Turtles All the Way Down

What John Horgan means by his teasing title, inspired evidently by Francis Fukuyama’s view of history, is not that scientists will run out of work worthy of all that trouble and expense, but that the great discoveries, on which the intellectual edifice rests, have carried us up to or beyond the point of diminishing returns. Not only are the major problems that confronted physics before, say, Einstein, and biology before Darwin, now solved, but the mysteries that remain are of their nature inaccessible to the scientific process: we can formulate no testable hypotheses about such posers as the origin, structure and fate of the universe or the nature of consciousness. It is no good reminding Horgan that at least one British university disestablished its Chair of Experimental Philosophy at the end of the 19th century on the grounds that physics had hit the buffers, or that Baeyer, the leading organic chemist of his day, urged his assistants to finish off the structure of the terpenes, so that a line could be drawn and the field abandoned to the despised Schmierchemiker (or as we would call them, biochemists). He is doubtless also aware that Kelvin gave the composition of the sun as an example of the kind of question that would never be answered; and that soon afterwards Bunsen and Kirchhoff, on their daily constitutional around the Philosophers’ Walk at Heidelberg, stopped in their tracks, struck by the thought that a spectroscopic analysis of the sun’s light could indeed reveal what it was made of. For Horgan assures us that he has heard this facile argument too often and that it crumbles under the weight of what science has achieved since those days of innocence. All avenues have been explored and nothing remains but to clear up the details (numerous, to be sure) and apply what we have learned to improving the human lot.

Epistemological disputes about what constitutes an understanding of physical phenomena were of course stirred up by the decline of classical physics. The debate between Niels Bohr and Einstein on the meaning of quantum theory was ended only by Bohr’s death. Bohr was in essence satisfied that quantum theory encapsulated reality, for it accounted with marvellous accuracy for experimental observations. Einstein could not accept such complacency: to him, quantum theory was only a formalism and did not offer us a picture of the real world. In a letter to Max Born he declared: ‘The idea that an electron exposed to a ray by its own free decision chooses the moment and the direction in which it wants to eject is intolerable to me.’ If that were so, he concluded, he would rather be a cobbler or a croupier in a casino than a physicist. Horgan’s judgment on superstring theory – a representation of fundamental particles espoused by many of today’s leading theoreticians – is in like vein. He asserts that the theory is incapable of verification and that even if it were proved right, we could bear with equanimity, if not indifference, the conclusion that all physical reality comes down to loops of energy in ten-dimensional hyperspace. I cannot myself see the force of this argument, which could equally have been applied to quantum theory at its inception. Superstrings have their critics (though it has been said that only ten or so people in the world fully understand the theory); I have only the haziest notion of the points of contention, but if a leader in the field, such as Ed Whitten, states that the theory ‘can’t be wrong’, I am not sure I would rely on a science journalist like Horgan to tell me otherwise.

The notion that the boundaries of physics have been pushed out so far that what lies on the other side is beyond the grasp of the human mind was used by some philosophers to dismiss the Theory of Relativity, on the fatuous grounds that we perceive the world through our senses and therefore that which affronts what our senses tell us is ipso facto false. This saved them the trouble of getting to grips with the intellectual rigours of theoretical physics. J.B.S. Haldane hinted at the problem more cogently when he suggested that the universe might be not only queerer than we suppose but queerer than we can suppose. Are we then up against questions that by their very magnitude become trivial? Horgan’s term for the activities of those who toil at these desolate frontiers is ‘ironic’ science – somewhere between exegesis and speculation, leading to no enlightening conclusions. He derives the term from Northrop Frye, who taught that all texts have multiple meanings, no single one of them paramount. Horgan discerns a further parallel between the state of science and that of contemporary literature, when he draws on the views of Harold Bloom, who holds that the creative Wellsprings have been drained by the giants of the past. The scientist thus shares the plight of the poet, and ‘irony’ is the only escape. Among the ‘ironic’ scientists are numbered many of the best-known figures (and popularisers) of our day, such as Stephen Hawking, Steven Weinberg and Roger Penrose, not to mention all the proponents of superstring theory.

But Horgan has also found some more fitting targets for his scorn. The expansion of science, the increasingly brutish struggle for survival that scientists must endure and the opportunities that now exist for public display, have combined to encourage the merchants of hype. They could, as the physicist, Marty Perl, puts it, ‘also have done very well in the retail garment trade’. When Horgan takes on what he calls the ‘chaoplexologists’ – those who claim computer-based algorithms can solve the world’s most complex problems, from the economy to Aids, and others who will tell you that they have created in the computer sentient life-forms to be treated with compassion and respect – I am happy to hold his coat and cheer.

