Imperial College London scientists have learned how to turn light into matter, completing a quest that began 80 years ago when the idea was first theorized.

In 1934, scientists Breit and Wheeler theorized that it should be possible to create matter from light by smashing together only two particles of light, to generate an electron and a positron. However, Breit and Wheeler never expected anybody to physically demonstrate their idea.

The new research reveals for the first time how the scientists’ theory could be proven in practice. This “photon-photon collider,” which would change light directly into matter utilizing technology that is already accessible, would be a novel kind of high-energy physics experiment.

The scientists had been conducting research on unrelated problems in fusion energy when they arrived at the conclusion that their work could be applied to the Breit-Wheeler theory.

The collider experiment involves two key steps. First, the scientists would utilize a very powerful high-intensity laser to accelerate the electrons to just below the speed of light. They would then fire these electrons into a hunk of gold to produce a beam of photons a billion times more energetic than visible light.

Next, scientists would fire a high-energy laser at the inner surface of a small gold can called a hohlraum, to produce a thermal radiation field. They would then direct the photon beam from the first stage of the experiment through the center of the can, forcing the photons from the two sources to collide and form electrons and positrons.

“The race to carry out and complete the experiment is on!” said lead researcher Oliver Pike.

The findings are published in the journal Nature Photonics.