Nuclear fusion has long been thought to have the potential to be a cheap and virtually unlimited source of energy. However, fusion requires extremely high temperatures or pressures. Cold fusion is fusion occurring at moderate temperatures and pressures. Cold fusion could make fusion more practical.

Fusion refers to a process where atomic nuclei collide and fuse together, forming larger particles and releasing energy. The fusion of hydrogen nuclei inside the sun is what makes the heat that warms our planet. But outside the enormous pressure in the center of a star like the sun, nuclei are unlikely to fuse. All atomic nuclei are positively charged, and thus repel each other. Some outside force, such as high temperature or pressure, is needed to make the nuclei overcome their natural repulsion and come together. If nuclei could be forced to fuse at low temperatures in a practical device...