The theory that describes the behavior of matter and antimatter predicts that if two high-energy photons collide in the right way, they’ll annihilate into pairs of matter and antimatter particles. This was first described by Gregory Breit and John Archibald Wheeler in 1934. The experiment the physicists describe requires the construction of a new type of subatomic particle collider. It could be built in less than a year. A few experimental facilities have lasers of the right kind to create photon-photon annihilation, including SLAC in the United States and the Orion laser in the UK. The experiment would involve blasting electrons, sped up by lasers to just below the speed of light, into a slab of gold to create photons a billion times more energetic than visible light. This ‘photon-photon collider’ would be a new type of high-energy physics experiment. If this sort of matter will be created, at this stage the end result would not be visible to the naked eye. This process was important in the first 100 seconds of the universe.