A team of scientists may have given hydrogen a squeeze strong enough to turn it into a metal. But critics vigorously dispute the claim.
Researchers from Harvard University report that under extremely high pressures hydrogen became reflective — one of the key properties of a metal. The feat required compressing hydrogen to 4.9 million times atmospheric pressure, the scientists report online January 26 in Science.
If correct, the result would be the culmination of a decades-long search for a material that could have unusual properties such as superconductivity — the ability to conduct electricity without resistance.