WHY is the work of Einstein constantly injected into this discussion? Is not semantics difficult enough to grasp without dragging in a scientist whom only a handful of men are said to understand? I sympathize with the harassed reader. For my own sake as well as for his, I wish that in this particular study we could give modern physics a wide berth. But we cannot. We must face the music. I am not, however, going to take you far into technical depths, because, among other reasons, I do not know enough.
Einstein not only turned the physicists upside down; he also revolutionized certain aspects of human communication. A shock went around the world comparable to that produced by Darwin’s theory of evolution. In the long run, relativity may prove a more important factor in language than in physics. Its impact has caused thoughtful men everywhere to look to their words, to question the validity of their concepts. In the domain of physics, chemistry, biology, relativity has been responsible for an unprecedented crop of young geniuses, due to the sudden expansion of understanding which- its concepts promote. To see the outside world primarily in terms of relations rather than in terms of absolute substances and properties seems to develop an intellectual keenness hitherto unknown. Rest on this thought for a moment. Since 1905, when relativity was first announced, and especially since the 1920’s when the quantum concept began to bulk large in physics, a gathering number of human beings have been thinking and communicating in ways more sure, more powerful, than have any human beings before. The new weapon is so sharp that it sometimes wounds them; there is much to be done in reconciling certain aspects of relativity and quantum theories; but they have set out upon an adventure whose excitement and importance it is difficult to overestimate.
Einstein separated the observer from the observed. He threw the ego out of physics. He derived a picture of the world relatively undeflected by the human senses. As a result he produced the closest fit yet made to happenings in nature. To communicate what he had done, Einstein employed a mathematical language, the calculus of tensors, which, says E. T. Bell, “threshes out the laws of nature, separating the observer’s eccentricities from what is independent of him, with the superb efficiency of a modern harvester.”
To measure anything accurately a man must take a scaled rule, a clock, a telescope, or other instruments, and make readings. Every reading depends on the finite velocity of light from meter stick to eye, and on the finite velocity of nerve currents from eye to cortex. Although the finite velocity of light was indicated more than two centuries ago (1676), up to the time of Einstein it was assumed that readings were instantaneous.
Newton did not take into consideration the finite velocity of the ray of light from instrument to eye. Einstein did, and Newtonian physics had to be revised. Measurements were found to be distorted, especially measurements over long distances. Newton’s rules of mechanics still work in terrestrial magnitudes with close approximation, but his absolutes have lost their majesty. It was found that “infinite velocity” was but a polite way of ‘speaking about blunders in observation.
Einstein thus gave a new cast to meaning. He found the meaning of “length” no longer in absolute space, but in the operations by which the length of physical objects was determined; he checked the meaning of “simultaneity” by operations, and found the concept untenable. It followed that “absolute space” and “absolute time” were metaphysical notions in our heads. When operations were called for, the notions disappeared—to the acute dismay of the majority of physicists.
This brings us to another matter of the first importance. If Einstein challenged the massed knowledge of the past, including the immortal Newton, and gave contemporary physicists severe mental indigestion, why did they tolerate such brashness? Why did they not arise as one man and say in effect, “To thunder with you, Mr. Einstein!”? If I challenged the whole structure of money and credit, however persuasively, the economists and statesmen would say, “To thunder with you, Chase!” and turn on their heels. That would probably be the end of it.
Einstein could not be dismissed because he was working within the rigor of the scientific method. I could be dismissed because scientific method is unknown in the domain of money and credit; there is no standard by which sane men can agree that I am wrong or right. Honest scientists applied standards of proof to Einstein’s findings, and much as it pained their inner feelings, they had to agree that he was right. If and when Homo sapiens perishes from this planet, I hope that some creature, somewhere, will remember that once men climbed to this high place. A few members of the race acknowledged a discipline which made them bow, because they knew that it was true, to something that in their hearts they hated.
Science does not consist of gentlemen with Vandyke beards in white coats squinting down microscopes, as per the toothpaste advertisements headed “Science Says.” Science is actually a high-order abstraction, and cannot say anything. A given scientist may speak from time to time, judiciously or injudiciously as the case may be. The scientific method, or what a scientist does, may be described in some such terms as these, to follow E. T. Bell:
1. The central position is held by experiment. The experiment must be conducted under rigidly standard conditions, so that another trained man can repeat it. If A claims that he has raised a four months’ corpse from the dead, he must describe his procedure so that B can revivify another corpse, or prove to the world, on A’s
own say-so, that A was mistaken, to use no harsher term.
2. Next comes a tying-up of experiments into bundles having one or more characteristics in common, a period of classification.
3. From the group of experiments, deductions or conclusions are then drawn. Many scientists stop here. (But some of them begin to believe in the ghostly existence of classes as “entities,” and thus fall out of science into philosophy.
4. Laws or generalizations may then be attempted, such as Newton’s law of gravity. The laws of nature are not Mosaic tablets, but practical rules for human action with nature. Obey them or get into trouble.
