Science Friday - Superconductivity Search, Ride-Share Congestion, Lions Vs. Porcupines. May 10, 2019, Part 1

Episode Date: May 10, 2019

Six decades ago, a group of physicists came up with a theory that described electrons at a low temperature that could attract a second electron. If the electrons were in the right configuration, they could conduct electricity with zero resistance. The Bardeen-Cooper-Schrieffer theory, named after the three physicists, is the basis for how superconductivity works at a quantum level. Superconductivity would allow electricity to flow with no loss of heat from its system. Since that time, scientists have been trying to find a real-world material that fits that theory. One way to achieve this is by turning hydrogen into a metal. This is accomplished by squeezing hydrogen gas between two diamonds at such a high pressure that it solidifies. That metal then becomes a superconductor at room temperature. Previously, achieving zero resistance had only been possible by cooling the superconductor to near absolute zero. Ira and Gizmodo science writer Ryan Mandelbaum talk with physicist Maddury Somayazulu and theoretical chemist Eva Zurek about the progress towards creating a room-temperature superconductor and how this type of material could be used in quantum computing and other technology. During times of drought or disease, lions have to turn to other sources of food like the East African porcupine. But while the lion may get a quick meal when it attacks a porcupine, the porcupine may win in the long run. Writing in the Journal of East African Natural History, Julian Kerbis Peterhans and colleagues found that an untreated porcupine quill wound is often enough to severely injure a lion. If the wound becomes infected or hinders eating, it can lead to death. And, when a lion is injured and has difficulty hunting its usual prey, it can sometimes turn to easier sources of food—like humans. Kerbis joins Ira to talk about the study, and what this seemingly mismatched battle can teach us about survival in the animal kingdom. Plus, a new study found that the presence of services like Uber and Lyft increased road congestion in San Francisco. And a roundup of the week's science news, including a rattling remark about climate change from U.S. Secretary of State Mike Pompeo at an Arctic Council meeting. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Hey, podcast listeners, Ira here. Science Friday is cooking up a new podcast, and we want to hear what you think. This new show is all about science history. We're reaching back into the science history vaults, dusting off stories you've never heard in school. So go to ScienceFriday.com slash survey to hear an exclusive sneak peek of our first episode. And then please answer a few questions about it. The answers will help shape this new show. Science Friday.com slash survey.

Listen and tell us what you think. Science Friday.com slash survey. And thanks. This is Science Friday. I'm Ira Flato. A quick program note. Our degrees of change series about the problems of climate change and how we as a planet are adapting to it, happy to announce it returns next week.

And we've been asking what you're doing in your community. And we're getting a lot of great stories. just highlight one of them? My name is Lynn Spiddley Handlin, and I live in Happy Valley, Oregon. I recently organized a combat climate change public ritual in a park in a suburban area, not at all known for any kind of activism. People gathered in the local park. We created sacred space and then shared ideas on what we can do to combat climate change, big and small ideas, like not using single-use plastic cups, contacting elective officials weekly, giving up dairy, joining a climate change organization and volunteering, doing habitat restoration, and so on.

Then we each chose a single idea and made a commitment to doing that action for a year and a day. Lynn spent a Larry Hanlon, and she sent in her idea. Would you like to send in your idea? We would love to hear from you. Maybe get you on the radio. Go to ScienceFriday.com slash degrees of change to get involved and tune in to hear a new chapter. It's going to be next week. And as climate change marches on, the Arctic is warming twice as fast as the rest of the globe,

leaving people in places like Greenland, Alaska, Canada, and Russia to try to adapt. But as the International Arctic Council convened this week to discuss cooperating on how to best protect their shared interest against, say, climate change, the United States delegation, let's say, went in a different direction. Here with that story and other short subjects in science, Sophie Bushwick, technology editor, scientific American. Hi, Ira. It's good to see you, Sophie. You too.

So U.S. Secretary of State Mike Pompeo said some unexpected things with the Arctic Council this week, right? That's right. So the Arctic Council normally avoids, for example, security issues, but he spoke about developing the Arctic and about how the opportunities that warming opened up for things like drilling and transportation through the Arctic and about how the U.S. would be protecting its interests in those areas, as opposed to signing on to a declaration that the other seven nations in the Arctic Council wanted to have a joint declaration saying, essentially, we should combat climate change and we should reduce black carbon emissions to do so.

And that's because he would not agree to the word climate change in any agreement. Right, right. So they didn't sign an agreement for the first time in a long time. Yes, and that's very, it's very frustrating because it's called global warming because it affects everyone across the globe. It affects Americans who live in Alaska, for example, where global warming is already having an effect. The Arctic is warming something like four times faster than the rest of the planet.

