If you’ve ever taken a look at the periodic table, you’ll notice that hydrogen sits alone on the left edge atop Earth’s six alkali metal elements. The situation is odd. If hydrogen’s not a metal, why is it positioned there in the first place? Turns out, hydrogen can be a metal, if the conditions are right. And for the first time after being theorized nearly 100 years ago, scientists have been able to make that a reality.
Two Harvard scientists, Thomas D. Cabot Professor of Natural Sciences Isaac Silvera and post-doctoral fellow Ranga Dias, created the world’s first sample of metallic hydrogen by squeezing a small hydrogen sample at 495 gigapascal (that’s over 71.7 million pounds-per-square inch, more pressure than you’d experience sitting at the center of the earth). With that much pressure, the non-metallic solid hydrogen molecule breaks down into atomic hydrogen, a metal.
The now metallic hydrogen should remain metallic once the pressure is removed, the same way graphite, put under intense pressure, turns into diamond and remains diamond, Silvera explains in the press announcement. (In fact, as the hydrogen transformed into a metal, the researchers could actually see it happening: “The hydrogen went from being transparent, to non-transparent and black, and suddenly it became lustrous,” Silvera told Science Alert.)
While the scientists published their findings in Science this week, a number of critics have voiced their doubts at the duo’s achievement. The shininess they observed could simply be aluminium oxide, for example. And as for the intense pressure needed to achieve the feat, peers in the field want to see a more detailed evolution of the pressure, rather than one single static measurement.
If it’s true, however, the scientists’ discovery has a host of valuable uses in the real world. Perhaps most importantly, metallic hydrogen could be used as a room temperature superconductor. Today’s superconductors, which transmit electricity with perfect efficiency, only work at temperatures just above absolute zero—decidedly inefficient conditions to maintain. As for traditional room temperature conductors, 15 percent of energy is lost during transmission over today’s electrical infrastructure. So, making wires from this new material could make our electrical grid far more efficient. Those same superconductive properties could be used in other developments too, from high-speed trains that levitate over their tracks, to more efficient electric cars and mobile devices.
Metallic hydrogen has another potential use too, as the world’s strongest rocket propellant.
“It takes a tremendous amount of energy to make metallic hydrogen,” Silvera explained. He’s been trying to create the material for 45 years. “And if you convert it back to molecular hydrogen, all that energy is released, so it would make it the most powerful rocket propellant known to man, and could revolutionize rocketry.”
That propellant would be more than 3.7 times more powerful than today’s most powerful rocket fuels, and it could be strong enough to make exploration of our solar system’s outer planets feasible.
The 10 micron diameter, 1 to 1.5 microns thick sample created by Silvera and Dias has remained stable since October, and they will begin conducting more detailed analysis of the material.
H/T Business Insider