Harder Than Diamond? The New Hexagonal Diamond Breakthrough (EP 38)

Hosted by Lester Nare and Krishna Choudhary, this episode is a deep dive into one of the strangest and most hard-fought materials science stories in decades: the claim that researchers have finally synthesized bulk hexagonal diamond, also known as lonsdaleite. They break down why this material matters, how it differs from ordinary cubic diamond, why scientists argued about its existence for more than 50 years, and what the new Nature paper actually did to convince skeptical reviewers. Summary Why hexagonal diamond matters — if real, it is a long-sought carbon phase that could be slightly harder than conventional diamond and useful in extreme industrial settings. The first-principles chemistry — carbon allotropes, x-ray crystallography, cubic diamond, and the ABAB stacking that makes hexagonal diamond different. The experimental breakthrough — how the new team engineered around the default pathway to ordinary diamond by controlling graphite orientation and pressure direction. The controversy — why the peer review was intense, and how the new paper relates to an earlier 2025 Nature paper with a similar claim. Support the show Donate: FFPod.com/donate Follow: @FFPod on X / Instagram / TikTok / Facebook

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Krishna Choudhary?

  So imagine you've spent about 50 years arguing as a scientific community about whether a legendary material exists. And then finally, someone has made it and they're holding it in their hand. We're talking about a material that, in theory, is harder than the hardest-known material, which is conventional diamond. This, this, this is- Like, this is some beef, dude. Yeah, this is what beef looks like- Yeah. In the research committee. Clearly, there's something, right? Hello, internet. This is your captain speaking, Lester Nare, joined as always by my co-host and our resident PhD, Krishna Choudhary. Today, we're going to be diving into a paper that is actually a follow-up to our episode five story on unbreakable hexagonal diamonds.

• 0:45Krishna Choudhary?

  This paper was published in Nature on March 4th of 2026 from three Chinese teams from Zhengzhou, Nanjing, and Henan Universities. As always, we're going to learn about the science from the ground up today on this follow-up episode because this is from First Principles.

• 1:19Krishna Choudhary?

  So imagine you've spent about 50 years arguing as a scientific community about whether a legendary material exists. And then finally, someone has made it and they're holding it in their hand and you can see it with the naked eye. And that's roughly the situation when it comes to hexagonal diamond or Laun's delight. It's a form of carbon that was first proposed in the 1960s and material scientists have been seeking this holy grail ever since. Okay? There's been debate about whether it even exists in the first place. Okay. There's a new paper that's saying that they've actually made it. And the stakes are quite enormous because we're talking about a material that in theory

• 2:01Krishna Choudhary?

  is harder than the hardest known material, which is conventional diamond. This is an upgrade on diamonds that we normally have on our ring, finger and things like that. The current benchmark for the hardest material is a conventional diamond. And here we've gone a step further. So it's a very big deal because in industry, diamonds are applied all over the place. Okay, it's not just used as jewelry. In fact, the, the reason why a diamond is so expensive is because the jewelers are artificially crunching the supply while the demand is really high because of all of Hollywood and pop culture and things like that.

• 2:40Krishna Choudhary?

  But diamond in its core is really effective in all sorts of industry. For example, diamond, um, diamond tipped drill bits, they can board through rock for any type of stuff, oil exploration, mining, anything. Diamond coated cutting tools, they can machine aerospace grade titanium. Titanium is a hard metal, but if you've got a diamond coated saw, you can cut through titanium. Diamond windows, they protect infrared sensors and military systems. And the other cool one that I hadn't really thought about was diamond heat sinks. So Oh, interesting. Diamond is a really good insulator and it's also a really good heat sink in the,

• 3:22Krishna Choudhary?

  in the means that like it can extract heat out of its environment and dump it to something else. And those are being explored for next generation computer chips because silicon is sort of meeting its thermal limit when it comes to heat dissipation. This is why everyone is saying that, you know, the data centers up in space won't work. Right. Is because silicon is really bad at dissipating heat. Right. We have to have giant cooling systems in order to do that. Well, if you have a chip that has integrated silicon and diamond to manage that heat dissipation, you could now push even further, right? On how big you can make a server rack and things like that. And so we desperately need these types of materials. Diamond is one of these things.

• 4:04Krishna Choudhary?

  And imagine now you can make an upgraded diamond that's going to upgrade all of these in, in industrial applications, right? And the other reason why this matters, this particular story is because for the longest time, Computational simulations, meaning I take the material, I take all of the atoms and the arrangements of that material. I put that into a computer and I ask the computer to just churn Frodinger's equations and what we know about physics and material physics. If we do that in computer simulation, those simulations suggest that this thing is real. But for the longest time, we don't have any material samples to analyze.

• 4:45Krishna Choudhary?

  And so there's a fundamental problem now because our physics of what a material should look like is saying one thing. And we've never been able to do it. So it's almost like a bedrock foundational problem for the field. Right. That theoretically, this thing should be possible. Why is it so hard and is it even possible, right? Because if it's, if it's truly not, then we have to go back to the drawing board on fundamental material science. And that is a very uncomfortable scenario. Right. For everyone in the field. Right. Right? Yes. And so the status now is we've got a team in China that synthesized millimeter sized, pure hexagonal diamond. And it's resolving this 50 year academic debate.

• 5:29Krishna Choudhary?

  This happened earlier as well in 2005, as you alluded to, we covered a story in. 25, 2025. Yeah, 2025, sorry. We covered a story last year that purportedly made hexagonal diamond. This is another research team in China that is doing the same thing, maybe a bit better. And we'll get into some of the drama there because there's a lot of drama and it's quite hilarious. We got the tea, everybody. Okay, so let's start from the basics. Yes. Carbon. Carbon is the sixth element on the periodic table. It has six protons in its nucleus, usually six electrons, six neutrons, usually six neutrons in its nucleus, sometimes seven, sometimes eight.

• 6:11Krishna Choudhary?

  But six protons in the nucleus mean you've got six electrons revolving around the atom. Two are in the inner shell, but that means there's four that are left for that outer shell. And if there's four that are left for the outer shell, that means there's four holes. There's four valence positions where other electrons can come in. That is the maximum because the total number that you can have in that outer shell on that second ring is eight. Yes. So if you have three, that means you can have like.

• 6:40Krishna Choudhary?

  Five holes? Yes. But with four, you can either give four or you can take four. You can, so you can make the most. Yes. Bonds that way, right? Oxygen can only really make two bonds. The other ones can only make, you know, whatever is less. But four is right in the middle where I can give four or I can take four. So I can make the most number of bonds. That's why it's so important in organic chemistry for life in general. The big thing is carbon is able to make bonds with itself. And sometimes it makes these things called alotropes. This is pure carbon. There is nothing other than carbon in these substances. For the longest time, we thought there were only two. Graphite, which is the pencil lead. Yes. That's pure carbon, nothing else.

• 7:22Krishna Choudhary?

  And then there is obviously diamond, again, pure carbon. Now, how do we know what the structure of the carbon in these materials is?

• 7:34Krishna Choudhary?

  Well, usually what we do is we do something called X-ray crystallography. This was a technique pioneered by William Henry Bragg and his son, William Lawrence Bragg. We covered some of the drama there. The fact that William Lawrence Bragg, the son, did all of the math and did all of the actual groundwork. But William Henry Bragg, his father, published a paper about the technique and did not put his son's name on it. And that was a sticking point for his son Lawrence, who always wanted to be called by his middle name because that distinguished him from his father. William Lawrence Bragg and Henry Bragg, they both won the Nobel Prize in 1915. The only father-son duo to win the same Nobel Prize.

• 8:19Krishna Choudhary?

  And he was 25 at the time, the youngest Nobel Prize winner in the sciences. He went on to be the head of Cavendish Lab at Cambridge and managed the empire that was Cavendish Lab at Cambridge University. The idea is the following, you shoot X-rays out of crystal. Yep. The crystal is going to have a lattice structure, meaning all of the atoms are going to be arranged in a very nice, regular fashion. Like, we'll see some of the fashions that they're arranged. But in any case, it's like Lego blocks that are repetitive. And because they're repetitive, the X-rays are going to interfere at certain angles. And if I have a detector on the end, I can find spots where the X-rays added up and other spots where the X-rays cancelled out.

• 9:01Krishna Choudhary?

  And using that pattern, I can discern what is the structure of the crystal inside. Okay, that's the whole game with X-ray crystallography.

• 9:10Lester Nare?

  As a crude analogy, it's almost like making hand puppets with a light source on a wall. And you're looking at the shadow to determine what is the actual figure.

• 9:21Krishna Choudhary?

  Yeah, that's basically it, but in like all three dimensions with like frequency and everything.

• 9:26Lester Nare?

  Extremely more, much more complex.

• 9:29Krishna Choudhary?

  Yeah, but at the end of the day, what you can do is through that, you can figure out what is the cubic, what is the structure of that crystal inside. And when we do this with diamond, we figure out that it's a cubic structure. This is what diamond looks like at the atomic scale. Each of these blue orbs is a carbon atom. And each carbon atom is attached to four other carbon atoms in this tetrahedral structure. That orange tetrahedron, that is triangles on triangles. There's four triangles that are connected together. It's the first platonic solid that is on our logo right here. And it's a beautiful structure.

• 10:08Lester Nare?

  Yeah.

• 10:08Krishna Choudhary?

  The reason why it's called a cubic diamond is notice that the repetitive fundamental unit of the crystal is in the shape of a cube.