And so in Alaska, for example, people who live there rely on frozen rivers for transportation during a big chunk of the year. And normally these frozen rivers start kind of melting and becoming unsafe for use in May. They've started this year they were starting to become unsafe in March, and people actually died by trying to use the roads for transport and falling through. So this is not just dangerous for loss of life, but it's a huge financial hardship for people who live in the area. You know, they've got to get on a plane to go buy groceries, and they can't hunt because you can't

take the road out. Wow. So are the other countries going to go along by themselves without the U.S.? The other country signed a partial agreement just mentioned in climate change, but the joint one couldn't, wouldn't work out. Man, it sounds like Mike Pompeo might want. want to talk to a kid, right, if he needs some better perspective on climate change. Right. So some researchers in North Carolina noticed that we've had this wave of teen climate change activists, including Greta Toonberg, who's sort of spearheaded this movement to strike for awareness of climate change.

And so they decided to see, well, are these kids changing their parents' minds? So they set up a study where they looked at more than 200 families. Some of the students in these families were exposed to a climate. change curriculum, a few classes that focused on educating them about climate change and they did a project and they were encouraged to interact with their parents about it and to interview their parents and show off what they were learning. And they found that all of the parents actually over the course of two years became more concerned about climate change. But in particular, the ones who children took this curriculum, their worry about their awareness of climate change increased the most.

And it was particularly notable among fathers and among parents who identified as conservative. So they were actually able to change minds? They were. They found that the parents went certain, these groups that were more affected. So fathers and conservative parents went from being a negative two rating, which meant they weren't particularly concerned to a positive two, which meant they were. I know the kids are going to save us. We went. Let's hope so.

I don't think we can rely on the grown-ups too. Oh, Lord. I'm moving on. I hear you got some good news for plastic recycling. That's right. So plastic is really difficult to recycle. A lot of times if you melt it down and then try to make something new out of it, it won't necessarily be as functional as something made fresh would be.

And that's because when you make plastics, a lot of times they're mixed in with additives, color or something that might be like flame retardant to help make them more useful. And then it's hard to reuse. So what researchers have done is developed a new type. of plastic that's much easier. You can add acid and it will break down to its very basic building block components called monomers. And from that, it can be built back up into a totally different type of plastic.

That's terrific. Let's talk about one last cute little story and cute in the terms of a dinosaur, a tiny T-Rex? That's right. Predacesar. Right. So this is a little possibly ancestor or cousin of T-Rex called Susque-Tirannis Hazelay. It was just identified officially. And one of the neat things about this find is the researcher who wrote the paper identifying it is actually the one who found these remains back when he was a teenager.

So he found these remains in the 90s when he was on a dig. And he's been interested in paleontology ever since. He grew up. He became a professor and he's just written this paper identifying this new species. And so he's been hanging out with this bag of bones? Kind of. Would you look at this? He's actually, he has, as he's gone to different posts,

He's brought the bones with him, and then they've identified it as a species that probably lived about 20 million years before T-Rex. It was about three feet tall, nine feet long, a little bit, you know, a little bit more tiny than its more famous cousin. I'll bet. Yeah, it's certainly not one you're going to bring home either. Not necessarily. Even a tiny dinosaur could be pretty dangerous. Just look at cassowaries if you're worried. Absolutely.

Thank you, Sophia, as always. Great to have you. Sophie Bushwick, Technology Editor for a Scientific American. And now it's time to play good thing, bad thing. Because every story has a flip side. And this week, Uber became a publicly traded company in a tumultuous day of trading. Their IPO comes the same week as a strike by their drivers. Ride-sharing companies, like Uber, sometimes tout their services as a greener option,

reducing the need for individually owned personal cars. But a study out this week questions the results of those good intentions. Joining me now is Greg Earhart. He's an assistant professor in the Department of Civil Engineering, University of Kentucky in Lexington, and one of the authors of the study in the journal Science Advances, looking at the effects those ride-hailing app companies have had on the city of San Francisco. Welcome to Science Friday. Thank you. It's a pleasure to be here, Ira. Oh, you're welcome. So those ride-hailing app companies say it'll reduce the number of cars. Is that accurate from your study? No, it's not. What we find, in fact, is that most users, about two-thirds of the vehicles on the trip, are actually new cars on the road that otherwise would not be here.

