A BIOLOGICAL BLIND ALLEY?

We may, I believe, regard it as extremely improbable that our understanding of the world represents any definite or final stage, a maximum or optimum in any respect. By this I do not mean merely that the continuation of our research in the various sciences, our philosophical studies and religious endeavour are likely to enhance and improve our present outlook. What we are likely to gain in this way in the next, say, two and a half millennia – estimating from what we have gained since Protagoras, Democritus and Antisthenes – is insignificant compared with what I am here alluding to. There is no reason whatever for believing that our brain is the supreme ne plus ultra of an organ of thought in which the world is reflected. It is more likely than not that a species could acquire a similar contraption whose corresponding imagery compares with ours as ours with that of the dog, or his in turn with that of a snail.

If this be so, then – though it is not relevant in principle – it interests us, as it were for personal reasons, whether anything of the sort could be reached on our globe by our own offspring or the offspring of some of us.

THE PROBLEM

The world is a construct of our sensations, perceptions, memories. It is convenient to regard it as existing objectively on its own. But it certainly does not become manifest by its mere existence. Its becoming manifest is conditional on very special goings-on in very special parts of this very world, namely on certain events that happen in a brain. That is an inordinately peculiar kind of implication, which prompts the question: What particular properties distinguish these brain processes and enable them to produce the manifestation? Can we guess which material processes have this power, which not? Or simpler: What kind of material process is directly associated with consciousness?

A rationalist may be inclined to deal curtly with this question, roughly as follows. From our own experience, and as regards the higher animals from analogy, consciousness is linked up with certain kinds of events in organized, living matter, namely, with certain nervous functions. How far back or ‘down’ in the animal kingdom there is still some sort of consciousness, and what it may be like in its early stages, are gratuitous speculations, questions that cannot be answered and which ought to be left to idle dreamers. It is still more gratuitous to indulge in thoughts about whether perhaps other events as well, events in inorganic matter, let alone all material events, are in some way or other associated with consciousness.

When I was a young mathematics student in the early 1950s I did not read a great deal, but what I did read – at least if I completed the book – was usually by Erwin Schrödinger. I always found his writing to be compelling, and there was an excitement of discovery, with the prospect of gaining some genuinely new understanding about this mysterious world in which we live. None of his writings possesses more of this quality than his short classic What is Life? – which, as I now realize, must surely rank among the most influential of scientific writings in this century. It represents a powerful attempt to comprehend some of the genuine mysteries of life, made by a physicist whose own deep insights had done so much to change the way in which we understand what the world is made of. The book's cross-disciplinary sweep was unusual for its time – yet it is written with an endearing, if perhaps disarming, modesty, at a level that makes it accessible to non-specialists and to the young who might aspire to be scientists. Indeed, many scientists who have made fundamental contributions in biology, such as J. B. S. Haldane and Francis Crick, have admitted to being strongly influenced by (although not always in complete agreement with) the broad-ranging ideas put forward here by this highly original and profoundly thoughtful physicist.

After dinner on their first evening in the Beach Hotel with the old professor talking about cosmology, and his daughter chatting about art, Mr Tompkins finally got to his room, collapsed on to the bed, and pulled the blanket over his head. Botticelli and Bondi, Salvador Dali and Fred Hoyle, Lemaître and La Fontaine got all mixed up in his tired brain, and finally he fell into a deep sleep.…

Sometime in the middle of the night he woke up with a strange feeling that instead of lying on a comfortable spring mattress he was lying on something hard. He opened his eyes and found himself prostrated on what he first thought to be a big rock on the seashore. Later he discovered that it was actually a very big rock, about 30 feet in diameter, suspended in space without any visible support. The rock was covered with some green moss, and in a few places little bushes were growing from cracks in the stone. The space around the rock was illuminated by some glimmering light and was very dusty. In fact, there was more dust in the air than he had ever seen, even in the films representing dust storms in the middle west. He tied his handkerchief round his nose and felt, after this, considerably relieved. But there were more dangerous things than the dust in the surrounding space.

The reason why our sentient, percipient and thinking ego is met nowhere within our scientific world picture can easily be indicated in seven words: because it is itself that world picture. It is identical with the whole and therefore cannot be contained in it as a part of it. But, of course, here we knock against the arithmetical paradox; there appears to be a great multitude of these conscious egos, the world however is only one. This comes from the fashion in which the world-concept produces itself. The several domains of ‘private’ consciousnesses partly overlap. The region common to all where they all overlap is the construct of the ‘real world around us’. With all that an uncomfortable feeling remains, prompting such questions as: Is my world really the same as yours? Is there one real world to be distinguished from its pictures introjected by way of perception into every one of us? And if so, are these pictures like unto the real world or is the latter, the world ‘in itself’, perhaps very different from the one we perceive?

