights of the various atoms are known to a few tenths of one per cent, and are published periodically in the International Table of Atomic Weights, using as a unit of weight .000,000,000,000,000,000,000,001,649 grammes. Even the important properties of the electron have been measured. Science knows how much the electron weighs, and how fast electrons travel, and is beginning to find out how they are arranged in the atoms of the chemical elements.
As indicating how far the mind can probe the minutiæ of the infinitesimal, I cite but one example, and for the rest will leave exactness to the brochures through which scientists talk to each other of such important trifles. The mass of an electron is .000,000,000,000,000,000,000,000,000,901 grammes. What electrons lack in mass, however, they make up in number, since enough of them pass through a fifty-watt lamp each second to keep the entire population of Chicago — 2,500,000 persons — busy 20,000 years counting them, even though each of its 2,500,000 persons counted four electrons per second.
Electrons are of equal mass, which encourages scientists to believe that in finding them they have isolated, even if they cannot yet solve, the age-old riddle of matter. Atoms are believed to contain a tiny ‘sun’ of positive electricity (proton) at the centre, surrounded by a sort of solar system of electrons (negative electricity). The number and arrangement of these electrons in the atom of a chemical element presumably determine all the chemical properties and most of the physical properties of that element. Thus, while electrons present uniformity both in kind and conduct, and come obediently forth from their atomic lairs whenever any atom is broken down, the atoms themselves present an engaging variety. There are more than eighty elements, each with its characteristic atomic structure. Combinations of these elements — their atomic unions being known as molecules — form the broad field of chemistry.
But to the physicist the crystal adds still another field for exploration, since not all compounds crystallize molecularly. One of the tasks undertaken by the General Electric Company scientists has therefore been to recheck, using the X-ray method of measurement, the atomic dimensions of common metals. The result is a revision which revealed noticeable errors in the commonly accepted figures of the densities, based upon older methods, of the following metals: aluminum, nickel, silver, tungsten, gold, and lead. Dr. W. P. Davey’s findings, reported to the American Society for Steel Treating, and since reprinted under the title ‘X-Ray Crystal Analysis,’ are likely to result eventually in better alloys, not only for the company financing the research, but for the finealloy trade generally.
Another development of crystallographic research at Schenectady which, while in itself incidental to the continuing search for knowledge of the infinitesimal, holds out at least possibilities of commercial utility is the discovery that single crystals of pure copper are fourteen per cent more efficient conductors of electricity than the many-crystaled copper of commerce. It has long been known that slow cooling produces large crystals, and by extreme precautions in that direction the General Electric laboratories have produced copper crystals six inches long and seven eighths of an inch in diameter. These large crystals are so ductile, however, that they bend of their own weight like so much wax, and, once bent, remain as rigid as ordinary copper. This is because the bending breaks up the large crystal into small fragments and at the same time rotates these crystal fragments, giving them such a direction that the planes of atoms can no longer slide easily over one another. Whether this extreme ductility can be overcome sufficiently for the product to be used and still retain its superior conductivity remains to be seen. It may be that science has found only a fact and not a commodity, but even if single-crystal copper never comes into use the fact of its ultraconductivity may explain other phenomena and lead indirectly to serviceable adaptations in other lines.
Once a fact like this gets going there is no telling where it will stop. Watt’s steam engine remained a laboratory toy for nearly a decade, until Wilkinson’s two-way borer made possible the boring of cylinders closely enough machined to hold compression. Then the steam engine was put to work, at first upon the relatively humble task of pumping water from coal mines: then it went on to running looms, driving ships, and otherwise instituting the Age of Power. I would not for an instant compare single-crystal copper with the steam engine in social or economic importance, and yet if ways and means could be found to save even ten per cent of the electricity now lost in transmission through inefficient conductors the annual saving of energy would be far greater than that wrought by the steam engine at the start of its revolutionary activities.