And that includes people who are switching from transit, switching from walking or biking, as well as the drivers driving around deadheading, as we call it, or looking for passengers with an empty vehicle. And also the number of rides, not just the number of cars, but the number of rides went up. Why was that? The number of rides went up because what happens is people are, it's a more convenient way. It's a more convenient way to get there. But the total delay and the total traffic congestion caused by this goes up as well. Between 2010 and 2016, we found the traffic congestion in San Francisco, measured by vehicle hours of delay or sort of how much extra time it spends in order to get to my destination. Went up by about 60%.

and Uber and Lyft responsible for about two-thirds of that increase. So do we have these drivers just hanging out on the roads waiting to be hailed, and that congests the roads also? Yes, that's correct. They spend somewhere between 20 and 30 percent of their miles driven, driving around with no passenger looking for a ride. How did you get the data for this study? So that was a challenge.

I mean, we live in an era where everyone wants to talk about big data, but the reality is most big data is controlled by a particular company. Uber and Lyft have plenty of it themselves, but they have no interest in sharing with researchers like us or with the Transportation Authority in San Francisco. So what we did is we teamed with some partners who wrote sort of a computer program that simulates what your smartphone does in talking to their servers. And it tells you where each of the nearest closest drivers are. We had them collect that information every second for a period of six weeks in a grid across San Francisco, and you can get a trace of where the driver is driving around,

and then when it disappears from the map, shows up a few minutes later somewhere else, we can infer that there's a trip in between. So you were able basically to map all those little cars we see on the app where they were driving? That's exactly right. You open up your app, you see the cars, and that's actual real data showing where real drivers are. And so if you collect enough of it, put that together, we can paint a picture of where all those vehicles are in the city. And what we find is that they're actually concentrated in the most congested part of the city, very concentrated in downtown, and concentrated in the most congested times of day during the a.m. rush hour in the afternoon rush hour.

And so how much of an impact did the presence of these companies have on that congestion? I mean, traffic is congested anyhow. Could you tweeze out how much Uber and Lyft accounts for the congestion? Exactly. So it's about two-thirds of the increase between 2010 and 2016 as our metric, and that increase is about 60% in vehicle hours of delay. So it's quite a bit. And the reason for that is because traffic is sort of non-linear, if you will,

adding a few cars to the road in the middle of night when no one else is around makes very little difference in travel time, but adding a small number of cars to the road in the middle of a rush hour makes a very big difference, and it's very concentrated in places that are already congested. Fascinating. Thank you. Thank you for that work. Thank you. Greg Earhart is an assistant professor in the Department of Civil Engineering at the University of Kentucky. We're going to take a break, and afterwards we're going to come back and talk about the search for superconductivity,

the next super material. Why is it in such high demand? You know, we have it at really cold temperatures. How do we get it up, up in the Kelvin scale so we can use it at room temperature? That is the holy grail of this. We'll talk about it with Ryan Mandelbaum after the break. Stay with us. This is Science Friday. I'm Ira Flato.

You know, all of our electronics works by conducting a charge and passing along. Almost every material can carry a charge, even wood, metal glass. But some of our materials are better. They're better conductors than others in shuttling those electrons around. Well, what if there was a material that could perfectly carry a charge? No resistance, no loss of heat, everything stays in that system, and what if you could get it to work at room temperature? That's a very hard thing to accomplish, and scientists out there are trying to create this type of superconductor. And they're using a material that you might not think of hydrogen, the most abundant known gas in the universe.

The scientists are trying to turn that free-floating gas into a metal and then into a superconductor. How do you do that? That's the topic of a story that my next guest reported on, and he is here to talk about it. Ryan Mandelbaum, a science writer for Gizmodo here in our studios. Hey, Ira, how's everything going? That's great, you know. This is like the Holy Grail, sort of. Yeah, I mean, it's amazing.

If it could exist, it could be revolutionary. Okay, let's talk about back up a little bit and talk about the theory that predicted superconductivity. What does it say? How does it work? Sure. So superconductivity is interesting because it was over 100 years ago where a scientist found that liquid mercury could, you know, at very cold temperatures, could carry charge without resistance, which basically that just means that the wire doesn't heat up when you pass electric charge to it. it's resistance list. And this would be big for transferring energy.

Now, that was at really, really, really cold temperatures. I mean, we're talking negative 452 degrees Fahrenheit, just a few degrees above absolute zero, which, you know, you all might know, is the temperature at which matter has no heat. So it's hard to do this. But since then, theorists finally developed a theory to understand and explain what was going on, and this is now driven research into finding superconductors at higher temperature. is where the ideal superconductor would be one at room temperature, so you could operate it in a room.

But theoretically, is it possible to create a superconductor? It's so cold now, and we have them, powering MRI machines and a large Hadron Collider, is theoretically it's possible, then? To create one, maybe it's room temperature. Yeah, I mean, the hope is that theoretically, I think that I haven't seen what the most recent theories, but they get close. I mean, right now, even experimentally, actually, they've been able to create tiny amounts of superconducting material at, it seems almost, you know, the temperature in Chicago on a cold day.

