Astronomy

Men, Atoms, and Stars

My friend or your friend marvels nightly at the wonders of the latest scientific achievement which has swept over the civilized world. His radio “receiving set,” without any material connection with the outside world, accurately reproduces for him the music or speech which is delivered to a “sending set” located a thousand miles away. This to him is marvelous, perhaps awesome, and in most cases profoundly mysterious. But let us detach him from the radio and take him to a window. We point to that brilliant star, Sirius, and ask him if he sees it. Of course, he sees it, but “What of it,” he asks? Seeing the light of that star is even more wonderful than hearing music transmitted a thousand miles by “wireless.” Let us see if we cannot convince him.

Sirius is 500,000 times farther away from us than the sun is.

It is at a distance of 54 million, million miles. It takes light nearly nine years to travel the distance and the velocity of light according to modern views is the highest attainable. Furthermore, the light that travels from Sirius to our eyes is electromagnetic energy in the form of waves similar to those intercepted by the radio set. The only difference is in wavelength or frequency. Off there at that almost inconceivable distance is Sirius, a station sending forth electromagnetic waves of such frequencies or wavelengths as are within the range for which our eyes - the radio receiving sets of the human body - are tuned. This is not a mere analogy. The two cases are practically identical from a physical viewpoint.

Minute particles of electricity - electrons - are playing a vital part in the radio tube. They are one link in the chain of reception and transformation of invisible electromagnetic radio waves into audible sounds. Out there at such a tremendous distance that it would take the fastest airplane 25 million years to travel that far, are electrons in the atoms of the elements of which Sirius consists. These are sending forth electromagnetic energy to be seen by us. Each atom operates exactly like any other of the same element, sending forth electromagnetic waves of the same frequencies. Here on Earth by means of the spectroscope, we measure the wavelengths and tell what the elements are that are sending their wireless messages to us. From the viewpoint of the physical world, signaling to Mars would be but a commonplace achievement.

All around us are wonders just as surprising. Most of them are passed by without interest because they are not understood or because they are commonplace experiences. However, the most wonderful and stupendous picture is the physical universe. Nothing can excel it in magnitude. Each detail is interesting in itself, but the dovetailing of the details gives us not only a picture of great magnitude, but also one of surprising harmony, for there is unity in the whole.

Our interest in the physical world generally is not so much in itself, but in our relation to it. Atoms and stars, their compositions, properties and relations, are the physical universe. Man is incidental and of no influence or consequence. He finds himself in this physical world and strives to learn something of the mechanism. He naturally desires to know what “makes it go” and wishes to understand its laws so that he may harness them to his advantage during his sojourn. What an insignificant mite he is and what an instant of time is occupied by his journey in this physical world!

But here, we are not as concerned with man’s insignificance as we are with the confusion which he introduces into the universe, for man himself is the cause of much of the apparent complexity of the physical universe as it appears to him.

Man’s contact with the physical world is complicated by the multiplicity of his senses and is limited by the capabilities of these sense-organs. We can see light; hear sounds; feel temperatures; experience weights and forces. The senses involved divide the physical phenomena into such branches as optics, acoustics, heat and mechanics. We have no special sense-organ for the phenomena of electricity and magnetism which are more foundational from the viewpoint of the physical universe than light, heat, and mass. The picture of Nature that we obtain through our senses is a subjective one. It is not the real fundamental one. Although without these senses we would have no doorways from which to view the universe, they complicate matters by giving us a picture of a subjective world. We must eliminate the prejudices of these senses before we can develop a true picture of the objective or physical world.

As we look downward from the present heights of scientific achievement we cannot help wondering at the slow progress of science during the early centuries when civilization in many respects had attained great heights. The scientific achievements of the first quarter of the present century compare favorably with the aggregate of all the centuries preceding. The wonderful practical applications of electricity have nearly all appeared during the past fifty years. The science of electricity is only about a century old. It is true that earlier centuries had marvelous men who helped to lay the foundation upon which later men built, but much of the foundation was quicksand. A few men built well, considering the paucity of authentic data. Roger Bacon lived in the thirteenth century and Copernicus was of the fifteenth century. But it was the sixteenth century with such men as Gilbert, Tycho Brahe, Galileo, and Kepler that first witnessed a great deal of advancement in physical science that was to supply foundations of more or less permanency. Scientific ‘achievement was ever gaining momentum, but it was still feeble and uncertain. There was too much speculation and too little experimentation, but fortunately the proportion was to change in the seventeenth century with such experimenters as Torricelli, Boyle, Huygens and Hooke appearing on the stage. Then came Isaac Newton, eclipsing all his predecessors.

