You Do Realize… That’s Impossible

SUCHITRA SEBASTIAN: That was the moment when the discovery happened. And, at that point, I call a senior colleague and there was a pause. And then he says very kindly, but you do realize that’s impossible. I’m like, I know, but all I can tell you is it’s what’s happening.

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And yeah, over the years, people told me that in less kind of fashion, clearly something was wrong with this finding.

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FLORA LICHTMAN: This is The Leap, a series about gutsy scientists who are risking their careers, their reputations, and even their lives to discover something new.

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People often describe science as a method for generating new knowledge about the world. Another way of saying that is that science makes the world feel like less of a stranger. Finding by finding, we get to the world a little bit better. And, in that way, science can be a comfort. But that’s not always how science goes. Sometimes a discovery does the exact opposite. It makes our world feel more alien. It thrusts us into the deep unknown. It suggests what we knew for sure isn’t a sure thing at all.

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So if you make a discovery like that, how do you navigate in those uncharted waters? How do you make sure you’re not pulled under by an old way of thinking?

SUCHITRA SEBASTIAN: It’s scary. There’s the fear or the discomfort of being unfamiliar, not knowing what’s happening. But that’s the only way you will find something new.

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FLORA LICHTMAN: This is Cambridge University physicist Suchitra Sebastian. She made a discovery like this, a possible new state of matter. It was baffling, and strange, and pushed her into the limelight of her field, which was a surprising place to find herself because for a long time Suchitra wasn’t sure she wanted to be a physicist at all.

SUCHITRA SEBASTIAN: Looking into physicists, it seemed like physics was their whole world. And I just didn’t see myself as that person. Academics sleep in their offices, and I’m like, this is terrible. I do not want to be– and, yeah, that sort of singularity didn’t make any sense to me.

FLORA LICHTMAN: So Suchitra’s path to science had some wiggles. She grew up in India, went to a Christian liberal arts college, where she got involved in theater and activism and got interested in physics, but she wasn’t sure she was cut out for that career.

So after college, she got an MBA, became a consultant, and found that wasn’t her calling either. She missed learning, being in school. So she applied to grad school at Stanford for physics and she got in.

SUCHITRA SEBASTIAN: And I still did everything because I discovered this loophole that when they said have to take 50% of credits, they didn’t say in what. So I took it in theater and I was involved in a lot of activism. So, yeah, I continued to do everything. So I really enjoyed grad school, but I didn’t find a specific research thing I wanted to do. So I was still actually not sure whether I would continue the PhD or anything. I was still–

FLORA LICHTMAN: Wow.

SUCHITRA SEBASTIAN: Yeah. And then in the fourth year, I found a result that didn’t match and that was when I actually understood what research was about. It’s like, oh, that’s great, so things don’t do what they’re supposed to do. So then suddenly I started showing up in lab. My supervisor was like, what happened?

FLORA LICHTMAN: Where have you been? Who are you?

SUCHITRA SEBASTIAN: I’m like burning the candle at both ends. It was very funny.

FLORA LICHTMAN: It sounds like a drug a little bit. A good drug, but there’s probably some dopamine hit from being like, whoa, new thing no one’s ever found.

SUCHITRA SEBASTIAN: Yeah, first you go through the period of I don’t what is happening, this is really confusing to this is really exciting.

FLORA LICHTMAN: The field that lit Suchitra up was condensed matter physics. It’s not easy to sum up, but think of it like this. It’s how tiny components of matter– the atoms, their electrons– interact with each other in mysterious ways to shape the world that we see, and touch, and feel. Suchitra’s PhD discovery, a material doing a weird magnetic thing no one had ever seen before, landed in the journal Nature. It gave her a direction and soon she was on a roll making other big findings. But even though she was successful, she didn’t feel like she belonged.

SUCHITRA SEBASTIAN: It is really cutthroat. It’s dog-eat-dog. It’s all you care about– if all you care about is the physics, then you will do anything.

FLORA LICHTMAN: Can you give me an example of that dog-eat-dogness?

SUCHITRA SEBASTIAN: Oh, yeah, smaller versions of it are not giving credit to someone, presenting your results without recognizing that other people’s results exist. But, also, in physics, anyone– whether it’s me, whether it’s someone else– if they report something, you know the instant reaction is going to be to tear them down, is to find what’s wrong with it. And just the fact of constantly being attacked, constantly being on the defense, knowing a conversation is never just a conversation. When you report something, it’s never just, oh, look at this interesting finding. It’s always what could be wrong with it, which goes as rigor but is really taking someone down.

FLORA LICHTMAN: And Suchitra felt pressure to fit in with this culture.