Such questions are ingenious, but in my opinion very apt to confuse the issue. They have no adequate answers. They all are, or lead to, antinomies springing from the one source, which I called the arithmetical paradox; the many conscious egos from whose mental experiences the one world is concocted.

The next lecture which Mr Tompkins attended was devoted to the interior of the nuclei which make the pivot point for the revolution of atomic electrons.

Ladies and Gentlemen—said the professor—

Digging deeper and deeper into the structure of matter, we will now try to penetrate with our mental eye into the interior of the atomic nucleus, the mysterious region occupying only one thousand billionth part of the total volume of the atom itself. Yet, in spite of the almost incredibly small dimensions of our new field of investigation we shall find it full of very animated activity. In fact, the nucleus is after all the heart of the atom, and, in spite of its relatively small size, contains about 99.97% of total atomic mass.

Entering the nuclear region from the thinly populated electronic atmosphere of the atom, we shall be surprised at once by the extremely overcrowded state of the local population. Whereas electrons of atomic atmosphere move, on the average, distances exceeding by a factor of several hundred thousand their own diameters, the particles living inside the nucleus would literally be rubbing elbows with one another, if only they had elbows. In this sense the picture represented by the nuclear interior is very similar to that of an ordinary liquid, except that instead of molecules we encounter here much smaller and also much more elementary particles known as protons and neutrons.

What can more than two thousand years of human thought and several hundred years of hard science tell us finally about the true nature of space and time? This is the question that the philosopher Jeremy Butterfield and I posed to a unique panel of top mathematicians, physicists and theologians in a public discussion that took place at Emmanuel College, Cambridge in September 2006, and this is the book that grew out of that event. All four other panellists, myself and the astronomer Andy Taylor who spoke at a related workshop, now present our personal but passionately held insights in rather more depth.

The first thing that can be said is we do not honestly know the true nature of space and time. Therefore this book is not about selling a particular theory but rather it provides six refreshingly diverse points of view from which the reader can see that the topic is very much as alive today as it was at the time of St Augustine or of Newton or of Einstein. Our goal is not only to expose to the modern public revolutionary ideas at the cutting edge of theoretical physics, mathematics and astronomy but to expose that there is a debate to be had in the first place and at all levels, including a wider human context. Moreover, the reader will find here essays from leading figures unconstrained by peer pressure, fashion or dogma.

A REMARKABLE GENERAL CONCLUSION FROM THE MODEL

Let me refer to the phrase on p. 62, in which I tried to explain that the molecular picture of the gene made it at least conceivable that the miniature code should be in one-to-one correspondence with a highly complicated and specified plan of development and should somehow contain the means of putting it into operation. Very well then, but how does it do this? How are we going to turn ‘conceivability’ into true understanding?

Delbrück's molecular model, in its complete generality, seems to contain no hint as to how the hereditary substance works. Indeed, I do not expect that any detailed information on this question is likely to come from physics in the near future. The advance is proceeding and will, I am sure, continue to do so, from biochemistry under the guidance of physiology and genetics.

No detailed information about the functioning of the genetical mechanism can emerge from a description of its structure so general as has been given above. That is obvious. But, strangely enough, there is just one general conclusion to be obtained from it, and that, I confess, was my only motive for writing this book.

When, that morning at breakfast, Mr Tompkins told the professor about his dream the previous night, the old man listened rather sceptically.

‘The collapse of the universe,’ said he, ‘would of course be a very dramatic ending, but I think that the velocities of mutual recession of galaxies are so high that present expansion will never turn into a collapse, and that the universe will continue to expand beyond any limit with the distribution of galaxies in space becoming more and more diluted. When all the stars forming the galaxies burn out because of the exhaustion of nuclear fuel, the universe will become a collection of cold and dark celestial aggregations dispersing into infinity.’

‘There are, however, some astronomers who think otherwise. They suggest the so-called steady state cosmology, according to which the universe remains unchanging in time: it has existed in about the same state as we see it today from infinity in the past, and will continue so to exist to infinity in the future. Of course it is in accordance with the good old principle of the British empire to preserve the status quo in the world, but I am not inclined to believe that this steady state theory is true. By the way, one of the originators of this new theory, a professor of theoretical astronomy at Cambridge University, wrote an opera on the subject which will have its premiere in Covent Garden next week.’

INTRODUCTION

Physics and metaphysics are two distinct occupations of human beings, and not long ago a lot of effort was invested into keeping them strictly apart. Nowadays, however, the situation seems to be changing. A couple of years ago, an international conference was organised at Cambridge, UK, the proceedings of which bear the title ‘Physics Meets Philosophy at the Planck Scale’. What is special about the Planck Scale that physics and philosophy (of which metaphysics is an essential part) seem to have something to tell to each other?