Okay, we'll talk about that a little bit more after we talk a little bit about the experiments with hydrogen. You wrote about hydrogen. It doesn't sound like the easiest thing to work with. How do you turn hydrogen into a metal and then a superconductor? Well, you might remember from high school chemistry that matter is sensitive to both temperature and pressure. So if you compress things enough, they might become a liquid or a solid. So hydrogen, it's theorized under high enough pressure, would become a metal and would potentially be a superconducting metal. And so just sort of both for curiosity's sake and for hoping to find the superconductor scientists have begun these high pressure experiments hunting for metallic hydrogen.

Yeah, and you visited one of these labs? I did. I was actually at the Carnegie Institute in Washington, and I wasn't able to watch sort of the creation of this, but I saw all of the equipment used to actually compress hydrogen gas, and you can't, nobody's actually, we don't know, but it seems that nobody's created metallic hydrogen yet, but by adding a new element like certain, like lanthanum, for example,

you can sort of dope it in a way that it takes on some of these higher temperature superconductive properties. And then they, to create it, they squeeze it, between two diamonds? Is that giant pressure? Yeah. So what I saw them do was essentially you have a foil made out of the sort of doping lanthanum

material. And then they used a special kind of powder that under high pressure will spit out hydrogen like protons. And they have these little they're like the size of desol batteries and they're diamonds at the tips of each of these halves and they screw them together with basically

Allen wrenches and they create pressures inside the between the diamond tips that are equivalent to approximately those in the earth's core. Wow. That is our number 844-724-8255 if you want to talk about this. You can also tweet us at SciFri. I want to bring on a couple of more guests to talk about people who are also involved in the research that's doing this.

I want to bring on Medera Samayaluzzo. Madeira Samayazulu. Sorry. you got that butcher everybody's name. Yes, I'm glad to be on the show. And Eva Zurich, who is Professor of Chemistry at my alma mater, University of Buffalo in Buffalo. Welcome to Science Friday. Thank you. It's a pleasure to be here.

Madera, you're at Argonne National Laboratory. That's right, I am. Two weeks in a row, we've had a scientist on from Argonne. That's kind of cool. So let's talk about what we're seeing here. Eva, can you tell us what is happening down on the electron level when you squeeze that hydrogen that Ryan was talking about? Right. So first of all, what's really interesting is when you go to these very high pressures,

what can happen is that you can get compounds that become stable that you would never have at one atmosphere, so at the earth's surface. So the first thing that's happening is that you're getting a very new type of compound that's forming. Without pressure, you might have like lanthanum H3, for example. But under pressure, you get this lanthanum H-10. So there's really a lot of high. hydrogen. And it forms this quite complex structure that's similar to what people refer to as a cloth rate, what's a three-dimensional hydrogen cage around the atoms, the metal atoms. And then the interesting bonding between the hydrogen atoms is just right in order to create what is known as a strong electron-falon coupling. And that is the dry-and-examination.

for the superconductivity in these systems. Maduri, why do you need to use diamonds? I mean, what's the advantage there? Diamond is the hardest material known to mankind, and when you squeeze something between it, the diamonds hopefully don't shatter, and you can subject the materials to immensely high pressures. The only problem is that, as all of us learned in high school,

pressure is force per unit area. So higher the pressure you want to go, smaller is the area you want to be at. So the tips of the diamonds are really, really small, and the samples are really, really, really small. And so therefore we have to work at the advanced photon source here in the Argonne National Labs to be able to understand what's going on between them. Now, why did you choose hydrogen?

I mean, years ago, people were looking at copper, were they not? Yes, but hydrogen is the, is the, is the material we want to understand what happens to it at very high pressures because of the fact that there were these theories which talked about how you can metallize hydrogen at extremely high pressures. And as Eva would chime in, hydrogen is probably the most well-understood molecule in the quantum mechanical world. So that's putting two together and trying to understand what happens with pressure on hydrogen. Right, there was actually, so there's the BCS theory of superconductivity that explains a certain class of superconductors.

It doesn't explain why the copper oxides are superconducting. We still don't really know that. But BCS, we understand, and we can use it to make predictions, therefore. And there was a prediction in 1968, I believe, that if you could make hydrogen and metal, then it would have all of the properties to be a high temperature. superconductor at high pressure. Hmm. And so where does the art stand?