• 10:16Lester Nare?

  Yes.

• 10:17Krishna Choudhary?

  Right? If you imagine, you can take that same cube, put one right next to it, put one right next to it, and stack, and you get bigger and bigger. And a diamond is going to have, you know, 10 to the 20 of these carbon atoms, or something like that, an enormous amount. But at the fundamental scale, that is what the diamond looks like. The reason why it's so hard is each of those bonds are highly tight covalent bonds, where the carbon atoms are sharing an electron with the neighboring carbon atom. Remember I said carbons can do four bonds? All four bonds are other carbon atoms. This thing is extremely tightly packed. Okay? And it's single bonds that are going in.

• 10:56Lester Nare?

  Yes.

• 10:56Krishna Choudhary?

  Okay, so. That's the fundamental unit of stacking. It's a cube, hence, normal diamond is called a cubic diamond. Yeah, right. Okay. Now, in 1962, researchers predicted that there would be a possible hexagonal polymorph of the diamond. They went through the, this is, you know, 1960, so this is before computers and stuff. But you can literally sort of do the mathematics of Schrodinger's equation around a carbon atom, and you can make the argument that instead of this cubic structure, there could be a kind of hexagonal structure that is even more stable and even more hard. Okay? The question is, is that real? Right.

• 11:41Krishna Choudhary?

  So 1962, they published this paper in Nature, and in the 1967, they came up with the Canyon Diablo meteorite. There were people who were analyzing a meteorite that fell in Arizona 50,000 years ago. If you've ever been to the Grand Canyon, the south side, there's meteor crater right next to the Grand Canyon sort of exit on the 40 freeway. I was there when I was very young. It was one of the first sort of science field trips that my family took, and I got to see the meteor crater in Arizona. It is an awesome, awesome place. 50 meters is about the size of the meteorite that hit Arizona, and it has a bunch of shards that fell all over Arizona, and that they've been recovered.

• 12:26Krishna Choudhary?

  Okay? Now, this meteor hit Arizona extremely fast, and meteors are made a lot of out of carbon. There's a lot of carbon in meteors. When they hit the earth at this incredible velocity with incredible pressure, there's incredible heat, perhaps the carbon is going to form a weird allotrope. And so, in 1967, a paper came out again in Nature.

• 12:56Krishna Choudhary?

  Lonsdylite, a hexagonal polymorph of diamond. They're saying that they found that hexagonal polymorph that was suggested in theory five years ago, right? They named it Lonsdylite. And just a brief sort of digression into why Lonsdylite. It's named after Dame Kathleen Lonsdale. She was a foundational X-ray crystallographer and prison reform advocate. Very, very cool person. Okay. Yes. She pioneered the use of X-ray crystallography. She actually did her PhD under William Henry Bragg, the dad. Yep. Okay. And she wanted to understand the structure of aromatic compounds.

• 13:38Krishna Choudhary?

  Specifically, she figured out that benzene, which is a six-carbon ring with six hydrogens, that thing is a flat ring. She figured out that the structure of that thing was flat. She's one of the first to actually use something called Fourier transforms, which is where you go from frequency space to position space. The real mathematics behind X-ray crystallography, she's the one, first one to figure out how to quantitatively use the mathematical theory to understand even more complicated patterns with X-ray crystallography. Okay. And so she laid the foundations of, for example, later on, when X-ray crystallography was being used for proteins and other kinds of really weird amorphous solids or DNA,

• 14:20Krishna Choudhary?

  the famous DNA picture that Rosalind Franklin took of the X-ray crystallography with the X. Yes. Her theories are what laid the foundation for that kind of work. To be like, what is the kind of molecule that would give me an X? Yep. And Francis Crick was the one who figured out, okay, it's got to be a spiral. Right. Right? And the spacing of the DNA, of the spacing of the dots on that photo tell you how far away nucleotides are in DNA and how far away the turn is on a helix and things like that. So incredible individual. She's one of the first to First two women elected to the Royal Society. She was also a Quaker, which is like, it's the religion that Benjamin Franklin is famous for in Pennsylvania and things like that.

• 15:03Krishna Choudhary?

  So she refused to register for civil defense duties during World War II because they're very nonviolent people, right? And she was in prison for a month and her experience in that prison was like, she used that experience to become a passionate prison reform advocate.

• 15:20Lester Nare?

  Right.

• 15:20Krishna Choudhary?

  So, all over the place she was.

• 15:23Lester Nare?

  Great scientific impact, great social impact, not only by being a pioneer as a woman at the time, who were not allowed in these scientific spaces, as a generalization, but also still being grounded to that the world is still a society. And it's not just the work we do in a lab.

• 15:44Krishna Choudhary?

  Exactly. Yeah, so incredible woman. This paper that comes out in 1967 by Frondell and Marvin, they claim to have found the hexagonal diamond, they named it after Dame Kathleen Lonsdale, they call it Lons Delight. They did x-ray diffraction on this thing and they showed that it has the same pattern as something called wortite, which is a zinc sulfur mineral that has hexagonal symmetry. Here, what you're looking at is an animation of wortite. Just imagine instead of the two different colors, which are zinc and sulfur, all of them are the same color because they're all carbon atoms. That's where all the carbon atoms would be. There's two things that are different about this compared to the cubic diamond. Okay? First thing obviously is, look at the unit cell. It's a hexagonal prism, right?

• 16:29Krishna Choudhary?

  There's a hexagon face on the top and the bottom. And the other thing is, you're actually packing the carbon atoms closer together because the tetrahedral, the tetrahedral surfaces are flat compared to before, they were sort of at an angle, at that 104.5 degree angle. Here they're flat, you're packing more carbon atoms, the bond length in between these carbon atoms is smaller. And so, the hardness mechanism is because of the resistance to like any form of

• 17:06Krishna Choudhary?

  Stress.

• 17:07Lester Nare?

  Right.

• 17:07Krishna Choudhary?

  This thing is going to be harder.

• 17:09Lester Nare?

  Right.

• 17:09Krishna Choudhary?

  Than cubic diamond.

• 17:11Lester Nare?

  Yes.

• 17:11Krishna Choudhary?

  Okay.

• 17:12Lester Nare?

  And I have one just brief question on this visual, just because there's, as a layman, the other visual difference here. And I understand that we're looking at wort site in this example. And the key difference is there's sort of that bottom row.

• 17:27Krishna Choudhary?

  Mm hmm.

• 17:27Lester Nare?

  Right. So you have the sort of, all the tetrahedals packed in the hexagonal prism at the top.

• 17:32Krishna Choudhary?

  Yeah.

• 17:33Lester Nare?

  And then there's just like a bottom row of empty space that kind of closes it out.

• 17:36Krishna Choudhary?

  Yeah. Well, that thing is just going to be repeating over and over. I think they're only showing.

• 17:41Lester Nare?

  One segment.

• 17:41Krishna Choudhary?

  Yeah, exactly. But because it's a crystal, it's like gonna just keep repeating.

• 17:45Lester Nare?

  Makes sense.

• 17:46Krishna Choudhary?

  Okay.

• 17:46Lester Nare?

  Just wanted to clarify.

• 17:47Krishna Choudhary?

  Yeah, no, that's a good question. Now, if we think about how this is different from cubic diamond at a grand scale. Not just that, okay, the fundamental unit is hexagonal rather than cubic.

• 17:59Lester Nare?

  Yes.

• 17:59Krishna Choudhary?

  That's the first thing. But now let's, let's consider like packing a bunch of carbon atoms, like spheres, in a, in a enclosed space.

• 18:08Lester Nare?

  Okay.

• 18:09Krishna Choudhary?

  How do we do that? Well, there's two ways of doing it. On the left is your cubic diamond.

• 18:14Lester Nare?

  Mm hmm.

• 18:15Krishna Choudhary?

  Okay, that's the, the one that we had seen earlier where the tetrahedals are in a cubic sort of repeating unit.

• 18:22Lester Nare?

  Yes.

• 18:22Krishna Choudhary?

  When you do that, layers of carbon atoms repeat, but they repeat in a A, B, C, A, B, C, A, B, C kind of manner, meaning you're gonna get one layer of carbon atoms.

• 18:35Lester Nare?

  Mm hmm.

• 18:36Krishna Choudhary?

  The B layer, which is on top, is gonna fit somewhere in the gaps of that.

• 18:40Lester Nare?

  Yep.

• 18:40Krishna Choudhary?

  The C layer is gonna fit somewhere on the gaps above that, but it's gonna be slightly offset from the A layer.

• 18:45Lester Nare?

  Yeah, yeah, yeah.

• 18:45Krishna Choudhary?

  So I'm gonna get three distinct layers and it'll repeat like that.

• 18:48Lester Nare?

  Yep.

• 18:49Krishna Choudhary?

  Okay?

• 18:49Lester Nare?

  Yep.

• 18:49Krishna Choudhary?

  With hexagonal diamond, just because of the nature of the geometry, I only need two layers of stacking.

• 18:54Lester Nare?

  Mm hmm.

• 18:55Krishna Choudhary?

  It's gonna be A, then B is gonna fit exactly in the gaps, but because A is slightly different from the previous A.

• 19:02Lester Nare?

  Yeah.

• 19:03Krishna Choudhary?

  The next layer can just repeat.

• 19:05Lester Nare?

  Yes.

• 19:06Krishna Choudhary?

  The bottom layer. So my stacking is gonna go A, B, A, B, A, B. Instead of A, B, C, A, B, C, A, B, C.

