Word: helium
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Dates: during 1940-1949
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...nuclear explosive. Perfect efficiency (probably impossible) would therefore give about ten times as much power, certainly not 1,000 times as much. So, figured the amateur physicists, the talkative Senator must have meant a bomb made out of hydrogen. It is well known that the conversion of hydrogen into helium is the nuclear reaction that gives the sun its energy...
Science speaks of few absolutes. One of the few is absolute zero: -273.16 centigrade. At this temperature, the haphazard motion of the molecules (the action called heat) is wholly stilled. Close to this point of death-still cold, matter acts in strange ways. Liquid helium climbs out of containers; the electrical resistance of metals disappears. Because scientists see stranger phenomena the closer they get to absolute zero, experimenters like to imagine working their way down to the very bottom of the temperature scale...
Inside the stars, where the temperature may reach a "scorching" 20 million degrees centigrade, thermonuclear reactions are constantly at work changing hydrogen into helium. The University of Chicago's Dr. Otto Struve, head of the 42-man U.S. delegation, repeated a solemn prediction: in 3 billion years some stars will have burned up most of their hydrogen, leaving the helium "as 'ashes' of this stupendous nuclear transformation furnace...
Hydrogen and its helium "ashes," while by far the most abundant, are not the only chemical elements which can be detected by sharp-eyed astronomers. The "main sequence" stars have, identically the same-composition as the sun: for every atom of any metal there are some six atoms of carbon, nitrogen and oxygen, 500 atoms of helium, and 5,000 atoms of hydrogen (still to be burned). The same proportions of atoms exist in the near vacuum of interstellar space. Not only do the universe's largest bodies behave in much the same fashion as its smallest atoms...
...great cyclotron at Berkeley is just barely strong enough. Dr. Eugene Gardner, 35, and Brazilian-born Dr. C.M.G. Lattes, 23, put a thin carbon target in a beam of alpha particles (helium nuclei) in the cyclotron chamber. Figuring that the alpha particles had enough power (380 million electron volts) to knock mesons out of the carbon atoms, Gardner & Lattes put a stack of special photographic plates at the spot where the mesons should hit. Then they turned on the cyclotron. When they developed the plates, they found the characteristic wavy tracks of negative mesons. Some of them ended in "stars...