’Physicist Eugene Paul Wigner predicted more than 80 years ago that hydrogen, the most abundant element in the universe, could turn into an electricity-conducting solid metal at the right temperature and pressure. Scientists have spent decades since attempting to synthesize this material—and may have finally done so.
A team of researchers in France has posted a paper on the arXiv physics preprint server describing their observation of metallic hydrogen under pressures greater than those inside Earth’s core. Several times, other researchers have claimed to discover this phase of matter, claims that are generally met with varying levels of skepticism. But some experts think that this newest claim could be the real deal.
Metallic hydrogen is exactly what it sounds like—a state of the element hydrogen where it has the properties of a metal. The substance should “indisputably” exist, according to the new paper, thanks to something called quantum confinement: restrict electrons’ motion enough, and the electronic and optical properties of the material change thanks to the rules of quantum mechanics. At high enough pressures, any insulator should become a conductive metal, according to the paper; oxygen becomes a metal at 100 GPa, around a million times the pressure of Earth’s air at sea level, for example.
The discovery of metallic hydrogen would be exciting for a few reasons. Of course, it would prove experimentally that the material existed. It might transmit electricity without heating up, meaning it would be a superconductor, perhaps even a room-temperature superconductor. That’s another long-sought goal of physicists and could revolutionize electronics. Further, such a metal might fill the centers of massive planets like Jupiter, so being able to create it here on Earth could help us learn more about those planets.…’