LIGHT-WEIGHT HELIUM

Evening Star, Issue 23565, 2 May 1940, Page 14

LIGHT-WEIGHT HELIUM

SURPRISE ELEMENT IN AIR Discovery in the earth’s atmosphere of a surprise element, light-weight helium, was reported recently by researchers working with the University of California’s atom-bursting machine, the cyclotron. Known heretofore only as a ghost clement that appeared and disappeared like a lightning Hash incidental to certain transmutation, it turned out to he a stable substance in the air. This light-weight helium, known technically as helium 3, would he ideal for giving dirigibles and other balloons a combination of high lifting power and non-inflammability, but it is extremely scarce and hard to get. Professor Luis W. Alvarez, physicist, who, with Robert Cornog, made the discovery, found that tho light-weight stuff comprised only one ten-millionth of the already minute regular helium content of the atmosphere. Professor Alvarez and Mr Comog obtained only a few million atoms—not enough to bo seen under a microscope ii bunched together. But they established that it was a real substance existing in nature, and not just a laboratory freak.

Previously, Professor 'Alvarez said, physics laboratories had taken it for granted that helium 3 did not exist, and then for only a few millionths of a second. Thus it supposedly did not last long enough to he found in nature. The experiment, Professor Alvarez added, was undertaken in tho expectation that it would fail and therefore support the correctness of the suppositions. , But tho experiment succeeded and surprised even the researchers. DECAY OF RADIUM. Virtually all tho helium used hy man comes from tho wells in the earth, the most of it from Texas and other southwestern States. It is supposed to be a product of tho natural disintegration of radium. This decay process is constant and very slow, and it also involves the formation of the metal lead as an “ end product.” By determining the proportion of lead in an ore deposit containing radium, natural scientists have calculated the minimum age of the earth at several billion years. During that period, helium has been accumulating. But radium decay has been observed to produce only regular helium. Professor Alvarez and Mr Cornog tested some of it, however, and found a tiny trace of light-weight helium in it. Ordinary helium is the second lightest of the conventional elements, hydrogen being the lightest. Helium 3 is 25 per cent, lighter than the ordinary element, but about three times as heavy ns regular hydrogen. Nevertheless the lighting power of light-weight helium is close to that of hydrogen. It was calculated that light-weight helium would lift 95.7 per cent, as much weight as hydrogen. Ordinary helium has only about 92.3 per cent, of the lifting power of hvdrogon. Thus helium 3 would be ideal for lighter-than-air craft.