I mean, the art of making this work stand. How close are we to getting that stuff that's in between those diamonds to actually superconduct, Eva? Well, Zulu measured it, and it does. The problem is that it is at these very high pressures, and there are still issues. and there are still issues, for example, the experiments are so difficult that right now they've only been able to measure the resistivity, and as far as I know, they do not have the perfect Meisner result data yet, and there's only been two labs in the world that can accomplish this feat.

So it's very difficult right now, but it's still, it's a proof of concept that hydrogen-riched materials have what it takes to reach potentially room temperature superconductivity. And then the question is, how do we make these stable without pressure? And so, Maduri, can you tell us a little bit about, we know that there are multiple teams working on this idea. So what has it been like to sort of be working in tandem with these groups? I know that there's, you know, there's you, and then there's, I know that it's the other group in Germany.

So can you tell us a bit about that? Yeah, I mean, it's impossible to think that we can achieve these kinds of incredible experiments working all alone in a lab, you know, like in the old times we used to be thought people would do. So there are these teams which come together. And, you know, we worked at the advanced photon source for many years trying to hone our techniques. And having done that, we established the first evidence for superconductivity, which were preliminary results, which were presented at Madrid, which triggered the race. And the other group at Marx-Blanc Institute in Germany charged ahead, and a few months down the road, both of us almost simultaneously could

revisit and, you know, re-show or show the results to be consistent with each other. And that's great because, you know, now we have two different groups charging ahead and trying to come up with innovative ideas about how to make these materials. And even today, we are collaborating with, you know, the group which I work with has now spread to the University of Illinois at Chicago here to be concerned. close proximity with us in the Argon Labs. We're working together with them. There are groups in University of Alabama.

There is a group in National High Magnetic Field Lab in Tallahassee coming together. So it's not something one person can do or one group can do. So a lot of these groups are coming together and trying to understand how we can make this material reproducibly and understand the physics of what's happening because that's what is most important. 844-7-24-8255 is our number. We're talking about creating superconducting devices. Let's go to Tim in Wilmington, Delaware. Hi, Tim.

Hi there. Hey there. Go ahead. Yeah, so I had a question. If you are trying to put hydrogen under high pressure in order to turn it into a metal or whatnot, check its conductivity, couldn't we just look at our sun, which is made up of hydrogen? and under extreme pressure. What do we know about that?

Oh, somebody's thinking. So we know for sure we have metallized hydrogen at high temperatures. The problem is we want to do it at very low temperatures. Yeah. And also the superconductors are going to be working presumably at not temperatures that are the temperature of the sun. So we have done those types of experiments in shock. And it is quite well believed that, for example, the core of Jupiter would be liquid metallic hydrogen.

That's cold. Yeah. So I was actually wondering, you know, as a theoretical chemist, you know, it's your job to tell folks like Maduri what compounds they should be trying out. So how do you figure out the direction that you should take this research? You know, how do we land on lanthanum hydride and how do we, you know, know when it's time to look to try and get metallic hydrogen and what temperatures and what pressures? Right. So I've started this work about a decade ago, and I use programs that try to solve the Schrodinger equation approximately for materials. And if you can do that, you can calculate any property of a material that you want. And we use supercomputers. And into this supercomputer programs, we can say, okay, this is the chemical composition that we want, and this is the pressure that we want. Can you help me using various algorithms predict the most stable structure at this given composition and at this given pressure? And I mean it takes a long time to do these computations, but we can get the results and then calculate the properties, including estimating the superconducting critical temperature.

So like I said, people have been doing these types of simulations for about 10 years, and so far we have looked at most systems containing two elements, so hydrogen. plus another element. And at first, this kind of work is experimental because you don't know what will happen. It's very high pressures and you don't have an intuition. But at some point, when there was enough theoretical calculations available, there was work done on calcium hydrogen system. And that showed that it should be a high-temperature superconductor. And then you think, well, what's similar to calcium?

Well, you might have strontium or you might have scandium. and then computations looked at those types of systems. And also the lanthanum and yitrium have similar properties to calcium and so on. So people looked at that. And actually it was a group that Zulu collaborates with that and also the group in Chicago that were the first to predict the lanthinem hydride system computationally. And that's why they looked at it experimentally. I have to interrupt the same Ira Plato.

This is Science Friday from WNYC Studios. So, rude of me to interrupt. That's okay. Get that in. Let me go to the phones. We have a call from Whitney in Moorhead, Minnesota. Hi, Whitney. Hello.

It seems the point to be able to get superconductivity and conditions on Earth that don't require continuous introduction of electricity for, like, creating pressures and stuff. So when you're talking about all this high pressure or condition, aside from we need more volume if we're going to make this practical. We also need, it seems like, an exception to the whole temperature thing, because obviously high pressure is not, continuous high pressure is just going to take more electricity than it's going to save.

