WEBVTT - Is There Anything Harder Than Diamonds? 0:00:00.880 --> 0:00:04.520 Hey, welcome to Sign Stuff, a production of iHeartRadio. I'm 0:00:04.559 --> 0:00:07.720 More hitch Ham, and today we are answering a really 0:00:07.880 --> 0:00:12.119 hard question, maybe the hardest we've ever tried to answer, 0:00:12.520 --> 0:00:17.599 which is is there anything harder than diamonds? Okay, that 0:00:17.680 --> 0:00:20.320 was a silly pun, but we've all heard the slogans 0:00:20.760 --> 0:00:24.439 the diamond is forever, it's a girl's best friend. But 0:00:24.480 --> 0:00:27.640 it's a diamond? Really that sturdy? Let break if I 0:00:27.720 --> 0:00:30.520 hit it with the hammer? What happens if I stick 0:00:30.560 --> 0:00:33.279 one in the oven? We're going to talk to an 0:00:33.280 --> 0:00:36.040 expert on heart materials and we're going to ask her 0:00:36.080 --> 0:00:40.480 all the tough questions. See I could have said hard, 0:00:40.640 --> 0:00:44.080 but I didn't. Anyways, get ready to quit our ring 0:00:44.120 --> 0:00:47.559 on it as we bling out and find out is 0:00:47.600 --> 0:00:58.160 there anything harder than diamonds? Enjoy? Hey everyone, Today we're 0:00:58.160 --> 0:01:02.520 answering a pretty basic question, which is are diamonds the 0:01:02.600 --> 0:01:06.959 hardest material known to humans? Now, for this episode, I 0:01:07.040 --> 0:01:10.800 interviewed a really cool expert, Professor Jody Bradby, from the 0:01:10.840 --> 0:01:13.720 Australian National University, and I learned a lot of cool 0:01:13.760 --> 0:01:17.480 things about diamonds I didn't know before, Like, for example, 0:01:17.640 --> 0:01:19.920 did you know you can make a diamond out of 0:01:20.080 --> 0:01:25.000 peanut butter. Yeah, this is something scientists actually tested and 0:01:25.600 --> 0:01:29.200 it's true. Okay, I'm gonna let doctor Bradby explain it. 0:01:30.600 --> 0:01:33.319 I'm Professor Jody Bradby. I'm head of a high pressure 0:01:33.319 --> 0:01:35.759 physics group at the Australian National University. 0:01:36.040 --> 0:01:38.280 Great. Now, when you say it's high pressure, is it 0:01:38.400 --> 0:01:41.000 like there's a lot of pressure on everyone working there or. 0:01:41.880 --> 0:01:44.959 There are so many puns. In my fields, we have 0:01:45.000 --> 0:01:50.639 a high stress environment. Yeah, definitely, but we create really 0:01:50.720 --> 0:01:52.880 high pressures to make new materials. 0:01:53.320 --> 0:01:56.000 Oh, very exciting. So today we're trying to answer the 0:01:56.080 --> 0:01:59.640 question is there anything harder than diamonds? So I thought 0:01:59.680 --> 0:02:02.000 we could start having you talked to us just about 0:02:02.080 --> 0:02:05.480 diamonds themselves. What makes diamonds so hard? 0:02:05.920 --> 0:02:11.079 Yeah, So basically diamond consists of carbon atoms. So if 0:02:11.120 --> 0:02:15.040 you arrange the carbon atoms in a particular crystal structure, 0:02:15.200 --> 0:02:16.959 then that's what makes the diamond. 0:02:17.320 --> 0:02:19.800 How do the atoms get into a crystal structure? 0:02:20.280 --> 0:02:23.120 Okay, so you get your carbon atoms, and now we've 0:02:23.120 --> 0:02:25.679 got to do something to trick those carbon atoms to 0:02:25.720 --> 0:02:30.320 form a crystal lattice. So nature uses two things to 0:02:30.360 --> 0:02:33.200 do this. It uses temperature and pressure, so we have 0:02:33.280 --> 0:02:37.200 to have really high pressures and really high temperatures. So 0:02:37.240 --> 0:02:41.040 the pressure forces the carbon atoms close together, and then 0:02:41.080 --> 0:02:43.799 the little electrons in the atoms go, oh dear, we're 0:02:43.800 --> 0:02:45.600 going to have to rearrange and we need to make 0:02:45.639 --> 0:02:49.519 different friends. So they form different bonds, and they form 0:02:49.560 --> 0:02:50.959 what's called a convalent bond. 0:02:51.480 --> 0:02:52.440 So it's just carbon. 