In 1905 Albert Einstein wrote four groundbreaking papers on quantum theory and relativity. It became known as Einstein’s annus mirabilis or wonderous year.
The paper is just two pages long, and it outlines how special relativity might explain a strange aspect of radioactive decay.
As Marie Curie most famously demonstrated, some materials such as radium salts can emit particles with much more energy than is possible from simple chemistry.
Einstein’s little paper speculated that the excess energy might be balanced by a loss of mass of the nuclear particles. This idea eventually led to Einstein’s most famous equation, E = mc2.
If you can convert matter entirely into energy, you should be able to do the reverse. It’s known as the Breit–Wheeler process and involves colliding two photons to create an electron-positron pair. While we have used light to create matter several times, converting two photons directly into the matter is very difficult.
But a recent experiment shows it can be done.
The team used data from the Relativistic Heavy Ion Collider and looked at more than 6,000 events that created electron-positron pairs. They didn’t simply beam two lasers at each other but instead used high-energy particle collisions to create intense bursts of photons.
In some cases, these photons collided to create an electron-positron pair. From the data, they could show when a pair was created directly from light.
Matter from light!