SUCHITRA SEBASTIAN: It definitely felt like, yeah, do physics in the way we expect you to do, which also meant be the kind of person we expect you to be– crazy things like you laugh too much. And I’m like, well–

FLORA LICHTMAN: Someone told you laugh too much?

SUCHITRA SEBASTIAN: Oh, yeah, yeah, yeah. A couple of times it’s been said to me. It’s very sexist. So I was very confused by this because I was like, I am not an aggressive person. I’m not like going out and trying to make you do things in my way. I’m just existing. Why are you so upset just at who I am?

FLORA LICHTMAN: Physics is one of the most male-dominated fields in STEM. While the gender gap is closing in other sciences, like in biology and chemistry, the gap in US college physics majors is still wide– 4 to 1, men to women. In 2021, about 80% of full physics professors were men and the overwhelming majority white. While that stat has improved, there’s no question that there’s a dominant culture.

SUCHITRA SEBASTIAN: And I’ve questioned it. I’ve spoken to people about it a lot of times when they say, why are there no women in physics? I’m like, look at how toxic it is. Why do you think people would actively choose this? And then they would say, oh, but that’s needed for good science. And people are emotional and they get heated. And I’m like, no. And they’re like, there’s only so many spots in academia and, of course, it’s competitive. I’m like, yeah, there’s competitive. This is not just competitive, this is hostile. But every time it gets justified to me like the culture has to be like this for good science to happen. And, I think, how about all the people you’ve lost?

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You don’t know all the people who were pushed out of this culture and they might have made the biggest contribution. Because, for people like me, it is toxic.

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FLORA LICHTMAN: So Suchitra tried to adapt.

SUCHITRA SEBASTIAN: Initially, I would try to mellow myself. I’d be trying to, I guess, be a little more under the radar so I was like less picked on.

FLORA LICHTMAN: Like laugh less?

SUCHITRA SEBASTIAN: Yeah, yeah, yeah, definitely. It’s a small compromise here or there, not even talk about the fact that I did theater, activism, or I might go to church. And when I would go to experiments, I stopped doing that. But, yeah, also talk less, be more mellow, be a little more like the scientist with gravitas that they expected you to be.

FLORA LICHTMAN: Compromise by compromise, Suchitra was becoming the very person who turned her off of physics as an undergraduate, that physicist who’d give up anything for their research. And that transformation was hard to face.

SUCHITRA SEBASTIAN: I never wanted to recognize to myself that physics had become the most important thing because all through my career, all through my life, of course, I was like, no, it’s not. And at every level I knew I didn’t want it to be that, but it is– it’s unrelenting. And that was a very hard moment to recognize that if it was not the most important thing, then I had to be willing to walk away from it because I think that was always what was being held over you– do it in this way or you can’t progress in physics.

FLORA LICHTMAN: What was the most important thing, if it wasn’t physics?

SUCHITRA SEBASTIAN: Oh, I think knowing that there’s something bigger, knowing that there’s purpose in life, meaning to life, being Christian, knowing that actually there is a greater purpose that is not people’s approval, and really that people are not your audience, they’re not your judge.

FLORA LICHTMAN: It’s interesting to hear you talk about Christianity and religion in this way because, I think, for some people, it can be so stifling and prevent them from being their full selves.

SUCHITRA SEBASTIAN: Yeah.

FLORA LICHTMAN: And it’s interesting to hear that for you it’s the opposite.

SUCHITRA SEBASTIAN: Yeah, I completely recognize why people think this. I think a lot of the time how Christianity is practiced is it’s very judgmental. But, I think, for me, being Christian, knowing there’s a greater purpose is what frees me to explore, to do things that are not popular, to step out into the unknown, to take risks knowing that research is going to go well, it’s not going to go well. The experiment is going to work, it’s not going to work. But that isn’t what defines you.

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FLORA LICHTMAN: Did you have a moment where you recognized this and decided to make a change?

SUCHITRA SEBASTIAN: So, yeah, there was a moment, but it was just me in my apartment literally breaking down, being like, I cannot do this anymore. Something has to give.

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And I will do things in the way I’m doing them and not just in physics. It’s who I am. And if it means I don’t do physics anymore, so be it. And I did make that decision.

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And, of course, it’s not been easy. But, actually, I became my creative best when I wasn’t constrained. And it was very freeing.

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SUCHITRA SEBASTIAN: Suchitra was free to make a leap–

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–which brings us to the state of Florida.

SUCHITRA SEBASTIAN: We were at Tallahassee. We were the High Magnetic Field Laboratory in Tallahassee.

