The Acheson-Lilienthal Report


The Adequacy of Present Scientific Knowledge

There can be no question that its dynamic changing quality is one of the dominant features of the present situation in the field of atomic energy. Advances in knowledge must be expected in a constant stream. Does this mean that a system of safeguards is impossible because new knowledge will completely change the nature of the problem from year to year or even month to month? The answer is in the negative.

When the atomic bomb was first used there was a widespread belief that its development involved a few simple, static secrets. As it became possible for people to learn how rapidly ideas and techniques had changed in this field in the last year, and how many further developments the future seemed to have in store, the original opinion was replaced by another: that we knew very little of the possibilities and limitations of this field and that it was so rapidly changing that no account of the present technical situation would have much validity. This view has been expressed both in the preamble to a pending Bill, which indicates that too little is known of the technical facts to provide a firm basis for political action, and in such statements as one attributed to a high official, that it would not be long before we could extract atomic energy from common materials such as clay.

Neither the initial view of a static body of knowledge nor the later one of unpredictably rapid change accurately describes the present situation. As the preceding chapter has shown, there is a great deal that we know about nuclear reactions--know solidly, firmly, and with vast, interrelated experimental checks on the soundness of the description. Novelty will of course appear in scientific discoveries, but it will appear for the most part not as a negation of present knowledge but as the result of new types of physical experience made possible by new methods of physical exploration, and in turn requiring new modes of description. This future experience may have something to do with the basic knowledge involved in release of atomic energy, but there is no basis for believing this, and the chances are against it. There is another type of novelty that lies in ingenious applications of the fundamental facts as they are now known. This does not lessen the importance of the underlying facts and of conclusions which can unambiguously be drawn from them.

For the limited but useful objective of devising a system of control valid for the reasonably foreseeable future, we believe the present knowledge in the field of atomic energy is adequate. We know for example, that uranium occupies a unique role in the production of fissionable substances and that without it atomic explosives cannot be made. We know that there is no evidence whatever that this situation will soon change. We know that a vast scientific and industrial effort is necessary in order to produce atomic bombs. This is not to say that the effort, however vast, cannot be concealed--although we believe that measures can be taken to reduce this danger. We know that the release of atomic energy does demonstrate the convertibility of mass to energy, but we also know that the familiar example of this physical principle--that the annihilation of a kilogram of any kind of matter is equivalent to all the power consumed in the United States in a period of three months--is a statement of a possibility, the realization of which is so remote that for the purposes of devising a system of safeguards it may be entirely disregarded.

We know, too, that many areas in this field which are now unclear will be clarified by further investigations. Within a few years much more could be learned about atomic explosives. Within a relatively few years the technology of atomic energy power plants will become clearer. It seems likely that before very long we shall have discovered many useful therapeutic and technological applications for the radioactive substances which can be made in the production of fissionable materials. Nor can there be much question that ways will be found to cheapen and simplify the processes involved in the production of the fissionable materials themselves.

But what needs most to be emphasized is that the dynamic quality which has so excited popular interest must be seen in its proper perspective in relation to the general field of scientific knowledge. The prophecies as to future discoveries must not be permitted to obscure the fact that there are at key places throughout the field of knowledge firm anchor points around which it should be possible to construct an effective and adequate system of control.

In this report it is possible for us to do little more than record our own sense of the soundness of this statement. Those who must assume responsibility for political action should test for themselves the correctness of our conclusions. This testing will require an examination of difficult and complicated technical facts, but we are confident that the process is one which other laymen with the appropriate help of experts can readily repeat. We are also confident that unless the effort is made it will be impossible to come to grips with the problem of devising political measures to prevent atomic warfare and to promote the beneficent use of atomic energy.