—Christine Spraut, Fleetwood, Pennsylvania “Burn” is an earthly term that we use to describe the activation of a chemical reaction between a fuel and an oxidant. The most familiar example involves atmospheric oxygen, such as striking a match to produce a flame. The sun, by contrast, gives off its great heat and light by smashing hydrogen atoms together in its core. This is a nuclear reaction, and the process is known as nuclear fusion. If such a process could be safely harnessed, it would surely solve the energy needs of the world.