So much for the possibilities that lie on the way to the electron — in this fascinating search for the final reality that lies at the heart of both the infinite and the infinitesimal.
III
Let us follow science into the heart of the infinitesimal by degrees. The smallest interval on an ordinary school or office ruler is one sixteenth of an inch. That is close enough for most of us. Engineers’ scales, however, are graduated to sixty-fourths of an inch, which is about as close work as the eye can stand in steady study. But industry needs ever and ever more precise instruments. It was a notable achievement when the micrometer screw was developed to the point where a spider web could be measured. But that seems like the Dark Ages to a modern machinist with a Johannsen gauge at his disposal, accurate to five hundred-thousandths of an inch. The ‘master-flat’ of a Van Keuren lightwave measuring outfit is accurate to twenty-five hundred-millionths of an inch. Moreover these superprccise instruments function, not merely in laboratory experiments, but in quantity production. They are necessary to hold up the standards of quality in large-scale production. They had their part in building your automobile, and your house is probably lighted by current generated by a dynamo in which the allowance between the bore of the commutator and the shaft upon which it is shrunk is only five ten-thousandths of an inch.
In measuring distances between atoms, expressed in terms of hundred-millionths of an inch, all of the above methods fail. Science has found a way of measuring such distances, with an accuracy of hundred-billionths of an inch, by using X-rays. If a substance is crystalline in its structure — and most substances are — its interatomic distances can be measured by this means with ease and dispatch. The distances between atoms, and the arrangement of the particles, are specific properties of the substance, just as are its weight and other characteristics.
Small distances can be measured most easily by measuring some larger distances related to them by a known law. As an example, the movement of the head of the screw of a micrometer permits measurements of thousandths of an inch, since the pitch of the screw and the diameter of the head are known. The deflection of a beam of X-rays of known wave-length is used similarly in measuring interatomic distances. Bragg’s law gives the relationship between these distances, the wave-length of the X-rays, and the angle of bending of the waves. In the X-ray crystal-analysis apparatus used in the research laboratory of the General Electric Company, the wave-length of the X-ray is known, and the angle of bending of the rays is calculated by measuring distances between lines on a photographic film. Thus, with two of the three unknowns of the equation determined, the third — the distance between atoms — can be found.
Laue discovered that single crystals caused beams of X-rays to be deflected, and it was found that interatomic distances could be measured by calculations based on measurements of the deflections. Later, Dr. A. W. Hull of the General Electric Company, and Debye and Sherrer in Germany, independently developed a more convenient method of obtaining like results — by using a finely powdered substance rather than large crystals.
X-rays are produced by a watercooled Coolidge tube which is capable of running continuously without variations. X-rays of many wave-lengths are given off. Those characteristic of the metal molybdenum, which is used as a target, are produced in much greater amounts than the rest of the wave-lengths. Only one wave-length is desired, so a thin sheet of a zirconium compound is placed in the path of the rays to absorb all rays except those of the particular wave-length desired. The Coolidge tube is placed in a metal housing to protect the experimenter from the X-rays. This housing contains a ‘slit-system’ which allows the X-rays to emerge only in one definite, predetermined direction. The powdered crystal is mounted in a holder in the path of this beam of X-rays, and a specially prepared photographic film is mounted in the arc of a circle whose centre is the specimen of powdered crystal.
When the X-rays strike the powdered substance, some pass directly through and are recorded as a line on one end of the film. Others are deflected according to Bragg’s law, and recorded as lines on the film in different positions. Each family of planes of atoms in the crystal will deflect the X-rays, thus causing a line on the film if the planes make the correct angle with the direction of the incident X-rays. Since a fine powder is used for the specimen under examination, the crystalline particles face in all directions, giving a chaotic arrangement which results in every atomic plane having some representative at the correct angle. In this way a large number of lines are recorded on the film. Then, by measuring deflection distances on the film, distances of millionths and billionths of an inch may be calculated with ease. This work has been so systematized that the determination of the crystalline structure of a substance is relatively simple.