Another standard procedure among scientists is to construct from the facts available a hypothesis, or hunch. State it frankly as a hypothesis; or better, keep it to yourself. Then arrange a series of experiments by which the hypothesis can be proved or disproved. As in the case of the revivified corpse, other investigators must be able to repeat the experiments and check the proof. This was essentially Einstein’s procedure. He got an idea; he expressed it in mathematical language, arrived at the shattering hypothesis of relativity, and called for experimental proof.
It is interesting to follow the course of that proof. Among other predictions which arose from the hypothesis, three were held to be of primary importance: (1) that the motion of the perihelion of Mercury must be approximately 42.9 seconds a century; (2) that a ray of light coming from a distant star must be bent as it passed the sun at an angle of approximately 1.745 seconds; (3) that the displacement of certain lines in the solar spectrum ought to be approximately .008 Angstrom units. Many experiments have been made, and as the measurements have grown more precise, the results have approached more closely to the predictions. The motion of the perihelion of Mercury has been verified with high precision; measurements of the angle of bending light-rays near the sun are now down to 1.72 seconds, with a probable error of . 11 seconds plus or minus; the displacement of lines in the spectrum is down to .009 units, where the prediction called for .008.
The hypothesis was thus proved correct within the limits of current knowledge, which is enough to expect. But relativity was not made into “eternal truth.” Good scientists were through with “eternals.” Relativity was simply the truest picture of certain aspects of the world yet discovered. In 1938 it still remains so. In 1988 it may be superseded by a concept which shows a closer fit. Darwin, Pasteur, and Chamberlin also began with preliminary hypotheses which were later verified in whole or in part. Unverified remainders go down the drainpipe with the dishwater.
Here is a scientist investigating a contagious fever. He wants to find out how the disease is transferred from one victim to the next. First he browses around in the literature of contagious diseases. In due time he gets an idea that it might be conveyed by some bloodsucking creatare. By prolonged and painstaking research in the field and in the laboratory, in which many bloodsucking creatures are examined and discarded, he finally verifies the hypothesis. The mosquito is found guilty. Any competent man can repeat the experiment and prove it. A conquest has been made far greater than that of Cortes.
Look at another picture for the sake of contrast. A devoted socialist asks if the misery caused by poverty can be cured. Long experience with poor people and rich people leads him to the hypothesis that capitalism is at fault. He cannot verify it by any conclusive experiment which another man can check, so he argues and affirms that capitalism is the mosquito. It may be so, but his only support is a series of scattered observations, logic in his head, and goodwill in his heart. Scientific knowledge moves steadily forward; social reform plunges, rears, falls back to plunge again. The scientist finds his referents and makes positive that others can find them in the dark. The reformer can seldom locate his referents, even if there are any to be found. I have tried to be a reformer and I ought to know.
The scientific method is concerned with how things do happen, not how they ought to happen. Knowledge of the way things do happen, with no ifs, ands, or buts, allows us to deal more effectively with our environment. The method is no more an exclusive matter for professionals than it is a matter of white coats and goggles. Most of us are amateur scientists today, though we are seldom aware of it. You are driving along a strange road
and become lost. In what direction are you going? The sun is shining. You look at shadows cast by telephone poles and then look at your watch. It is near noon, so the shadows must run approximately north and south. The operation is crude, but it saves gasoline. I am waging war on tent caterpillars in my orchard. I douse a nest with kerosene. Then one of similar size beside it I paint lightly with kerosene. Next day I look to see if the second method is as effective as the first in killing caterpillars. If it is, I use it on other nests and so save time and kerosene. This is a crude controlled experiment. The scientific method is not primarily a matter of laboratories and atom-smashers or even meter sticks; it is a way of looking at things, a way of gathering from the world outside knowledge which will stay put, and not go wandering off like the wickets in Alice’s croquet game.
Greek philosophers argued bitterly about what water was. People today no longer become angry and take sides as to the composition of water. Agreement has been reached and the mind rests. We no longer burn witches as responsible for the outbreak of plague. We burn up the cables for antitoxins and the Red Cross.
Every spring the Nile came down and washed out the field boundaries of the ancient Egyptians. It was a damned nuisance. Whose field was where? This question marked the beginning of surveying and geometry. First, the Egyptians had to agree that the problem was worth attacking. Second, they had to see the possibility of a solution on which sane men could agree. Third, the
solution had to be such that other sane men, then and in the future, proceeding by the rules laid down, could reach similar conclusions from the given facts. A’s field was here, B’s was there, and no more quarrels and uncertainties. According to Bell, these steps of agreeing to agree, and producing a set of rules on which sane men could agree and obtain similar results, “were the most important ever taken by our race.”
By the scientific method, men are brought to agreement; in it emotion and passion have no place. The degree of emotion displayed by a disputant, observes Bertrand Russell, is a direct indication of his lack of knowledge of the subject at issue. At the stage of unproved hypothesis, scientists can let themselves go to squabble and scratch, but when the experimental proof comes in, they must cease their bickering and remove their hats.
The fact has alwayH^een for the physicist the one ultimate thing from which there is no appeal, and in the face of which the only possible attitude is a humility almost religious.