Experiments underway to turn light into matter
In laser facilities in the UK, Imperial physicists are testing an 84-year-old theory which was once thought impossible to prove. The theory of the Breit-Wheeler process says it should be possible to turn light into matter by smashing two particles of light (photons) together to create an electron and a positron. However, past attempts to do this have required the addition of other high-energy particles. Physicists from Imperial College London, led by Professor Steven Rose, came up with a way of testing the theory that did not rely on these added extras in 2014, and today an experiment is running in the hope of turning light directly into matter for the first time. Professor Rose said: "This would be a pure demonstration of Einstein's famous equation that relates energy and mass: E=mc2, which tells us how much energy is produced when matter is turned to energy. What we are doing is the same but backwards: turning photon energy into mass, i.e. m=E/c2." The system involves two high-power laser beams, which are being used to create the photons of light to be smashed together. One of the photons has about 1000 times the energy of photons that produce visible light, and the other has 1,000,000,000 times the energy.