• 19:13Lester Nare?

  Yes. And just for folks who may be listening, I just want to put a disclaimer. This is a slightly important episode for visual reference points. Because it's, it's very obvious visually. It's kind of hard to describe.

• 19:25Krishna Choudhary?

  It is.

• 19:26Lester Nare?

  It just with audio or with voice. But I, I think sort of like, what's interesting is you can kind of see the, the offset you're talking about. Like imagine a staircase that has three stairs.

• 19:37Krishna Choudhary?

  Mm hmm.

• 19:37Lester Nare?

  One and then two, like when you're looking at it from the side.

• 19:40Krishna Choudhary?

  Yeah.

• 19:41Lester Nare?

  So, you know, the cubic diamond is almost like three steps on a staircase.

• 19:44Krishna Choudhary?

  Yeah.

• 19:45Lester Nare?

  Uh, where the offset on the C is significantly farther away from the A.

• 19:49Krishna Choudhary?

  Yeah.

• 19:50Lester Nare?

  But in the hexagonal, it's just two steps.

• 19:51Krishna Choudhary?

  Mm hmm.

• 19:52Lester Nare?

  Uh, and so imagine you're creating like this staircase that's going back and forth.

• 19:55Krishna Choudhary?

  Yeah.

• 19:55Lester Nare?

  Like this. Having two versus three.

• 19:59Krishna Choudhary?

  Yeah.

• 19:59Lester Nare?

  You can already think.

• 20:00Krishna Choudhary?

  You can already think, yes.

• 20:01Lester Nare?

  Structurally. That it would be.

• 20:03Krishna Choudhary?

  It would be better. It would be harder. The things would be closer packed.

• 20:06Lester Nare?

  Right.

• 20:07Krishna Choudhary?

  The bonds would be a bit stronger. The layers would be a bit stronger.

• 20:10Lester Nare?

  Right.

• 20:10Krishna Choudhary?

  And just theoretically, you can just like, kind of imagine that this hexagonal diamond is going to be harder and better than a cubic diamond.

• 20:17Lester Nare?

  Right.

• 20:18Krishna Choudhary?

  Right?

• 20:18Lester Nare?

  Right. We will not be playing the Daft Punk song Harder, Better, Faster, Stronger. However, it would be a good theme for this episode.

• 20:24Krishna Choudhary?

  Yeah, yeah, yeah. We'll put it in the socials, right? So, okay, discovery in the 1960s, this is when they're like, okay, I think we found it, right?

• 20:31Lester Nare?

  Yes.

• 20:32Krishna Choudhary?

  So, in the 1960s, in parallel, it's kind of a golden age for high pressure physics. Because General Electric, GE, the company, they achieved the first reproducible synthesis of diamond from graphite. You know, lab diamonds, synthetic diamonds. They invented it in the 1960s. This is General Electric, actually 1954. They use a kind of belt apparatus. It's, it's effectively high pressure, high temperature.

• 20:58Lester Nare?

  Yeah.

• 20:59Krishna Choudhary?

  Okay. So you take graphite, you would subject it to 10 gigapac skulls, which is 100,000 times atmospheric pressure. You raise the temperature up to 1,000 degrees and you get diamond. This was a triumph in material science. Francis Bundy, Hall, Strong and Wentworth. They got enormous recognition. They, they're in the Inventors Hall of Fame. Very controversially, no Nobel Prize for them. It might be because there's four people. And the Nobel Prize can only go to three. But usually when that happens, you just wait for one of them to die.

• 21:31Lester Nare?

  Right.

• 21:32Krishna Choudhary?

  And then you give it to the other three, you know? But they didn't even do that, which I think is quite controversial because like lab grown diamonds are a game changer for all of these industrial applications that I was telling you about, right? So very much has changed the landscape of material science and industry. They probably should have gotten the Nobel Prize, but I think now all four of them have passed away. So it's too late.

• 21:53Lester Nare?

  Understood.

• 21:54Krishna Choudhary?

  In any case, they've shown that we can make cubic diamond.

• 21:58Lester Nare?

  And they, this is also where we get the meme and the like colloquialism about uh, strong as a diamond, diamond under pressure, like all of these various thingies.

• 22:08Krishna Choudhary?

  Yes.

• 22:09Lester Nare?

  Is because the way you make diamonds is through, it's almost like, like almost, most people kind of know it's like hot heat.

• 22:14Krishna Choudhary?

  Yeah.

• 22:14Lester Nare?

  And squeezing.

• 22:15Krishna Choudhary?

  Yeah.

• 22:15Lester Nare?

  Diamond.

• 22:16Krishna Choudhary?

  Yeah, that's why it happens deep in the earth's crust if it's natural. And here we're just trying to sort of replicate that natural mechanism. That's why, yeah, exactly. Harder than a diamond. The diamond is forever stuff. That's Hollywood.

• 22:27Lester Nare?

  That's Hollywood.

• 22:27Krishna Choudhary?

  Right, that's Hollywood and the De Beers Corporation. The as hard as a diamond, diamond under pressure, that's physics.

• 22:34Lester Nare?

  Right, right, right. Right, just to be clear.

• 22:36Krishna Choudhary?

  Yeah, just to be clear, there is a difference here in, in how we approach things. So people start making lab grown diamonds and now we want to make Laundalite. We want to make hexagonal diamond.

• 22:46Lester Nare?

  We've made cubic diamonds. We still have not yet made the, the thing we've already theoretically identified as being possible.

• 22:53Krishna Choudhary?

  Yeah, yeah, but there's a lot of problems. The samples are too small, the crystals are sub micron in size, and there's no real definitive proof. Because you need a lot of a sample. And by a lot, I mean even like a millimeter worth of stuff to do anything.

• 23:09Lester Nare?

  Right.

• 23:10Krishna Choudhary?

  Right? So with all of this comes skepticism. It's like, well, why can't I just make?

• 23:16Lester Nare?

  Right.

• 23:17Krishna Choudhary?

  Hexagonal diamond. Well, how come every time I'm trying to make diamond, I always get cubic diamond?

• 23:22Lester Nare?

  Right.

• 23:22Krishna Choudhary?

  Which is the stuff that I see on earth.

• 23:24Lester Nare?

  Right.

• 23:24Krishna Choudhary?

  And now you're telling me that this meteor has it, but like even the meteorite sample might not be that good. And that's where we come to 2014. Nature Communications, there's a paper. Um, Launce the Light is faulted and twinned cubic diamond and does not exist as a discrete material. What a banger of a title. Okay, it's just like, no, this is fake.

• 23:46Lester Nare?

  For those who might not understand, this is like def- the definition of a clapback.

• 23:52Krishna Choudhary?

  Yes, yeah, like to put in the title does not exist as a discrete material, when for like the past forty, fifty years, people have been like talking about how this is a thing.

• 24:02Lester Nare?

  Yes.

• 24:02Krishna Choudhary?

  Right? And so here is the argument that he's making. He's saying that Launce the Light is just cubic diamond, but with something called stacking faults. What he's saying is, if you look at the meteorite samples, okay? There's a bunch of cubic diamond lattice structure, but that cubic diamond lattice structure is not contiguous. There's like cubic diamond here, and then there's another domain of cubic diamond on over here. And the boundary between them is slightly offset.

• 24:28Lester Nare?

  Yeah, yeah.

• 24:29Krishna Choudhary?

  So when I put this through X-ray diffraction, I am going to get artifacts that suggest that there are spots where there is hexagonal diamond. And he goes through and does transmission electron microscopy of the sample of that meteorite, the Cannon Diablo meteorite. And he's showing that there are these stacking faults, there are these boundaries, right?

• 24:48Lester Nare?

  Yep.

• 24:48Krishna Choudhary?

  And so if you have enough stacking faults in your cubic diamond, the diffraction pattern is going to resemble the hexagonal stuff. And so you're not actually making hexagonal diamond, you're just making a bunch of cubic diamond with defects. And then when you put it through the X-ray diffraction, oh, it's hexagonal. You can't say that.

• 25:06Lester Nare?

  So he called it fugazi.

• 25:08Krishna Choudhary?

  Yeah, he's like, he's like, no, this is, this is nothing.

• 25:10Lester Nare?

  This is nothing.

• 25:11Krishna Choudhary?

  Right? But meanwhile, computational studies are refusing to give up. And this is what I was talking about, right? Like, you go, you go through and you, and you, and you put it in the computer, and the computer's saying this is fine. This is totally a possible ala trip of carbon.

• 25:25Lester Nare?

  Yep.

• 25:25Krishna Choudhary?

  This works, the carbon atoms are all happy, they don't want to go into another phase. Like, you set them up like this, they'll stay like this.

• 25:33Lester Nare?

  Based on the rules of, of just foundational and basic physics that we understand to be true, you can extrapolate in a computer and it, it's fine.

• 25:43Krishna Choudhary?

  Yeah, it's fine. It totally works. So, so what, what gives?

• 25:47Lester Nare?

  Which means the theory of the case here is that it is an engineering problem.

• 25:50Krishna Choudhary?

  Yes.

• 25:51Lester Nare?

  Not a fundamental physics or science problem.

• 25:53Krishna Choudhary?

  Yes.

• 25:53Lester Nare?

  That's kind of the, what's been the argument.

• 25:55Krishna Choudhary?

  It's been the argument and, but in order to prove that, you gotta just solve the engineering problem.

• 26:00Lester Nare?

  Right.

• 26:00Krishna Choudhary?

  Yeah, right?

