An eighty-year-old theory looks set to become a reality, after researchers managed to develop the technique in less than a day during their coffee break!
The concept of turning light into matter sounds inconceivable, yet however far-fetched it sounds, the Universe that we inhabit was created when energy was transformed into substance.
The idea to recreate this process was first proposed in 1934 by two US scientists, Gregory Breit and John Wheeler, who suggested that it would be possible merely by colliding two photons – mass-less particles of light – to form an electron and a positron. At that time, the theory seemed to be wildly unachievable but now, eighty years later, the subject posed little challenge to a collusion between scientists at Imperial College London and a representative from the Max Planck Institute for Nuclear Physics, who claim that they formulated a method for doing so after chatting it through "over several cups of coffee."
Their original area of interest was fusion energy, but then realised that their project could also be used to develop the old Breit-Wheeler concept. Their method involves the use of a photon-photon collider, created by using a high-intensity laser to buzz up the speed of electrons to just less than the speed of light then, by propelling these electrons into a block of gold, a beam of photons would be produced that were a billion times more energetic than visible light.
The process would be completed using a small hollow gold cylinder known as a hohlraum (derived from the German for "empty room"), then a high-energy laser would be aimed at the inner surface of the gold to create a thermal radiation field, generating light similar to the light emitted by stars.
Scientists would then direct the photon beam from the first stage of the experiment through the centre of the cylinder to cause 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 after they exit the cylinder.
Electrons would make it through the gold slab, but they’d all be filtered out from the photons using a magnetic field.
“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.
“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, who published their proposals in the journal Nature Photonics, have not said whether they intend to make and test the new type of collider, but they have said that it should be reasonably straightforward to produce using existing technology.
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