The Second Kind of Impossible

by Paul Steinhardt

  I finally understood why the Razin paper had been so devoid of details. It wasn’t because Razin was trying to fictionalize characters and locations in order to hide his location from competitors. It wasn’t because Kryachko was a Chukchi who had disappeared back into the wilderness. And it clearly wasn’t because Kryachko was deceased.

  I concluded that Razin had written the text based on what he recalled from Valery Kryachko’s oral account instead of inviting him to be a coauthor. Perhaps it was because Valery was only a lowly student at the time. For whatever reason, Razin simply did not share the credit with him. It took nearly a quarter of a century after the publication of that paper to discover the truth: Let the record show it was Valery Kryachko who first discovered samples that later proved to have the new crystalline minerals khatyrkite and cupalite and the first natural quasicrystal.

  To my surprise, Valery was already familiar with our Science paper, published about seven months earlier, announcing the discovery of the first-ever natural quasicrystal. Since it involved a Russian sample, the news had been broadcast on national media.

  Until I had contacted him, though, Valery had no idea that he might be personally connected to the natural quasicrystal story. It was my honor to inform him that he was a central figure in the discovery. Valery was elated to hear the news and immediately volunteered to do anything he could to help.

  * * *

  PRINCETON, JANUARY 2010: Later the same month, I met with Lincoln to bring him up to date on the latest series of incredible happenings. I told him the story about how Luca and I had managed to track down Valery Kryachko and that he was indisputably the person who had pulled the St. Petersburg holotype out of the ground, which was very likely the source of the Florence sample as well.

  Over the past few months, I learned the hard way that Lincoln never attempts to hide his displeasure. Now, I was about to experience the opposite was true, as well. Once Lincoln heard the good news, it was as if a dark cloud suddenly vanished from the room. I watched a grin come over his face and knew that the legendary Lincoln Hollister was officially on board. It was just the reaction I had been hoping for.

  I was still relishing the moment when he made a startling proposition: The next step is an expedition to the Kamchatka Peninsula to look for more samples. You simply must go, Lincoln insisted.

  Lincoln then wrote to his red team colleague, Glenn MacPherson, at the Smithsonian:

  Paul has come up with stuff that points to the provenance of the sample in the eastern Koryak Mts. He found the guy that collected the original sample, and the connection between the Florence sample and the St. Petersburg sample is persuasive. I think there is enough to support a proposal to NSF to go to the locality and figure out the geological setting of the locality and, with luck, get more sample.

  I was not quite sure what to make of it. But I could sense that the search for natural quasicrystals was about to switch gears, and would be moving from the laboratory into a realm I knew nothing about.

  FIFTEEN

  * * *

  SOMETHING RARE SURROUNDING SOMETHING IMPOSSIBLE

  PASADENA, MARCH 19, 2010: It was a beautiful day in Pasadena and a warm reminder of one of the things I enjoy the most about Southern California—the weather. Patchy snow was still on the ground back home in Princeton. But here, spring was already in full bloom. I soaked up the sun as I headed across the Caltech campus.

  I walked along one of the main routes, which took me down the Olive Walk and past a familiar two-story building. Lloyd House, my freshman dorm. I was flooded with memories as I walked by. I had experienced my first-ever earthquake in that dorm, a frightful jolt that knocked me out of bed in the middle of the night. I remembered the awkward moment, also as a freshman, when I screwed up enough courage to offer a timid greeting to my physics hero and eventual mentor, Richard Feynman.

  I recalled again his famous admonition: You are the easiest person to fool. And all these years later, it was Feynman’s advice that brought me back here. I wanted to be absolutely certain that I was not fooling myself about our quasicrystal investigation.