• 26:01Lester Nare?

  Right.

• 26:01Krishna Choudhary?

  And that requires a lot of fundamental physics.

• 26:03Lester Nare?

  Right.

• 26:03Krishna Choudhary?

  At the end of the day.

• 26:04Lester Nare?

  Right.

• 26:04Krishna Choudhary?

  And so in 2024, we were at this interesting state, right? The theory says laws of light should be real. The experiment says nah. This is where we get into this paper. Bulk hexagonal diamond. Great name.

• 26:19Lester Nare?

  Yes.

• 26:20Krishna Choudhary?

  Three word. I, I haven't seen a shorter nature paper title, to be honest.

• 26:26Lester Nare?

  Well done.

• 26:26Krishna Choudhary?

  Right?

• 26:27Lester Nare?

  Well done.

• 26:27Krishna Choudhary?

  Bulk hexagonal diamond. That's it.

• 26:29Lester Nare?

  That's it.

• 26:29Krishna Choudhary?

  That's it.

• 26:30Lester Nare?

  No, no, no narrating.

• 26:33Krishna Choudhary?

  Yeah.

• 26:33Lester Nare?

  No, just.

• 26:34Krishna Choudhary?

  Yeah. Just, this is what we, this is what it is. Right?

• 26:37Lester Nare?

  It's quite nice.

• 26:38Krishna Choudhary?

  It's quite nice. It's a, it's a macroscopic pure sample that they've created.

• 26:42Lester Nare?

  Okay.

• 26:43Krishna Choudhary?

  Um, they're showing that it's not an artifact.

• 26:45Lester Nare?

  Mm hmm.

• 26:46Krishna Choudhary?

  And let's get into how exactly they did it.

• 26:49Lester Nare?

  Yes.

• 26:49Krishna Choudhary?

  All right.

• 26:49Lester Nare?

  And before we do.

• 26:51Krishna Choudhary?

  Yes.

• 26:52Lester Nare?

  I'm going to do some brief show notes. So if you are listening to this and you were a listener on episode five, when we talked about the other group of Chinese teams that did this story, you're, this is going to be very exciting because all of the stuff we do here, much like science and science research itself, builds on top of each other. The Nobel Prize aspect, all of these people, all these people and aspects that we really try to weave together is the joy that we get of doing this show. And you, as the supporting community and audience, are a huge part of why we're able to do that. So a simple like, share, follow, comment. You would not believe how much comments change how much our video gets shown to other people.

• 27:35Lester Nare?

  Let's talk more about science, experimental design, breaking science research. And any way that you can engage in our content is super, super helpful for us getting this show to more people. If you would like to become a patron, you can go over to our website, ffpod.com backslash donate. Make a one-time donation. If you think this is better than Netflix, you can make a monthly recurring donation. But every little bit helps. It is the two of us here who both produce, write, distribute, and run the entire show. And we really like to make sure it's at a high level, high-quality overlays, great breakdowns, and your support is the key aspect that allows us to do so. And with that, let's get back into the story.

• 28:20Krishna Choudhary?

  Yep, bulk hexagonal diamond. How did they do it?

• 28:23Lester Nare?

  How did they do it?

• 28:24Krishna Choudhary?

  The challenge is the following, actually, okay?

• 28:28Krishna Choudhary?

  You know, let's ask, why is it so easy now? I mean, it's hard, but why is it so easy to create cubic diamond, normal diamond, but it's so hard to create hexagonal diamond, right? We're just pressing graphite, but every single time, we're just getting the lab-grown standard diamond. I want to create hexagonal diamond. The reason why is that standard, high-pressure, high-temperature conditions favor the formation of cubic diamond, because cubic diamond is actually a global energy minimum. You know, when we think about energy landscapes, we can think about orientations and how different orientations of the diamond have different energies.

• 29:07Lester Nare?

  Yes.

• 29:08Krishna Choudhary?

  And it turns out, the cubic diamond, even though it's sort of bigger and has that ABC, ABC stacking,

• 29:14Lester Nare?

  Yes.

• 29:14Krishna Choudhary?

  that has a lower energy and is more favorable than this ABA B smaller configuration.

• 29:21Lester Nare?

  Interesting.

• 29:22Krishna Choudhary?

  So it's, you gotta go through a very specific route in order to get to this local minima and avoid the global minimum.

• 29:31Lester Nare?

  That makes total sense.

• 29:32Krishna Choudhary?

  That's what it turns out. And that has a lot to do with a lot of the computational work that was done around the hexagonal diamond to figure out, why is this?

• 29:39Lester Nare?

  Right.

• 29:40Krishna Choudhary?

  Why is this not working? Other people had done that work, okay?

• 29:43Lester Nare?

  Yes.

• 29:43Krishna Choudhary?

  So this team is like, all right, how are we gonna make? Oppress, how are we gonna make an experimental apparatus that is going to avoid that global minimum, not create a normal diamond and create our hexagonal diamond?

• 29:58Lester Nare?

  Is it almost like saying we intentionally have to create a, uh, uh, an experimental apparatus that is not optimizing for the easy, like the best path?

• 30:10Krishna Choudhary?

  Yeah, yeah.

• 30:10Lester Nare?

  Like we're intent, yeah, the easiest.

• 30:12Krishna Choudhary?

  We need to go and figure out some way to like go off.

• 30:16Lester Nare?

  Off the, right, right.

• 30:17Krishna Choudhary?

  Like, it's like, we got two depressions on a hill. It's like when you're skiing, right?

• 30:21Lester Nare?

  Yeah.

• 30:21Krishna Choudhary?

  You don't want to go all the way down.

• 30:22Lester Nare?

  Right.

• 30:23Krishna Choudhary?

  To the, the chairlift.

• 30:25Lester Nare?

  Yes.

• 30:25Krishna Choudhary?

  You, in mammoth, you, sometimes you want to go to the outhouse in the back.

• 30:29Lester Nare?

  Yeah, yeah, yeah.

• 30:29Krishna Choudhary?

  To get your grilled cheese sandwich, right? But that requires being very cognizant of which turns you're taking.

• 30:35Lester Nare?

  Right.

• 30:35Krishna Choudhary?

  Down the ski hill.

• 30:36Lester Nare?

  Yes.

• 30:37Krishna Choudhary?

  Right? Otherwise, you're just gonna end up in the lodge like everyone else.

• 30:40Lester Nare?

  Yes.

• 30:40Krishna Choudhary?

  And then have to wait like two hours to go up the mountain. We've, we've all been there.

• 30:45Lester Nare?

  Yeah, we've all been there. But no, but that's actually really, that's a really interesting insight in that a suboptimal path. Can actually lead to the, the derivative effects that we are looking for.

• 31:01Krishna Choudhary?

  Yes.

• 31:02Lester Nare?

  That are not necessarily naturally occurring.

• 31:04Krishna Choudhary?

  Yes, exactly. The reason why naturally occurring diamond is always naturally occurring, that cubic diamond, is because it's not a controlled process in the earth's crust, right?

• 31:14Lester Nare?

  Right.

• 31:14Krishna Choudhary?

  So it's just easy for the carbon to settle into the natural cubic diamond.

• 31:18Lester Nare?

  Yes.

• 31:18Krishna Choudhary?

  But if we really want to go for this hexagonal thing, it's gotta be real tight and real specific. And perhaps that's why the meteorite was showing these cases, right? Because like, I mean, the scenario is crazy.

• 31:29Lester Nare?

  Yes.

• 31:29Krishna Choudhary?

  It's a space rock coming at, like, very high speed.

• 31:33Lester Nare?

  Yes.

• 31:33Krishna Choudhary?

  Tens of kilometers per second.

• 31:35Lester Nare?

  Right.

• 31:35Krishna Choudhary?

  Slamming into rock.

• 31:36Lester Nare?

  Right.

• 31:37Krishna Choudhary?

  Right? This is a very key, like, scenario.

• 31:40Lester Nare?

  Yes, that makes sense.

• 31:41Krishna Choudhary?

  So with that in mind, let's try to figure out, how are we gonna do this, right? How are we gonna manufacture our hexagonal diamond and not cubic diamond?

• 31:49Lester Nare?

  Yes.

• 31:49Krishna Choudhary?

  They use something called a Kawai type large volume press. So this was conceptualized by Professor Naoto Kawai. It's a uniaxial hydraulic press with six steel anvils that are inward. Here's the key idea here. There's multiple stages. There's the inner stage, then there's the second stage anvil, and then there's an outer stage anvil. What I want to do is press. And when I press, the intermediate stage is going to press from all directions. Okay, so it's not just going to give me this kind of force, it's gonna give me an all-direction type of force.

• 32:27Lester Nare?

  Yes.

• 32:27Krishna Choudhary?

  And then that all-direction type of force is gonna press on an even smaller thing that is going to then let me control how and in what direction and how much I am able to put pressure. So that's my high pressure. And then high temperature, I can just like make the thing hot from a variety of different mechanisms.

• 32:45Lester Nare?

  Because you see, the variable here that it needs to be modified is not the heat, but the pressure.

• 32:50Krishna Choudhary?

  And here's why, the pressure is what matters.

• 32:55Krishna Choudhary?