Okay. So, any reaction? Yeah, how do we make it useful? Yeah. How are you going to get it out of that pressure cooker you have it in? Yeah, I would say that, you know, whenever anybody asked me about this, I point to one of the greatest things in nature. Graphite converts to diamond under pressure. But if we can find a way of using diamond, or we all want to use diamonds, we have found ways of creating it in other ways, of, you know, quenching the diamond state at lower pressures.

So I would say going forward, of course, we still have to understand the physics of what's going on here, and we have to go back to people like EVA to increase their calculations to predict other complex systems where we could lower the pressure or we could quench them to atmospheric pressures, like diamond is quenched to atmospheric pressure and stable. And then you have a situation where you can make a practical material which we can use. So we're not quite at, I mean, I know that we've demonstrated it basically evidence that these Lanthan-hydride systems are superconducting now. And so before we even think about turning down the pressure, you know, Ava, what steps do we actually have to go through to get to the level where we've totally convinced ourselves that we've created, you know, a room temperature or near-room temperature superconductor? Eva, I'm going to ask you to wait for that answer because we have to take a break.

It's always that. It's always something. Stay with this way. We're talking about superconducting with Maduro. Somayazulu and also we're talking with Ava Zirk and we're asking answering your questions on Science Friday 844-724-8255. Stay with us. We'll be right back after this break. This is Science Friday. I'm Ira Flato. We're talking this hour about the search for superconductors. My guests are Ryan Mandelbaum, science writer for Gizmoto, sort of serving as my partner today.

Maduri Samayazulu is a group leader of the X-ray science. Division at Argonne National Lab in Lamont, Illinois. Ava Zerick is a theoretical chemist and professor of chemistry at the University at Buffalo. Our number 844-8255, and Dr. Zerk, when I rudely interrupted you, you were about to answer the question for us. That's all right. So the question was, what do we need to do to prove the superconductivity in the lanthanum hydride system, I believe?

So the experimental groups, they have shown the drops in RELMAN, and RUMPRUES system, resistivity, the disappearance of the resistance. And the other thing that needs to be shown is something called the Meister effect. So when a superconductor is put into a magnetic field, it expels the magnetic field. And that's what lets, you have these levitating trains, for example, that go on superconducting tracks. And it has been published on the archive. The change is in the superconducting critical temperature with the magnetic field. But as far as I know, the Meister effect has not yet been published. I know that Zulu is working on it.

I don't know how far that has gotten, but that's something that needs to be demonstrated. Let's go to the phones to... Well, was I going to go to the phone stuff? Let me ask you this question. There was a call there, and somebody dropped off the phone line, about graphene. There was research, I know Ryan, we were talking about this, published this week, that take two sheets of graphene and sort of twist them around, and there are superconducting spots on them. Did I get that right? Close at all. Is graphene a good candidate, Eva, for using superconductivity?

So from what I know about this topic, it's not my main research, but you need to have a very precise angle of rotation between the two graphenectivity. sheets of about 1.1 degree. And I do not think the T.C. Is that high? I think that people find it extremely interesting. Also, this was first theoretically predicted before it was experimentally shown. But I don't think it's going to reach room temperature superconductivity as far as I can tell. I think what I'm wondering is how the not just graphene, but also lanthanum hydride and other kinds of superconductors we're not talking about tie into the bina.

bigger picture. I mean, is there going to be a future where there's just one kind of superconductor or where they'll, how will that look? Maduri, you want to weigh in on that? Yeah, I think, I mean, if you look at, if you look at technology today, almost every superconductor we talk about, which is being used in, let's say, MRI machines or in magnets and other places, is Niobeam tin. And for a variety of reasons, it was the material of choice. although it doesn't have the highest superconducting transition temperature. So I think going forward, the way I would look at it in the future,

is that there are a lot of materials which we will discover based on these kind of materials which we have recently discovered. And of these, technology will choose the one which is most, should I say, cost-effective. You know, it may not necessarily be room temperature superconductor, But even if it's superconducting it, let's say, in a Siberian winter, it's still a better superconductor than having something in, you know, at slow temperatures. Well, Madurai, what would be a room temperature? What number would we say, hey, it's truly room temperature?

