Imagined Worlds 
by Freeman Dyson.
Harvard, 216 pp., £14.50, May 1997, 0 674 53908 7
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Freeman Dyson warns us in Imagined Worlds that he is now ‘an old scientist pretending to be a sage’ and that ‘we learn from science and from history that the future is unpredictable.’ As well as diagnosing our present ills, however, Dyson offers strong hopes that our descendants will colonise not just their own galaxy in its entirety, but others too. They could continue onwards for infinitely many years. Humans would have first to survive the difficulties of the next few centuries. On the grounds, however, that he has ‘nothing fresh to say’, Dyson resolves to pass over in silence ‘fashionable environmental problems such as global warming and overpopulation’ – although he does later indicate that his hopes are pinned on local, not global solutions. ‘People who try to impose global solutions should remember,’ he writes, ‘the words of the poet William Blake, “One Law for the Lion and Ox is Tyranny”.’

To scientists, Dyson may be best known for his work in physics shortly after World War Two. Many equations in quantum field theory were producing meaningless, infinite figures. Dyson helped, if not to eliminate the infinities, then at least to sweep them under the carpet so that calculations gave sensible results. It was, however, Disturbing the Universe (1979) and Infinite in All Directions (1988) which captured the imagination of the general public. He fired off ideas everywhere, but particularly towards the future.

In Imagined Worlds, the object of Dyson’s interest, and animosity, is ‘ideology’. Nuclear energy programmes have failed because bureaucratic idealists were determined they should succeed. In the intense desire ‘to create something peaceful and useful out of the ruins of Hiroshima and Nagasaki’, ‘rules for environmental cleanliness were written so that the ultimate disposal of spent fuel and worn-out machinery was left out of consideration.’ ‘Technological arrogance’ led to Earth’s ‘defilement’ by radioactivity. We need ‘concerned scientists, educators and entrepreneurs’, all ‘working together’ for human well-being; yet not as ideologues or even, it would seem, in committees. It is ‘the power of committees in the administration and funding of science’ that made nuclear reactors into ‘toys for the rich’ acting ‘mostly for evil’, and gave us ‘the laptop computer and the cellular telephone’ as ‘the latest of the new toys’. The conduct of ‘Henry Ford, with dictatorial power over his business’ was preferable. No committee would have acted like Ford when he dared ‘to create a mass market for automobiles by arbitrarily setting his prices low enough and his wages high enough so that his workers could afford to buy his product’.

True, Ford’s approach was of the kind Dyson calls ‘Napoleonic’, and in general he much prefers ‘creative chaos and freedom’, which he labels ‘Tolstoyan’. When he started off in particle physics, the field was in ‘a Tolstoyan phase’. Major discoveries were reached with home-made instruments for detecting cosmic rays: particles were accelerated free of charge by astronomical processes. Later came large, man-made accelerators. Particle physics entered ‘a long Napoleonic phase’ and became ‘a welfare programme for scientists and engineers’. Luckily, the gigantic Superconducting Supercollider was cancelled in 1993, after some $3 billion had been spent on it. More spending would have been ‘immensely harmful to the future of science’.

Dyson sees the shameful gap between the rich and the impoverished as sure to widen in the near future, under the pressure of new technology. Families with access to computers ‘are rapidly becoming a hereditary caste’. Poor individuals and poor nations may well turn to ‘irrational and violent remedies’. Yet ‘even if economic inequalities can be greatly reduced, racial and religious animosities will persist’ – ‘a hundred years from now, our planet will not be a peaceful utopia.’ And although Dyson sees the nuclear arms race, at least in its ‘military’ as distinct from its ‘political’ form, as having ‘petered out in the Seventies, after the development of reliable and invulnerable missiles and submarines’, actually getting rid of nuclear bombs, ‘the most serious danger to mankind’, is still ‘perhaps a hundred years away’.

