Scientists at Imperial College London are attempting to use powerful lasers turn light into matter, potentially proving the 84-year-old theory known as the Breit-Wheeler process. According to this theory, it is technically possible to turn light into matter by smashing two photons to create a positron and an electron. While previous efforts to achieve this feat have required added high-energy particles, the Imperial scientists believe they have discovered a method that does not need additional energy to function. “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,” explained Imperial Professor Steven Rose. “What we are doing is the same but backwards: turning photon energy into mass, i.e. m=E/c2.”
The Imperial team’s system centers around two lasers, which create two different kinds of photons to be smashed. One photon has the energy equivalent to ten thousand times that produced by visible light, while the other has that of one billion times that of visible light. Both lasers are aimed at two small targets in the target chamber, where the charged particles are deflected and documented. The team will be observing the particles bouncing from the collision to see if they were successful in creating matter from light.
If the scientists successfully convert light into matter, they will have proven an old theory once thought impossible to confirm while offering a glimpse into the earliest moments of our universe. “When Gregory Breit and John Wheeler first proposed the mechanism in 1934, they used the then new theory of the interaction between light and matter known as quantum electrodynamics (QED),” explained study co-leader Dr. Stuart Mangles. “Whereas every other fundamental prediction of QED has since been demonstrated experimentally, the ‘two-photon Breit-Wheeler process’ has never been seen. If we can demonstrate it now, we would be recreating a process that was important in the first 100 seconds of the universe and that is also seen in gamma ray bursts, which are the biggest explosions in the universe and one of physics‘ greatest unsolved mysteries.”
Images via Imperial College London