In the early days of crystal analysis, the results were of scientific interest only. But now the all-penetrating eye of the X-ray has been focused on the metals, laying bare basic facts regarding the arrangement of the particles. Who can say that at some future time it will not be possible for metallurgists to produce alloys on demand to meet specifications now impossible, for they will be equipped with newly discovered information made available by the X-ray.
Dr. W. P. Davey, of the General Electric Research Laboratory, has offered an explanation of why some metals are brittle and others are not. In ductile metals, like copper and lead, the atoms of the crystal are arranged in cubic formation, with one atom at each corner of the cube, and another in the centre of each face of the cube. When such a metal is bent, the planes which contain the more closely packed atoms, and which are relatively far apart, slide on each other, like children’s blocks, and the planes hold tightly to each other. There is very little tendency for the crystal to crack open, and the metal may be bent, hammered, or drawn into wire without cracking.
Brittle metals, such as tungsten, also have an atom at each corner of the unit cubes, but instead of one in the centre of each face of the unit cube there is one in the centre of the cube itself. In such a structure the planes which contain closely packed atoms are not held together tightly. When such planes slide on each other, they tend to crack apart, and such metals, therefore, cannot be worked mechanically so easily as the others.
X-ray analysis shows that in single-crystal copper, referred to earlier, all of the atoms are arranged in columns, equally spaced. When the bar is bent, the spacing is very slightly changed. The atoms on the inside curve are pressed together and those on the outside are spread apart. Strains are set up which cause the bar to become an ordinary piece of copper, made up of smaller crystals facing in all directions. If the surface of the large crystal is nicked, dented, filed, or polished, the structure of the crystal in the neighborhood of the abrasion is affected in the same way that it would be by bending.
No one has seen — possibly no one will ever see — a molecule, much less an atom or an electron. It has been pointed out that the molecule of starch, one of the largest known, is so small that the ultramicroscope will not permit its observation. The diameter of the starch molecule is about one two-hundredth of the diameter of the smallest particle the microscope will reveal, yet the starch molecule is far larger than most molecules.
Inaccessibility to visible study has not meant that molecules, atoms, and electrons have remained secrets. The electron has been conquered in more ways than one, and scientists can count the number of particles given off by a bit of radium with more ease and more accuracy than is possible in counting the population of New York City. In fact, the count can be made automatically with a photographic equipment. Yet the mass of the electron is only one seventeen-hundredth that of the hydrogen atom — the lightest of elements.
French scientists recently ‘listened’ to the star Capella, distant more than 216,000,000,000 miles from the earth. Its light, which had been traveling more than forty years to reach our globe, was transmuted into sound by use of photoelectric cells.
In a similar sense, electrons may be heard. The hissing sound in the receiver of a high-power radio receivingset, heard even when there are no signals in the air, is the effect of electrons striking the plate of the tubes as they are released from the hot filament.
Dr. Albert W. Hull of Schenectady and Professor N. H. Williams of the University of Michigan have made a careful study of this phenomenon, which was predicted several years ago by Dr. Schottky of Berlin and named by him the ‘shot effect.’ The sound is due to the electrical oscillation which is set up by the impacts of the individual electrons on the plate, and it is proportional to the number of electrons in flight across the tube and to the charge carried by each electron. Each blow is extremely minute, but since the impacts are separate and independent, like raindrops, the energies add, and their sum, when amplified and transformed into sound by telephone, becomes a roar. Hence science can produce out of the apparent silence of the infinitesimal a roar that equals, as far as the ear at the microphone can determine, the thunder of Niagara.
While discussing the possibilities of amplifying minute traces of energy by the millionfold through the use of the vacuum tube, it is interesting to recall the statement of Dr. Willis R. Whitney that a fly crawling up one inch on a wall uses enough energy to operate a radio receiving-set for twenty-five years. The vacuum tube amplifier makes audible this minute energy. Just as the physical world is filled with movements so slight that they escape observation, so it is likewise filled with sounds inaudible to our poor ears. The inadequacy of man’s natural sensory equipment for anything like a complete understanding of the physical universe has long been realized; but, by applying his sovereign mental powers to matter and force with the aid of the delicate mechanisms described herein, man little by little is drawing aside the veil that shrouds the fundamental realities.
