Study Plucks Rare Quasicrystal From Wreckage of First Atomic Bomb Test

Researchers found the strange material inside a piece of red trinitite, a glass-like amalgam formed by the blast’s intense heat and pressure

 red trinitite
This sample of red trinitite contained the quasicrystal described in a new study. Luca Bindi and Paul J. Steinhardt

The atomic age dawned at 5:30 a.m. on July 16, 1945, when the United States detonated a device nicknamed “Gadget” in the New Mexico desert, triggering Earth’s first ever atomic blast.

The plutonium-powered test explosion, codenamed “Trinity,” unleashed 18.6 kilotons of power, producing temperatures hotter than the surface of the sun. The bomb vaporized the 100-foot tower it had been hoisted into for the test, and liquified the asphalt and sand below. The amalgam of melted sand, asphalt and other debris including copper and iron cooled into a glass-like material dubbed trinitite after the name of the test.

Now, researchers studying the otherworldly wreckage of that first atomic test say the extraordinary heat and pressure of the event also produced an exceedingly rare form of matter called a quasicrystal, reports Emily Conover for Science News.

Quasicrystals may aid in non-proliferation efforts

Normal crystals have a regular, repeating structure like a brick wall or a lattice. Quasicrystals, on the other hand, have been dubbed “impossible” materials by scientists because of their unusual, non-repeating structures, reports Davide Castelvecchi for Nature. The quasicrystal scientists discovered was nestled amid a hunk of red trinitite and measures just ten micrometers across. It’s the first known example of a quasicrystal that combines iron, silicon, copper and calcium, the researchers report this week in the journal the Proceedings of the National Academy of Sciences.

One of the only other places quasicrystals have been found is on meteorites and that was what spurred researchers to look for them in the aftermath of a nuclear bomb.

“It was a surprising discovery,” Luca Bindi, a geologist from the University of Florence and the paper’s first author, tells Sarah Wells of Inverse. “[T]he idea behind it was: if these materials can really form in the collision of extraterrestrial objects in outer space, then it is conceivable that they formed also in an atomic blast. And they were there.”

Quasicrystals are “impossible” because they violate the rules scientists use to define crystalline materials. Bindi tells Inverse that crystals are “allowed” to have what’s called rotational symmetries—that is, places where the structure could be symmetrically split in half—along one, two, three, four and six axes.

The newly discovered quasicrystal doesn’t play by these rules.

“Icosahedral symmetry, which includes six independent five-fold symmetry axes, is super-forbidden,” Bindi tells Inverse. “Quasicrystals are solids with these rotational symmetries that are forbidden for crystals.”

The researchers discovered the tiny grain of quasicrystal by “looking through every little microscopic speck” of the trinitite sample, Paul Steinhardt, a theoretical physicist at Princeton University and co-author of the study, tells Science News. Researchers confirmed the novel material’s unorthodox structure by scattering X-rays through it to reveal it’s “forbidden” symmetry.

In a statement, Terry C. Wallace, director emeritus of Los Alamos National Laboratory and co-author of the paper, says that quasicrystals might one day be able to be used to piece together information about old nuclear tests.

“Understanding another country’s nuclear weapons requires that we have a clear understanding of their nuclear testing programs,” says Wallace. “We typically analyze radioactive debris and gases to understand how the weapons were built or what materials they contained, but those signatures decay. A quasicrystal that is formed at the site of a nuclear blast can potentially tell us new types of information—and they’ll exist forever.”

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