To disregard Peter Medawar’s aphorism that science is the art of the soluble, and hurl oneself at the seemingly insoluble, requires unusual, perhaps messianic self-confidence. Cosmologists in particular belong to a calling that predisposes to extravagant (if intellectually rarefied) conjecture. Horgan quotes the opinion of an eminent particle physicist that quantum cosmology, time-reversal and wormholes between parallel universes are nothing more than entertainment, ‘at least as good as any other creation myth’. For the theoretical physicist Lev Landau, cosmologists are often wrong, but never in doubt. It may be that to dwell too long and too intensely on the nature of the universe or life or consciousness ultimately weakens one’s grip on reality. It is probably unwise to inhale too deeply the fumes that emerge from such centres as the Santa Fe Institute, set up to promote the study of these fringe disciplines. When Stuart Kauffman of the Institute announces that he has computer models to prove life must emerge from any sufficiently complex chemical milieu and that such generation of order accounts for (among other things) Evolution, the evolutionary biologist John Maynard-Smith sees him off with ‘I just find the whole enterprise contemptible.’ When you are told that in the rosy future that now beckons you may have all the information stored in your brain downloaded onto disk (with back-up copies to ensure immortality), you might wonder whether this is a jeu d’esprit.

The utterances of Marvin Minsky of MIT, who believes that a computer ‘is extremely conscious’, are uncannily prefigured by those of Macintosh, the master of the computers in Michael Frayn’s novel The Tin Men, published thirty-some years ago. Macintosh is programming his computers to pray – automated devotion, he calls it – which the machine will do better than man: ‘It wouldn’t pray for things it oughtn’t to pray for, and its thoughts wouldn’t wander.’ When a sceptical colleague interjects that a man would mean it, Macintosh replies:

So does the computer. Or at any rate, it would take a damned complicated computer to say the words without meaning them. I mean, what do we mean by ‘mean’? If we want to know whether a man or a computer means ‘O Lord, bless the Queen and her Ministers’, we look to see whether it’s grinning insincerely or ironically as it says the words. We try to find out whether it belongs to the Communist Party. We observe whether it simultaneously passes notes about lunch or fornication. If it passes all the tests of this sort, what other tests are there for telling if it means what it says?

It seems that some of the science Horgan describes is now beyond the reach of satire.

So do such effusions as I have been quoting, some from the choice intellects of our time, prove Horgan’s thesis? As Niels Bohr also said, prediction is very difficult, especially of the future. Science has always proceeded by surprises. ‘Who ordered that?’ I.I. Rabi exclaimed when a new fundamental particle turned up in the accelerator and shifted the focus of particle physics yet again. There are endless anomalies, a few of which will conceal something wholly unexpected. The biochemist, Albert Szent-Györgyi, defined successful research as seeing what everyone else has seen and thinking what nobody else has thought. So old questions are reformulated in new terms and in a good question lies half the answer. It is true that a Theory of Relativity or of Evolution does not turn up very often, but equally, science does not advance by lurching between what Thomas Kuhn (for whom Horgan has no time either) called fresh paradigms. Few scientists seek to operate at that level anyway. The discovery of the structure of DNA was the most important event in biology this century; yet it did not supplant the established principles of genetics, it merely revealed the direction that could most profitably be taken next, and so launched the new science of molecular biology. Mostly one tries to solve the problems that have been brought to the surface by what has gone before. Horgan is distressed that biology is confined to what we find on our planet, and that we are therefore destined to eternal frustration when we ask the ‘deepest questions’ – about the inevitability or otherwise of life on earth and whether Darwinian evolution is a universal or only a terrestrial phenomenon. But such abstractions are of small concern to any biologist, outside an isolated, but vocal, coterie. Horgan’s trawl through deep waters has not netted the science that mostly matters to scientists. He does not reveal how much progress there is in finding out what tells a limb or an organ of an embryo when to stop growing, why we age and die, how one might design an enzyme to make a refractory chemical reaction go or when and why carbon atoms form themselves into the polygonal cages that nobody knew about until a few years ago.

Horgan has based his book mainly on interviews and has done a masterly job in drawing out, and indeed sending up, his subjects. His own approach can properly be described as ironic, in the Socratic sense, whereby the interlocutor asks seemingly innocent questions that lure the victim ever deeper into contradiction. Some emerge serenely superior; others probably felt that he had won their trust only to betray it. Science will not run out of problems, however, because every answer discloses a new problem. A parable has it that a cosmologist was approached after a lecture by an old lady, who informed him that what he had spoken was great nonsense, because she knew that the earth rested on the back of a huge turtle. Then on what, the cosmologist asked, did the turtle stand? Why, another, even bigger turtle, came the reply. But what ...? The old lady interrupted him: ‘It’s no good, young man. It’s turtles all the way down.’