Nevertheless, I felt encouraged when, some eight years later, Hoyle, Bondi and Gold published the hypothesis that they called Continuous Creation, for it agreed with my own view at least insofar as it postulated the random and causeless continuous origin of matter. Although these later authors could not accept my contention that a methodologically sound hypothesis about the duration of matter required that continuous origin be coupled with continuous extinction, they did help to prepare the scientific world for new insight into the relation between matter, space, time, and causation.
Time was passing and I was being forced reluctantly to realize that, unless I followed up my own suggestion, no one else was likely to do so. So, some six years ago, I began to give the subject more concentrated attention, regretting that I had neglected it for so long. But I never ceased to feel sure that a team would do the job better.
My method had to be adapted to the theme and yet to differ from that appropriate to research in a less extensive field. It is important to an understanding of what is presented here that this be appreciated. The aim of perhaps 90 per cent of all researches is to discover new detailed facts in a limited field. The starting point is experiment and observation. A collection of data is found that provides a useful addition to existing knowledge. Occasionally, the research worker finds himself confronted with a puzzling fact. This gives his work a new direction. An explanatory hypothesis has to be sought. It is an ad hoc hypothesis and, when found, has to be tested. If it stands the test, it becomes one of the generalizations of science; a new law, it is said, has been discovered. This pattern is so recurrent and familiar that any other is often deprecated. One must always start with a problem, it seems to be taken for granted, and devote oneself exclusively to the discovery of a law that will solve it.
Nevertheless, the familiar pattern cannot be applied here. Throughout the years while the theme of this book has been claiming some of my attention, it has not been my aim to find explanatory hypotheses. I have been seeking instead a literal and uncompromising justification in physics for the famous maxim: hypotheses non fingo. I have wanted not to discover, but to test. And the assumption that I have sought to test is the Principle of Minimum Assumption itself.
Thus the Principle of Minimum Assumption has withstood every test to which I have been able to subject it. But if the principle is valid and universal in physics, it must govern every branch of the physical sciences. So the tests must continue. Whenever they are successful, one may expect the experience recorded here to be repeated: something obscure will have been illuminated; new insight will have been gained. I should like this book to be regarded primarily as a more determined effort than my previous ones have been to encourage research workers to tread more often than they now do the path signposted with the word 'Testing' and not all to crowd along the path with the signpost bearing the legend 'To a discovery'.
Every theme calls for its own most appropriate treatment. When the theme belongs to a highly specialized field of study, there is no excuse for a research worker who fails to comb the world literature on his theme before he commences his own research. In the thesis that he prepares at the end of it, he is expected to quote from all the authorities whom he has consulted, to give a detailed account of the existing state of knowledge on his subject, to assign priorities where they are due, critically to discuss all previous theories with mention of the names of their authors and the dates of their publication, to define precisely the point of view adopted by himself in relation to that of other workers in the same field.
It cannot be denied that the present study would be more reliable and better in every respect if I had done all this. But it is manifestly impossible for a single research worker to do so much when the subject is as comprehensive as it is here. I had to face the dilemma of either presenting something that I knew to be imperfect or of presenting nothing at all. So I decided that my aim should not be perfection but that I could, nevertheless, stimulate thought along new lines.
If the author of new theories waits, moreover, until he has found a satisfactory answer to every question that arises from the theories, he will wait for ever. Would that this were more widely appreciated. It is a common observation that those who dislike a new theory but are unable to refute it seek only too often to have it ignored by drawing attention to some problem that remains unsolved. 'No answer has yet been provided to such-and-such a question', they say. 'And so the theory must be wrong. It is best forgotten.'
I cannot hope to escape this shallow kind of comment but I may forestall it if I define the status of my theories as it appears to me. I show in this book that Symmetrical Impermanence can be justified on methodological grounds and provides answers to an impressive list of questions in a variety of scientific disciplines. This does not suffice to prove it true but it suffices to warrant a serious attempt to answer those questions that arise out of my theory.
Some of the problems of presentation that arise from the great breadth of the subject are worth mentioning.
There was the question how to quote chapter and verse for those statements for which I could claim the backing of authority. The usual method is by citations, footnotes, and a comprehensive bibliography. But for the present purpose I decided to dispense with the ostentatious support of authority. So long as I avoided any suggestion that the discoveries of others were my own, I could not mislead by omission of an author's name and I might do an injustice if, through ignorance, I assigned a wrong priority to anyone. I have, therefore, been very sparing of references and footnotes. If anyone says that these omissions prove my ignorance, he will be right. If he says that they prove my ignorance in some particular instance, he may be wrong.
What held for the past holds, unfortunately, for the present day. In the course of my reading I have met many theories in the field of cosmology that are quite recent and yet, I am afraid, quite untenable. But they are so close to my subject that I cannot ignore them. Without extensive research into the literature of the subject, I cannot always know for certain who their original authors have been, nor whether they still sponsor them, nor how strong their present backing is. So to quote from the particular passages that I happened to have found might do someone an injustice. To discuss such theories while coupling them with the names of particular authorities would introduce an undesirable polemical note. It would also be unkind. I have compromised by introducing such theories with some such form of words as 'one might think for a moment that', or 'the possibility has to be considered that'. Those who have not met the particular theory before may be misled into thinking that I have set up a dummy in order to knock it down; but that is here the lesser evil.
Those parts of the book in which relativity theory has to be discussed have raised particularly difficult problems of presentation. This is because only a small fraction of those whom I am addressing here are likely to be familiar with the mathematics of general relativity, though some of them may have no difficulty with special relativity. The mathematics is not as difficult as is often supposed, but the notation is unfamiliar and does not occur in most other branches of science. Many scientists can do all their work without ever using this notation. The letter symbols used by relativists constitute a highly condensed kind of shorthand in which one letter represents a great deal. It need not surprise that those who do not use the notation daily easily lose sight of the physical concepts for which the letter symbols stand. Even expert relativists do so sometimes — which explains why there is still some doubt about the correct physical interpretation of certain aspects of general relativity. It also explains the occasional reluctance of relativists to give any physical interpretations at all; but here I have repeatedly found myself obliged to do just this. Interpretations given by others have all too often failed to secure general acceptance and I cannot hope for a better fate for mine. From correspondence and conversation I have been led to expect, in particular, somewhat violent opposition to my claim that, in the relativity equations, the letter symbol that represents mass must usually be interpreted as representing inert and gravitational mass only and that great care must be taken to ensure that the same letter symbol is not wrongly interpreted as also representing attracting mass. I have written with the express purpose of inviting critical comment and have to add that, while the majority of those whom I am addressing are competent to provide critical comment on most of what is presented here, only a minority of experts in general relativity are competent to do so about my interpretations of the relativity equations. It places rather a big responsibility on these few.
I wish to acknowledge the valuable help with the presentation of my material that has been given me by Mr B. C. Brookes and Mr C. R. Howe. I also wish to acknowledge much scientific advice and information from Professor Schieldrop of the University of Oslo, to whom I showed an early draft.
Chapters 1 and 2, and passages from other parts of the book in which space is discussed, have been pubhshed in The British Journal for the Philosophy of Science. I am indebted to the editor and publishers of that journal for permission to publish them here.
REGINALD 0. KAPP