January 2008 (Volume 17, Number 1)

# The Back Page

## The Highest Aim of the Physicist

By Henry A. Rowland

Editor’s Note: Henry A. Rowland, one of the few great 19th-century American physicists, was born 160 years ago. He was the first President of the American Physical Society, and the following is adapted from his presidential address, delivered at the second meeting of the Society on October 28, 1899. In some sense, it is a statement of the founding principles of APS. Of course, a lot has changed in more than 108 years. For example, readers may find the exclusive use of the male pronoun by Rowland grating. But one must remember that he was speaking in the language of 1899. His discussion of the impotence of the physician in the face of mortal illness is particularly poignant, because he knew he was dying of diabetes, a disease to which he succumbed less than a year and a half later. The treatment of diabetes by injection of insulin would not be discovered for another 20 years.

In a country where the doctrine of the equal rights of man has been distorted to mean the equality of man in other respects, we form a small and unique body of men, a new variety of the human race, as one of our greatest scientists calls it, whose views of what constitutes the greatest achievement in life are very different from those around us. In this respect we form an aristocracy, not of wealth, not of pedigree, but of intellect and of ideals, holding him in the highest respect who adds the most to our knowledge or who strives after it as the highest good.

Let us cultivate the idea of the dignity of our pursuit, so that this feeling may sustain us in the midst of a world which gives its highest praise, not to the investigation in the pure etherial physics which our society is formed to cultivate, but to the one who uses it for satisfying the physical rather than the intellectual needs of mankind. He who makes two blades of grass grow where one grew before is the benefactor of mankind; but he who obscurely worked to find the laws of such growth is the intellectual superior as well as the greater benefactor of the two.

The progress of every science shows us the condition of its growth. Very few persons, if isolated in a semi-civilized land, have either the desire or the opportunity of pursuing the higher branches of science. Even if they should be able to do so, their influence on their science depends upon what they publish and make known to the world. A hermit philosopher we can imagine might make many useful discoveries. Yet, if he keeps them to himself, he can never claim to have benefited the world in any degree. His unpublished results are his private gain, but the world is no better off until he has made them known in language strong enough to call attention to them and to convince the world of their truth.

Thus, to encourage the growth of any science, the best thing we call do is to meet together in its interest, to discuss its problems, to criticise each other’s work and, best of all, to provide means by which the better portion of it may be made known to the world. Furthermore, let us encourage discrimination in our thoughts and work. Let us recognize the eras when great thoughts have been introduced into our subject and let us honor the great men who introduced and proved them correct. In choosing the subjects for our investigation, let us, if possible, work upon those subjects which will finally give us all advanced knowledge of some great subject. I am aware that we cannot always do this: our ideas will often flow in side channels: but, with the great problems of the Universe before us, we may sometime be able to do our share toward the greater end.

What is matter; what is gravitation; what is ether and the radiation through it; what is electricity and magnetism; how are these connected together and what is their relation to heat? These are the greater problems of the universe. But infinitely smaller problems we must attack and solve before we call even guess at the solution of the greater ones.

When it comes to exact knowledge, the limits are far more circumscribed. How is it, then, that we hear physicists and others constantly stating what will happen beyond these limits? Take velocities, for instance, such as that of a material body moving with the velocity of light. There is no known process by which such a velocity can be obtained even though the body fell from an infinite distance upon the largest aggregation of matter in the Universe. If we electrify it, as in the cathode rays, its properties are so changed that the matter properties are completely masked by the electromagnetic.

It is a common error which young physicists are apt to fall into to obtain a law, a curve, or a mathematical expression for given experimental limits and then to apply it to points outside those limits. This is sometimes called extrapolation. Such a process, unless carefully guarded, ceases to be a reasoning process and becomes one of pure imagination specially liable to error when the distance is too great.

It is a curious fact that, having minds tending to the infinite, with imaginations unlimited by time and space, the limits of our exact knowledge are very small indeed. In time, we are limited by a few hundred or possibly thousand years: the limit in our science is far less than the smaller of these periods. In space, we have exact knowledge limited to portions of our earth’s surface and a mile or so below the surface, together with what little we can learn from looking through powerful telescopes into the space beyond.

In temperature our knowledge extends from near the absolute zero to that of the sun, but exact knowledge is far more limited. In pressures we go from the Crookes vacuum still containing myriads of flying atoms, to pressures limited by the strength of steel, but still very minute compared with the pressure at the center of the earth and sun, where the hardest steel would flow like the most limpid water. In velocities, we are limited to a few miles per second. In forces, to possibly 100 tons to the square inch. In mechanic rotations to a few hundred times per second.

All the facts which we have considered, the liability to error whatever direction we go, the infirmity of our minds in their reasoning power, the fallibility of witnesses and experimenters, lead the scientist to be specially skeptical with reference to any statement made to him or any so-called knowledge which may be brought to his attention. The facts and theories of our science are so much more certain than those of history, of the testimony of ordinary people in which the facts of ordinary history or of legal evidence, or of the value of medicines to which we trust when we are ill, indeed to the whole fabric of supposed truth by which an ordinary person guides his belief and the actions of his life, that it may seem ominous or strange if what I have said of the imperfections of the knowledge of physics is correct.