All the same, life seems fairly sure to improve soon, thanks largely to the biotechnology and neurotechnology which will become dominant during the next century. ‘Probably within a few decades’ we shall read the language of the genes ‘fluently’, and ‘as soon as we are able to read the language, we shall also be able to write it.’ ‘Genetically engineered crop plants adapted to harsh environments and resistant to disease will transform the economy of nations’; ‘little genetically engineered dinosaurs may be ubiquitous in the lives of our great-grandchildren’; ‘genetically engineered babies, guaranteed to be free of hereditary defects, will be available.’ And the human brain will be far better understood, thanks to new hardware ‘to detect neural signals non-invasively’ and new computer software for interpreting the signals. Note, though, that if much is to be detected then ‘non-invasive’ detection would probably involve deploying ‘large arrays of small transmitters inside a living brain’. The resulting techniques of ‘radio-neurology’ could then turn quickly into ‘radio-telepathy’, with transfer of information ‘directly from brain to brain’.

Artificial intelligence, too, will be progressing so swiftly that, like genetic engineering, it will be ‘mature’ and, indeed, ‘ready to be superseded’ as a dominant technology just a hundred years from now. Dyson predicts intelligent automata – for instance, ‘an intelligent automobile that takes us where we wish to go’ – which will be cheap because they are self-reproducing. Probably, ‘the self-reproducing machine will be partly made of genes and enzymes.’

During the next thousand years ‘we must expect’ that ‘collective memory and collective consciousness’ made available by radio-telepathy will be enjoyed by ‘at least some of our descendants’. Only by some, however. Humans will have spread throughout the solar system, maybe becoming more numerous by ‘a factor of five hundred million’, and it is likely that ‘our one species will become many’ in a way perhaps greatly speeded by genetic engineering. Some humans could be adapted to zero gravity, some to high pressure, some ‘to living in the vacuum of space’, and in ‘biological battles, fought between different conceptions of what a human being ought to be’, the coming millennium is likely to see ‘societies of collective minds’ pitted against ‘societies of old-fashioned individuals’.

‘A hundred thousand years in the future, we could have spread life all over our galaxy.’ (Are we to take this completely literally? Perhaps not. Such fast results could be achieved only by spreading at a rate a hundred times greater than Dyson had initially estimated, back in 1966, and it takes even light a good hundred thousand years to cross our galaxy at its widest.) After a million years, ‘our descendants will be reaching out toward other galaxies.’

Meanwhile ‘immortality’, if only through development of ‘an immortal group-mind’, may well have been achieved, somewhere, inside as little as ten thousand years. Immortality would be possible if, as Dyson believes to be indicated by the astronomical evidence, our universe is destined to expand for ever instead of collapsing in a Big Crunch. ‘It would be wise,’ all the same, ‘to keep a population of mortal humans on Earth.’ A ‘Cult of Evanescence’ could then maintain ‘contact with the reality of death’, essential to ‘sanity’ and ‘emotional balance’. (Surprisingly, Dyson combines these words with a denial of ‘absolute standards by which to judge one set of values right and another wrong’. Can it be absolutely bad, then, to be insane, emotionally unbalanced, out of touch with reality?)

I confess to finding the Cult of Evanescence a bit macabre. More generally, many of Dyson’s ideas are quite hard to accept. How would you react to the following questions, for instance? Of the automobiles they were so highly paid to produce, what percentage could Henry Ford’s workers themselves have purchased? At least until the Chernobyl disaster – a result of fantastic fool-hardiness – wasn’t uranium perhaps an environmentally cleaner source of energy than coal? May the Nobel Prize-winner Steven Weinberg not have been right in his superbly argued Dreams of a Final Theory, a passionate defence of the Superconducting Supercollider particle accelerator (less expensive than the Sea Wolf submarine)? And was the collapse of the Soviet Union really a consequence of rumours bouncing around in the ‘echo-chamber’ (the image is from Bruce Chatwin’s Utz) of a society deprived of free speech? How about glasnost? How about the heavy load of bureaucracy and ideology, the apathetic workers, and the ruinous expense of trying to counter (long after that ‘petering out in the Seventies’) American improvements in nuclear missile accuracies, better tracking of nuclear submarines, deployment of Cruise missiles, and plans for Star Wars defences?