There is no doubt that scientific achievement before Newton’s time is insignificant compared with that which has accumulated since the sojourn of that great man. Naturally we wonder why the great minds of earlier centuries in Greece, in Rome and elsewhere achieved so little in unraveling the mysteries of the physical universe. We cannot believe that there were not mighty intellects in those centuries and fortunately such an assumption is unnecessary. The reason for the slow progress in science up to Newton’s time and for the rapid advances in the past century is not found in mind, but in method. Now we build theories only upon a reasonable foundation of facts. Experimentation is the watchword of modern science. This method yields knowledge of the physical world, which is used for building the solid foundations of theories. In earlier centuries the great minds theorized without many facts and the result was largely uncertain speculation. Science has learned a great and lasting lesson which would be beneficial to all given to theorizing without a “working knowledge.” As we look backward we see that the earlier peoples cheated themselves out of many things we now enjoy, by misplaced faith, by scorning experimentation and by trying to build without knowledge. What a relief the present age would enjoy if reformers, politicians and many others would profit by what science has learned and would begin with facts instead of theory.

Let us not be misunderstood. Theory is the greatest tool that science has had. It even exceeds experimentation in value. The great epochs in scientific progress which have changed the course of thought and development have been theories built by mathematical treatment of the physical facts yielded by experimentation. For example, Newton contributed the theory of gravitation; Maxwell the electromagnetic theory of light or radiation; Planck the quantum theory of energy; Einstein the theory of relativity. These are conspicuous milestones along the highway of scientific progress.

Let us take a glimpse of scientific work as it is achieved in modem times. Here and there we have experimenters penetrating the unknown. These scouts bring back many authentic data. Various branches of physical science grow here and there. When enough data have accumulated some kind of unity may be constructed. Eventually a great mind comes along and erects a structure from these facts by arranging them systematically and cementing them together with philosophy and mathematics. If the facts are sufficiently authentic and complete, the structure is a theory. It remains so until all the gaps have been filled. Perhaps some alterations must be made to admit new data. If, as is often the case, the erected structure contains a great many gaps and some misfits, it is better named a hypothesis. It retains this name until it is safe enough to be termed a theory. The gaps in the structure are the predictions of the incomplete assembly and scientific men set about to ascertain their validity. For example, expeditions set out for the southern hemisphere in the midst of the World War in order to determine during a solar eclipse the validity of Einstein’s prediction that light from a star would be bent from its path due to the gravitational force of the sun. It was. During the construction of a theory it is often necessary to make alterations and to add final touches until finally we behold a beautiful structure of perfect unity of harmonized facts. Obviously, attempts at hypothesis and theory are necessary. Otherwise the data of experiments would merely accumulate without unification.

Many of the so-called theories which appeared in earlier centuries are misnamed. They were little more than speculations because of the scarcity of authentic observational data. Many of them are interesting and even fascinating. They prove that great minds and thoughtful men existed throughout the ages. Some of these speculations hit close to the truth as revealed by the facts garnered by later experimenters. But the hits were mere accidents for the most part. Just as the fertile imagination of Jules Verne pictured flying-machines and submarines, some of the earlier speculators pictured possibilities which are now known to be realities. It is a popular pastime among superficial writers to credit some of the early speculators with uncanny insight and foresight, but this is unwarranted. Given enough speculations, particularly when these are the products of great intellects, some of them are bound to strike close to the truth.

Thoughtful men of all times have recognized that the physical world is more likely to be simpler than it would appear to man with scanty knowledge of its mechanism and with several inadequate sense-organs. Simplicity appeared more likely than complexity. Harmonious cosmos appeared more likely than discordant chaos. Basing their speculations on these reasonable assumptions some of the earlier philosophers drew word-pictures that are quite close to the realities as we now know them to be. For example, Democritus (460-360 B.C.) developed certain principles which, after twenty-four centuries, can be made to fit the facts by slightly modifying them. He concluded that the only existing things are atoms and empty space and that nothing existing can be destroyed. He struck close to the truth of the atomic and the electronic theories as they have recently been developed. He tried to construct a picture in which motion was the only physical phenomenon. While it now appears that physics cannot be reduced entirely to mechanics, some of the speculations of Democritus are substantially correct. However, it would be unfair to those modern philosophers such as Newton, Maxwell and Einstein, who built upon known facts and who coordinated authentic data by mathematical genius, to credit early philosophers with comparable achievements. The earlier ones speculated thoughtfully without being fettered by a multitude of facts. The modern ones must develop principles which harmonize a vast amount of data.