I would, as I understand, if you can make something superconducting at about 300 plus Kelvin, which is about, let's say, 25, 30 degrees centigrade or so on. And, you know, that's the proper temperature. That's higher than room temperature. Like, it's 85, 90 degrees Fahrenheit, something like that. Yeah. The reason why you want it to be higher than room temperature is for simply the reason that if there is a collapse of superconductivity,

there are few strands of the superconductor which stop being superconducting, and they become normal, they will start heating up, then the rest of the superconductors will collapse. So, you know, if I envisage a wire of superconductor, of whatever this material, which is going to be room temperature superconductor, it should be superconducting well above room temperature to make it technologically useful at room temperature. And what temperature are we at now and sort of what temperature do

present theories say we can go to? With lanthanum hydride, we have seen nebulous signatures of superconductivity even as high as 280 Kelvin, which is roughly, you know, which is almost close to room temperature or a little above normal room temperature, I'm saying. But the theory predicts other materials, if I remember right, if it's eutriam hydride and others, which would be superconducting at 320 Kelvin, which is about 40 degrees above room temperature. So that would be the kind of materials to look for.

Eva, did you want to weigh in there? Yes, the highest prediction that I know is for Yatrium H-10. That is at about 325 Kelvin, 250-Gapascals. Got it. And actually, Ava, kind of moving to the bigger picture, we had a question which was just, you know, we're asking some of the most basic science questions here. And, you know, when we, I come and talk about theoretical physics with Ira, we talk about dark matter. So what are some of those biggest mysteries right now in this field, in theory?

radical chemistry. I mean, what are some of the biggest outstanding questions that we're working towards? I guess for these types of superconductors, the question for me is you have these different structures with the way that hydrogen is arranged, and we're seeing that these three-dimensional cage-like structures only appear in certain types of combinations with certain elements. Why? And why is it that you need these geometries to get this very high T-C? You don't get it when you have stuff with H2 units and you just don't get that high TC. So what's special about that? And if we can understand that, then we can use that knowledge to try to engineer other

materials that might be stable at lower pressures or metastable, like Zulu said. If you take off the pressure, it won't decompose. I'm glad you guys are working on that because we'll have to end it right there. I want to thank my buddy in the studio with me, Ryan Mandelbaum, science writer for Guzmodo. Thanks for. Always great to be here, Ira. Thanks for having me. I love it.

Maduri Somaya Zulu is a group leader of the X-ray Science Division at Argonne National Lab in Lamont, Illinois, and Eva Zurek is a theoretical chemist and professor of chemistry at Buffalo. Thank you all for taking time to be with us today. Thank you. For the rest of the hour, we're going to take a trip to Africa, or at least a trip to the museum, to look at the remains of some stuffed African lions, because when you think a lion's hunting, you probably imagine them feasting on a lion's large animal, like a water buffalo or an antelope.

But during times of drought or disease, those preferred kinds of prey may be in short supply, and lions have to turn to less desirable sources of food like porcupines. Yes, porcupines. So what happens when lion meets porcupine? Julian Curbis, Peter Hans, is Professor of Natural Science at Roosevelt University and adjunct curator at the Field Museum. Famous Field Museum of Natural History in Chicago. His article on this topic is published this week in the Journal of East African Natural History.

Welcome, Dr. Curbis. Thank you. Thanks for having me. Why would a big lion, you know, go after a porcupine knowing about the quills and all that kind of stuff? Well, as you said in your intro, there are certain conditions, especially drought and prey-de-popperate environments where lions have very little. alternative. And so they do seek, quote-unquote, less desirable prey, sometimes with harmful or even occasionally fatal results. So a little eight-pound porcupine can kill a lion? Well, what, yeah, fortuitously, the one in a million shot attacking a porcupine, a quill might go

through a heart or a carotid artery or femoral artery. But more often than that, what happens as they get impaled and have long-term suffering wounds, which leads to their debilitation, their weakness, inability to pursue fleet-footed prey or might have quills in their paw, for example. And it's kind of a downward spiral from there. And then they may turn to livestock or people, in which case they get eliminated. Let me back on that because that seems to be a major point. So after they attack a porcupine, they may say, oh, this hurts a little too much. Let's find easier prey.

Go after a person. Well, they are forced to do to starvation. I mean, lions do not typically attack people or livestock, but when they're forced to make those decisions due to starvation, they may pursue those items, and then they get in big trouble with humanity. So your museum collections have lots of lions in them, and you used them those old specimens for your research? Yeah, one of the great field museum exhibits is the man-eating lines of Savo,

an exhibit that Tom Noski and I have been studying for 25 years, and my doctoral work was actually on African carnivores, and so this story is near and dear to our hearts, and years ago Tom was doing some forensic investigations of the tooth contents of the broken teeth of both Savo man-eaters, and indeed found porcupine quill fragments embedded within these broken teeth. And so these animals that were shot in 1898, 120 years later, are still providing evidence on their lifestyle and behavior. And so it's a real tribute to the museum collections.

