Brad Lemley writes in the April issue of Discover about a metal strip as thin as aluminum foil that cannot be even be severed by wire cutters. When a steel ball is dropped onto it, the ball bounces back and will not go through it.

Lemley writes, "It's all astounding, yet oddly familiar. In the typical science fiction film circa 1950, there's that scene in which scientists return from the just-landed flying saucer and tell the Army brass that no tool known to humankind an cut, burn, bend or otherwise scar the hull. But the metal in front of me is decidedly terrestrial in origin—it was developed in Pasadena…

"It's called metallic glass, or amorphous metal, and it appears to be nothing less than an entirely new class of material that can be used to build lighter, stronger versions of anything." Amorphous metal is made by rearranging the atoms in metal so they react differently to heat. William Johnson, who helped discover it, says, "This is the structural material of the future." Was it also the structural material of the past for another civilization?

A strange type of foam, made up of magnesium and bismuth, with gaps between elements which do not reveal how they are sandwiched together, was also found at Roswell. Johnson says, "A sandwich made of two thin sheets of amorphous metal flanking amorphous foam would be strong, light, insulating fireproof, bug-proof, rustproof, sound dampening, and difficult to penetrate with bombs."

“Try to tear it,” says William Johnson, a materials science professor at Caltech in Pasadena.

Lemley pulls—first gently, but soon with all his might. No go.

“See if you can cut this,” suggests Johnson’s postgraduate assistant Jason Kang, handing him a mirror-bright piece of the same metal. It’s an inch long, a quarter inch wide, and thinner than a dime. He bears down with a heavy-duty pair of wire cutters. The metal will not cut. He tries again, squeezing with both hands until his fingers ache. Nothing.

But the most amazing act in this show is yet to come.

“Watch,” says Johnson. From a height of about two feet, he drops a steel ball onto a brick-size chunk of the metal. The ball bounces so high and for so long—1 minute and 17 seconds, with a metronomic tick, tick, tick—that it looks unreal, like some kind of cinematic special effect. “When you try that with regular steel, it goes ‘clunk, clunk, clunk’ and stops,” says Johnson. If the metal were glued to an unyielding surface such as concrete (instead of sitting on Johnson’s oak coffee table, which absorbs a lot of the energy), “the ball would bounce for more than two minutes,” he says. “I’ve done it.”