Mind stretch

"Science is my territory, but science fiction is the landscape of my dreams."

Freeman Dyson is one of the last survivors of the heroic age of theoretical physics and contributed greatly to the standard theory of quantum electrodynamics. However, as the above quotation shows, unlike many scientists, he does not suffer from tunnel vision. His imagination embraces the entire cosmos and all the possibilities of future technology. Like his earlier works, Disturbing the Universe and Infinite in All Directions, Imagined Worlds is one of those mind-stretching books that any intelligent reader can enjoy. I particularly recommend it to all politicians and civil servants who have any dealings with technology - and in these days, who does not?

The book opens with a classic example of the disasters that can ensue when politics conflicts with technology. After 67 years, I can still remember my own feeling of shock when the pride of British aviation, the airship R101, carrying air minister Lord Thompson and his entourage, crashed in France on its maiden flight. The minister insisted that the airship should take him to India and back in time for an imperial conference in London.

As Dyson remarks: "There was no time to give the ship adequate shake-down trials before the voyage to India. It finally took off on its maiden voyage soaking wet in foul weather with Lord Thompson and several thousand pounds of lordly baggage on board. The ship had barely enough lift to rise above its mooring mast. Eight hours later it crashed and burned on a field in northern France. Of the 54 people on board, six survived. Lord Thompson was not among them."

That was the end of the airship as far as the United Kingdom was concerned, although the Hindenburg carried on the tradition for a while before it also crashed, even more spectacularly. Today it is hard to remember that up to the 1930s it was uncertain whether the ultimate conquest of the air would be by dirigible or heavier-than-air machine. Jules Verne knew the answer in the last century - see The Clipper of the Clouds.

As Dyson points out, we are lucky to have the story of this disaster fully recorded by N. S. Norway, an engineer working on the rival airship, the R100, in his autobiography Slide Rule (another title made obsolete by technology). As his later novels under the more famous name Nevil Shute amply proved, he was not without imagination. Yet in 1929, still wearing his engineer's hat, Norway wrote: "The forecast is freely made that within a few years, passenger-carrying aeroplanes will be travelling at over 300 mph, the speed record today. This is gross journalistic exaggeration, as the commercial aeroplane will have a definite range of development ahead of it beyond which no further advance can be anticipated."

Here are the "advances" this far-sighted prophet anticipated, when the aeroplane had reached the limit of its development, probably by 1980! Speed: 110-130 mph. Range: 600 miles. Payload: 4 tons. Total weight: 20 tons.

This is a perfect example of the way in which well-informed men may be sadly lacking in the gift of foresight. Two men who did not lack that gift were J. D. Bernal and J. B. S. Haldane, and Dyson pays his respects to both of them.

Bernal's The World, The Flesh and the Devil (1924) opened with a striking sentence: "There are two futures, the future of desire and the future of fate, and man's reason has never learnt to separate them." In the 1950s, I met Bernal and tried to persuade him to revise his little masterpiece. Although he never did so, he re-issued it with a new introduction in 1968, and it is still well worth reading. Dyson rightly classes Haldane's Daedalus or Science and the Future (1923) with Bernal's as one of the finest books ever written about the future. Yet in some ways, Haldane was surprisingly conservative. He did not believe that we would be able to harness nuclear energy, but in this he was in the best possible company - Rutherford said so with even greater vehemence. Once again, the science-fiction writers got it right.

Haldane, doubtless influenced by his experience in the trenches of the second world war, had a pessimistic view of the future of mankind and the consequences of scientific and technological development. He was particularly concerned with biological research, and as is well known, Aldous Huxley borrowed lavishly from Daedalus. The recent news that the first mammal has been cloned inevitably revives memories of Brave New World's "human hatcheries". Can anyone now doubt that sooner or later, for better or worse, human beings will be cloned?

Both Bernal and Haldane were Marxists, but Haldane split with the Communist party because of the Lysenko scandal over the quasi-scientific discrediting of genetics by Lysenko/Stalin. One cannot help wondering what they would have thought of the second Russian revolution. I suspect that Bernal would have been devastated, whereas Haldane would probably have viewed the event with wry amusement.

And here is Dyson's verdict on another gigantic debacle: "The tragedy of nuclear fission energy is now almost at an end . . . but another tragedy is still being played out, the tragedy of nuclear fusion. The usual claims are made that fusion power will be safe and clean, although even the promoters are no longer saying that it will be cheap . . . What the world needs is a small, compact, flexible fusion technology that could make electricity where and when it is needed. It is likely the existing fusion programme will sooner or later collapse as the fission programme collapsed, and we can only hope that some more useful form of fusion technology may rise from the wreckage. . ."

