Scientists Say They Have to Discovered How to Turn Light Into Matter

Posted on May 19, 2014

Light matter experiment with a vacuum hohlraum


Scientists from Imperial College London and the Max Planck Institute for Nuclear Physics say they have discovered how to create matter from light. Physicists from the college says they have worked out a "simple" way to physically prove a theory first devised by U.S. physicists Gregory Breit and John Wheeler in 1934. The Guardian reports that the scientists plan to demonstrate the feat within a year.

Breit and Wheeler suggested that it should be possible to turn light into matter by smashing together only two particles of light (photons), to create an electron and a positron. The calculation was found to be theoretically sound. Breit and Wheeler said at the time that they never expected anybody to physically demonstrate their prediction.

Scientists published a research paper here in Nature Photonics that shows how Breit and Wheeler's theory could be demonstrated in the lab using a photon-photon collider, which would convert light into matter. This experiment would recreate a process that was important in the first 100 seconds of the universe and occurs in gamma ray bursts.

Professor Steve Rose, from the Department of Physics at Imperial College London, says in a statement, "Despite all physicists accepting the theory to be true, when Breit and Wheeler first proposed the theory, they said that they never expected it be shown in the laboratory. Today, nearly 80 years later, we prove them wrong. What was so surprising to us was the discovery of how we can create matter directly from light using the technology that we have today in the UK. As we are theorists we are now talking to others who can use our ideas to undertake this landmark experiment."

The researchers say the experiment will involve using an extremely powerful high-intensity laser to speed up electrons to just below the speed of light. These electrons will be fired into a slab of gold to create a beam of photons a billion times more energetic than visible light.

The next stage of the experiment requires a tiny gold can called a hohlraum. Scientists will fire a high-energy laser at the inner surface of the hohlraum to create a thermal radiation field. Scientists will then direct the photon beam from the first stage of the experiment through the center of the can, causing the photons from the two sources to collide and form electrons and positrons. Scientists will then be able to detect the formation of the electrons and positrons when they exit the can.

Oliver Pike, a PhD researcher in plasma physics, says in a statement, "Although the theory is conceptually simple, it has been very difficult to verify experimentally. We were able to develop the idea for the collider very quickly, but the experimental design we propose can be carried out with relative ease and with existing technology. Within a few hours of looking for applications of hohlraums outside their traditional role in fusion energy research, we were astonished to find they provided the perfect conditions for creating a photon collider. The race to carry out and complete the experiment is on!"

Image: O. J. Pike et. al./Nature Photonics