Part I

Nature of the Subject

For out of olde feldes, as men seith, Cometh al this newe corn fro yeer to yere; And out of olde bokes, in good feith, Cometh al this newe science that men lere.

Chaucer

1

The Meaning of Space Science

The science managers in the new National Aeronautics and Space Administration of 1958 for the most part had limited experience in the management of science programs. By comparison with the broad program about to unfold, the previous sounding rocket work and even the International Geophysical Year programs were modest indeed. Yet the evolving perceptions of these individuals as to the nature and needs of science would play a major role in the development of the U.S. space science program. At first those perceptions were largely intuitive, growing out of personal needs and experience in scientific research, although a rather extensive literature made the thoughts and experience of others available. In addition, in launching the new program the space science managers had the benefit of the wise counsel of Deputy Administrator Hugh Dryden and Administrator T. Keith Glennan, both of whom had had considerable experience in managing science and technology programs.

Because of the central role played by the concepts of science that NASA managers brought to bear-sometimes consciously, sometimes subconsciously-on the planning and conduct of the NASA space science program, some of those concepts are set forth here at the outset. Moreover, the reader should bear in mind that these concepts are implicit in the author's treatment of space science in this book. The exposition below, while a substantial elaboration of a summary presented to Congress in the spring of 1966, is still highly condensed, and runs the risk of oversimplification.'

SCIENCE A PROCESS

A major theme throughout this book is that of science as a worldwide cooperative activity, a process, by which scientists, individually and collectively, seek to derive a commonly accepted explanation of the universe. The author recalls learning in the ninth grade that science was "classified (i.e., organized) knowledge," only to have to discard that definition years later as the very active nature of science became apparent. To be sure, organized

knowledge is one of the valuable products of science, but science is far more than a mere accumulation of facts and figures.

Science defies attempts at simple definition. Many-both professional scientists and others-who have sought to set forth an accurate description of the nature of science have found it necessary to devote entire volumes of elaborate discussion to the subject.2 None has found it possible to give in a few sentences a complete and simple definition, although James B. Conant perhaps came close: "Science is an interconnected series of concepts and conceptual schemes that have developed as a result of experimentation and observation and are fruitful of further experimentation and observations."3

On a casual reading, this definition may again appear to characterize science as a static collection of facts and figures. One must add to the definition the activity of scientists, their continuing exchange of information and ideas, and their penetrating criticism of new ideas, working hypotheses, and theories. A static mental construct alone is insufficient; one must include the process that constantly adds to, elaborates, and modifies the construct. All of this Conant-himself an eminently successful chemist— does actually include in what he is trying to convey in his brief definition, as is patent from the amplification he provides in the rest of his treatment. Indeed, the last clause of the quoted definition, requiring that the concepts and conceptual schemes of science be "fruitful of further experimentation and observations," clearly implies the ongoing nature of science.

The difficulty of conveying in brief the nature of science, particularly to the layman, has led in exasperation to such statements as, "Science is what scientists do." The circularity of this definition can be frustrating to one seriously trying to understand the subject—a legislator, for example, endeavoring to appreciate the significance of science for the country and his constituents, and to discern what science needs to keep it healthy and productive. Yet the definition suggests probably the best way of approaching the subject; that is, to tell just what it is that scientists do.

Scientists work together to develop a commonly accepted explanation of the universe. In this process, the scientist uses observation and measurement, imagination, induction, hypothesis, generalization and theory, deduction, test, communication, and mutual criticism in a constant assault on the unknown or poorly understood. Consider briefly each of these activities.

The scientist observes and measures. A fundamental rule of modern science is that its conclusions must be based on what actually happens in the physical world. To determine this the scientist collects experimental data. He makes measurements under the most carefully controlled conditions. possible. He insists that the results of experiment and measurement be repeatable and repeated. When possible, he measures the same phenomenon in different ways, to eliminate any possible errors of method.

To experimental and observational results the scientist applies imagination in an effort to discern or induce common elements that may give further

insight into what is going on. In this process he may discover relationships that lead him to formulate laws of action or behavior, such as Newton's law of gravitation or the three fundamental laws of motion, or to make hypotheses, like Avogadro's hypothesis that under the same pressures and temperatures, equal volumes of different gases contain equal numbers of molecules. It is not enough that these laws be expressed in qualitative terms; they must also be expressed in quantitative form so that they may be subjected to further test and measurement.

The scientist generalizes from the measured data and the relationships and laws that he has discerned to develop a theory that can "explain" a collection of what might otherwise appear to be unconnected or unrelated facts. In seeking generalization, the scientist requires that the new theory be broader than existing theory about the subject. If the new theory explains only what is already known and nothing more, it is of very limited value and basically unacceptable.

The new theory must predict by deduction new phenomena and new laws as yet unobserved. These predictions can then serve as guides to new experiments and observations. By taking predictions and working them together with other known facts and accepted ideas, the scientist can often deduce a result that can be put to immediate test either by observation of natural phenomena or by conducting a controlled experiment. Out of all the possible tests, the scientist attempts to choose those of such a clear-cut nature that a negative result would discredit the theory being tested, while a positive result would provide the strongest possible support for the theory.

In this connection, it must be emphasized that the scientist is not seeking “the theory," the absolute explanation of the phenomena in question. One can never claim to have the ultimate explanation. In testing hypotheses and theories the scientist can definitely eliminate theories as unacceptable when the results of a properly designed experiment contradict in a fundamental way the proposed theory. In the other direction, however, the scientist can do no more than show a theory to be acceptable in the light of currently known facts and accepted concepts. Even a long-accepted theory may be incomplete, having been based on inadequate observations. With the continuing accumulation of new data, that theory may suddenly prove incapable of explaining some newly discovered aspect of nature. Then the old theory must be modified or expanded, or even replaced by an entirely new theory embodying new concepts. Thus, in his efforts to push back the frontiers of knowledge, the scientist is continually attempting to develop an acceptable "best-for-the-time-being" explanation of available data.

For what scientists mean by the terms hypothesis, law, and theory, the reader is referred to Robert Bruce Lindsay and Henry Margenau, Foundations of Physics (New York: John Wiley & Sons, 1936), pp. 14-29.