In physicists' jargon the ‘Planck Scale’ or the ‘Planck era’ means either the most fundamental level of the physical Universe, or an edge at which our present theories of physics break down (this is why the Planck era is also called the Planck threshold). Currently, these two meanings are almost synonymous since the fundamental theory of physics lies beyond the reach of our well-founded physical theories and models.

There are two directions along which we could approach the Planck era. We can either adopt the path followed by cosmologists, or that followed by elementary particle physicists. In cosmology, one tries to reconstruct the history of the Universe starting from our present era as far backward in time as possible. As one moves in this direction, the Universe contracts and becomes denser and denser, till one reaches a density of the order of 1095 g/cm3, and then one finds oneself at the Planck era.

As a reward for the serious trouble I have taken to expound the purely scientific aspects of our problem sine ira et studio, I beg leave to add my own, necessarily subjective, view of the philosophical implications.

According to the evidence put forward in the preceding pages the space-time events in the body of a living being which correspond to the activity of its mind, to its self-conscious or any other actions, are (considering also their complex structure and the accepted statistical explanation of physico-chemistry) if not strictly deterministic at any rate statistico-deterministic. To the physicist I wish to emphasize that in my opinion, and contrary to the opinion upheld in some quarters, quantum indeterminacy plays no biologically relevant role in them, except perhaps by enhancing their purely accidental character in such events as meiosis, natural and X-ray-induced mutation and so on – and this is in any case obvious and well recognized.

For the sake of argument, let me regard this as a fact, as I believe every unbiased biologist would, if there were not the well-known, unpleasant feeling about ‘declaring oneself to be a pure mechanism’. For it is deemed to contradict Free Will as warranted by direct introspection.

Not many of us are perplexed about space. We can move around in it and its nature seems experientially obvious. Yet even in the case of spatial properties, the philosophically minded can deem the existence of reliable measuring rods, capable of metricating space, as not being as straightforward a matter as commonsense might suppose. Moreover, when physical cosmologists theorise about the Universe, they find that its vast spatial domains exhibit an intrinsic curvature, corresponding to General Relativity's account of the nature of gravity. There are certainly subtleties about the nature of space, which go beyond the expectations of everyday thought, but they are nothing like as perplexing as those we encounter when we attempt to think about the nature of time.

Time travel is not available to us and we have to take our experience of time ‘as it comes to us’, in the succession of those fleeting present moments which as soon as we experience them recede immediately into the inaccessible fixity of the past. Famously, St Augustine, meditating on temporality in the Confessions, said that as long as he did not think about it, he knew what time was, but as soon as he reflected on the nature of temporal flux, he began to be perplexed. To commonsense, the one thing that does seem clear is that time flows. Yet one of the central issues in the modern discussion of temporality is whether this is indeed the case, or whether our human sense of the flow of time is merely a trick of psychological perspective, and the fundamental reality of time is quite different.

I lived far apart from my best friend, actually the only close friend I ever had, for the greater part of my life. (Maybe that is why I have often been accused of flirtatiousness instead of true friendship.) He studied biology (botany to be exact); I physics. And many a night we would stroll back and forth between Gluckgasse and Schlüsselgasse engrossed in philosophical conversation. Little did we know then that what seemed original to us had occupied great minds for centuries already. Don't teachers always do their best to avoid these topics for fear that they might conflict with religious doctrines and cause uncomfortable questions? This is the main reason for my turning against religion, which has never done me any harm.

I am not sure whether it was right after the First World War or during the time I spent in Zurich (1921–7) or even later in Berlin (1927–33) that Fränzel and I spent a long evening together again. The small hours of the morning found us still talking in a cafe on the outskirts of Vienna. He seemed to have changed a lot with the years. After all, our letters had been few and far between and of very little substance.

I might have added earlier that we also spent our time together reading Richard Semon. Never before or after did I read a serious book with anyone else.

In fact, in the year 1808, an English chemist JOHN DALTON showed that the relative proportions of various chemical elements which are needed to form more complicated chemical compounds can always be expressed by the ratio of integral numbers, and he interpreted this empirical law as due to the fact that all compound substances are built up from a varying number of particles representing simple chemical elements. The failure of medieval alchemy to turn one chemical element into another supplied a proof of apparent indivisibility of these particles, and without much hesitation they were christened by the old Greek name: ‘atoms’ Once given, the name stuck, and although we know now that these ‘Dalton's atoms’ are not at all indivisible, and are, in fact, formed by a large number of still smaller particles, we close our eyes to the philological inconsistency of their name.

Thus the entities called ‘atoms’ by modern physics are not at all the elementary and indivisible constituent units of matter imagined by Democritus, and the term ‘atom’ would actually be more correct if it were applied to such much smaller particles as electrons and protons, from which ‘Dalton's atoms’ are built. But such a change of names would cause too much confusion, and nobody in physics cares much about philological consistency anyway! Thus we retain the old name of ‘atoms’ in Dalton's sense, and refer to electrons, protons, etc. as ‘elementary particles’.