THE CURRENT EINSTEIN celebrations have been marred in only one respect-the continuing lack of public access to the unpublished documents of this great and public man. The result is that all biographical or historical books on Einstein are tantalizingly incomplete. The explanation is merely that Einstein's papers are still jealously guarded by his two literary executors, Helen Dukas and Dr. Otto Nathan of New York, no doubt out of a sense of loyalty that seems more misguided as each year goes by. Scholars and writers everywhere will be hoping that Princeton University Press will now be able to get on and publish an archive that should have been published long ago.
The importance of that task is evident in the incompleteness and the hesitancies of the centenary books which have now appeared and which are of three kinds-accounts of the development of Einstein's scientific work, explanations of the same, and attempts to explain what he was really like. All of them remark on the phenomenon of Einstein's first appearance on the scientific scene in 1905, when three of the five articles which he published in the German physics journal-Annalen Der Physik -would each have earned a lifetime's renown.
Einstein: A Centenary Volume offers in many ways the most comfortable reading. Planned by the International Commission on Physics Education and edited by A.P. French of the Massachusetts Institute of Technology, it is what it sets out to be-an account of Einstein's work for students (in high school as well as college) and for others with a smattering of technical education. To help ease the reader into the main part of the argument, there is an introdu ction made from a miscellany of reminiscences and biographical essays, among which that by the lat J. Robert Oppenheimer has the merits of being literate, moving, humane and explanatory.
The book deals well and fairly with the five themes in Einstein's scientific life-four triumphs and a wild-goose chase. His first great achievement, in 1905, was surprisingly his penetrating inference about the nature of light. By the end of the 19th century, physicists had been persuaded that light (and other kinds of radiation such as radar or ultraviolet radiation) are really just waves in the now infamous ether, but there were snags. In particular, it was not possible to account for the radiation actually given off by material objects-the tungsten filaments of electric famps, for example. Einstein, radical at the beginning as to the end, gave as his explanation the notion that light can in certain circumstances behave as a stream of particles and not as a train of waves. He called them quanta and thus made explicit the first principles of what is now called the quantum theory. He kept on adding to what he had done until, in the mid-'20s, he became disaffected from his followers in quantum theory.
The two theories of relativity, however, made Einstein a legend in his lifetime, and this centenary volume has a clear explanation of how they arose. The first of them, now known as the special theory (1905), was Einstein's radical exorcism, almost by pure thought, of the inconsistencies that plagued 19th-centruy physics, the all-pervading but intangible ether in particular. This is the theory that prompted a host of limericks on the themes that nothing can travel faster than light, that all objects become more massive as they seem to travel faster, that energy means mass and vice versa, and that time seems to pass more slowly on objects (spacecraft) moving quickly away from one. The book gives a good account of why this revolution inscience was necessary, and of how it came about.
But Einstein's general theory of relativity, published in 1917, was his outstanding triumph. It amounts to nothing less than the first explanation of how objects such the earth and the sun attract each other. Around each of them, the argument goes, space and time are no longer flat (in the sense that a beam of light will travel straight) but curved (so that the beam of light will bend). And these puckerings of space and time tend to coalesce, or the objects associated with them to pull together.
From the first, the majesty of this theory has been palin. It provide for the first time a way of calculating how the universe behaves (and, in particular, expands). Now, after half a century, it has been amply confirmed, most spectacularly in the past few weeks by the observations of Professor Joseph Taylor at the University of Massachusetts of the motion of a distant radio star. To be sure, the theory is not a true explanation in that it does not say why space and time should be puckered when there is matter about, but it carried the argument to a much deeper level than had previously seemed possible. Telling why space and time should be like this is now one of the principal objectives of physics.
Einstein's fourth triumph in 1905 was less spectacular, even pedestrian. He worked out the statistical rules that account for Brownian Movement, the motion of tiny objects, say pollen grains, suspended in liquids and continually exposed to random collisions with molecules. In its time, it neatly tied together some loose ends that had puzzled people for 20 years. Looking back, the techniques that Einstein used in solving that simple problem remained for the rest of his life his own special test of the validity of other theories.
The puzzle then, is why Einstein, who in the early part of this century had helped to found the quantum theory-with relativity the other great hallmark of 20th-century physics-should have been so much at odds with those who turned it into the quantum theory of two decades later. The issue was simple. The quantum theory requires that some questions in physics can be answered only statistically. It is possible, for example, to measure the "average" length of time for which a particular kind of radioactive atom will exist, bu "impossible" to tell how long it will be before an individual atom breaks up.Einstein was offended by this notion, for reasons which are well described in the centenary volume. He spent the rest of his life looking for a way of making these uncertainties go away. It was a fruitless search, but one to which a man of such stature was surely entitled.
All the threads of this tale are woven together in the centenary volume, whose defects are those of the unavoidable bittiness of what is, after all, a compilation and which has more algebra than everybody will welcome. Nigel Calder's Einstein's Universe is very different. He sets out to explain relativity to the man in the street. It is also the book of the film-the television film shown recently on both sides of the Atlantic, Calder's claim on the common reader audience is justified, but there are many who will find that their task is made unnecessarily difficult by the overblown prose and the repeated changes of location. Those who fail to get the message will at least have the comfort of knowing that this is how Mr. Peter Ustionov learned relativity.
Albert Einstein : The Human Side compiled by two of his closest colleagues in later life, Helen Dukas and Banesh Hoffmann, aims to show what kind of a person Einstein was. By a series of quotations from letters, jottings and unpublished documents, for example, Dukas and Hoffmann demonstrate as clearly as anybody could expect that Einstein was a courteous, kindly, witty, fearless and lonely man. It is almost a book of aphorisms, such as, "Politics is a pendulum whose swings between anarchy and tyranny are fueled by perennially rejuvenated illusions." It is a bedside book. And, even more urgently than the others, it is a reminder that the Einstein archive must soon be unlocked. CAPTION: Picture, Photo of Albert Einstein; Copyright (c) Karsh of Ottawa