And these are the lines that are a research gift that keeps on producing new and intriguing possibilities and results. And we have other things down the pike that are still evolving. Good. Can you tell how many porcupines, an average lion eats, or what percentage of its diet could be porcupine? Well, in one study in the Kalahari-Gembach National Park in Botswana, they represented about 35% of lion kills. That's not total meat intake because they might take an eel and get several hundred pounds of meat from that single animal. But in terms of number of kills, 35% in this prey-de-popperate landscape, which didn't have their typical prey of wildebeest or zebra, something like that.

The problem these days is a lot of the landscapes have been, quote-unquote, contaminated with water wells and boreholes to keep animals in place for benefit of tourists or for livestock, and that's kind of changed the ecological dynamics. So we kind of dove deep into the historical literature to come up with our pre-altered landscape theories and hypotheses. This is Science Friday from WNYC Studios. On Ira Flato, we're talking with Julian Kirby about porcupines versus lions.

Do we know that they prefer porcupines over other prey? Do they taste good to a lion? Yeah, the problem with that is these are small animals, and it's hard to document everything a lion eats, and a smaller animal will disappear, or there won't be much, won't be much of a skeletal pile to examine the next day. So the studies we had to refer to tracked lions 24-7,

and those are very hard to come by. So a lot of the classic lion studies by George Scheller and others, we had to throw out. We couldn't use them because they didn't track everything a lion ate, but these fellows in Botswana did, and we got very good details on dietary remains. So there's a lot of work to do in the subject, perhaps by my colleague Tom Nossky,

you're just suggesting today, just retrieving scat of lions on a year-round basis and try to document prey as it changes over time. Are there any, you know, do certain lions at certain ages prefer porcupines over other, you know, lines at other ages? Or do you get a little smarter as you grow up or afraid you might get hurt or killed by the porcupine? Yeah, the evidence is anecdotal, but there does appear to be a, tendency of younger male lines to get impaled more often, certainly than females and certainly

than older males. And this was something that over 100 years ago, a famous game warden in South Africa, Stevenson Hamilton, came up with. I can kind of casually refer to it as the foolish young male hypothesis, but he had a great quote in this paper about the frequency of injured young male lines as opposed to adult female or even older male lions. So there does seem to be a correlation in that regard. I think we had 15 out of 20 instances in our literature research about over 3 to 400 years.

15 out of 20 of these seriously wounded lions were male as opposed to female and several of the dead ones as well. So if porcupines can be that fatal to lions, do the part? Rangers keep an eye out for the porcupines, so you might reduce the risk. Well, that's a really good question. One of the take-home messages is that any lion that is seen in a park impaled with a porcupine quill should be taken care of. And so authorities should be notified. The lion can be treated.

They recover easily once the quill is removed. But if that quill is getting irritated continuously, it just leads to this festering wound. And so that is one of the outcomes that take care of the lions right away. You can't get rid of the porcupines. That's part of the landscape. And there is a mobile unit in Kenya called the Savo Mobile Veterinary Unit. And that's exactly what they do, removing snares from wounded animals or something. Because in desperation, that's when the behavior will change.

Final question. Have you ever tasted porcupine, me? I've been asked that, and I am actually embarrassed to say, I have not tasted porcupine meat, but they are apprised food preferentially by both people and animals. So somehow, whether it be North American, South American porcupines, or African porcupines, it's very cherished food. We had a little data in our paper that suggests they are taken disproportionate to their abundance in a slightly elevated rate. Despite the dangers in taking them, they are taken with some kind of favorability by lions. In terms of human preferences for porcupines, we could look at the cost of meat per kilo in bush markets

to see if porcupine meat's going for higher prices, but that's a whole other project. Okay. Well, there's a little trivia fact for the weekend. Thank you very much, Julian Kerbis, for talking to us about porcupines and lions. Dr. Kirpice is a professor of natural science at Roosevelt University and adjunct curator at the Field Museum of Natural History in Chicago. One last thing before we go. Every year we celebrate Cephalopod Week, you know, those amazing squids,

cuttlefish and octopuses, and this June, you can join us in 10 cities across the country for Cephalopod Movie Night. Circle this calendar day, June 21 to 28th. Come on out for an evening of talks, tentacles, and talent. Go to Science Friday.com slash movie night to grab your ticket before someone with four times as many arms grabs them first. That is June 21st to 28. come on out for an evening of talks, tentacles and talent, Science Friday.com slash movie night. We'll see you at the movies. That's about all the time we have today.

I just want to have a shout out to all STEM teachers across the country. We appreciate all that you do. Happy Teacher Appreciation Week, and we certainly appreciate what you're doing. Have a great weekend. I'm Ira Flato in New York.