  I was heading toward a lunch meeting at the faculty club with Ed Stolper, the highly respected Caltech provost and well-known geologist. Ed had a reputation as a critical thinker who could be unsparingly, perhaps even brutally honest. I was betting on his frank assessment of our investigation. Ed had spent his career studying both natural and man-made materials. Working on JPL’s Mars Exploration Rover mission, he had discovered remarkable similarities between a rock on the Martian surface and a rare rock sample found on Earth. He had also made special studies of man-made materials exposed to the elements, weathered pieces of slag that could easily be mistaken for a natural sample. That made his work directly relevant to our investigation. I was armed with a huge binder stuffed with our accumulated research. With his vast expertise, Ed would be able to judge if the sample we were studying was potentially worthwhile, or if there was any possibility it was just an old beat-up piece of scrap metal.

  I had reviewed my presentation with Luca. But I had not told him everything. The meeting carried more downside risk than I cared to admit. The truth would have made him sick with worry. Ed was well known and highly respected throughout the scientific community, so any hint of disapproval from him would be disastrous. If he expressed any serious doubts, Lincoln and Glenn would run away from the project. Rumors would spread and eventually undermine my relationships with other respected geologists, whose support was crucial to our research efforts.

  Ed and I had never met, but we recognized each other immediately from photographs. He had wavy brown hair, glasses, and a welcoming demeanor that helped put me at ease. We sat down for lunch and got to business fairly quickly.

  He listened patiently as I made my lengthy presentation using figures and tables from my thick notebook. By now, our investigation was a complicated story, and I had spent quite a bit of time organizing all of the relevant details.

  Ed took note of our theories of how the quasicrystal might have formed. He also considered the fact that many other experts believed the Florence sample must be slag and the evidence that Luca and I had collected suggesting otherwise. He interrupted me occasionally to ask incisive questions but never revealed what he was thinking, not even when I admitted that we had not found any decisive evidence to support our theory that the Florence khatyrkite sample was natural.

  Lunch was nearly over by the time I finished laying out our case. I sat back, knowing I had given it my best shot and waited to hear his reaction. Would this be the end? I wondered.

  Just as I expected, Ed delivered a frank, no-nonsense opinion, beginning with the bottom line. He firmly declared that there was “no chance” that our sample was synthetic. It was definitely not slag, he said, or anthropogenic.

  Fantastic! I thought. The gamble had paid off! I wish Luca were here to share this moment.

  Ed pointed to several of the chemical and geological clues from my presentation to support his conclusion. He also weighed in on the possible theories I had mentioned about the sample’s formation: lightning strikes; volcanoes; hydrothermal vents; collisions between tectonic plates; debris from rockets or jets; and, of course, deep Earth processes and meteorites. He thought the meteorite explanation was unlikely and preferred some of the other theories we were still considering.

  My pent-up anxiety was slowly melting away as I listened to Ed. It is always hard for me to explain to my university students how difficult it is for a scientist, even an established scientist such as myself, to challenge conventional wisdom. Everything always appears to be so simple to others in retrospect. They lose sight of the fact that making scientific progress is always a struggle that requires a great deal of personal endurance. There is a huge amount of peer pressure to conform. For example, after Luca and I suggested that our sample of metallic aluminum might be of natural origin, which was generally thought to be impossible at the time, we were subjected to more than a year of skepticism and
withering criticism from certain experts, including our own colleagues on the red team. It had not been easy. The negative comments were sometimes so harsh that the two of us were left dispirited. But work is a great coping mechanism. We kept plowing ahead, incrementally gathering additional evidence to test our thesis. After fourteen months of hard work, it was greatly satisfying for me to hear Ed validate our efforts.

  As the meeting ended and I expressed my gratitude for his time and expertise, Ed left me with one last, and as it would turn out, crucial piece of advice. He suggested that we analyze the abundance of rare oxygen isotopes in our sample. It was a novel line of inquiry that Luca and I had never considered, and something Ed thought would help us reduce the remaining list of possible explanations.

  I sat alone at the table for a short while after Ed returned to his office and marveled to myself at what had just happened. I gathered up the pages from my notebook that were strewn about the table and wrote a careful record of the meeting to share with Luca.

