May 19, 2014
Matter From Light
It was Antoine Laurent Lavoisier who coined the phrase “matter is neither created or destroyed” back in 1789. While not the one who originally came up with the theory, he is often credited for it. This one simple statement is one of the most well-known quotes in science, also known as the law of the conservation of matter. It is also known that energy can be translated into matter, and by that we have the theory of the Big Bang that gave form to our universe, yet scientists have never been able to replicate the act of transforming light into matter. First theorized 80 years ago, it was always viewed as theoretically possible, but simply not plausible to enact within a controlled environment. That is, until now.
Physicists Breit and Wheeler first suggested that it should be theoretically possible to transform light into matter by smashing together two photons in order to create an electron and a positron back in 1934. While a sound theory, neither of them ever expected it to be physically demonstrated within a lab. However, one day over coffee at Imperial’s Blackett Physics Laboratory, three physicists formulated a plan to put Breit and Wheeler’s theory to practice. They postulated that by using a tiny gold can called a hohlraum (which is German for “empty room”), they could create a thermal radiation field by firing a high-energy laser into it. This would generate light similar to that emitted by stars. Then, using a high-intensity laser to speed up electrons to just below the speed of light, they would direct the beam through the center of the hohlraum, which would cause the photons from the two sources to collide and form electrons and positrons. Following that, it would be possible for researchers to detect the formation of these electrons and positrons – in short, matter – when they exited the hohlraum.
According to Professor Steve Rose from the Department of Physics at Imperial College London, “Despite all physicists accepting the theory to be true, when Breit and Wheeler first proposed the theory, they said that they never expected it to be shown in the laboratory. Today, nearly 80 years later, we prove them wrong. 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.”
Theoretically, this incredible breakthrough in demonstrating the Breit-Wheeler theory could provide researchers with the final piece of the physics puzzle that describes the simplest ways that light and mater interact with one another. In addition to this one, there are six other pieces that include Dirac’s 1930 theory of the annihilation of electrons and positrons, as well as Albert Einstein’s 1905 theory on the photoelectric effect, all of which are associated with Nobel Prize-winning research. This plan to put Breit and Wheeler’s theory to the test marks an incredible achievement for science and the understanding of the formation of our universe.
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