  But they actually started, not with just normal graphite, but with a specific type of graphite called highly-oriented pyrolytic graphite. This is a photo from their supplement. On the top is the normal graphite that you use in lead, in pencil lead. Graphite is a bunch of layers of carbon rings, okay? It's layers on layers of carbon rings. But in naturally occurring graphite, the layers are kind of, you know, off each other. They're not completely flat, okay? What I want is exactly flat graphite, okay? Not off where like some, some carbon atoms are closer than other carbon atoms. I want exactly flat. So they created a high-pressure environment and then a rapid cooling thing

• 33:40Krishna Choudhary?

  to make your amorphous graphite, so to speak.

• 33:43Lester Nare?

  Yes.

• 33:43Krishna Choudhary?

  This very highly-oriented pyrolytic graphite. Now, what is the advantage there? The advantage there is that the graphite itself has A B A B memory.

• 33:56Lester Nare?

  Oh, very interesting. Yeah, yep, yep, yep.

• 34:01Krishna Choudhary?

  The cooking, the, the material that they're trying to cook with already has the geometry of their end product.

• 34:07Lester Nare?

  Right, right. And, and naturally occurring graphite is naturally imperfect.

• 34:12Krishna Choudhary?

  Yes.

• 34:13Lester Nare?

  And those imperfections lead to getting to, lead to the destination of the, the global minima. But And that's so interesting, but because we are now making sure that we're having A5 wagyu beef going in and not around the corner grocery store beef going in. We're going to get exactly what we want as the chef on the out.

• 34:36Krishna Choudhary?

  Exactly. And so this, you can already see the ABA B stacking. You can imagine the lower layer is B, the upper layer is A. And now I can just stack this on top of one another, right?

• 34:46Lester Nare?

  Yes.

• 34:46Krishna Choudhary?

  And so now when I press on them.

• 34:48Lester Nare?

  Yes.

• 34:48Krishna Choudhary?

  Perhaps that geometry is going to be preserved.

• 34:52Lester Nare?

  That makes sense.

• 34:53Krishna Choudhary?

  There's another problem though.

• 34:54Lester Nare?

  Okay.

• 34:54Krishna Choudhary?

  Just because you start with ABA B graphite, right? It's going to be ABA B one on top of the other. If I push from all directions, that might cause the graphite to scrunch up, losing that symmetry. So I need to be able to only press from the top and bottom.

• 35:10Lester Nare?

  Okay.

• 35:11Krishna Choudhary?

  Okay. Now, in any type of press, that's very difficult. But what they did was they added a layer of aluminum on top and the bottom. And what that alumina does is not distribute any of the stress laterally, just because of the way aluminum works. And all of the stress was in the up and down direction. So they had the press and on the press, they layered aluminum on the top and the bottom. So that when they were pressing, the stress was only in the vertical direction.

• 35:39Lester Nare?

  Yes.

• 35:39Krishna Choudhary?

  Okay.

• 35:40Lester Nare?

  Yes.

• 35:41Krishna Choudhary?

  Once they do that, finally, this is how it should work in theory. They did large scale molecular dynamics simulations. Here we've got layers on layers of that ABA B graphite.

• 35:50Lester Nare?

  Yes.

• 35:51Krishna Choudhary?

  And you can see a tiny defect is forming. And as you press, the orange is that hexagonal diamond. It rapidly forms, right? There's kind of a nucleation zone.

• 36:00Lester Nare?

  Yes.

• 36:01Krishna Choudhary?

  Where the defect kind of starts and the layers of graphite are covalently bonding to one another. And then as you press more and more, it rapidly sort of like, like a, like a contagion.

• 36:13Lester Nare?

  Yes.

• 36:14Krishna Choudhary?

  Right? That, that bond sort of spreads out.

• 36:17Lester Nare?

  It propagates from this like initial inciting incident location. And this is so now, understanding the, the component parts. This makes a lot more sense in terms of, you know. Because normally what you would get in this use case is the spreading of cubic diamonds.

• 36:38Krishna Choudhary?

  Yeah.

• 36:38Lester Nare?

  But because we've created our specific type of graphite, because we've created the specific pressure mechanism, and we've coded it at the top and bottom to make sure the pressure was distributed.

• 36:49Krishna Choudhary?

  Is only, yeah, and as you can see, the, it's only being squished this way vertically, right? It's not being squished the other way.

• 36:55Lester Nare?

  Right, right.

• 36:55Krishna Choudhary?

  And so that, those two dimensions, this dimension and the one inside and out, is being preserved. The only part that's getting squished is vertical, and that's why we're getting very specific hexagonal graphite, sorry, hexagonal diamond.

• 37:07Lester Nare?

  Yes.

• 37:07Krishna Choudhary?

  And so this is the molecular dynamic simulation.

• 37:09Lester Nare?

  Right.

• 37:10Krishna Choudhary?

  That they, where they showed, this is how we think it should happen.

• 37:13Lester Nare?

  Right.

• 37:13Krishna Choudhary?

  This was part of their paper, and obviously for, like, this type of paper, you want to show the mechanism. Okay, so this was a very cool molecular dynamic simulation.

• 37:21Lester Nare?

  Okay.

• 37:22Krishna Choudhary?

  That they're showing. So, they do the, they do the experiment, and they come up with samples. These are what the samples look like.

• 37:29Lester Nare?

  Yes.

• 37:30Krishna Choudhary?

  You've got some pretty large samples, so that bar is 200 microns.

• 37:34Lester Nare?

  Yes.

• 37:34Krishna Choudhary?

  Five of those is a millimeter.

• 37:36Lester Nare?

  Okay.

• 37:36Krishna Choudhary?

  So, this is about the size of a millimeter plus, which means I can see it with my naked eye.

• 37:40Lester Nare?

  Right.

• 37:40Krishna Choudhary?

  Before, everything was like sub-micron.

• 37:42Lester Nare?

  Right.

• 37:42Krishna Choudhary?

  Level, like, I had to go into the canyon Diablo meteorite, go under a scanning tunneling microscope, and even then, there was that dude who was like, no, this is just cubic diamond, right? Here, the whole thing, they're saying is hexagonal diamond.

• 37:54Lester Nare?

  Yes.

• 37:55Krishna Choudhary?

  Okay?

• 37:55Lester Nare?

  Yes. And, and the, the, the idea being, it both passes just like the kind of, the sniff test because of its size, like, it's just like, oh, well, if you can't make it that big, then I don't care. But it then also makes it easier to look at it.

• 38:09Krishna Choudhary?

  Yeah, because now with something this big, I can actually start doing X-ray diffraction studies in a clean manner, I can do transmission electron microscopy in a clean manner. And so at first, all they did was X-ray diffraction, and this thing called selected area electron diffraction, which is just, instead of X-rays, you're using electrons, and they did a Vickers hardness scale. On the left, you're seeing the X-ray diffraction.

• 38:35Lester Nare?

  Yes.

• 38:36Krishna Choudhary?

  On the x-axis is like an angle of like how the x-ray that's coming in is getting bumped out. And then on the y-axis, you're seeing like what the absorption rate is, right? Like the detector.

• 38:46Lester Nare?

  Yes.

• 38:47Krishna Choudhary?

  And the little spots are where you're seeing the distances between atoms. And they're saying that this is key to showing that this is hexagonal diamond.

• 38:59Lester Nare?

  Yes.

• 38:59Krishna Choudhary?

  They also do the Vickers hardness scale. Now I can read the peer review.

• 39:04Lester Nare?

  Yes.

• 39:05Krishna Choudhary?

  Okay.

• 39:05Lester Nare?

  Yes.

• 39:05Krishna Choudhary?

  So what do you think, right?

• 39:07Lester Nare?

  Yes.

• 39:07Krishna Choudhary?

  The peer reviewers are gonna read this and.

• 39:09Lester Nare?

  I just want, I just want to note really briefly.

• 39:11Krishna Choudhary?

  Yeah.

• 39:11Lester Nare?

  Because you know, there is a little bit of in the zeitgeist right now, there is a public debate about Chinese universities.

• 39:19Krishna Choudhary?

  Yeah.

• 39:20Lester Nare?

  And the legitimacy of the work that they do.

• 39:23Krishna Choudhary?

  Yeah.

• 39:24Lester Nare?

  I'm saying this is what the zeitgeist conversation is like in the US. And this was published in Nature.

• 39:31Krishna Choudhary?

  Yeah. Which is a Springer publication from the UK.

• 39:35Lester Nare?

  So, you know, and there, what's great, which you talked about this recently, is they're now putting the reviewer notes.

• 39:41Krishna Choudhary?

  Mm hmm.

• 39:42Lester Nare?

  On these papers.

• 39:43Krishna Choudhary?

  Yeah.

• 39:43Lester Nare?

  So you can get a little bit more of an insight into how the sausage was made.

• 39:47Krishna Choudhary?

  Yeah.

• 39:47Lester Nare?

  To make a better characterization about your own perspective of the study.

• 39:51Krishna Choudhary?

  Yeah.

• 39:51Lester Nare?

  And so I'm just, I know that there's, I think there's been a little bit of poo pooing that's been undeserved.

• 39:55Krishna Choudhary?

  Yeah.

• 39:56Lester Nare?

  And you can go just look.

• 39:58Krishna Choudhary?

  Yeah, and you can look and see what people are saying.

• 40:00Lester Nare?

  Right.

• 40:01Krishna Choudhary?

  And if we look at that peer review paper, so version zero, that's the one that they initially submit to the editor, the editor then deems, okay, I mean, if it's bulk hexagonal diamond, this does deserve getting published in a nature. So now I'm gonna put it off and give it for review to some of the top scientists in the field who know what they're talking about, okay? In this case, reviewer one comes back after version zero, and he says, overall, this paper should be rejected. Classic.

