This chapter discusses the historical impact of the advent of general relativity, in 1916, on British physicists and astronomers, and, at a personal level, its effect on Eddington's life. In this way I prepare for the next chapter in which I shall show that the intellectual effect of the general theory on Eddington was to accentuate certain philosophical ideas which he already had. These ideas take us some way along the road to understand the mystery described in Chapter 1.

The genesis of general relativity

We left Eddington reinstalled in Cambridge in 1914, clearing up his earlier astronomical work and just about to begin the investigation directed towards the understanding of the mechanism of the Cepheid variables. By that time the dust was beginning to settle on Einstein's 1905 paper in which the concept of time had been so strikingly changed. The Cambridge aether-theorists were working their way towards reconciliation but, doubtless, were more concerned in 1914 with the international disaster that was to sweep away the comforts of the long Edwardian summer. Then in 1915–16 there appeared a new paper by Einstein (Einstein 1916) which followed up his earlier one by changing completely the concept of space. This is usually described as Einstein's successful attempt to extend the idea of relativity to include gravitation. The problem of gravitation was considered particularly important because special relativity seemed to give a privileged position to the other well-known field theory, electromagnetism. The Lorentz transformations left Maxwell's equations unchanged. Yet in some ways gravitation was the more fundamental field because of its universal action.

In this chapter I shall describe the last decade of Eddington's life and answer the remaining three questions I raised – those appropriate to FT. This last decade was less happy than his earlier life. Here again the temper of his internal intellectual activity was in tune with the external circumstances. The world outside Cambridge was initially preparing for war and afterwards involved in it. The depression produced by this failure of humankind to act rationally was augmented for Eddington by his own failure to put over his ideas in RTPE. As I argued in the last chapter, this was evidenced less by the uncomprehending reviews than by the lack of follow-up of the ideas. Eddington became less in evidence at the Royal Astronomical Society and in the University as he busied himself at the Observatory in writing what was meant to be the definitive exposition of his work, Fundamental Theory (Eddington 1946).

Schrödinger

There are two personal details of his life in these latter years that bear on this. The first of these arose in 1942 when an invitation came from Dublin. In 1940 de Valera, an applied mathematician at heart, had achieved a long-standing ambition to persuade the Daíl to set up an Institute of Advanced Studies, including a School of Theoretical Physics. His move at that time owed much to the availability of Erwin Schrödinger, who had been dismissed from his chair in Graz not very long after the Anschluss. The essentially political life of de Valera had left him little time to keep in touch with academic happenings but he had many friends who could advise him, especially Sir Edmund Whittaker.

It will be clear from Chapter 1 that the story of Eddington's intellectual life cannot be dissociated from that of the fascinating revolution of ideas in physics between 1900 and 1930.1 shall not try to do so, but my history of the general scientific ideas will be a very partial one, directed to those aspects which bear in any way on Eddington's development. The first part of this chapter is concerned with personal features of Eddington's earlier life that I believe to be relevant in judging his later work. More detailed biographical detail is to be found in Arthur Stanley Eddington (Douglas 1956) on which I have relied. The historical context of the advent of special relativity comes next, and finally I deal with Eddington's definitive account of stellar structure as the rounding off of his earliest preoccupations.

Eddington's early life

Eddington was born in Kendal on 28 December 1882, into a Quaker family, and his faith played an important part throughout his life. He showed evidence from an early age of a prodigious memory and an interest in very large numbers. The family removed to Somerset after his father's death and Eddington received a Somerset County Council Scholarship in 1896 to go to Owen's College, Manchester though he was still under sixteen. His four year course there began with a general year, and then followed three years of physics (under Schuster) and mathematics (under Lamb). Lamb provided more than mathematics; his prose style was the model for Eddington's own carefully nurtured style.

The adverse criticisms of RTPE centred on two aspects – its obscurity and its claim to calculate physical constants. I shall deal with these two aspects in turn.

Obscurity

One reason that RTPE was found obscure by its readers, I have argued, was that they expected something different in style. But there was a more important reason; they also expected something different in content. For, though they had read MTR with approval, they had not appreciated the novel philosophical positions Eddington had taken up already by 1923. These positions arose out of general relativity but the main lesson of Eddington's book was, as its name implies, the mathematics of the theory. This could be read and the philosophical standpoints ignored.

