THIS century, then, has not just been the triumphant age of pure physics. The successes achieved by pure physics will continue. Prediction in science, as Peter Medawar has often told us, is by definition impossible: but it will be a puzzle if those alive in fifty years’ time haven’t seen this process continuing and cumulative. They will understand more than anyone can now imagine.
But this is also a century that has seen the profound practical results of the physicists’ triumphs. There are some which lurk in the minds of reflective persons. One, which has been touched on in the last chapter, is the effect of micro-processors on industrial living everywhere. This still, in 1980, hasn’t clearly entered the public consciousness. In this year, we haven’t yet recognized what is going to hit us. We shall. For the moment, or for this account, we had better leave it there.
The other profound result is that reflective persons – and persons not usually reflective – have been living with anxiety. Here there has been a recognition, dark, looming, that something really might hit us – the something being, of course, the supreme technical accomplishment, the fusion (hydrogen) bomb. The questions in many minds have been ‘if’ and ‘when’. Is there going to be a nuclear war? When will it happen?
That dread has been hanging over us for thirty-five years, which is a long time in modern history. It wouldn’t have been candid not to mention it in the first words of this book. It will continue to darken thoughts of the future for a long time yet. Some have doubted whether there is going to be a future.
And yet, it is possible to suggest that this may not be realistic. Of all the dangers in front of us, it may very well be that nuclear war is the least likely. It doesn’t need saying that our world is precarious. It will remain so. But there is a subdued irony. It might have been more precarious if the hydrogen bomb had never been made. For the past thirty-five years, the two super-powers, and all others involved, have been divided by suspicion almost absolute, and by distrust even stronger than suspicion. They have exchanged insults and abuse which, by any previous precedent, would have been near declarations of war, and sometimes nearer than that. Just remember the diplomatic to-ing and fro-ing which set in motion (as if by Einstein’s ‘weird inevitability’) the 1914–18 war. The language and the protests were mild compared with what we now read in each morning’s paper. Austria finally sent an ultimatum to Serbia. That didn’t affect real power relations any more than if America today sent an ultimatum to Cuba. At that time, it immediately led to a cataclysmic war. We have come through more articulate conflicts than that in the present in at least superficial peace. That is due to the mutual threat of nuclear bombs.
Far-sighted military commentators realized, soon after such bombs were made, that they had one curious property. Granted that both sides had enough to inflict ‘unacceptable’ damage, it was going to be impossible for sane governments or commanders to use them.
This is a peculiarity possessed by no other weapon of war ever made. What is ‘unacceptable’ damage? Here an Englishman can comment with a certain detachment. It happens that, owing to the small size of Britain, the density of population, and the extreme articulation of the whole organism, the country would be more easily destroyed in nuclear war than any other sizeable power. During one of the meetings between Harold Macmillan and President Kennedy, the British Prime Minister wished to illustrate this point. He summoned his chief expert on nuclear weapons, William Penney. ‘Sir William, would you please tell the President how many hydrogen bombs would be needed to finish our country off?’ Penney answered: ‘Five, I should think, Prime Minister.’ Pause for reflection, and Penney continued: ‘Oh, just to be on the safe side, let’s say eight.’
Just to be on the safe side: those words will make a neat footnote to history. But what is true for Britain doesn’t begin to apply to the United States and the Soviet Union. The United States is a very large expanse. The Soviet Union is much larger. Both sides could, in theory, inflict about the same amount of annihilation. That will remain true. There will be no help from new gadgets or technological differences. The only prospect of survival would be through the wide distribution of the population over those great areas. In this grisly arithmetic, anyone’s guess is about as good as anyone else’s. Things go askew in war, and it seems likely that estimates of something like total annihilation on both sides are an exaggeration. To destroy half of all Americans and half of all Soviet people would seem nearer to what nuclear exchanges could do.
Is that unacceptable, to use the egregious military terminology again? Probably: even more so, since that preliminary exchange would almost certainly be succeeded by a particularly atrocious land war with ‘conventional’ weapons. These calculations have to be made by military commanders and politicians. Unless the world goes even madder than the most pessimistic expect, that particular doomsday doesn’t appear within the range of our potential fate.
One side comment. Nuclear war between the super-powers will continue to remain a dread, like a fear of mortal disease, but will also continue to have a low degree of probability. That, unfortunately, is not true of minor nuclear wars, as more countries come to possess the bombs. In addition to the super-powers, Britain, France, and China have demonstrated that they have them. At least two other countries certainly have them also, and very likely three or four more already. These bombs are not too difficult to make, which is a pity. In favourable circumstances, where the constraints of the super-powers did not operate, they might be used.
That is a more realistic worry than the prospect of nuclear war between the super-powers. So is the thought of such bombs getting into the hands of terrorists. These are minor anxieties by the side of the major one which has weighed on so many for so long. But these anxieties exist, and they are a negative legacy of the physicists’ triumph.
Applied science, however, is two-faced. There is likely to be another, and a very great, positive legacy from that same scientific triumph. There is a chance, and a good one, that humankind will within the lifetime of today’s children be certain of their supplies of energy forever. Forever is a long time: perhaps it would be better to say until the seas run dry or until the human species has had a transmutation. Which, since there is a rough rule that species tend to change in a million years, gives a nice comfortable stretch ahead.
This chance, of the answer to the problem of energy, comes from the identical mechanism which produces the hydrogen bomb. The process is the fusion of hydrogen nuclei to make up helium nuclei. It is the way in which the sun makes its own continuous output of energy. In the hydrogen bomb, the fusion produces – by terrestrial standards – a very large but indiscriminate and uncontrolled outburst of energy. If this can be controlled, and domesticated for workaday uses, then the major practical problem of how to keep the human race fed and warmed and physically equipped, no longer exists. Fossil fuels – oil, coal – will be exhausted in an uncomfortably short time: we have wasted them with the utmost carelessness. With fusion energy as a source, the only need is hydrogen. Although hydrogen gas is not found free on our planet, the oceans are full of it, for water is made of two atoms of hydrogen to one of oxygen. There will be no side-products and nothing to disturb the apprehensive.
That is the prospect. It is the most glowing material prospect which has ever been dangled before us. It is as well to cross our fingers, touch wood, knock on wood, or do whatever our various superstitions tell us to do with wood. Controlling fusion energy is the most difficult job that applied physics or physical-engineering has yet been given. The technological problems are vast, such as raising the hydrogen gas to a temperature of a hundred million degrees, the temperature needed to start the fusion reaction.
There are a good many people working on the project in America, the Soviet Union, and Britain, and the international exchange has been close. These people have been kept going by hope, faith, and reason. Which has been the most useful impulse would be hard to say. The faith is that there hasn’t been a technological problem, certainly not one of supreme significance, to which an answer hasn’t in due course been found. Various different attempts were started in the three countries shortly after the war. Within a few years the British believed that, in principle, they had done it. They shouted too soon. Men, usually level-headed, temporarily lost their judgement. Judicious Americans said that they were disappointed in the British: this wasn’t their traditional behaviour. But perhaps there was some excuse. After all, this was the most tremendous of all scientific prizes.
That was a false start. More recently, the Soviet scientists, who had been following two radically dissimilar lines, discovered one that was promising, maybe more than promising. It has been christened by the acronym ‘tokamak’. The Americans, who were following a similar path, took up tokamak with vigour, using, as a pleasant cordiality, the same nickname. There had been signs, still being argued about, of a step forward. The tokamak is a ring-shaped tube, like a hollow doughnut. Magnetic fields keep the super-hot hydrogen at the central axis of the tube, so that it cannot touch the metal walls and burn its way out. Another, completely different, approach to fusion power is to package the hydrogen into small pellets only a few millimetres across, and blast them from all sides with laser power or beams of electrons.
At present, no outsider could say more about the state of fusion power with meaning, and the insiders, if they can, prefer not to. It may be years before they know for sure, and longer before either society gets to work on practical engineering. The cost, to begin with, will be stupendous but the rewards will be stupendous too.
What the physicists have done, speaks for itself. It would be jejune to add anything. Their own intellectual structure waits there to be added to, but is unshakeable. The application which has come out of that structure has left us with some threats and more promises. It is for the general intelligence of us all to make the best of both.