  Ed had grilled me with penetrating questions. Time after time, I was able to reach into my thick notebook and locate a figure or table that provided a precise, unambiguous answer. Being able to answer all of Ed’s questions so completely made me appreciate the wealth of evidence that Luca and I had assembled. Our seemingly scattergun, all-out approach of pursuing every possible lead and conducting every possible test had paid off. Thanks to Ed Stolper, the case for a natural quasicrystal would have to be taken seriously by everyone in the scientific community.

  Our investigation is definitely legitimate, I told myself.

  I spent the next few hours alone, strolling through campus and the surrounding neighborhood. I reveled in the wondrous arrival of spring and reminisced about Feynman, wondering what he might say.

  * * *

  PRINCETON, LATE MARCH 2010: A few days later, I returned home to winter’s cold embrace. Lincoln and Glenn were suitably impressed when I told them about Ed Stolper’s analysis and generally positive reaction. It was promising, they conceded. But they continued to grouse that we still did not have decisive evidence that our sample was natural.

  * * *

  FLORENCE, MAY 17, 2010: Six weeks later, the blue team was finally prepared to deliver what the red team was asking for.

  Ever since our initial discovery of a natural quasicrystal fifteen months earlier, Luca and I had been grinding away in our separate laboratories, searching for clues among the dwindling number of ever-smaller grains of the Florence sample. A month after my discussion with Ed, Luca began examining a grain that was only 70 nanometers across, about one-hundredth the width of a human hair, when he spotted something truly remarkable. Rather than send me an email explaining what he had found, he made an appointment for us to Skype chat the next day, with the promise of “some news” he wanted to present.

  When we connected the next day, Luca typed into the Skype chat box: “Please give me five minutes to prepare the file for you. . . . I have amazing news . . .”

  My immediate response was to type: “Ok!!! But I have been on the edge of my seat all night!” Luca was not one to exaggerate test results, so I was anticipating an important development.

  “The surprise will be great,” Luca typed. “Trust in me.”

  I sat waiting impatiently for what felt like an eternity. Finally, a large electronic file arrived from Florence. I opened the file, and my eyes went wide as the image appeared on my screen. I caught my breath. I could not believe what I was seeing. Luca had discovered a grain of stishovite.

  My mind began to reel at the implications. “This is amazing!” I wrote. “How sure is the identification of stishovite?”

  “100% plus,” he replied.

  Stishovite is a famous mineral named after the Russian physicist Sergey Stishov, who first manufactured it in his laboratory in 1961. It can only form at extremely high pressures, about 100,000 times the pressure exerted by the Earth’s atmosphere at sea level. A short time after it was discovered in the lab, a natural example of stishovite was discovered at Meteor Crater in Arizona. Upon further study, scientists proved it had formed as the direct result of the hypervelocity impact of a meteor with the Earth.

  The discovery of stishovite in the Florence khatyrkite sample supported our opinion that it was, indeed, natural. The pressures needed to create it could never be reached in any industrial process. Stishovite is well known as an indicator of an ultra-high-pressure phenomenon, something far beyond the scope of any of the normal geological processes that occur on the surface of the Earth.

  The chemical composition of stishovite is very familiar: SiO2, silicon dioxide. One part silicon to two parts oxygen, which is the same chemical formula that applies to ordinary sand or window glass. What makes stishovite so distinctive is the way the atoms are arranged. The process is directly analogous to carbon atoms, which form one kind of crystal arrangement on the surface of the Earth, resulting in graphite, and a different arrangement of atoms at high subterranean pressures, resulting in diamonds. Silicon dioxide molecules also make different crystal arrangements depending on whether they are created at ordinary pressures, resulting in sand, or ultra-high pressures, resulting in stishovite.

  The difference between stishovite and sand can be unambiguously detected by looking at the spacing and arrangement of sharp Bragg peaks in an electron diffraction pattern. Luca had already performed those tests and sent me a series of diffraction patterns that left no doubt about the sample’s identity.