I distinguished eight novel ideas that Eddington exhibited in MTR. All are relevant to RTPE and I discuss their relevance here in three groups of increasing importance:

1. (i) The notions of selective subjectivism and of falsifiability are neither of much importance, though for different reasons. It is hardly surprising that selective subjectivism fits well, for it is consciously followed by Eddington and expresses his Kantian preoccupation. Falsifiability is not important because it has taken a back seat. Eddington allows himself such freedom to change to a new model half-way through an argument that the ostensible falsifiability of an exact numerical prediction is a hoax.

2. (ii) Intermediate in importance are non-redundancy, descriptive tolerance and structure. Non-redundancy is taken for granted and used without mention from time to time. For example, the fact that just four Ea give rise to a fifth E5 which anti-commutes with all the four gives rise to various attempts at interpretation. It is taken for granted that there must be an interpretation and that it will be physically important.

3. […]

The year 1933 marked the real turning point in the development of Eddington's thoughts. In this chapter I shall try to reconstruct his state of mind in that year, so as to assess the way in which he decided to go ahead with the writing of RTPE. My discussion up to now makes it possible to be more precise about the questions raised in Chapter 1. They can be broken down into six separate ones:

1. What made Eddington write RTPE?

2. Why is it so obscure?

3. What important and valuable aspects does it have?

Then 4, 5,6 are the same questions for FT. It already seems likely from my argument, and it will prove to be the case, that the answers for FT are independent of those for RTPE. As a first stage the answer to 1 and in part to 2 will be found in this chapter.

The outside world

The last three chapters have been inward looking. I have not tried to relate the excitement that the world of physics was going through to the more pedestrian doings of the outside world. I think that is in keeping with the mood in Britain in the late 1920s. But it will not do for 1933. By then the world was showing sinister changes. In Germany Hitler had come to power in January. By the middle of the year the consequences were becoming clear. In particular the German preparations for a second world war and for attacks on Jews in Germany were seen to be in train.

It is my aim to introduce the themes brought up by Paul Feyerabend, Ernan McMullin and Bas van Fraassen by means of a brief overview — partly historical and partly systematical — of the realist and empiricist positions with respect to science. My selection and presentation of topics has been influenced by the wish to make a connection with some of the points raised in other contributions to this volume, especially the earlier chapters. (What do the results of modern physics tell us about reality?)

The traditional view of science

In the traditional Aristotelian view, science is the unique enterprise in which humanity discovers fundamental truths about the world in a systematic, rational, way. According to this view the result of scientific investigation is knowledge, to be contrasted with mere opinion; knowledge is defined as provably true, fundamental and universal. There are a number of characteristic ingredients in this conception.

Realism

Inherent in the traditional view is the realist position that science deals with an independent external world, which for its greater part is not accessible to the human senses but can nevertheless be discovered, investigated and described. Science actually focuses on these unobservable traits of the world, in order to give fundamental explanations.

Dennis Dieks, in Chapter 3, sketches a framework which, he says, has guided the work of many physicists. He implies that the remaining conflicts are a purely philosophical phenomenon. Being fond of quarrels philosophers have split into schools. There are now empiricists, positivists, rationalists, anarchists, realists, apriorists, pragmatists and they all have different views about the nature of science. Scientists, on the other hand, collaborate. Collaboration creates uniformity and, with it, a single way of looking at things: it does make sense to ask about the status of the scientific world-view.

In contrast I want to argue that scientists are as contentious as philosophers. But while philosophers merely talk, scientists act on their convictions; scientists from different areas use different procedures and construct their theories in different ways. Moreover, they often succeed: the world-views we find in the sciences have empirical substance. This is a fact, not a philosophical position. I shall explain it by considering the following four questions:

1. What is the scientific view of the world and is there a single such view?

2. Assuming there is a single scientific world-view — for whom is it supposed to be special?

3. What kind of status are we talking about? Popularity? Practical advantages? Truth?

4. What ‘other views’ are being considered?

My answer to the first question is that the wide divergence of individuals, schools, historical periods and entire sciences makes it difficult to identify comprehensive principles either of method, or of fact.

Introduction

It has been said that ‘scientific realism is a majority opinion whose advocates are so divided as to appear a minority’ (Leplin 1984, p. 1). Something similar happens in the reflections on physics and theology in this volume: even though most contributors share a positive attitude towards religion, they are strongly divided. The discussion is not merely one about answers, for instance whether or not the Universe had a beginning, and whether that supports belief in a divine ‘first cause’. The real disagreements concern the questions, the way the problem is posed. Failures to communicate may have their roots in that which is considered obvious, and thus often left implicit, rather than in that which is the explicit topic of the debate. Thus, the aim of this chapter is to achieve a clearer view of the variety of approaches in relating physics to religion.

Before embarking on the main topic, I will briefly argue for the relevance of such reflections.