FLORA LICHTMAN: This national lab is home to the strongest magnet in the world. And a super strong magnet is one of the ways to reveal how the electrons in a material are moving, which is why Suchitra was there.

SUCHITRA SEBASTIAN: So high magnetic fields, in this case, are like a magnifying glass to make the oscillations much bigger.

FLORA LICHTMAN: That’s the physics term for the paths of electrons, oscillations. They’re also sometimes called, very adorably, wiggles.

SUCHITRA SEBASTIAN: Yeah, wiggles. And from how fast the wiggles are, how big they are, what shape they have, you can say something about the trajectory, the paths the electrons are taking. So we were in Tallahassee using these very big magnetic fields and looked to see if we could see oscillations.

FLORA LICHTMAN: Which sounds chill when you hear Suchitra describe it– like pop in the sample, let the machine do the work, but that is not the vibe of these magnet runs, as they’re called.

BENG TAN: Magnet runs are actually very, very tiring affairs.

FLORA LICHTMAN: This is Beng Tan, Suchitra’s former PhD student, who was on this magnet run.

BENG TAN: You really need to be very flexible and very nimble because sometimes your measurements fail for some reasons or that you get results you didn’t expect.

FLORA LICHTMAN: It’s high stakes. You plan for months or more, you only get a certain amount of time to use the machines. Things break. Experiments fail. You’re troubleshooting around the clock.

BENG TAN: So typically in the magnet run, I have an average of maybe something like three or four hours of sleep every night. And there was one night– all I remember was that we didn’t sleep for the night, so we just worked throughout the night and continued the next day on the next magnet run.

FLORA LICHTMAN: Beng says Suchitra always seemed to have an infinite well of energy during these runs.

BENG TAN: It’s amazing how Suchitra can always get through all this with all the enthusiasm and excitement that she has and doesn’t seem to get tired. It’s like– I don’t where she gets all her energy from.

FLORA LICHTMAN: So, in Tallahassee, Beng and Suchitra were studying this crystal called samarium hexaboride. And in very niche physics circles, it has celebrity status because it behaves in bizarre ways. Physicists like to put things in boxes and this material doesn’t fit neatly.

For instance, sometimes it seems to be an insulator. Its electrons are largely stuck in place and no current passes through it. And sometimes it acts like a metal, the electrons flow, it conducts current.

Its weirdness required new theories to be devised. And by the time Beng and Suchitra were working in Tallahassee, one leading theory was that the inside of the crystal is an insulator, while the surface is a metal. This is really strange, but, OK, people could get their minds around it. So Suchitra decides to kick the tires on this theory.

SUCHITRA SEBASTIAN: So we go ahead and we mount the sample and– so we take it up to high fields, the resistive doesn’t do anything.

FLORA LICHTMAN: As expected, the bulk of the material acted like an insulator. The electrons were not moving, but then they took a different measurement and saw something that did not fit with any existing theory.

SUCHITRA SEBASTIAN: There’s wiggles on the data and this is completely confusing to us.

FLORA LICHTMAN: The wiggles were coming from the inside. That means the electrons were moving. So basically one measurement says the electrons are stuck, the other shows the electrons are moving.

SUCHITRA SEBASTIAN: And so it’s impossible. If they’re almost stuck in place, how could they be going round and round.

FLORA LICHTMAN: So the first feeling that Suchitra has is not like, ooh, joyful, I discovered something big and new. It’s panic.

SUCHITRA SEBASTIAN: I mean, the first reaction is definitely something has gone wrong because it doesn’t fit what I thought would happen. If it’s a little bit different than what you expect, that’s OK. I can believe that. But if it’s completely different from what you expect, the first few things are always like something has gone wrong. What should I check? Then you check all the obvious things. And then you think of what else have I not thought of that I should check.

FLORA LICHTMAN: They ran the experiment again and again, changing variables, doing every check they could think of, asking collaborators what checks they should do, and each time the data suggested this material was doing something no one had ever observed.

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It didn’t seem to be an insulator on the inside and a metal on the outside, it seemed like the inside was acting like an insulator and a metal at the same time.

BENG TAN: That’s a magical moment.

FLORA LICHTMAN: It was a magical moment?

BENG TAN: Yeah, because you were really not expecting to see that kind of oscillations at all, yeah. So it’s really quite amazing.

SUCHITRA SEBASTIAN: Yeah, it becomes a moment of like, wow, this is amazing. We’ve discovered this thing that literally rewrites textbooks. That’s excitement.

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FLORA LICHTMAN: Samarium hexaboride was strange before, now it was baffling.