Peering into my own cloudy crystal ball, it is my suspicion that such a technology may indeed arise, perhaps in the very near future. However, it may not depend on fusion, but on something even more fundamental, so-called zero point energy, the inconceivably vast store of energy in the apparently empty vacuum of space itself. Dyson's own studies pointed towards it, and its potential was once summed up by the famed Nobel laureate Richard Feynman when he remarked that the energy in a volume of space no larger than a coffee mug was "sufficient to boil all the oceans of the world".

Well, only a few weeks ago, the first experimental detection of this energy was made at, appropriately enough, Los Alamos. It may explain some of the excess energy (aka "cold fusion") reports which are not honest mistakes - or downright fraud. If we can indeed tap this source of energy, all our future "imagined worlds" may be changed beyond recognition. But as Dyson points out, advances in science and technology invariably lead to danger as well as hope. The release of nuclear energy merely threatened the home planet: tapping zero point energy could put the solar system at risk. I have often wondered how many supernovae are industrial accidents.

Imagined Worlds is full of striking phrases which cry out for quotation: "A few years ago, I walked into a room where there were 42 hydrogen bombs lying around on the floor."

"Until now, astronomy has traditionally been a spectator sport."

"My copy of Daedalus once belonged to Einstein."

"Successful technologies often begin as hobbies. The Wright brothers invented flying as a relief from the monotony of repairing and selling bicycles."

"Even if Brave New World is a greater work of literature, Jurassic Park comes closer to being a true statement of the human condition. Animal rights activists may fight against the private ownership of dinosaurs, but it will be difficult to argue that giving a child a dinosaur is more cruel than giving a child a puppy." I must admit an interest here - my most recent novel contains the sentence: "There's a 500-year-old joke: 'Would you trust your kids to a dinosaur?' 'What - and risk injuring it?'" Dyson also touches on another of my own pet themes: asteroid impacts and what should be done about them. As he says: "The public rightly concludes that if hydrogen bombs are the answer to the impact problem, then the cure is worse than the disease." He suggests that the best answer, as I pointed out in The Hammer of God (1993), would be to divert the approaching object by installing a reaction device on it - a kind of rocket motor operating with electrical rather than chemical energy. If I may be allowed the modest cough of the minor prophet, I believe I was the first to propose the use of such electromagnetic "mass drivers" in the Journal of the British Interplanetary Society in 1950.

The last member of Dyson's trinity of 20th-century futurists is the author-philosopher Olaf Stapledon whose history of the next two billion years, Last and First Men (1930), is one of the greatest works of imaginative fiction ever written. Its contents are summed-up in five ever-expanding time scales - the first ("Today" plus and minus 2,000 years) begins with the birth of Christ and ends after the founding of the first "Americanised world state" circa 2300. In the final time scale, "planets formed", and "end of Man" lie only a fraction of an inch apart, with no notable events between them. Hopefully, this will not be the case; if our species survives its present time of troubles, it may yet play a significant role in the history of the universe.

In a 1960 paper Dyson suggested that any really advanced civilisation could not allow its sun to squander all its energy into space, but would eventually surround it by a shell - not necessarily a continuous one, but a cloud of orbiting worldlets. These "Dyson spheres" could be detected by their infra-red radiations, and several searches have been made for such artefacts. Though they have so far been unsuccessful, perhaps the first evidence of extra-terrestrial civilisations would be not through radio signals but by the detection of similar examples of cosmic engineering. However, like ants crawling round the base of the Empire State Building, we might not recognise it . . .

A short pause while I release another bee from my bonnet. The cover of the February/March 1997 Astronomy and Geophysics, the journal of the Royal Astronomical Society carries a dramatic and thought-provoking illustration - a radio image of the gas-clouds expanding from the galaxy 3C 123. Their source is a strange-looking object that I can only describe as a gearwheel, some of whose teeth have been slightly displaced. Whatever its explanation, it's far too large to be a common-or-garden Dyson sphere.

Just over 100 years ago a failed draper's assistant (whose autographed photo, in prosperous middle age, is looking down at me at this very moment) began working on a story with the unpromising title The Chronic Argonauts. When it finally metamorphosed as The Time Machine its influence was enormous: H. G. Wells made all succeeding generations realise that history stretched in both directions.

Science fiction writers are often accused, not always unfairly, of a form of escapism that has been wittily called "nostalgia for the future". But the future is where we are all going to live: before we can create it, we have - as Dyson has done - to imagine it.

Some years ago, my trade union, The Science Fiction Writers of America, adopted the motto "The future isn't what it used to be". When we consider most of the futures past, let us hope this optimism will be justified.

Arthur C. Clarke's latest novel, 3001: The Final Odyssey, will be published on March 20.