Harvard physicists may have created solid metallic hydrogen, a discovery which could lead to many cool things, including room-temperature superconductivity.
More testing needs to happen in order for the researchers to be sure of their find, and as the story at Physics World notes, some other physicists are skeptical. Hydrogen is the lightest of all elements, with its atoms consisting of just one proton and one neutron. Liquid and solid forms of elements exist when the atoms in them lose enough energy that they begin to connect with each other -- the solid form having the least amount of energy in it of all. Apply enough energy to a solid and it will melt into a liquid. Apply even more and it will boil into a gas. At almost any temperature and pressure in the universe, hydrogen stays a gas.
That's almost any temperature and pressure, that is. Jupiter and Saturn are formed largely from liquid metallic hydrogen, as the conditions in their huge interiors allow for it. But solid metallic hydrogen remains elusive, even though two physicists predicted its existence more than 80 years ago. The Harvard team may be able to fulfill that prediction if their initial findings bear out.
If solid metallic hydrogen has been created, it could be candidate for superconductivity for electrical currents. Conductive materials that are cooled down below even some of the coldest temperatures ever recorded have been shown to lose their resistance to that current flow, reducing the amount of energy needed to push current through the medium. Those temperatures are almost always too low to maintain without great effort. But if the solid metallic hydrogen exists, it could be a candidate to become such a material at regular temperatures, which could open up all kinds of new fun stuff for scientists to play with. In the meantime, they'll keep checking their work to see if they're right.