More important: will humans survive even the next five centuries? Might not, say, depletion of the ozone layer, our planet’s shield against ultraviolet light, be quite as dangerous as hydrogen bombs? Dyson points to James Lovelock’s Gaia, the notion that ‘the chemistry and ecology of Earth are linked in a single system that keeps the environment of the planet within limits tolerable to life.’ ‘I find the Gaia theory plausible,’ he comments, adding that ‘we know that Gaia somehow maintained this planet as a home for life, in spite of many climatic changes and geological jolts, for three billion years.’ Well, how much confidence can we draw from this? Lovelock has been saying recently that Gaia’s method of protecting Earth’s health could be to kill off all humans. Perhaps all we really know is that the planet did remain life-supporting for three billion years, rather than that Gaia was responsible.

When Dyson’s book gives several pages of fascinating suggestions for preventing collisions with asteroids and comets, why does germ warfare receive nothing more than a French cartoon, circa 1900, showing a ‘Corps Médical Offensif’ bombarding the enemy with typhus? In 1985, Mrs Thatcher thought biological weapons potentially as dangerous as nuclear ones. Genetic engineers may soon design something considerably worse than typhus.

The message of J.B.S. Haldane’s Daedalus, Dyson tells us, is that ‘the destiny of the scientist is to turn good into evil,’ yet ‘Haldane had far too much respect for ordinary people to be a pessimist.’ Ordinary people will almost surely be able to resist totalitarian governments, for example. How can Dyson be so confident, when at the same time he predicts a ‘Neurotechnological Age, driven by neural sensors and exposing the inner workings of human emotion and personality to manipulation’, plus a possibility of ‘telepathic eavesdropping and coercion’?

Why, too, does he think artificial intelligence will no longer be a dominant technology after just another century? In Mind Children: the Future of Robot and Human Intelligence Hans Moravec, a leading expert, takes the view that the human race is in its very last century since he expects it to be outstripped and replaced by computers within that period, the distant future perhaps holding ‘systems with a million million million million million times the power of a human mind’. And Frank Tipler’s The Physics of Immortality, possibly the book nearest in flavour to Dyson’s, goes so far as to predict a system with infinite computing power.

Again, why is Dyson so confident that spreading through their galaxy will make humans too far apart for fights – ‘we shall no longer be capable of physically attacking our neighbours’ – while so hopeful of cooperation between galaxies ‘in large-scale engineering projects to keep the universe in trim’? Why should co-operation be so much easier than battle?

An unrepentant optimist myself, I said in a recent book that I saw ‘an encouragingly high probability, perhaps as high as 70 per cent’, of our surviving the next five centuries, after which colonising the entire galaxy would be very much on the cards. Also that I took seriously Dyson’s vision of an infinitely prolonged future for our descendants. Even in something as concise as Imagined Worlds, a work of some two hundred pages with very few words per page, it is startling to find Dyson doing so little to explain this unusual vision. He simply refers his readers to his article of July 1979 in Reviews of Modern Physics, in which he ‘was able to show’ that in a universe whose expansion never ceased ‘the laws of physics and information theory allow life to survive for ever using a finite store of energy.’ How could this be defended? As follows. In an ever-expanding, ever-cooling universe, the energy needed for processing each bit of information grows perpetually less and less. Dyson’s article reasons that the energy resources of a single galaxy could therefore support eternally a society about a trillion trillion times more complex than our own. Admittedly, intelligent life-forms might need to alter very radically as the universe cooled, yet sufficiently clever beings could plan for this. Such speculations seem much less wild than first appearances suggest.