0:02:52.800 --> 0:02:55.960 Yes, yes, it's one of the beauties of diamond making. 0:02:56.240 --> 0:03:00.400 There's like carbon everywhere. I think some scientists famously a 0:03:00.440 --> 0:03:03.440 diamond out of peanut butter once just to prove that 0:03:03.480 --> 0:03:04.080 you could do it. 0:03:05.560 --> 0:03:07.200 How do you make a diamond out of peanut butter? 0:03:07.360 --> 0:03:09.440 So they just got a bit of peanut butter and 0:03:09.600 --> 0:03:13.320 squeeze the life out of it. Basically it released a 0:03:13.360 --> 0:03:15.639 lot of other things like hydrogen and things. I think 0:03:15.680 --> 0:03:18.680 it actually broke the system that they were using, but 0:03:18.720 --> 0:03:21.360 they did make like tiny little diamonds, which is a 0:03:21.400 --> 0:03:22.440 really cute experiment. 0:03:22.639 --> 0:03:27.239 Oh wow, was it the chunky or the smooth kine 0:03:27.360 --> 0:03:28.280 or the shiny. 0:03:27.960 --> 0:03:28.680 Code I don't know. 0:03:31.280 --> 0:03:34.360 Yeah, So you can make diamonds out of anything with carbon, 0:03:34.639 --> 0:03:38.200 even peanut butter, which means you can make diamonds in 0:03:38.200 --> 0:03:42.080 a jiff, get it like peanut butter brand No, actually, 0:03:42.480 --> 0:03:46.360 naturally occurring diamonds take a long time. But here's the 0:03:46.400 --> 0:03:50.520 next interesting thing I learned about diamonds. Scientists don't really 0:03:50.600 --> 0:03:54.960 know how long it takes to make them. 0:03:55.040 --> 0:03:57.800 So we famously know that diamonds are formed deep into 0:03:57.840 --> 0:04:00.680 the earth in a kind of a GOLDI lie for 0:04:00.920 --> 0:04:01.800 diamond formation. 0:04:02.160 --> 0:04:03.360 It also takes. 0:04:03.080 --> 0:04:06.360 Potentially billions of years for this process to happen. 0:04:06.640 --> 0:04:07.880 Why does it take a long time? 0:04:08.240 --> 0:04:11.560 Well, that's actually interesting. We don't really know how long 0:04:11.600 --> 0:04:14.160 diamonds take to form deep in the earth. We don't 0:04:14.200 --> 0:04:17.400 know exactly how the process works. It's one of those 0:04:17.400 --> 0:04:20.279 things you do if you read the textbook, it says, yes, 0:04:20.320 --> 0:04:22.679 you need this temperature and this pressure, but we can't 0:04:22.760 --> 0:04:25.440 actually explain the science so that we can't look down 0:04:25.520 --> 0:04:27.760 that deep in the earth and watch what's happening. 0:04:29.839 --> 0:04:33.560 That's right. The actual way in which diamonds form is 0:04:33.600 --> 0:04:36.960 still a mystery. The only reason we think it takes 0:04:37.000 --> 0:04:39.520 a long time is that when we take carbon in 0:04:39.600 --> 0:04:42.680 a lab and squeeze it super hard and make it 0:04:42.720 --> 0:04:47.920 super duper hard, nothing happens. So we assume that it 0:04:48.000 --> 0:04:52.320 must take a long time, maybe billions of years, but 0:04:52.640 --> 0:04:55.680 we're not really sure. Now you might be thinking, wait 0:04:55.720 --> 0:04:58.039 a minute, a joorhe I thought we could make diamonds 0:04:58.080 --> 0:05:02.359 in the lab and in factories, we can make artificial diamonds. 0:05:02.720 --> 0:05:05.640 How do we make those? Well, it turns out that 0:05:05.720 --> 0:05:09.920 to make a diamond in a lab you have to sheath. 