There is a public relations problem for theology in an age of science. Affiliation with churches is declining. ‘Belief in God’ is considered by many to be an option which is superfluous, outdated, falsified, meaningless, or a matter of private taste.

When I was a student in Vienna, in the late 1940s, we had three physicists who were known to a wider public: Karl Przibram, Felix Ehrenhaft and Hans Thirring. Przibram was an experimentalist, a pupil of J. J. Thomson whom he often mentioned with reverence. Philosophers of science know him as the editor of a correspondence on wave mechanics between Schrödinger, Lorentz, Planck and Einstein. He was the brother of Hans Przibram, the biologist, and, I believe, the uncle of the neurophysiologist Karl Przibram. He talked with a subdued voice and wrote tiny equations on the blackboard. Occasionally his lectures were interrupted by shouting, laughing and trampling from below; that was Ehrenhaft's audience.

Ehrenhaft had been professor of theoretical and experimental physics in Vienna. He left when the Nazis came; he returned in 1947. By that time many physicists regarded him as a charlatan. He had produced and kept producing evidence for subelectrons, magnetic monopoles of mesoscopic size and magnetolysis, and he held that the inertial path was a spiral, not a geodesic. His attitude towards theory was identical with that of Lenard and Stark whom he often mentioned with approval. He challenged us to criticize him and laughed when he realized how strongly we believed in the excellence of say, Maxwell's equations without having calculated and tested specific effects.

It is a commonplace that the natural sciences ‘enlarge’ our world, that they enable us to reach outside the narrow circle of our sense-knowledge to more complex domains of many layers. But it is not so simple to specify in what this enlargement consists. Most would say that we come to know of the existence of myriads of entities of which our ancestors knew nothing. But how exactly do we do that? And how reliable can such knowledge-claims be? Questions like these continue to divide philosophers of science. Conventionally, the main division is said to lie between ‘realists’ and their critics (‘anti-realists’). But there are, notoriously, almost as many realisms as realists. And the critics of realism represent a wide variety of philosophical positions. So boundary-lines shift, and differences that at first sight appeared fundamental vanish as the debate continues. Still, there is in the end a genuine disagreement here, and it concerns the most important philosophical question that can be raised about the significance of the natural sciences: what quality of understanding do they afford of the underlying structures of the world around us?

After a preliminary discussion of the tangle of differences separating realism and anti-realism, I shall argue for a broadly realist answer to this last question, taking care to avoid the overstated versions of realism on which critics have too often focussed, versions that they have in some instances themselves created.

In this chapter I shall address the realism—empiricism opposition only obliquely. My focus will be on the question: to what extent can we conceive of science as representation? Both the natural sciences and the fine arts, throughout their respective histories, have been characterized as activities whose primary goal is representation. This view is now widely rejected in the philosophy of art. Science too is now often characterized as interpretation rather than representation of nature.

While Paul Feyerabend's early writings were crucially involved in the (re-)emergence of scientific realism, they were always somewhat subversive of that view as well. After all, the summaries and slogans of realism have often depicted science as straightforward representation of nature, while Feyerabend's papers had as perhaps their most salient theme the role of interpretation at all levels of scientific observation and theorizing. Our contributions to this book are therefore not likely to be confrontational — all the more so because one of my main inspirations in this topic area has been Feyerabend's Wissenschaft als Kunst.

I want to explore three levels of interpretation: the interpretative elements in a work, the interpretations which these works admit, and finally our interpretation of the very activity in which these works are produced.

Until quite recently physicists rarely speculated about relations between the laws of fundamental physics, the physics of elementary particles and the Universe, and our existence on earth as conscious beings. They admitted that no physical reason for our existence was known, and that man was an alien in the physical world, but they did not perceive any conflict between our existence and the basic laws of physics.

A first attempt to connect humankind and elementary particle physics was Fritjof Capra's The Tao of Physics (1975). In this book Capra tried to relate the so-called ‘bootstrap’ theory of elementary particles to Eastern mysticism by pointing to similarities between the picture that bootstrap physics gives of the behaviour of elementary particles and the utterances of certain Eastern mystics. To Capra these similarities suggested a deep analogy between the world at the level of elementary particles and the world of personal experience. Such a relation would lessen the deplorable alienation of advanced abstract physics from what can be directly and personally experienced.

The Tao of Physics was a great success. The book was welcomed by supporters of holism and of the New Age Movement. It has been translated into many languages and has been followed by related books by Capra and others, but it was conspicuously ignored by the physicists, who found it at best wishful thinking and a lot of nonsense and at worst pure deception.