Despite this, my confidence in a long future for our descendants is a good deal less than Dyson’s. If it weren’t, I would be on a collision course with the powerful ‘doomsday argument’ or ‘limited breeding argument’ discovered by Brandon Carter. Carter, a mathematical cosmologist, hit on the doomsday argument nearly fifteen years ago. Think about the population explosion. If the human race suffered extinction shortly, something like one in ten humans would have lived at much the same time as you and me. In contrast, Doom Delayed could mean that only an extremely tiny proportion would have lived when we did. (Remember, if Dyson is right then inside a mere thousand years our galaxy could contain five hundred million times as many humans as today.) Now, what grounds have you and I for considering ourselves so exceptional? Mightn’t it instead make sense to expect Doom Soon, extinction through environmental destruction or germ warfare or whatever? Would this be any more improbable than finding oneself in the first thousandth, first millionth, or even first trillionth of all humans who will ever have existed?

Carter has never said that our chances of being in the earliest millionth, say, are no higher than one in a million. Instead, he is saying that we should not overlook whether some theory, Dyson’s for instance, places us fairly ordinarily, or extremely extraordinarily, among all humans who will ever have existed. It is one of the factors which make such a theory plausible or implausible.

Although he does not mention Carter’s argument in his book, Dyson has tried to refute it. It depends, he has written, on our assuming first that we ‘know nothing of our place in the history of our species’ and next, with gross inconsistency, that we do know we are placed ‘among the earliest hundred billion humans’. But his reasoning doesn’t work. Yes, you and I may know we are in the earliest hundred billion. What we don’t know, however, is just how early this is. In the total temporal spread of the human race, as measured by a Population Clock whose hand advances whenever a new human is born, where will the earliest hundred billion turn out to have been? Very close to the start, before many hundred thousand years of galactic colonisation? Or stretching nearly all the way to doomsday in, say, AD 2125? Is a hundred billion almost all of the Population Cake, or an extremely tiny slice?

It is wrong to object that the probability that you and I are among the earliest hundred billion is virtually 100 per cent, given that this is what we are told by our eyes and by archaeology. Wrong, because Carter does not doubt that we actually are among the earliest hundred billion. What he asks is how likely a human would have been to find him or herself in that position if the human race had been destined, say, to colonise the entire galaxy. Compare the case of eye colour. Surprisingly many people do not know theirs, if you ask them suddenly. Well, suppose you look in a mirror and find that your eyes are blue-green. Never having considered the point before, you ask yourself whether it is likely that only one in every thousand humans has eyes of that colour. If this were so, then there is an obvious sense in which you wouldn’t have expected to find yourself blue-green-eyed. By itself, this isn’t conclusive; yet it shouldn’t simply be disregarded.

Ought we to protest that 1997 is now and that later humans aren’t alive yet, so that you and I would be 100 per cent sure to find ourselves in 1997, no matter how many humans came to exist afterwards? No, as can be seen by considering the following story. In one century, three people would each be given an emerald. Then, if the project had been granted full funding, 5000 would get emeralds in some much later century. Not told which the centuries are, you find yourself given an emerald. Let us say you know for sure that full funding was granted. Shouldn’t you bet you are in the century of the 5000 emerald-getters? If every emerald-getter betted like this, there would be 5000 winners and only three losers. If you are in fact in the earlier century, then people of the later century won’t yet be able to get emeralds; but, believe it or not, that’s irrelevant.

What if you know instead that you are in the century of the three emerald-getters? This should strengthen any grounds you have for suspecting that the project was poorly funded, so that few emeralds will be distributed in the later century.

The moral could seem to be that Carter’s doomsday argument casts severe doubt on any claim that the humans still to be born are far more numerous than those alive today. Fortunately, however, the argument may contain a flaw. Maybe, as a consequence perhaps of physical indeterminism at the quantum level or perhaps of human free will, there isn’t yet any appropriate ‘fact of the matter’ of how many humans will ever have existed, like the fact that there would be 5003 emerald-getters because full funding was granted. In this case the doomsday argument could operate smoothly only as a means of destroying great confidence in humankind’s future – confidence that a long future ‘is as good as determined’ so that war and pollution need hardly frighten us. Provided we lack this sort of confidence, and are frightened enough to take considerable care, our descendants may well colonise the entire galaxy. They might even continue onwards eternally, as suggested in Dyson’s remarkable book.

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