IV
The research scientist, whether he works in a private, collegiate, or corporation laboratory, is primarily engaged in testing theories. He is an incorrigible skeptic, to the extent that he must proceed on the basis that any accepted theory may not be correct. If a theory has stood for a long time under many tests, he views it with greater respect than he does the theory born yesterday; nevertheless no theory, however old and tested, is sacrosanct in his eyes. In every way that he can conceive he proceeds to test it further, in the hope that his experiments and deductions may add to or detract from the sum of its probable correctness. This procedure he applies, not only to the theories advanced by others, but also, if he is a truly first-rate man, to those of which he is himself the author.
It is a fundamental of science that no theory can ever be proven. A single demonstrated fact that is contrary to a theory is enough to disprove the correctness of that theory and to necessitate a revision of the theory to the end that it shall be consistent, not only with all the facts known before, but also with the new fact. When new facts are discovered which are in agreement with a theory, they do not prove the theory; they merely make its truth more probable. A scientific theory is, after all, an analogy. Just as it was once said, ‘The kingdom of heaven is like unto leaven,’ so a physicist or a chemist says, ‘Matter acts like a thing made up of atoms.’ No analogy is ever perfect. There is always some point at which it breaks down. Although the Kingdom of Heaven is like a cake of yeast, it does n’t, come wrapped in tin foil — the analogy holds only up to a certain point. It is the aim of research scientists to make their analogies — theories — more and more perfect, in the hope that sometime in the distant future the theory will express the facts so closely that it may be regarded as constituting absolute truth.
Professor Merritt of Cornell University used to say that an uneducated man had two mental pigeonholes, one called absolute truth and the other called absolute falsehood. Every idea that comes to such a man has to be put into one pigeonhole or the other. An educated man, and especially a scientist, has a long row of pigeonholes. That at one end is labeled absolute truth. It is always empty. That on the other end is labeled absolute falsehood, and it too is always empty. Every idea that comes to such a man is put in the intervening pigeonholes, and as occasion requires he moves them closer to one end or the other. In this way, by a succession of approximations, he approaches absolute truth. It is the same with scientific theories. They are only approximate, but constant researchwork makes the approximation closer and closer. While this process is going on, the theory serves as a convenient device for remembering what would otherwise be a medley of detached facts. When we come close to absolute truth our command over nature becomes greater, and our position of ‘dominion over the earth’ is better entrenched. However, we do not have to await the final discovery of absolute truth to make all this of use to the human race. Every new fact has its practical application. The study of the arrangement of atoms in crystals is of immediate value in metallurgy. The study of electron-emission has given us the radiotron and radio broadcasting.
This more immediate result of scientific research is the justification for spending the money of corporation stockholders — millionaires, universities, trust funds, widows, and orphans — on large research-laboratories. The approach to absolute truth is a less tangible thing, which keeps up the enthusiasm of the scientist for his work and makes him feel that his job is, after all, the most important that the human race has ever undertaken.
Man still extends his knowledge chiefly by trial and error. Until he has exhausted all the possibilities of going wrong, he can never be quite sure that he is going right. That, definitely, is the attitude of the research scientist as he marshals the facts about the unseen and probes deeper into the mysteries of the electron. But industry stands hopefully by, providing the sinews of investigation and determined that whatever trial and error may find that is worth selling shall be speedily brought to market. The trials of at least one great industry have convinced it of the error of leaving discovery to chance, in so far as money and brains can offset luck. To that extent the search for electronic knowledge is being prosecuted more keenly than ever before. Big business has undertaken to read the riddle of the elemental little of which all things are made.