Another difficulty which has hindered man in forming a true picture of the objective world is that mixed blessing egoism. In early centuries he could not escape from the false assumption of his own preeminent importance and these same shackles are still prejudicing the observations of most persons. Under this handicap it is not surprising to find man placing himself at the center of the universe. When he began to speculate in regard to the motion of heavenly bodies naturally he conceived them as in motion around the earth. The latter was the stationary center of the cosmos. Many brilliant men were to suffer persecution for striking at this bigotry by attaching less importance to man and the earth by giving to the latter a motion and an importance comparable with the other heavenly bodies.

Pythagorean philosophers suggested a system in which the earth was not the center of the universe. It was not accepted, but the seed was sown which 2000 years later inspired Copernicus (1473-1543) to develop the system of planetary motions around the sun. This was destined to form the foundation of an accurate picture of our solar system. Galileo (1564-1642) was just the man to take up the Copernican theory. With the astronomical observations of Tycho Brahe (1546-1601), with better telescopes, with the friendship of Kepler (1571-1630), and with his own genius, it is not surprising that he placed the Copernican theory on a solid foundation from which it was never to be shaken.

Scientific men encountered obstacles in those days besides those naturally found in their physical researches. Throughout fifty years this great scientist successfully battled the churchmen and others. The controversy of Galileo with the Inquisition is famous. This searcher for truth was confronted by the hordes of bigotry and ignorance. Finally he was haled before the Inquisition and the judgment of the court was that his claim to the effect that the sun was in the center of the solar system and that the earth was not the center of the world was “absurd, philosophically false, and formally heretical because it is expressly contrary to the Holy Scriptures.” In appreciation of his great contribution to our knowledge of the foundations of the universe we cannot blame him when finally confronted with the terrors of the Inquisition, he recanted his doctrines. But the latter were the truth and they lived until a time when they could be openly proclaimed.

The foregoing is introduced to show what hindrances were encountered by scientists of the past. Fortunately, bigotry and ignorance no longer hinder scientific progress. But the new world did not escape the final struggles of that controversy. Perhaps it will shock some readers to learn that a half century ago a state university in the Middle West drove a young teacher of physics from the school because he dared by experimentation to lift the veil from Nature to view the” sacred realm.” There is in print a record of this persecution and controversy which took place in the latter part of the nineteenth century. The young man lived to a moderate old age and passed away only recently after a successful life of contribution to physical science.

Although such bigotry and ignorance have ceased to handicap scientific research, man finds it difficult to step aside and view the physical world quite apart from himself. For example, he cannot submerge his own dimensions and those of his daily contact. For this reason the distances in the stellar universe appear inconceivably large and those of atomic structure appear infinitely small. These difficulties are natural and man is wholly above criticism in this respect. Nevertheless, in order to obtain a proper view of this wonderful mechanism he must transport himself in his mind’s eye to great distances and must contract himself into the atom. He will see wonderful systems of bodies in orderly motion in both cases. It is a good exercise to attempt to conceive limitless space bounded by nothingness which extends forever. Out in the stellar universe he finds a great void inhabited by heavenly bodies relatively “few and far between.” In the atom he finds the same condition.

To the uninitiated person a glimpse of the night sky reveals what appears to be countless heavenly bodies scattered in confusion. Ask him to count the stars and he would be awed at what would appear an impossible task. Still, from a single viewpoint a person can see with the unaided eye only about three thousand stars. All the persons over the entire face of the earth from pole to pole can see less than ten thousand stars. Galileo’s telescope with its objective lens 2t inches in diameter revolutionized human thought because it multiplied the number of visible stars a hundred times. Each increase in diameter of lens or reflector up to the 100-inch Hooker telescope at Mount Wilson Observatory has revealed many more stars. Add to those the records of long photographic exposures and we have a billion stars revealed. How many stars are still behind the veil, of course, is not known, but there are many no doubt.

