U.S. scientists create metallic hydrogen

does it float away?

https://www.engadget.com/2017/01/27/first-hydrogen-metal-created-on-earth-draws-critical-doubt/
However, other researchers are not convinced that the Harvard team saw hydrogen metal. Rather, they think that the team may have misjudged the pressure, and that the shiny material glimpsed could be alumina residue from the anvil's diamonds. "I don't think the paper is convincing at all," French physicist Paul Loubeyre told Nature. "If they want to be convincing, they have to redo the measurement, really measuring the evolution of pressure."

However, Silvera's team only had one cryostat available, and wanted to avoid doing more tests for fear of breaking their specimen. "Now that that paper has been accepted, we're going to do further experiments," he said. Despite the skepticism, the team is confident of the findings. "It's a tremendous achievement, and even if it only exists in this diamond anvil cell at high pressure, it's a very fundamental and transformative discovery," Silvera said. Pending further testing, you might want to temper your own excitement, however.