What is more, cold fusion and nuclear bombs would have little in common. And supposing they were right, the reactions in question would, as they say, be nowhere near fast enough to produce interesting amounts of cold fusion. Now, during the recent furore over reports that 'cold fusion' had been produced in a test tube, S.E.Koonin and M.Nauenberg calculated that in some circumstances deuterium-deuterium fusion would proceed some ten billion times faster than had previously been estimated, while proton-deuterium fusion would be yet faster, by a factor of a hundred million.113 Naturally, these authors might be wrong. What had seemed potentially dangerous, though, were deuteriumdeuterium and proton-deuterium reactions. This presumably proves that 'objectively', 'out there in reality', the risk has been zero at the temperatures so far attained. Of course, neither the atmosphere nor the oceans (where, Bethe adds, 'the problem is more subtle') have been ignited even by H-bombs. Note that when H.A.Bethe stated in the Bulletin of the Atomic Scientists, June 1976,112 that an enormous safety factor would always be present, he felt a need to qualify this by adding 'unless, some time in the future, nuclear weapons of entirely different type are designed which produce much higher temperatures'. People were soon persuaded that there was no danger, a post-war technical report declaring that 'the impossibility of igniting the atmosphere was assured by science and by common sense' yet it is hard to see how mere common sense could have had much to say about a matter complicated enough to have worried the likes of Teller and Oppenheimer. E.Teller 'proposed to the assembled luminaries the possibility that their bombs might ignite the earth's oceans or its atmosphere and burn up the world'.111 J.R.Oppenheimer, the project leader, took the proposal fairly seriously. Probably the earliest such heart-searching took place when the first nuclear weapons were being developed. As R.Ruthen writes,110 'Since the beginning of the nuclear age, researchers have met many times to discuss whether there was any chance that a proposed experiment might initiate a catastrophe.' When physicists considered performing experiments at very high energies, fears of vacuum metastability were by no means the first to be voiced. We now come to two possible sources of risk which I take much less seriously, although it might be wrong to disregard them entirely.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |