The Physics of Fusion

The basic physics of thermonuclear energy is seductively simple. Fission produces energy by atomic fracture, fusion by tiny acts of atomic union. Every atom contains at least one proton, and all protons are positively charged, which means that they repel one another, like identical ends of a magnet. As protons are forced closer together, their electromagnetic opposition grows stronger. If electromagnetism were the only force in nature, the universe might exist only as single-proton hydrogen a...

 The Energy Game in a Dead Moth

The moth moves across the porch, millimeter by millimeter, a brief stage of a longer journey of energy from the core of the sun to the table of the ants. Protons fuse at the center of the sun, releasing energy. The energy diffuses upward, taking several million years to reach the sun's surface, where it is released as heat and light. The light streaks across ninety-three million miles of space, reaching the Earth eight minutes later, where it falls upon the green leaves of plants. The plants ...