• 40:31Lester Nare?

  Classic.

• 40:31Krishna Choudhary?

  Usually it's reviewer two.

• 40:33Lester Nare?

  Yeah.

• 40:34Krishna Choudhary?

  Because like reviewer one is like, because imagine you're like opening up your peer review file, right? And usually like reviewer one is like kinda nice about it, and then reviewer two is just going at it. Here, like, I guess the editor didn't change the, you know, because the editor could have just like changed, it doesn't matter who reviewer one and two is.

• 40:52Lester Nare?

  Right.

• 40:53Krishna Choudhary?

  But anyways, they opened up the peer review file and imagine the first overall this paper should be rejected. Okay?

• 41:00Lester Nare?

  Yes.

• 41:01Krishna Choudhary?

  So here's the complaint that reviewer number one is making. He's saying that basically the x-ray diffraction and this electron diffraction, those two data sets are inconsistent. We don't know what the original version of the figures are, right? So we can't see, but apparently they were inconsistent and they didn't analyze different axes. Like, you know, with, with, with a crystal, there's like different directions that I can sort of probe. I can just rotate my sample.

• 41:24Lester Nare?

  Yes.

• 41:25Krishna Choudhary?

  On my x-ray diffraction apparatus and then I can probe different directions of the crystal. They didn't do that.

• 41:31Lester Nare?

  Okay, that's, I think that's fair.

• 41:33Krishna Choudhary?

  That's totally fair.

• 41:34Lester Nare?

  I think.

• 41:34Krishna Choudhary?

  They also didn't do this thing called Wright-Weil refinement, which is a way to computationally clean up diffraction data.

• 41:40Lester Nare?

  Okay.

• 41:40Krishna Choudhary?

  Which apparently like everyone does, so they didn't do that.

• 41:42Lester Nare?

  Okay.

• 41:43Krishna Choudhary?

  And they're using, this is, this one I thought was really hilarious. They're using diamond, cubic diamond, the normal diamond to probe the hardness of this thing. And they're claiming that this thing is harder. That doesn't quite make any sense.

• 41:58Lester Nare?

  Yeah.

• 41:58Krishna Choudhary?

  Right? You're, you're, you're, you've got, you've got something that's really hard. And then you're scratching it with something that you're claiming is not as hard.

• 42:06Lester Nare?

  Right.

• 42:06Krishna Choudhary?

  But then how are you scratching it?

• 42:07Lester Nare?

  Right.

• 42:08Krishna Choudhary?

  Yeah. If the, if the original.

• 42:10Lester Nare?

  Thing is.

• 42:11Krishna Choudhary?

  Thing is not as hard, right? And if, are you really sure that the scratch you made is like enough to give you data for the Vickers hardness scale?

• 42:18Lester Nare?

  Right.

• 42:18Krishna Choudhary?

  Right? If it's harder than the thing that you're using to scratch like, like we're in unknown territory here. Cause usually when we talk about how hard is something, we take a normal diamond that we know is at a hardness of 10. And we scratch it and then we see what the indentation is. And then from that you can calculate, okay, where is it on the hardness scale? Here you're saying this is harder than the thing we're using to probe it.

• 42:37Lester Nare?

  Right.

• 42:38Krishna Choudhary?

  Doesn't make any sense.

• 42:38Lester Nare?

  No, it, it does. The, the radio speaker dial does not go to 11.

• 42:42Krishna Choudhary?

  Yeah. Okay. So that's reviewer one. Reviewer two was very nice about it.

• 42:46Lester Nare?

  Okay.

• 42:46Krishna Choudhary?

  Um, he said, you know, Bulk hexagonal diamond is a very important thing.

• 42:52Lester Nare?

  Yes.

• 42:52Krishna Choudhary?

  Therefore, the study seems important.

• 42:54Lester Nare?

  Yes.

• 42:54Krishna Choudhary?

  And could deserve to be published in a journal like Nature. He's saying you've got a chance.

• 42:58Lester Nare?

  Yes.

• 42:58Krishna Choudhary?

  But I'm not convinced.

• 43:00Lester Nare?

  Okay.

• 43:00Krishna Choudhary?

  He says the data obtained from these many different methods to characterize the sample looks convincing in principle, but there's some important questions that remain. So the authors go back.

• 43:10Lester Nare?

  Yes.

• 43:10Krishna Choudhary?

  And the key thing is with reviewer two, the concerns that he said the important questions that remain are very similar to author one.

• 43:18Lester Nare?

  Okay.

• 43:18Krishna Choudhary?

  To reviewer one.

• 43:19Lester Nare?

  Yeah.

• 43:19Krishna Choudhary?

  Except reviewer one was straight up like.

• 43:21Lester Nare?

  Yeah, this is not.

• 43:22Krishna Choudhary?

  This, this, I don't know what we're.

• 43:24Lester Nare?

  What are we doing here?

• 43:25Krishna Choudhary?

  Yeah. Okay, so the authors come back and they did do multiple directions.

• 43:29Lester Nare?

  Okay.

• 43:29Krishna Choudhary?

  Okay, so in this one, if you see, this is figure two, two A and B show A B stacking. You see that? You see the little orange dots? That's A B, A B, A B, A B. This is electron microscopy.

• 43:42Lester Nare?

  Yeah.

• 43:43Krishna Choudhary?

  Very clear.

• 43:44Lester Nare?

  Yes.

• 43:44Krishna Choudhary?

  Very clear, right? On the bottom row, you see hexagonal lattice.

• 43:48Lester Nare?

  Yeah.

• 43:48Krishna Choudhary?

  Okay?

• 43:49Lester Nare?

  Yeah, it is quite.

• 43:50Krishna Choudhary?

  It's like, it's there, right? The A B A B stacking is in the top row. They've, they've done the simulation on the right hand side of like what it should look like and on the bottom row.

• 43:58Lester Nare?

  Yeah.

• 43:58Krishna Choudhary?

  They're, they're, they're showing the hexagonal stacking.

• 44:01Lester Nare?

  Yep.

• 44:01Krishna Choudhary?

  Very nice.

• 44:02Lester Nare?

  Yep.

• 44:02Krishna Choudhary?

  Okay, so.

• 44:03Lester Nare?

  And this is exactly what the peer review process is.

• 44:06Krishna Choudhary?

  Yeah.

• 44:06Lester Nare?

  Like this is, the point was, is that we want to get things accurate, as accurately as possible and as correctly as possible. And so it's a, it's a natural back and.

• 44:15Krishna Choudhary?

  It's a natural back and forth. And credit to the editor of this thing. He didn't take the reviewer one feedback too seriously.

• 44:21Lester Nare?

  Right, right, right.

• 44:22Krishna Choudhary?

  And gave the authors another chance, right?

• 44:24Lester Nare?

  Yes.

• 44:24Krishna Choudhary?

  Um, especially because, I mean, reviewer two had like positive things to say and said that there is definitely a chance. I think if both editors, I mean, if both reviewers were like, no.

• 44:33Lester Nare?

  Yeah.

• 44:34Krishna Choudhary?

  It would have been kind of bad, right?

• 44:35Lester Nare?

  It would have been tough.

• 44:35Krishna Choudhary?

  So anyways, they did show the multiple directions. They showed that A B A B stacking and the hexagonal stuff. They also did this right field analysis. This is a kind of computational trick where you say, okay, what if, um, what if the sample is fully hexagonal or it's a mixture of hexagonal and cubic? What would the theoretical distribution look like?

• 44:55Lester Nare?

  Right.

• 44:55Krishna Choudhary?

  And then if I take a difference of the two, which model fits better?

• 44:58Lester Nare?

  Yes.

• 44:58Krishna Choudhary?

  And. The one that's purely hexagonal fits better than the one that's a mixture. Okay, so this is the analysis that reviewer one wanted.

• 45:05Lester Nare?

  Yes.

• 45:05Krishna Choudhary?

  He got it.

• 45:06Lester Nare?

  Yes.

• 45:06Krishna Choudhary?

  So the other thing, there's a question about uniformity. How uniform is the sample?

• 45:11Lester Nare?

  Which is a good question.

• 45:11Krishna Choudhary?

  Which is a good question. So here they took 11 different random samples of like a part of their sample. And they did x-ray diffraction on that to show that the x-ray diffraction that comes out of whatever part of the sample is pretty identical. Right?

• 45:27Lester Nare?

  This is.

• 45:28Krishna Choudhary?

  These are 11 different x-ray diffraction experiments, but they all look basically the same. Like the the spacing of the

• 45:33Lester Nare?

  Yeah.

• 45:34Krishna Choudhary?

  of the maxima

• 45:36Lester Nare?

  Yeah.

• 45:36Krishna Choudhary?

  of your x-ray diffraction is about the same.

• 45:37Lester Nare?

  Yeah.

• 45:38Krishna Choudhary?

  Right?

• 45:38Lester Nare?

  It's also just beautiful.

• 45:40Krishna Choudhary?

  Yeah, very beautiful. And the hexagonal structure that you see is indicative.

• 45:44Lester Nare?

  Yeah, like it's like, yeah, I have never looked at that much.

• 45:48Krishna Choudhary?

  Yeah.

• 45:48Lester Nare?

  Uh, x-ray crystallography or electron microscopy photography. But you can, I can see the thingy.

• 45:58Krishna Choudhary?

  Yeah.

• 45:59Lester Nare?

  Without much analysis.

• 46:01Krishna Choudhary?

