How to turn light into matter puzzle solved

The quest began 80 years ago but the answer has been found just now - how to turn light into matter.

Physicists at Imperial College London physicists have discovered how to create matter from light - an idea that was first theorised in 1934 by scientists Breit and Wheeler.

"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," said professor Steve Rose from the department of physics at Imperial College London.

The new research involves a "photon-photon collider" that would convert light directly into matter using technology that is already available.

The collider experiment involves two key steps.

First, the scientists would use an extremely powerful high-intensity laser to speed up electrons to just below the speed of light.

They would then fire these electrons 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 involves a tiny gold can called a hohlraum (German for 'empty room').

Scientists would fire a high-energy laser at the inner surface of this gold can to create a thermal radiation field, generating light similar to the light emitted by stars.

They would then direct the photon beam from the first stage of the experiment through the centre of the can, causing the photons from the two sources to collide and form electrons and positrons.

It would then be possible to detect the formation of the electrons and positrons when they exited the can.

The experiment would recreate a process that was important in the first 100 seconds of the universe and that is also seen in gamma ray bursts - the biggest explosions in the universe and one of physics' greatest unsolved mysteries.

"Within a few hours of looking for applications of hohlraums outside their traditional role, 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," explained lead researcher Oliver Pike.

The breakthrough has been achieved in collaboration with a fellow theoretical physicist from the Max Planck Institute for Nuclear Physics, said the study published in the journal Nature Photonics.