Metallic hydrogen. Did it finally happen?
More than 80 years ago, physicists Eugene Wigner and Hillard Bell Huntington predicted that hydrogen gas could be turned into a metal, under the right conditions.
For a small community of scientists working in high-pressure physics, achieving that has been somewhat of a holy grail.
It's no easy task: hydrogen gas has to be cooled to -433 degrees Fahrenheit, and squeezed under pressures that are far beyond those at the centre of the Earth.
If it's true, it's a major breakthrough in physics. But the claim is not without controversy.