SUCHITRA SEBASTIAN: And, at that point, I called a senior colleague and there was a pause. And then he says very kindly, but you do realize that’s impossible.

FLORA LICHTMAN: It was heretical.

SUCHITRA SEBASTIAN: Yeah, because what we about insulators has stood for decades. What we about quantum oscillations has stood for decades. And so, basically, it means everything we thought we knew about an insulator is not right.

FLORA LICHTMAN: By simply reporting this finding, Suchitra was suggesting that those boxes that physicists use to make sense of the world– maybe they’re not right, maybe we need a whole new box.

PIERS COLEMAN: See, in some sense, she proposed something that was completely avant-garde.

FLORA LICHTMAN: This is theoretical physicist Piers Coleman, who sometimes works with Suchitra and has studied this material for decades.

PIERS COLEMAN: A hypothesis requires a certain amount of madness because you’re going to be making an idea, which, by its very nature, is one that is contrary to perhaps the common viewpoint. And so what is avant-garde about the strange experiments that Suchitra and her colleagues have been engaged in is it seems to suggest that a central element of a metal is present in an insulator.

FLORA LICHTMAN: That’s the paradox.

PIERS COLEMAN: That’s the paradox. And I think, according to conventional wisdom, it’s completely impossible. And that’s what makes it so fascinating.

FLORA LICHTMAN: The data Suchitra put forward suggests that maybe electrons can behave in a way we didn’t know was possible.

PIERS COLEMAN: It is a result which, if it’s true, will constitute a new state of quantum matter. And we don’t for sure yet. But if it is, it does require a new idea. It really does. Many theoretical physicists are trying to resolve this paradox. I’m here in Aspen, Colorado, where we have a center for physics in the summer, and we’ve been discussing this over blackboards quite a lot in the last few days.

FLORA LICHTMAN: The physics community has not reached consensus on what exactly to make of Suchitra’s finding. These super pure crystals that Suchitra has access to are hard to come by, so it’s taking time to replicate the results. Also, an impurity in the material can create oscillations for all the wrong reasons. All of this, combined with the fact that the results are so surprising, has created robust debate about what to make of the finding.

Everyone we talked to said more experiments and more theory work are required to really understand whether or not textbooks have to be rewritten. And this is just the way that science goes. It takes time to build on and validate a new idea. But if the process of science is dispassionate, scientists sometimes are not.

SUCHITRA SEBASTIAN: There was a lot of pushback and people–

FLORA LICHTMAN: Like, give me the scale of pushback?

SUCHITRA SEBASTIAN: Yeah, the scale of pushback was literally, yeah, people standing up in my talk and saying– addressing the audience and saying, but we know, from Maxwell’s equations, this is impossible. I’ve had large 6 foot 5 guys that come really close to me and then– like physically intimidating way, and get red-faced, and yell at me. So heated– it’s like they’re going to come to blows over, what, some– one data point.

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PIERS COLEMAN: When you have Copernican moments, it requires courage.

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FLORA LICHTMAN: It takes courage because Suchitra is defying conventional wisdom?

PIERS COLEMAN: That’s right. And by its very nature, when you have a new interpretation, you don’t understand the full details of why your interpretation is right. So Copernicus came up with the idea that the Earth is going around the sun, but he had no idea why the Earth would go around the sun. And so it takes a lot of courage to– with incomplete understanding– to make a hypothesis. And that’s what Suchitra has done.

SUCHITRA SEBASTIAN: I may not understand it. I may not be able to explain it. That doesn’t mean it doesn’t exist, it’s not real. I think it is really about being open to what the data is telling you, letting the data speak, even if it doesn’t fit your template of the familiar.

[INAUDIBLE] speaks about it, the philosopher. She speaks about there being different ways of doing things. And, in one way, the goal is that someday we will know all there is to know. It’s like a closed map where you’re filling in the unknown bits. And it’s almost like we need to know in order to control. And I don’t want any of those things. I want to embrace the unknown. And the point is not to know everything. The point is the wonder, and the curiosity, and the joy of exploration.

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And in that way of doing things, it’s like the map is unrolling as you go into the unknown.

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It’s like taking a leap, knowing that there will be something without knowing what it’s going to be.

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FLORA LICHTMAN: The Leap is a production of the Hypothesis Fund. It’s hosted by me, Flora Lichtman, and produced by Annette Heist. Editing by Saidu Tejan-Thomas Jr., Pajau Vangay, and David Sanford. Fact checking by Nicole Pasulka. Mixing and scoring by Emma Munger. Music by Joshua “Budo” Karp. Special thanks to Jim Allen and Natalie Wolchover. Thank you for listening.

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