  Yeah. Yeah. And and finally, they also, instead of doing the Vickers hardness scale, which is like the scratching on the diamond thing.

• 46:07Lester Nare?

  Yes.

• 46:07Krishna Choudhary?

  Reviewer one suggested that they should do something called pulsed echo experiments.

• 46:13Lester Nare?

  Okay.

• 46:13Krishna Choudhary?

  This is a way that you can like basically send sound waves effectively through a material.

• 46:18Lester Nare?

  Yeah.

• 46:19Krishna Choudhary?

  And the response of that material lets you calculate the elastic modulus of that material. And then there's ways to back calculate what the hardness is.

• 46:27Lester Nare?

  That makes sense.

• 46:27Krishna Choudhary?

  So he said, if your scratch test and this echo experiment give you the same number, then I'll believe you.

• 46:33Lester Nare?

  Okay.

• 46:33Krishna Choudhary?

  So they did it. It did come out. It showed that the Young's modulus was bigger than diamond's. And so finally, version three, which is the fourth version, because you start with version zero.

• 46:44Lester Nare?

  Yes.

• 46:44Krishna Choudhary?

  So with version three, reviewer one finally says that he's happy with the version. He says, the authors revised the paper according to the recommendations. Now the paper and supplement provide all the relevant information and the results are truly convincing. Exclamation point. And at the end, and in the middle, he's saying that I believe refining all of this was worth it. So he's kind of saying like, I know I gave you guys a hard time. But I think it was worth it because now I think this paper is stellar. And at the end, he says, congratulations for this important work. And he signs his own name. Oliver, um.

• 47:17Krishna Choudhary?

  Xiaowenar.

• 47:17Lester Nare?

  Yeah.

• 47:18Krishna Choudhary?

  He's from the University of Nevada, Las Vegas, I believe. So he did, he put his name, he doesn't have to.

• 47:23Lester Nare?

  Right.

• 47:24Krishna Choudhary?

  Right? But he put his own name there to show, okay, this is who I was.

• 47:27Lester Nare?

  Yeah.

• 47:27Krishna Choudhary?

  Appreciate the work he did.

• 47:28Lester Nare?

  Right.

• 47:29Krishna Choudhary?

  So reviewer one turns out to be like, kind of a hard ass, but.

• 47:32Lester Nare?

  Right.

• 47:33Krishna Choudhary?

  The paper is quite incredible because now no one can say anything.

• 47:37Lester Nare?

  No, this is, and I think this is the key point of why I wanted to preface the cultural moment and the sort of judgment of, you know, it, it, it, this process really does matter. And I do think some of the feedback that was brought up makes total sense.

• 47:51Krishna Choudhary?

  Yeah, yeah, yeah.

• 47:52Lester Nare?

  Like very reasonable.

• 47:53Krishna Choudhary?

  And like reviewer two said the same stuff.

• 47:54Lester Nare?

  Right.

• 47:55Krishna Choudhary?

  Yeah.

• 47:55Lester Nare?

  And if it worked, it's, it was easily resolvable.

• 47:58Krishna Choudhary?

  Yeah.

• 47:59Lester Nare?

  It didn't require huge refactor or anything like that.

• 48:01Krishna Choudhary?

  You've got the sample.

• 48:02Lester Nare?

  Just.

• 48:03Krishna Choudhary?

  Yeah.

• 48:03Lester Nare?

  Do a little more double checking.

• 48:05Krishna Choudhary?

  Yeah.

• 48:06Lester Nare?

  And fascinating.

• 48:07Krishna Choudhary?

  Yeah.

• 48:08Lester Nare?

  I, I, and this is, and again, we covered this in episode five.

• 48:11Krishna Choudhary?

  Right.

• 48:11Lester Nare?

  And in a slightly different, similar, but slightly different way.

• 48:14Krishna Choudhary?

  Yes. So now let's talk about that.

• 48:16Lester Nare?

  Okay.

• 48:16Krishna Choudhary?

  All right. So this particular paper is coming out of Zhengzhou University in China, also Nanjing University in China. And you said Hunan University, right? In China. These are all sort of like in the northern, central part of China.

• 48:31Lester Nare?

  And I want to just pronounce.

• 48:32Krishna Choudhary?

  And in the east.

• 48:33Lester Nare?

  Hanan versus Hunan.

• 48:35Krishna Choudhary?

  Okay, sorry. Yeah.

• 48:36Lester Nare?

  Just be.

• 48:36Krishna Choudhary?

  Oh, okay.

• 48:37Lester Nare?

  Cause they're different.

• 48:38Krishna Choudhary?

  Fair, totally enough. And the paper that we covered last year.

• 48:42Lester Nare?

  Yes.

• 48:42Krishna Choudhary?

  Was out of the Shanghai Advanced Research.

• 48:44Lester Nare?

  Yes.

• 48:45Krishna Choudhary?

  In Physical Sciences Center in China, right? And that was synthesis of bulk hexagonal diamond. Already funny because these guys use synthesis of bulk hexagonal diamond and these guys are just like.

• 48:55Lester Nare?

  Ball hexagonal diamond.

• 48:58Krishna Choudhary?

  Okay. Also in nature.

• 49:00Lester Nare?

  Yes.

• 49:00Krishna Choudhary?

  Now, this new paper does not cite that older one from last year.

• 49:08Lester Nare?

  No, no.

• 49:10Krishna Choudhary?

  Okay. I thought that was pretty hilarious because the reviewer comments in reviewer two actually does acknowledge this, that a recent paper has come out.

• 49:21Lester Nare?

  Yeah.

• 49:21Krishna Choudhary?

  That shows bulk hexagonal synthesis of bulk hexagonal diamond. But he says that this paper was submitted before that one got accepted. So it's not like these guys knew about that paper, right?

• 49:32Lester Nare?

  Right.

• 49:33Krishna Choudhary?

  But what that also tells me is that.

• 49:37Krishna Choudhary?

  These guys Li and other authors from Zhengzhou University had the chance to cite that paper and did not.

• 49:45Lester Nare?

  Yes.

• 49:45Krishna Choudhary?

  Because they saw it in the reviewer comments. Also, if you're in the field, you're not going to not be aware of a nature paper that came out saying the same thing.

• 49:53Lester Nare?

  Right.

• 49:53Krishna Choudhary?

  Right? And in, they were in the process of revision, which means they could have easily snuck in that.

• 49:58Lester Nare?

  Yep.

• 49:58Krishna Choudhary?

  That, but they didn't.

• 49:59Lester Nare?

  Yep.

• 50:00Krishna Choudhary?

  Okay, I think already, that's hilarious.

• 50:02Lester Nare?

  Yeah, yeah, yeah.

• 50:02Krishna Choudhary?

  Okay, there's clearly something.

• 50:04Lester Nare?

  We didn't sample your, your, your chord from your 1967 hit. No, no, no, no, no.

• 50:09Krishna Choudhary?

  Yeah, yeah. And that same, that same group from the Shanghai University also did another paper in February. But this was in Nature Materials. And again, it was a general approach for synthesizing hexagonal diamond using postgraphite phases. So slightly different method, but still.

• 50:28Lester Nare?

  Right.

• 50:28Krishna Choudhary?

  No mention of even this paper?

• 50:32Lester Nare?

  This, this, this is.

• 50:33Krishna Choudhary?

  Like, this is some beef, dude.

• 50:34Lester Nare?

  Yeah, this is, this is what beef looks like.

• 50:36Krishna Choudhary?

  Yeah.

• 50:36Lester Nare?

  Like, clearly there's something, right?

• 50:39Krishna Choudhary?

  So, um, so I, I wanted to dig a little bit deeper.

• 50:44Lester Nare?

  Yes.

• 50:45Krishna Choudhary?

  So Nature has a news article about this, right? Where they talk about this, they, they talk about like this paper and all of the other research around it. And nature being nature, they have to acknowledge that they themselves published a previous paper on it, right? So what, what's going on?

• 51:02Lester Nare?

  Right.

• 51:02Krishna Choudhary?

  So I'm just going to read a little bit snippet of that.

• 51:04Lester Nare?

  Yes.

• 51:04Krishna Choudhary?

  Of that news article, right? First of all, we, we see Shauner, who's the, the reviewer number one. He gives a brief expose about, like, he says that the pattern of the deflation peaks that are obtained very closely mimic that of hexagonal diamond. And to demonstrate hexagonal structure conclusively, there's a few more peaks that I really wanted to see. Once I saw that, the new paper shows those peaks, that's why I believe it. Okay? So he's, you know, true to his word, reviewer number one, gave them a hard time, but.

• 51:39Lester Nare?

  And then went to go comment on the public, on a public thing.

• 51:43Krishna Choudhary?

  And said, I was the reviewer, I believe it, I stand by this paper along with the authors.

• 51:47Lester Nare?

  Right, which is a crazy.

• 51:49Krishna Choudhary?

  Yeah.

• 51:49Lester Nare?

  Okay, you know.

• 51:50Krishna Choudhary?

  That's cool.

• 51:50Lester Nare?

  Yeah.

• 51:51Krishna Choudhary?

  Right?

• 51:51Lester Nare?

  Yeah.

• 51:52Krishna Choudhary?

  Now, they mentioned, last year, another research group independently reported making hexagonal diamond. This is the 2025 paper.

• 51:58Lester Nare?

  Yes.

• 51:59Krishna Choudhary?

  Out of Shanghai. And would they get a quote from those authors?

• 52:04Lester Nare?

  Oh, no.

