Scientists discover technique to turn light into matter

Scientists have for the first time discovered a revolutionary technique that allows light to be turned into matter, a feat considered impossible when the idea was first theorised 80 years ago, The Times of India reports, quoting agencies.

Physicists at the Blackett Physics Laboratory of Imperial College London, devised a relatively simple way to physically prove a theory first advanced by scientists Breit and Wheeler in 1934.

According to the scientists, it should be possible to turn light into matter by simply smashing together only two particles of light (photons), to create an electron and a positron - the simplest method of turning light into matter ever predicted. Though the calculation was found to be theoretically sound, according to Breit and Wheeler, they did not expect anybody to physically demonstrate their prediction. It had never been observed in the laboratory and past experiments to test it had called for the addition of massive high-energy particles.

The new research, published in Nature Photonics, shows how Breit and Wheeler's theory could be proven in practice, using the 'photon-photon collider', for conversion of light directly into matter in a new type of high-energy experiment, but with technology that was already available.

According to commentators, the design adapted technology used in fusion research and could be implemented at existing UK facilities.

They say a race might start at several locations, to convert photons into positrons and electrons for the very first time.

According to professor Steven Rose from Imperial College London and his PhD student, Oliver Pike, who spoke to the BBC it could happen within a year.

Pike said with a good experimental team, it should be quite doable. If the experiment is undertaken it would provide the final piece in a puzzle that began in 1905, when Einstein explained the photoelectric effect with his model of light as a particle.

A number of other basic interactions between matter and light had been described and subsequently proved by experiment, which also included Dirac's 1930 proposal that an electron and its antimatter counterpart, a positron, could produce two photons annihilating the colliding particles.

However, Breit and Wheeler's theoretical prediction of two photons colliding to produce matter (a positron and an electron) had been difficult to demonstrate, and according to professor Rose, the reason was ''you need to throw an awful lot of photons together - because the probability of any two of them interconverting is very low."

But Rose and Pike proposes to go about it by gathering a vast number of very high-energy photons by firing an intense beam of gamma-rays into a further cloud of photons, created within a tiny, gold-lined cylinder.