234 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1951 



nuclei are very tightly bound together, sufficient energy would be 

 released to maintain the temperature of the star. If it were possible 

 to find a method by which heavier atoms could be synthesized from 

 hydrogen at will and under controlled conditions, very large amounts 

 of energy would be available. Thus, if four atoms of hydrogen con- 

 dense to form an atom of helium, the energy set free is about 5 million 

 times as great as that produced when an atom of carbon is burnt. In 

 other words, 1 pound of hydrogen transformed into helium would 

 produce about 100 million kilowatt-hours of heat energy, or about 

 130 million horsepower for an hour. Thus hydrogen as nuclear fuel 

 would be about 10 times as good, weight for weight, as uranium. 

 There are possible ways in which an explosive reaction of this type can 

 be produced by utilizing the very high temperature and pressures 

 developed in the explosion of an atomic bomb, but so far there is no 

 clue to a method for bringing about the reaction in a controllable 

 way. However, it is interesting to speculate on the possibility that 

 nuclear scientists may discover how to do this in the future. 



There is enough hydrogen in the sea, if it were all converted into 

 helium, to raise the temperature of the whole earth to at least 

 1,000,000° C, i.e., over 100 times the temperature of the surface of 

 the sun. Fortunately for us the possibility of bringing about such 

 an explosion can be ruled out, if for no other reason than that if it 

 were possible it would have happened in the past history of the earth. 

 However, if we accept as the desirable power level for civilization 

 that every individual should utilize, on the average, 1 kilowatt of 

 power continuously, we can calculate that 3,000 million inhabitants 

 of the earth could be supplied with power from the hydrogen of the 

 sea for 1,000 million million years, or for about a million times the 

 age of the earth itself. Thus, if this remote possibility is realized, 

 mankind would have no need to look elsewhere than to the sea for all 

 the power he can conceivably use in the lifetime of the solar system. 



In conclusion I would emphasize that industrial power from 

 uranium is on the doorstep and will almost certainly be used success- 

 fully, while power from hydrogen is only a remote possibility in the 

 light of existing knowledge. In any case, the probability is small 

 that any nuclear power will be available for useful purposes unless 

 the problems of war can be solved, and that is a question for all man- 

 kind and not for the scientist alone. There is danger in all knowledge 

 of nature. Scientific information can always yield guns as well as 

 butter. It is a source of great regret to men of science that their work 

 is made the basis of the indiscriminate destruction of man and his 

 civilization, instead of contributing to the well-being of all. 



