The Physicists

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by C. P. Snow


  This lack of need for workers applies to productive industry, not everywhere. Service industries cannot be worked to the same extent by these subtle devices. The trouble is, as we already know all over the industrialized world, there can be destructive unemployment in productive industry, and simultaneously a corresponding demand in service industry. People insist on their old jobs in factories where they are now obsolete: at the same time they are not prepared to be postmen. If service industries paid more than factories the problem would still not disappear.

  That dilemma is going to be sharpened by this most recent gift of applied physics. The curse of labour, laid on man after the Fall, is for many ready to be taken away. Like other gifts, this one may be two-edged or have two faces.

  11: The Double Legacy

  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.

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nbsp; 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.

  Appendices

  I: A New Means of Destruction

  Editorial by C P Snow in Discovery, September 1939

  Some physicists think that, within a few months, science will have produced for military use an explosive a million times more violent than dynamite. It is no secret; laboratories in the United States, Germany, France and England have been working on it feverishly since the Spring. It may not come off. The most competent opinion is divided upon whether the idea is practicable. If it is, science for the first time will at one bound have altered the scope of warfare. The power of most scientific weapons has been consistently exaggerated; but it would be difficult to exaggerate this.

  So there are two questions. Will it come off? How will the world be affected if it does?

  As to the practicability, most of our opinions are worth little. The most eminent physicist with whom I have discussed it thinks it improbable; I have talked to others who think it as good as done. In America, as soon as the possibility came to light, it seemed so urgent that a representative of American physicists telephoned the White House and arranged an interview with the President. That was about three months ago. And it is in America where the thing will in all probability be done, if it is done at all.

  The principle is fairly simple, and is discussed by Mr D W F Mayer in more detail on p. 459. Briefly, it is this: a slow neutron knocks a uranium nucleus into two approximately equal pieces, and two or more faster neutrons are discharged at the same time. These faster neutrons go on to disintegrate other uranium nuclei, and the process is self-accelerating. It is the old dream of the release of intra-atomic energy, suddenly made actual at a time when most scientists had long discarded it; energy is gained by the trigger action of the first neutrons.

  The idea of the uranium bomb is to disintegrate in this manner an entire lump of uranium. As I have said, many physicists of sound judgement consider that the technical difficulties have already been removed; but their critics ask – if this scheme were really workable, why have not the great uranium mines (the biggest are in Canada and the Congo) blown themselves up long ago? The percentage of uranium in pitchblende is very high: and there are always enough neutrons about to set such a trigger action going.

  Well, in such a scientific controversy, with some of the ablest physicists in the world on each side, it would be presumptuous to intrude. But on the result there may depend a good many lives, and perhaps more than that.

  For what will happen, if a new means of destruction, far more effective than any now existing, comes into our hands? I think most of us, certainly those working day and night this summer upon the problem in New York, are pessimistic about the result. We have seen too much of human selfishness and frailty to pretend that men can be trusted with a new weapon of gigantic power. Most scientists are by temperament fairly hopeful and simple-minded about political things: but in the last eight years that hope has been drained away. In our time, at least, life has been impoverished, and not enriched, by the invention of flight. We cannot delude ourselves that this new invention will be better used.

  Yet it must be made, if it really is a physical possibility. If it is not made in America this year, it may be next year in Germany. There is no ethical problem; if the invention is not prevented by physical laws, it will certainly be carried out somewhere in the world. It is better, at any rate, that America should have six months’ start.

  But again, we must not pretend. Such an invention will never be kept secret; the physical principles are too obvious, and within a year every big laboratory on earth would have come to the same result. For a short time, perhaps, the U S Government may have this power entrusted to it; but soon after it will be in less civilized hands.

  THE EDITOR

  II: Einstein’s Letter to President Roosevelt

  Albert Einstein

  Old Grove Rd.

  Nassau Point

  Peconic, Long Island

  August 2nd, 1939

  F D Roosevelt,

  President of the United States,

  White House

  Washington, DC

  Sir:

  Some recent work by E Fermi and L Szilard, which has been communicated to me in manuscript, leads me to expect that the element uranium may be turned into a new and important source of energy in the immediate future. Certain aspects of the situation which has arisen seem to call for watchfulness and, if necessary, quick action on the part of the Administration. I believe therefore that it is my duty to bring to your attention the following facts and recommendations:

  In the course of the last four months it has been made probable – through the work of Joliot in France as well as Fermi and Szilard in America – that it may become possible to set up a nuclear chain reaction in a large mass of uranium, by which vast amounts of power and large quantities of new radium-like elements would be generated. Now it appears almost certain that this could be achieved in the immediate future.

  This new phenomenon would also lead to the construction of bombs, and it is conceivable – though much less certain – that extremely powerful bombs of a new type may thus be constructed. A single bomb of this type, carried by boat and exploded in a port, might very well destroy the whole port together with some of the surrounding territory. However, such bombs might very well prove to be too heavy for transportation by air.r />
  The United States has only very poor ores of uranium in moderate quantities. There is some good ore in Canada and the former Czechoslovakia, while the most important source of uranium is Belgian Congo.

  In view of this situation you may think it desirable to have some permanent contact maintained between the Administration and the group of physicists working on chain reactions in America. One possible way of achieving this might be for you to entrust with this task a person who has your confidence and who could perhaps serve in an inofficial capacity. His task might comprise the following:

  a) to approach Government Departments, keep them informed of the further development, and put forward recommendations for Government action, giving particular attention to the problem of securing a supply of uranium ore for the United States;

  b) to speed up the experimental work, which is at present being carried on within the limits of the budgets of University laboratories, by providing funds, if such funds be required, through his contacts with private persons who are willing to make contributions for this cause, and perhaps also by obtaining the co-operation of industrial laboratories which have the necessary equipment.

  I understand that Germany has actually stopped the sale of uranium from the Czechoslovakian mines which she has taken over. That she should have taken such early action might perhaps be understood on the ground that the son of the German Under-Secretary of State, von Weizsäcker, is attached to the Kaiser-Wilhelm-Institut in Berlin where some of the American work on uranium is now being repeated.

  Yours very truly,

  (Albert Einstein)

  III: The Moral Un-neutrality of Science

 

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