Although the telescope has increased the complexity of our visible universe by revealing millions of its inhabitants, it is also simplifying the physical world by revealing the motions, the constituents, the relations, and the forms of the celestial bodies. Some of the experiments that the physicist would like to perform in the laboratory, but cannot owing to his inability to produce the proper conditions, are now daily and nightly performed by viewing the phenomena in those far-off celestial laboratories of nebulae, of comets, of glowing gaseous stars, of very hot suns, etc. The physicist now studies the spectra (the electromagnetic waves) emitted by elements at high temperatures as yet unattainable in man-made laboratories. He finds new elements in far-off stars before they are found on earth. He discovered helium in the sun twenty-eight years before its detection on earth. The telescope and its accessories, especially the spectroscope, have proved that the same elements are scattered throughout space; that all celestial bodies have a common origin. This is simplification indeed. And finally he is learning much of the evolution of matter from the myriad stars of all stages of evolution and levels of temperature.

If we reverse the telescope in our imagination, the stellar universe or particularly our solar system gives us a rough model of the atom. The microscope fails us long before the smallness of molecules or atoms is reached, but by indirect methods a still smaller particle, the electron, has been isolated and measured. The atom is now known to consist of a positive nucleus - protons - and negative particles of electricity - electrons. Usually electrons are considered to revolve around the nucleus, the number varying with the element. Thus everywhere from stellar space to atomic space we find bodies in motion, and when we think of how small the protons and the electrons are, we can see that Democritus came close to the mark in his bold speculation which reduced physical phenomena to a single one - motion.

As we take these intimate peeps into the mechanism of the physical world perhaps we are reminded of an attitude which crops out here and there. The scientist by his cold analysis is often considered to be robbing us of the pleasure that awe and mystery give. The artist often shows this attitude plainly. But knowledge is safer than ignorance in our present civilization. This is one of the defenses of the scientist if he needs any. As for the validity of the contention that knowledge lays Nature bare, thereby robbing it of its beauty and us of the pleasure of awe and mystery, it falls down completely. To know the reason for colors does not rob us of the pleasure that color gives. As for awe, the disintegration of radium, the mechanism of the atom, the motions of the planets, the great torches of flame which shoot out from the sun, the plunging of our own planetary system toward the galactic and many other facts of the physical world are more awesome than any observations through the eyes of ignorance. As for mystery, plenty remains. With each addition to the area of knowledge the horizon of the unknown grows larger. Science only replaces one mystery with another of greater magnitude. Some day possibly science will have revealed everything, but we have no need to worry on that score. We shall not see that day and if anyone ever does, it is quite likely that the compensation of knowledge will suffice for the disappearance of mystery.

We can only hope in a single volume devoted to such a large subject as the foundations of the universe, to show the reader the main portions of the structure. If we liken it to a tree we can consider only the main stem and the larger branches. From these branches we may glimpse some of the larger twigs, but all the many ramifications cannot even be suggested. Perhaps the reader’s imagination will contribute considerably to the picture of the more complete tree. We will concern ourselves primarily with such physical aspects as matter, mass, energy, and forces. These may appear prosaic and uninteresting, but their mechanisms, their relations, and their revelations are exceedingly interesting. The methods of the physicist are often picturesque. The experiments reveal really wonderful hidden processes. The relationships are often surprising and the contributions of these toward a picture of a unified universe are nothing less than marvelous. The harmony of the whole universe from atoms to stars, which knowledge is constructing, is beautiful-yes, that is the proper word - beautiful. Any failure to fascinate the reader will be due to the inability of the author primarily, and perhaps of the reader secondarily, to comprehend through mere human powers, the wonderful structure of an infinite universe.

Mere human beings, insignificant and of no influence or consequence, we find ourselves with our familiar dimensions midway in a universe of magnitudes almost infinitely large and small. The constituents of the atom are only a millionth the size of the smallest object that our unaided eyes can see. Most of the bodies of the stellar universe that are visible to us are billions of times larger and most of their distances are billions of times greater than the dimensions with which we are usually concerned. Well may we wonder that man attempts to unveil the mechanism of the physical universe. Here we must thank our egoism, for, where it sometimes handicaps us; it is responsible for the incentive which makes us desire to know all that we can of the world of which we are apart rather than a part.

“So man, who here seems principal alone, Perhaps acts second to some sphere unknown, Touches some wheel, or verges to some goal; ‘Tis but a part we see, and not a whole.” — Pope