0:05:11.880 --> 0:05:14.120 We can play tricks up on the surface of the 0:05:14.160 --> 0:05:17.200 earth where we add metallic catalysts, and that can just 0:05:17.279 --> 0:05:20.800 help the process go a lot faster, and therefore we 0:05:20.839 --> 0:05:23.320 can make it on a time period that you know, 0:05:23.360 --> 0:05:25.240 we don't have to wait around billions of years to 0:05:25.240 --> 0:05:28.280 get your engagement ring. That's where you could create like 0:05:28.320 --> 0:05:32.080 a coke cans worth of diamonds in about an hour. 0:05:32.200 --> 0:05:37.520 And these massive presses and really high temperatures, huge industrial 0:05:37.560 --> 0:05:40.760 process and the diamonds you're talking about here are generally 0:05:40.800 --> 0:05:43.160 in diamonds that you might put them on the top 0:05:43.200 --> 0:05:45.520 of a drill bit, and it did cost about the 0:05:45.560 --> 0:05:46.480 same as a sandwich. 0:05:48.640 --> 0:05:52.000 So we can make diamonds artificially in a lab or 0:05:52.040 --> 0:05:55.839 in a factory, but to get the really natural, pure ones, 0:05:56.200 --> 0:05:58.800 like the ones made inside the earth, you have to 0:05:58.839 --> 0:06:03.200 wait potentially billions of years. And by the way, if 0:06:03.200 --> 0:06:06.159 you're waiting billions of years for an engagement ring, you 0:06:06.240 --> 0:06:09.880 might want to consider either an artificial diamond or a 0:06:09.920 --> 0:06:13.280 new girlfriend or boyfriend. Okay, the next question I had 0:06:13.279 --> 0:06:18.040 for doctor Bradby was what makes diamonds so hard? If 0:06:18.080 --> 0:06:21.680 they're just carbon atoms, what makes them different than a 0:06:21.800 --> 0:06:25.240 lump of coal or graphite, which is what your pencil 0:06:25.320 --> 0:06:28.360 lead is made out of. Both of those things are 0:06:28.440 --> 0:06:32.320 also made of pure carbon, And the answer is that 0:06:32.360 --> 0:06:39.520 it's all about how those carbon atoms are arranged. So 0:06:39.760 --> 0:06:43.560 coal is just carbon. What's the difference between that and diamonds? 0:06:43.760 --> 0:06:47.279 Yeah, excellent question. So that is how we arrange those 0:06:47.440 --> 0:06:51.719 atoms within the structure. So diamond has what we call 0:06:51.760 --> 0:06:55.640 a tetrahedral lattice. That means each carbon atom is attached 0:06:55.680 --> 0:06:58.880 to four of its bodies in a particular structure. It's 0:06:59.040 --> 0:07:02.760 really really and it goes on forever. In this three 0:07:02.800 --> 0:07:07.960 dimensional structure. Coal is basically made of black carbon graphite, 0:07:08.040 --> 0:07:11.800 which is layers of carbon. Now those layers are attached 0:07:11.800 --> 0:07:16.000 to their bodies in three bonds in one sort of plane. 0:07:16.480 --> 0:07:19.920 They're really really strong, but they can move over each 0:07:19.920 --> 0:07:21.680 other really really easily. 0:07:21.720 --> 0:07:23.000 They're quite slippery. 0:07:23.360 --> 0:07:26.160 The sheets of graphites are slippery, that's right. 0:07:26.200 --> 0:07:27.240 They slip over each other. 0:07:27.240 --> 0:07:29.240 That's why when you touch coal, it comes off on 0:07:29.280 --> 0:07:31.920 your hand, but if you touch diamond it does not. 0:07:34.520 --> 0:07:38.080 So the secret beween diamond's heartners is a lucky combination 0:07:38.440 --> 0:07:42.080 of two things. The first is that the carbon atoms 0:07:42.280 --> 0:07:45.760 form really strong bonds with each other. If you remember 0:07:45.800 --> 0:07:49.440 from high school chemistry, carbon has four electrons in its 0:07:49.520 --> 0:07:53.640 outer shell, so it forms perfect covalent bonds with itself, 0:07:54.000 --> 0:07:56.560 and these are the strongest types of bonds there are, 0:07:57.080 --> 0:08:00.560 as opposed to ionic bonds, which is what all table 0:08:00.600 --> 0:08:04.200 salt together, for example, or hydrogen bonds, which is what 0:08:04.360 --> 0:08:08.560 holds water molecules to each other. But here's the kicker, though, 0:08:08.840 --> 0:08:12.360 The bonds that carbon forms in diamonds are not the 0:08:12.440 --> 0:08:16.560 strongest kinds of covalent bonds that carbon can make. The 0:08:16.600 --> 0:08:20.960 carbon in graphite actually form stronger bonds what are called 0:08:21.160 --> 0:08:24.880 SP two bonds, which are stronger than SP three bonds, 0:08:25.040 --> 0:08:29.560 which is what carbon uses in diamonds. So technically graphite, 0:08:29.760 --> 0:08:32.080 which is what you use in your pencil to write 0:08:32.120 --> 0:08:35.559 that smears when you rub it against paper, is stronger 0:08:35.800 --> 0:08:40.320 than diamonds. But how is that possible? Well, as doctor 0:08:40.360 --> 0:08:44.760 Bradby said, the carbon in diamonds forms a three D structure. 