SCIENCE, YESTERDAY, TODAY, TOMORROW — SWANN 235 



say that there is really no miracle about this matter. Ilis uncertainty 

 as regards the individual is simply something founded upon his 

 ignorance of the complete story and of the impracticability of sup- 

 plementing his knowledge to the end of making detailed predictions. 

 And so you might think that the same thing would apply to the 

 atom, and that, if you would only work hard enough to invent a more 

 complete set of laws to govern its actions, the complete life history 

 of every atom would be known and there would be no need to invoke 

 miracles. However, physicists have w^orked very hard in an endeavor 

 to do something of this kind, but without success, and the nature of 

 their thinking is such as to convince many of them that complete suc- 

 cess could never be attained, and that, as regards the atomic realm, 

 we shall always have to put up with miracles. And now we are 

 confronted with a curious psychological paradox. The average man 

 of science, secure in the conviction that, as regards matter in bulk, 

 nothing miraculous ever happens, is perfectly content to accept such 

 happenings in the atomic world. Miracles on the scale of size of 

 anything whicli we can see would be an abomination to him, but hap- 

 penings which he cannot see, which the mind can only think about, 

 but which he believes to occur, are acceptable. However, he avoids 

 clash with his conscience by refusing to give them a name. Perhaps 

 a still more curious thing is that Avitli the advance of experimental 

 techniques, man can actually observe certain of the miracles of the 

 individual atoms ; but here he feels his activities so far removed from 

 anything to do with mankind that again his philosophical conscience 

 makes no protest. 



I feel it quite safe to say that if I should describe to any intelligent 

 layman who was unacquainted with mathematical physics the prin- 

 ciples according to which our so-called laws of atomic and nuclear 

 structure operate; and if I could get my message across in a very 

 short time, so that the layman would not become inveigled step by step 

 into this way of thinking without encountering at each stage more 

 than his philosophic conscience could swallow, I think that if I could 

 do this, the layman would have to admit that the occurrences per- 

 mitted in nuclear physics are, in terms of his normal criteria of 

 common sense, more abstract and bizarre than any occult phenomenon 

 whicli had been said to have occurred and which, under tliat name, 

 he would probably dismiss immediately as evidence of insanity in 

 those who subscribe to it. 



During the last three-quarters of a century, science has brought 

 forth many marvelous things which seem commonplace today and 

 which have not startled mankind unduly at any stage of their 

 development because their development has come upon us gradually. 

 If, a hundred years ago, someone had awakened in the morning to find 



