Science: What Makes the Sun Hot

Last year Cornell University's brilliant, Alsatian-born atomic theorist, Professor Hans Albrecht Bethe, trotted out a plausible explanation of how the sun converts hydrogen into radiant energy, and so keeps on shining (TIME, Feb. 27, 1939). At temperatures above 15,000,000° C. (the sun's internal temperature is calculated at 20,000,000° C.), Dr. Bethe found that hydrogen atoms would attack carbon. The carbon would be transmitted into other forms, but after a series of six separate atomic conversions, it would reappear, while hydrogen atoms (of which the sun has enough to last some 12,000,000,000 years) would be consumed, leaving helium as ash. One cycle...

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