• 52:06Krishna Choudhary?

  From last year's paper. And that guy, Ho Kwang-Mao from Shanghai, he says, "It looks like the new paper is very similar to ours. I have to say, I cannot see any difference." He's quoted, right? And then, and then, and then he says, "But we're glad they have reproduced our results."

• 52:25Lester Nare?

  Sheesh.

• 52:26Krishna Choudhary?

  Which is effectively a scientific way of saying they didn't do anything new.

• 52:29Lester Nare?

  Right.

• 52:30Krishna Choudhary?

  They just, I can't, it's effectively, they're saying, "I can't believe a reproduction paper."

• 52:35Lester Nare?

  Yeah, right.

• 52:36Krishna Choudhary?

  Also got into nature.

• 52:37Lester Nare?

  Right.

• 52:37Krishna Choudhary?

  So, something happened, bro.

• 52:39Lester Nare?

  Yeah.

• 52:40Krishna Choudhary?

  Like, something happened with these two groups. And Shauner, who's the reviewer number one.

• 52:46Lester Nare?

  Yeah.

• 52:47Krishna Choudhary?

  He did a minor clapback.

• 52:48Lester Nare?

  Yeah.

• 52:49Krishna Choudhary?

  He said, "It's almost the same."

• 52:51Lester Nare?

  Yep.

• 52:51Krishna Choudhary?

  But he pointed out that the X-ray analysis by Mao and his colleagues, this is the previous paper.

• 52:55Lester Nare?

  Yeah.

• 52:57Krishna Choudhary?

  That X-ray analysis lacked one or two of the diffraction peaks that are expected to be seen in hexagonal diamond. So he's saying this paper has a definitive.

• 53:07Lester Nare?

  Right.

• 53:07Krishna Choudhary?

  Like, hexagonal diamond X-ray diffraction pattern.

• 53:10Lester Nare?

  Right.

• 53:10Krishna Choudhary?

  That perhaps the other one didn't.

• 53:12Lester Nare?

  Right.

• 53:12Krishna Choudhary?

  But I just, this whole saga is hilarious to me.

• 53:15Lester Nare?

  And you actually brought this up when we did episode five, where you, you said, "I think there might be another team."

• 53:22Krishna Choudhary?

  Yes.

• 53:22Lester Nare?

  That is working on this.

• 53:24Krishna Choudhary?

  Within China.

• 53:25Lester Nare?

  Within China, but the, this, these guys got out first.

• 53:28Krishna Choudhary?

  Yeah.

• 53:30Lester Nare?

  And you had literally, like, it was, I wish, I will try to see if we can do a, like, a, a, a throwback thing here, because your statement on that episode is almost literally.

• 53:40Krishna Choudhary?

  Yeah.

• 53:41Lester Nare?

  Exactly what happened.

• 53:42Krishna Choudhary?

  It was this, it was this team.

• 53:43Lester Nare?

  It was.

• 53:44Krishna Choudhary?

  That was doing it. I mean, so, two things. One, this is hilarious.

• 53:48Lester Nare?

  Yes.

• 53:48Krishna Choudhary?

  I love scientific beef.

• 53:49Lester Nare?

  Yes.

• 53:50Krishna Choudhary?

  And beef among scientists. I wonder what conferences are like.

• 53:53Lester Nare?

  Oh, yeah.

• 53:53Krishna Choudhary?

  You know?

• 53:55Lester Nare?

  Because, because I think the point is, like, this is, this is.

• 53:59Krishna Choudhary?

  It is a 50 plus year old.

• 54:01Lester Nare?

  Yeah.

• 54:02Krishna Choudhary?

  Unsolved problem. So the prestige and the street cred and yada yada that you'll get from it.

• 54:08Lester Nare?

  Yeah.

• 54:09Krishna Choudhary?

  For being first.

• 54:10Lester Nare?

  Yeah.

• 54:11Krishna Choudhary?

  Matters.

• 54:11Lester Nare?

  Yes.

• 54:12Krishna Choudhary?

  A lot.

• 54:12Lester Nare?

  Yeah.

• 54:13Krishna Choudhary?

  Especially in the material science, because this resolves the simulation. Like, people who are poo pooing, oh, the Sims are wrong. Well, I guess not.

• 54:22Lester Nare?

  Yeah, I guess not. I guess this thing is real, right? So that's one thing. This is hilarious and science beef is also funny. I think, too, this shows just how good China has gotten.

• 54:32Krishna Choudhary?

  Yes.

• 54:33Lester Nare?

  With fundamental material science research. Because they're having internal beef.

• 54:37Krishna Choudhary?

  Right.

• 54:38Lester Nare?

  Right.

• 54:38Krishna Choudhary?

  Okay.

• 54:38Lester Nare?

  Yeah.

• 54:39Krishna Choudhary?

  There's institutions within China.

• 54:41Lester Nare?

  Yes.

• 54:42Krishna Choudhary?

  That are beefing with each other.

• 54:43Lester Nare?

  Right.

• 54:44Krishna Choudhary?

  About, like, who came first.

• 54:45Lester Nare?

  Right.

• 54:46Krishna Choudhary?

  It's not even, China is saying, we're first.

• 54:48Lester Nare?

  Right.

• 54:49Krishna Choudhary?

  It's like, who among us?

• 54:50Lester Nare?

  Is first.

• 54:51Krishna Choudhary?

  Is first, right? It's China, Chinese science has made leaps and bounds in terms of where they were just 20 years ago, compared to where they are now, right?

• 55:01Lester Nare?

  Yep.

• 55:01Krishna Choudhary?

  Where 20 years ago, this kind of competition was unheard of.

• 55:04Lester Nare?

  Right.

• 55:05Krishna Choudhary?

  And now, and now we're at this stage.

• 55:07Lester Nare?

  It is.

• 55:07Krishna Choudhary?

  It's very impressive.

• 55:09Lester Nare?

  If you're watching this on a clip, be sure to watch the full episode because the details are very juicy.

• 55:16Krishna Choudhary?

  Yeah.

• 55:16Lester Nare?

  The actual science is fascinating. Why it worked is fascinating.

• 55:21Krishna Choudhary?

  How much grief the reviewers gave them, right? This was not easy.

• 55:25Lester Nare?

  Right.

• 55:25Krishna Choudhary?

  For these scientists to publish.

• 55:26Lester Nare?

  Right. And this is not coming out of the South China Morning Post.

• 55:30Krishna Choudhary?

  No.

• 55:31Lester Nare?

  Or, you know, an outlet that you can perceive to have geopolitical reason to frame it one way or another.

• 55:39Lester Nare?

  And also the material science implications of this, as you brought up at the beginning.

• 55:43Krishna Choudhary?

  Yeah.

• 55:43Lester Nare?

  From industrial application, etc. Obviously, there's a scaling issue.

• 55:46Krishna Choudhary?

  Yeah.

• 55:46Lester Nare?

  Yada yada.

• 55:46Krishna Choudhary?

  Yeah, yeah, yeah.

• 55:47Lester Nare?

  All this normal stuff we caveat. Regardless, hugely, hugely impactful.

• 55:54Lester Nare?

  And, and I think sort of. We'll see how the, because we, we've, this is now six, seven months later from our first coverage.

• 56:03Krishna Choudhary?

  Yeah.

• 56:04Lester Nare?

  We'll see how this story progresses, but this seems to be a little bit of the closing of the book on a couple of the aspects.

• 56:10Krishna Choudhary?

  Yeah, yeah. I think, I mean, there's two, there's two big research groups that have shown that this thing can work.

• 56:15Lester Nare?

  Right.

• 56:15Krishna Choudhary?

  I'm sure now other countries and other labs are going to replicate this thing. Now, the big question mark is, can this thing scale?

• 56:22Lester Nare?

  Yes.

• 56:23Krishna Choudhary?

  Or do we have to figure out a new way to create a hexagonal diamond that scales?

• 56:27Lester Nare?

  Industrially.

• 56:28Krishna Choudhary?

  Industrially, right?

• 56:28Lester Nare?

  But it works.

• 56:29Krishna Choudhary?

  Yeah.

• 56:30Lester Nare?

  We can do it.

• 56:32Lester Nare?

  Great story again out of, out of nature on March 4th, Zhengzhou, Nanjing and Hanan Universities in China. A follow-up to our episode five. If you liked this episode, if you like, again, seeing the connections, our last deep dive episode had a very similar thing. If you're a long time listener, you're probably like me where you're starting to get these things much quicker. You can see how they all relate to each other, how we build on top of the past work. We are truly standing on the shoulders of giants. Now, should we ask for the comment for this episode to create a replacement for the De Beers? Diamonds are forever. Some diamonds.

• 57:14Krishna Choudhary?

  Yeah.

• 57:14Lester Nare?

  Marketing.

• 57:15Krishna Choudhary?

  Yeah.

• 57:16Lester Nare?

  Some, not diamonds are hexagonal, but something.

• 57:18Krishna Choudhary?

  Something, yeah. Come up with your best tagline.

• 57:21Lester Nare?

  Best tagline, because we need to rebrand for diamonds now, because it's technically a different thing.

• 57:25Krishna Choudhary?

  Yeah. There's two types.

• 57:27Lester Nare?

  There's two types.

• 57:27Krishna Choudhary?

  Yeah.

• 57:28Lester Nare?

  Two types. I am your host, Lester Nare, joined as always by my co-host and our resident PhD, Krishna Choudhary. We appreciate you all joining us on this journey and we will see you later this week.