On this day, 87 years ago, on January 28, 1938 (December 27, 1937, the lunar calendar), scientists proposed that the explosion of atoms released 200 million volts of energy. On January 28, 1939, Enrico Fermi of the University of Rome told a conference of theoretical physicists in Washington that an atomic explosion could release 200 million volts of energy. Fermi said the huge energy was emitted when German scientist Otto Hahn bombarded a man-made synthetic element called metauranium with neutrons during an experiment. Physicists attending the meeting said Otto Hahn's achievement was no less than the discovery of radioactivity. But it will take at least 20 years to apply it in practice. They did not know that six years later, humans had created the "test specimen" to verify the theory-the atomic bomb.