How shall we regulate our mind with respect to it? There is only one way, and that is to avoid the discontinuity of the ordinary. There is no such thing as absolute truth or absolute falsehood. The scientific mind should never recognize the perfect truth or the perfect falsehood of a supposed theory or observation. It should carefully weigh the chances of truth and error and grade each in its proper position along the line joining absolute truth and absolute error.

The ordinary crude mind has only two compartments, one for truth and one for error; indeed, the contents of the two are sadly mixed in most cases. The ideal scientific mind, however, has an infinite number. Each theory or law is in its proper compartment, indicating the probability of its truth. As new fact arrives, the scientist changes it from one compartment to another so as, if possible, to always keep it in its proper relation to truth and error. Thus, the fluid nature of electricity was once in a compartment near the truth. Faraday’s and Maxwell’s researches have now caused us to move it to a compartment nearly up to that of absolute error. So the law of gravitation within planetary distances is far toward absolute truth, but may still need amending before it is advanced farther in that direction.

The ideal scientific mind, therefore, must always be held in a state of balance which the slightest new evidence may change in one direction or another. It is in a constant state of skepticism, knowing full well that nothing is certain. It is above all an agnostic with respect to all facts and theories of science, as well as to all other so-called beliefs and theories.

Yet it would be folly to reason from this that we need not guide our life according to the approach to knowledge that we possess. Nature is inexorable; it punishes the child who unknowingly steps off a precipice quite as severely as the grown scientist who steps over, with full knowledge of all the laws of falling bodies and the chances of their being correct. Both fall to the bottom and in their fall, obey the gravitational laws of inorganic matter, slightly modified by the muscular contortions of the falling object, but not in any degree changed by the previous belief of the person.

Natural laws there probably are, rigid and unchanging ones at that. Understand them, and they are beneficent: we can use them for our purposes and make them the slaves of our desires. Misunderstand them and they are monsters who may grind us to powder or crush us in the dust. Nothing is asked of us as to our belief: they act unswervingly and we must understand them or suffer the consequences. Our only course, then, is to act according to the chances of our knowing the right laws. If we act correctly, right. If we act incorrectly, we suffer. If we are ignorant, we die. What greater fool, then, than he who states that belief is of no consequence provided it is sincere.

An only child, a beloved wife, lies on a bed of illness. The physician says that the disease is mortal; a minute plant called a microbe has obtained entrance into the body and is growing at the expense of its tissues, forming deadly poisons in the blood or destroying some vital organ. The physician looks on without being able to do anything. Daily he comes and notes the failing strength of his patient, and daily the patient goes downward until he rests in his grave. But why has the physician allowed this? Can we doubt that there is a remedy which shall kill the microbe or neutralize its poison? Why, then, has he not used it?

The answer is ignorance. The remedy is yet unknown. The physician is waiting for others to discover it, or perhaps is experimenting in a crude and unscientific manner to find it. He is employed to cure but has failed. His bill we cheerfully pay because he has done is his best and given a chance of cure. Is not the inference correct, then, that the world has been paying the wrong class of men? Would not this ignorance have been dispelled had the proper money been used in the past to dispel it?

Such deaths some people consider an act of God. What blasphemy to attribute to God that which is due to our own and our ancestors’ selfishness in not founding institutions for medical research in sufficient number, and with sufficient means, to discover the truth. Such deaths are murder.

Thus, the present generation suffers for the sins of the past, and we die because our ancestors dissipated their wealth on armies and navies, in the foolish pomp and circumstance of society, and neglected to provide us with a knowledge of natural laws. In this sense, they were the murderers and robbers of future generations of unborn millions, and have made the world a charnel house and place of mourning where peace and happiness might have been. Only their ignorance of what they were doing can be their excuse, but this puts them in the class of boors and savages who act according to selfish desire and not to reason and to the calls of duty. Let the present generation take warning that this reproach be not cast upon it, for it cannot plead ignorance in this respect.

This illustration from medicine I have given because it appeals to all. But all the sciences are linked together and must advance in concert. The human body is a chemical and a physical problem, and these sciences must advance before we can conquer disease.

But the true lover of physics needs no such spur to his action. The cure of disease is a very important object and nothing can be nobler than a life devoted to its cure. The aims of a physicist, however, are in part purely intellectual: he strives to understand the Universe on account of the intellectual pleasure derived from the pursuit, but he is upheld in it by the knowledge that the study of nature’s secrets is the ordained method by which the greatest good and happiness shall finally come to the human race.

Where, then, are the great laboratories of research in this city, in this country, nay, in the world? We see a few miserable structures here and there, occupied by a few starving professors who are nobly striving to do the best with the feeble means at their disposal. But where in the world is the institute of pure research in any department of science with an income of $100,000,000 per year? Where can the discoverer in pure science earn more than the wages of a day laborer or cook? But$100,000,000 per year is but the price of an army or of a navy designed to kill other people. Just think of it, that one percent of this sum seems to most people too great to save our children and descendants from misery and even death.

But the 20th century is near–may we not hope for better things before its end? May we not hope to influence the public in this direction? Let us go forward, then, with confidence in the dignity of our pursuit. Let us hold our heads high with a pure conscience while we seek the truth, and may the American Physical Society do its share now and in generations yet to come in trying to unravel the great problem of the constitution and laws of the Universe.

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Editor: Alan Chodos
Contributing Editor: Jennifer Ouellette
Staff Writer: Ernie Tretkoff