Towards a Unified Cosmology

The wider the range of a piece of research the less adequately can any one worker deal with each of its specialized aspects. Breadth and depth compete for his attention and cannot both secure the whole of it. I am only too well aware how particularly this truism applies to the study presented here. The very words 'Unified Cosmology' are both a challenge and a reminder that every conclusion arrived at has to be consistent with all the facts that have their appropriate place in every intellectual discipline. No conclusion here can be considered sufficiently tested by establishing its consistency with what is known in one branch of science only. Anyone who would make the most modest contribution to the unification of science should never claim to be writing specifically as a nuclear physicist, or as an astronomer, or as a relativist, or as a classical physicist, or as a mathematician, or as any other specialist whatever. When he does so he introduces a misplaced emphasis. He must never forget that knowledge acquired by himself in his own particular field of study is not necessarily more relevant, and may well be less so, than knowledge acquired by others in fields remote from his own. In order to find means of confirming or falsifying his conclusions, he must look for facts belonging to every branch of science to which he can obtain access. He must be prepared some day to be refuted by facts known to others, but of which he himself is still in total ignorance.

Appreciation of this solemn truth restrained me for many years from publishing more than a small fraction of the material that is presented in these pages. It was over thirty years ago that I first came to believe that the principle called here the Principle of Minimum Assumption deserved to be applied in the physical sciences with uncompromising consistency. I can trace this conclusion, or at least its clarification, to the impact made on me by Eddington's writings shortly after the First World War. Thus stimulated, I was led to notice how often in physics a scientist would, though perhaps hardly consciously, apply this principle and how fruitful the result invariably was.

Among many derivatives of the Principle of Minimum Assumption the one that soon claimed my particular attention was the one that I have since called the Hypothesis of the Symmetrical Impermanence of Matter; the hypothesis that matter is both originating continuously and continuously becoming extinct. If the Principle of Minimum Assumption was valid, I saw that all its consequences ought to be explored, including this one, and that exploration of this hypothesis was likely to lead to new fields for research. But I did not regard myself as properly equipped for treading the path that was opening up before me. So I pointed it out to sundry scientists of my acquaintance in the hope that one or another of them would examine my suggestion critically. It seemed to me at the time that Symmetrical Impermanence would be difficult, though not impossible, either to confirm or to refute, but that the attempt to do so would lead to new insight, whatever the outcome. But none of those with whom I sought personal contact seemed to grasp the purport of my questions, and so I decided to approach a wider public by means of the printed page. I published the Hypothesis of Symmetrical Impermanence in 1940¹, though with a different name and in tentative terms. But still no one attempted to examine it.

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, causation.

This led me to return once again to the subject and also to renew my search for people willing to explore the implications of Symmetrical Impermanence. As a part of this quest I published a few of my own conclusions. They were necessarily tentative and were presented in the spirit of invitations to further research rather than as final, well-tested statements of fact. With these publications I approached a number of noted scientists and drew their attention to the promise of a solution of sundry problems that the subject seemed to offer to anyone who might feel inclined to pursue it, working either independently or in collaboration with myself. But again I failed to arouse any interest.

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.

My method for doing this has invariably been to consider first what inferences can be drawn from the Principle of Minimum Assumption and then to test these inferences for their compatibility with established knowledge. In other words, I constructed in thought the cosmological model that is implicit in the principle and then compared the model with actuality. Occasionally there seemed to be a contradiction between the inferred model and actuality, but further research always removed it. I was indeed surprised to find how many facts were explained that had hitherto had to be regarded as among those for which there is no explanation. The Principle of Minimum Assumption was found, again and again, to render ad hoc explanations unnecessary. This principle together with the Hypothesis of Symmetrical Impermanence, for which my justification had initially been purely methodological, came more and more to be also justified by their explanatory power.

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.'