By 1945 we had learned that many things were wrong in Professor Aston’s prophecy. It had been definitely established, for example, that it would be impossible to “transform all the hydrogen on earth at once,” no matter how many superduper hydrogen bombs were to be exploded. In fact, we had learned that, under conditions as they exist on earth, we could never use common hydrogen, the element that makes up one ninth by weight of all water, either in a superduper bomb or as an atomic fuel for power. On the other hand, ten years after Dr. Aston’s lecture a new type of hydrogen was discovered to exist in nature. It was found to constitute one five-thousandth part of the earth’s waters, including the water in the tissues of plants and animals. It was shown to have an atomic weight of two—double the weight of common hydrogen—and was named deuterium. The nucleus, or center, of the deuterium atom was named the deuteron, to distinguish it from the nucleus of common hydrogen, known as the proton. Deuterium also became popularly known as “heavy hydrogen.” Water containing two deuterium atoms in place of the two atoms of light hydrogen became known as “heavy water.” The most startling fact learned about deuterium soon after its discovery in 1932 was that it offered potentialities as an atomic fuel, or an explosive, of tremendous energy, provided one condition could be met. This condition was a “match” to light it with. And here was the catch. The flame of this match, it was found, would have to have a temperature of the order of 50,000,000 degrees centigrade, two and a half times the temperature in the interior of the sun. Oddly enough, the discovery of the principle that made the atomic bomb possible also brought with it the promise that a “deuterium fire” might, after all, be lighted on earth. Early studies had revealed that the explosion of an atomic bomb, if it lived up to expectations, would generate a central temperature of about 50,000,000 degrees centigrade. Here, at last, was the promise of realization of the impossible—the 50,000,000 degree match. The men of Los Alamos thus knew that if the atomic bomb they were just completing for its first test worked as they hoped it would, it could be used as the match to light the deuterium fire. They could build a superduper bomb of a thousand times the power of the atomic bomb by incorporating deuterium in the A-bomb, the explosion of which would act as the trigger for the superexplosion. And they also knew that the deuterium bomb held such additional potentialities of terror, beyond its vastly greater blasting and burning power, that the step from the duper to the super would be just as great as the step from TNT to the duper.