Nuclear reactions in the Sun and in nuclear power plants regularly convert matter into energy. Now, using Einstein’s famous E = mc² equation in reverse, scientists have converted light energy directly into matter. Scientists used the Relativistic Heavy Ion Collider (RHIC) at the Brookhaven National Laboratory in Upton, New York, to create matter directly from collisions of light. Gregory Breit and John A. Wheeler predicted this process in 1934, but it has never been achieved in a single direct step. The researchers accelerated two beams of heavy gold ions to close to the speed of light in opposite directions. At such speeds, each gold ion is surrounded by packets of light (that is, real photons) generated by the ion’s perpendicular magnetic and electric fields. When the ions graze past one another without colliding, the photons interact to produce electrons (matter) and positrons (antimatter). The momentum and angular distributions of the resulting electron-positron pairs indicate, within the high-precision limits of the experiment, that these particles come from real photons. This makes the experiment a direct demonstration of the Breit-Wheeler effect.