  A few days later, Luca emailed me the magnified image of a tiny region of the stishovite grain that provided even more stunning news.

  The blurry black-and-white image seen below may appear unimpressive. But from a scientific perspective the photo truly amazes.

  The image is a combination of something very rare surrounding something impossible. Stishovite, the silvery material, is the rare substance. It is seen surrounding an icosahedral quasicrystal, the black slug, something once considered to be impossible. Actually, “doubly impossible” would be a more apt description of the quasicrystal. Impossible because of the forbidden five-fold symmetry. Impossible again, because of the chemical composition that included metallic aluminum, which had never been seen to occur naturally.

  We knew that the stishovite was the product of a high-pressure phenomenon which is only possible under certain circumstances: deep under the surface of the Earth, during a collision in outer space, or as a result of the impact of a very large meteorite with the Earth’s surface. The pressures involved were far above what could be reached by any normal anthropogenic activity.

  In this particular sample’s case, we could immediately rule out the possibility that the quasicrystal formed when a large meteorite struck the Earth’s surface. That would have melted the aluminum-rich metal seen throughout the Florence sample and caused it to chemically react with the oxygen in the Earth’s atmosphere.

  The fact that the quasicrystal survived the high pressures required to make stishovite taught us another lesson. It told us that the quasicrystal already existed when the stishovite was formed, and that together they had managed to endure the kind of ultra-high pressures that can only be found far outside the influence of human activity.

  Here was the direct proof of a natural origin that Lincoln and Glenn had been seeking.

  I immediately called Lincoln to share the exciting news. I took great pleasure composing the email to Glenn, attaching Luca’s most recent image along with our analysis. I was eager to see if he would respond skeptically, as usual. He wound up hedging his bets:

  If it really is stishovite, and there really is QC inside of it, this is a game changer.

  Almost all our previous theories of how the Florence samples formed could now be discarded. The Florence sample could not be slag. It could not have been made by miners fooling around at a campfire. It could not be the result of exhaust from a jet airplane. It could not have been made by an explosion or manufactured in an ordinary laboratory. It could not be caused by lig
htning, or by hydrothermal vents or volcanoes. None of the theories others had postulated could produce the extraordinary pressures required to form stishovite.

  Equally revealing was the way the stishovite and the quasicrystal were fused together. This proved that quasicrystals are not as fragile as previously supposed. Since the quasicrystal was totally enclosed in the stishovite grain, it meant the quasicrystal could survive ultra-high pressures.

  Glenn conceded all these points but wanted to exhaust every conceivable alternate explanation, no matter how remote. As a last gasp, he asked us to consider whether the sample might be the result of an atomic bomb test. Luca and I were easily able to eliminate that idea because measurements showed the sample did not have any of the heavy elements that would be the by-products of a nuclear explosion.

  There were only two plausible theories left that could explain the presence of stishovite. The sample could have been created in inner space, formed thousands of miles below the Earth’s surface and conveyed to the outer crust in a superplume. Or it might be a visitor from outer space, a fragment created by the violent collision of two asteroids.

  Which possibility was right? And how could we prove it?

  SIXTEEN

  * * *

  ICOSAHEDRITE

  PASADENA, MAY 2010: Inner space or outer space? That was the question.

  In my mind, the meteorite theory, outer space, was always the leading explanation for the origin of our natural quasicrystals. Meteorites contain a much wider variety of metals and metal alloys than terrestrial minerals. But we needed something more than a rational argument. We needed incontrovertible evidence.

  Two months earlier, Ed Stolper had advised me that we could decide the issue by analyzing the abundance of rare oxygen isotopes in our sample. He referred me to geochemist John Eiler, who studied the origin and evolution of meteorites, among other things. But until we discovered the stishovite sample, I did not feel confident enough to impose on John and ask him to use his expensive equipment to test our sample.