Philly physicist's 30-year quest brings proof of unknown matter and prestigious award
November 16, 2012By Faye Flam
Back in the early 1980s, a young physicist named Paul Steinhardt imagined a new form of matter – one whose atoms were arranged in patterns with symmetries believed to be impossible.
In all known crystals, atoms or clusters of atoms repeat in regular intervals, like building blocks. Such regular repeating patterns are impossible to create with certain shapes, such as crystals with five-fold symmetry. Steinhardt realized that a crystal-like pattern with five-fold symmetry could work if there were two different types of building blocks that alternated in sequences that never repeated.
He and a graduate student named this theoretical form of matter quasicrystals, and demonstrated its physical possibility in a paper published in 1982, while they were working at the University of Pennsylvania.
Quasicrystals would lead to a Nobel Prize for someone else, but fate sent Steinhardt down a different path.
To prove his idea that quasicrystals were indeed a new form of matter of the same status as crystals, he launched a decades-long quest to find them in the natural world, leading him to a forbiddingly remote mountain range East of Siberia and a rock smuggled out of the former Soviet Union that had formed before the birth of our planet.
Friday evening at the American Philosophical Society, the Board of Directors of City Trusts will give Steinhardt the John Scott Award. The award was initiated in the 1800s by a Scottish Chemist who wanted to honor Ben Franklin's legacy. Past recipients include Marie Curie, Thomas Edison, Buckminster Fuller and Jonas Salk. Also winning the award this year are the husband and wife investigative team of John Q. Trojanowski and Virginia Lee, who have done groundbreaking work in understanding dementia and other neurodegenerative diseases. Virginia Lee is featured on the front page of the Philadelphia Inquirer on the same day, not for the award but for another important finding in the biology of Parkinson's Disease.
Steinhardt's quasicrystal tale started with a textbook-defying idea and a graduate student, Dov Levine, who wanted to collaborate on a theory that showed how this idea might be allowed by the laws of physics. (The early 80s was a productive time for Steinhart – he also made a major contribution to cosmology as one of the architects of "inflation" – the version of the big bang theory still favored today.)
Steinhardt said he went to IBM labs in 1984 to convince someone to try to make a quasicrystalline material, but in the meantime, a chemist at the National Bureau of Standards, now NIST, had written a paper describing a puzzling alloy that defied the known laws of crystallography. Scientists used a technique called electron diffraction to study crystal structure, and those electron patterns told Steinhardt that this material was a real example of his theoretical quasicrystals.
The chemist who made the material, Dan Schechtman, won the 2011 Chemistry Nobel.
"Schechtman's accidental discovery confirmed what we'd predicted," said Steinhardt, or at least partly confirmed it, since Steinhardt also predicted that quasicrystals should form in nature, and Sheckman's material was made under artificial laboratory conditions.
Years stretched into decades as Steinhardt screened different mineral samples. Then, in 2007, he got an email from a man named Luca Bindi, who headed a mineral museum in Florence, Italy. Bindi offered the chance to screen the museum's extensive collection. That led nowhere, until Bindi suggested they include some additional samples. One of those turned out to be a winner, Steinhardt said. Now, all they had to do was find a geologist to explain what kind of a rock they were looking at.
But geologists said this rock could not have formed naturally on this planet. It was full of metallic aluminum, and the oxygen in our atmosphere would have converted it to aluminum oxide. One thing they knew – this rock had a story.
Through letters and diary entries, Steinhardt and Bindi discovered the rock had been smuggled from the former U.S.S.R. It appeared the rock was originally found in 1979 by a Soviet prospector, sent to search for platinum at the very Eastern edge of the country, a nearly uninhabited area called Chukotka. The prospector hadn't found any platinum, said Steinhardt, just a rock with unusual looking grain. The prospector's boss discovered the rock included a new mineral, and therefore probably worth money. Little did the prospector's boss know he was selling a piece of an entirely new kind of matter.
Or new to science, at least. In his sleuthing, Steinhardt also turned to Caltech, where he'd been an undergraduate. The scientists there did some additional tests and told him, indeed, the rock had not formed naturally on Earth – it was born before Earth existed. It was a meteorite called a carbonaceous chondrite – a relic of the condensing cloud of material that would become the planets of the solar system. It must have been swirling around outer space for nearly 4.5 billion years before a chance collision brought it to earth within the last 15,000.
By the time they'd traced the story of the world's only known natural quasicrystal, however, Steinhardt said there wasn't much of it left, since parts of it get destroyed in the process of studying it. He realized the only way to get more of this material was to go back to where it was found.
And so he organized an expedition to Chukotka, which took place in the summer of 2011 and included Valery Kryachko, the Russian prospector who originally found the rock back in 1979. Steinhardt noticed that Google maps showed no roads anywhere near this place. When they arrived, they found themselves in vehicles, "like a tank of some kind with a beat-up van on top." For four days they crawled through the barren landscape at 10 miles an hour. Among his many worries were that they'd come back empty handed or worse, that someone would be attacked by a bear.
Instead he ended up with his team intact and more quasicrystals from before the birth of the solar system, he said. "It was a great adventure."
Follow Faye Flam's science writing at http://www.newsworks.org/lightningrod
or on Twitter: @fayeflam
Images of expedition leaders out in Chukotka:
Transmission electron microscope Image of a real quasicrystal overlaid with the theoretical drawing of the same pattern: