Sun in a Bottle Read Free Page B

compress the fuel into a tiny parcel. This keeps the atoms in close proximity to one another (so they have a chance of colliding). That, in itself, is not so hard; the trick is to keep the atoms very hot as well. Only at tens or hundreds of millions of degrees are the atoms moving fast enough to have a chance of fusing when they do collide. When you heat something, it expands—the atoms try to escape in all directions. Thus, it is very hard to keep a very hot thing compressed very tightly. So, the basic problem in fusion is that it is very difficult to heat something to the right temperature and, simultaneously, keep the atoms close enough together. Without both things working concurrently, a fusion reaction won’t get going.
    Making matters worse, if you are lucky enough to start a fusion reaction, your own success works against you. When the fusing atoms release energy, they pour heat into their surroundings. This makes the neighboring atoms hotter. The hotter the atoms get, the more the fuel expands and the harder the atoms try to escape. The packet of fuel attempts to blow itself apart. Unless the conditions are just right, a fusion reaction will snuff itself out before it produces any appreciable energy.
    Nevertheless, if scientists could get a fusion reaction going even for a few fractions of a second, its power would be virtually limitless. It could be much, much more deadly than a mere fission bomb.
    This is the idea that obsessed Teller soon after he arrived in Chicago. Unlike most of his colleagues, he was not terribly interested in working on the fission bomb. In his mind, the theoretical problems had already been solved, so he spent his energy trying to come up with even better weapons: fusion bombs. Within a month of his arrival, Teller had not only concluded that it was possible to create a fusion bomb that would dwarf anything the Manhattan Project would be able to offer, but had also convinced himself that he knew precisely how to build one. It would be years before he figured out how wrong he was.
    In 1942, though, Teller, full of enthusiasm, brought the idea to the attention of his colleagues. They quickly dubbed the new weapon the Super. By August, he and his fellow physicists were giving astounding estimates of the destructive power of a Super-like fusion weapon. A report at the time estimated that one would blow up with the energy of one hundred megatons of TNT, about seven thousand times bigger than the eventual size of the Hiroshima bomb. Teller, a tremendous optimist, 4 was convinced that fusion was easy.
    Once you have an atom bomb, he argued, you can dump the enormous power of an exploding atomic weapon into a tank of deuterium—heavy hydrogen. The hydrogen, heated to millions of degrees, would begin to fuse and generate energy in a thermonuclear reaction. This was essentially the idea behind Teller’s Super: it was, more or less, an atom bomb at one end of a vessel full of heavy hydrogen. The exploding bomb would trigger a wave of fusion in the vessel. If it worked, Teller argued, this Super had unlimited capacity for destruction. 5
    To Teller, the easy part was building a weapon of tremendous power. The hard part was building a weapon that would not be so destructive that it would kill everybody on Earth. In Teller’s fertile imagination, an atom bomb that ignited a tank of hydrogen might ignite the air itself. (The nitrogen that makes up 80 percent of the atmosphere is a light atom, and just like hydrogen it will fuse if the conditions are right.) Teller’s initial calculations showed that an atomic explosion might induce nitrogen atoms in the air to fuse with each other. The runaway explosion would quickly destroy the world in a gigantic nuclear furnace—even the weak Manhattan Project bomb might mean the end of life on Earth. When Hans Bethe double-checked Teller’s assumptions, though, he found reason to relax. “I very soon found some unjustified assumptions in Teller’s calculation