Turning Light Into Matter Might Finally Be Possible

Researchers have a formula for turning colliding photons into electrons and positrons

Photo: VOLKER STEGER/Science Photo Library/Corbis

In theory, it should be possible to create matter from pure light, but until recently physicists assumed the mathematics behind this idea would never actually be realized in laboratory experiments. Researchers at Imperial College London, however, just announced that modern high-powered lasers in fact make this elusive experiment a possibility. If their newly published research is accurate, the Guardian writes, by this time next year scientists will likely have successfully produced matter from light. 

To be clear, the researchers are talking about making subatomic particles—electrons, positrons—out of light, rather than objects that can be seen with the naked eye, the Guardian writes. Two physicists, who later worked on the atom bomb, came up with the theory in 1934. Here's the Guardian

They worked out that – very rarely – two particles of light, or photons, could combine to produce an electron and its antimatter equivalent, a positron. Electrons are particles of matter that form the outer shells of atoms in the everyday objects around us.

But [Gregory] Breit and [John] Wheeler had no expectations that their theory would be proved any time soon. In their study, the physicists noted that the process was so rare and hard to produce that it would be "hopeless to try to observe the pair formation in laboratory experiments".

Technology, however, has advanced beyond what those physicists ever imagined possible. The authors of the new study provide a step-by-step instruction manual for carrying out the experiment using high-powered lasers. The final product, they write, would be around 100,000 electron-positron pairs. Here's the Guardian again, on how the method would work: 

The first step fires electrons at a slab of gold to produce a beam of high-energy photons. Next, they fire a high-energy laser into a tiny gold capsule called a hohlraum, from the German for "empty room". This produces light as bright as that emitted from stars. In the final stage, they send the first beam of photons into the hohlraum where the two streams of photons collide.

Now, the researchers just need to find a specialized facility with a giant laser that is willing to let the team demonstrate that the technique works, the Guardian continues. They think that should happen within the next year—if another team doesn't beat them to it first. "The experimental design we propose can be carried out with relative ease and with existing technology," the researchers said in a statement. "The race to carry out and complete the experiment is on!"

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