“When Hahn and Strassman conducted their experiment, they launched a neutron into an atom of uranium, a metal that was made up of the largest and heaviest atoms known at the time. Because a neutron has no electrical charge, it can slip through the powerful wall of electrons that surrounds every atom. This extra neutron is absorbed into the already bloated uranium nucleus, upsetting the careful balance of forces that holds the atom together. And in a flash the whole atom fractures. Its protons and electrons and neutrons rearrange themselves into different elements. The reaction also releases stray neutrons, which fly off on their own. But the most significant by-product of this collision is energy. Lots of it…

Just how much energy comes from a nuclear reaction? About seventy million times more energy than from a chemical reaction. So if, for example, you fissioned one kilogram of uranium, it would make the same size explosion as 20,000 tons of TNT. One little chunk of uranium has more potential explosive energy than a pile of TNT stacked ten stories high. If fission could work on a large enough scale (instead of just one atom at a time), mankind stood to gain more than merely the ability to make explosions. In fact, fission promised to reveal some of the deepest mysteries of the universe.

The secret behind fission’s awesome power lies in the type of reaction that is taking place. For practically all of human history, the most energetic reactions that humans were aware of were chemical reactions. Fire is a good example. If you ignite a lump of coal and make sure there is enough oxygen around, the result is fire (energy) and smoke. On a molecular level, the heat from the flame disrupts the electrons in the coal, causing each carbon atom to bond with two atoms of oxygen. The result is a new molecule made from the old atoms: CO2. We put in carbon and oxygen, and we get out carbon and oxygen, though in slightly different arrangements. But in a nuclear reaction, such as fission, the original atom of uranium disappears. It actually becomes two new atoms. Instead of changing merely the arrangement of the atoms, fission changes their very identity. In fission, scientists had finally discovered the philosopher’s stone that had captivated the minds of medieval alchemists. With fission, we could finally turn lead into gold.”