0:08:45.200 --> 0:08:47.920 Think of it like the scaffolding and a building before 0:08:47.960 --> 0:08:50.559 you put on the walls and floors in it, whereas 0:08:50.600 --> 0:08:55.040 the carbon in graphite forms two D grids or sheets 0:08:55.280 --> 0:08:58.760 which slip past each other and make the graphite crumply. 0:09:01.240 --> 0:09:04.240 So you might have heard of carbon nanotubes. They were 0:09:04.320 --> 0:09:08.320 these sort of wrap around tubes of graphite essentially, and 0:09:08.360 --> 0:09:10.280 they joined up in a big tube and they were 0:09:10.600 --> 0:09:12.800 very very strong, and there were people saying that they 0:09:12.800 --> 0:09:15.400 were going to build elevators to the moon with these 0:09:15.480 --> 0:09:20.080 carbon nano structures because they were so very very strong. 0:09:20.120 --> 0:09:22.800 So that is a very strong bond, but it's only 0:09:22.880 --> 0:09:25.160 one layer, so you can play tricks to try to 0:09:25.160 --> 0:09:27.960 make it kind of three dimensionally strong. But you don't 0:09:27.960 --> 0:09:30.560 need to do that with diamond because its crystal structure 0:09:30.679 --> 0:09:33.760 is already three dimensional strong in all the directions, and 0:09:33.800 --> 0:09:38.520 that's why it's super hard. So nearly all materials that 0:09:38.600 --> 0:09:43.319 are relatively hard have the same properties, have that same 0:09:43.400 --> 0:09:49.240 two things, a really strong bond and a essentially isotropic 0:09:49.360 --> 0:09:52.160 or the same in every direction bonding network. 0:09:53.480 --> 0:09:57.719 It's just that magic combination and only carbon will do that. No, 0:09:57.760 --> 0:10:02.560 there's other materials as well, all right, and that brings 0:10:02.640 --> 0:10:06.080 us to the big question of the episode, which is 0:10:06.080 --> 0:10:09.920 is there anything harder than diamonds? We're going to find 0:10:09.920 --> 0:10:14.679 out and I think the answer will surprise you. Stay 0:10:14.720 --> 0:10:25.199 with us, We'll be right back. Welcome back. All right. 0:10:25.480 --> 0:10:28.040 We talked about how you can make diamonds out of 0:10:28.360 --> 0:10:31.920 peanut butter, how we're not quite sure how diamonds are 0:10:31.960 --> 0:10:35.320 made under the ground, and about the magic sauce that 0:10:35.400 --> 0:10:39.679 makes diamonds so hard. Now the question is how hard 0:10:39.880 --> 0:10:43.640 are they? Are there other materials that are harder? I 0:10:43.679 --> 0:10:48.480 asked our expert, doctor Bradby this question. Okay, so then 0:10:48.800 --> 0:10:52.640 now the question is harder materials that are harder than diamond? 0:10:52.840 --> 0:10:55.600 Or could there be materials harder than diamond? Yes? 0:10:55.880 --> 0:10:59.720 Yes, So this is one of those intriguing scientific questions 0:10:59.760 --> 0:11:02.560 because because when you get out into the literature, there's 0:11:02.600 --> 0:11:06.320 always a little bit of ajibaji discussion around this. So 0:11:06.400 --> 0:11:09.800 you have some groups claiming that they've created this material 0:11:10.000 --> 0:11:13.520 that is theory should be harder than diamond. And this 0:11:13.679 --> 0:11:16.040 is the crux of the things. There's a lot of 0:11:16.120 --> 0:11:20.080 theoretical calculations that might predict a material to be harder 0:11:20.120 --> 0:11:20.679 than diamond. 0:11:22.080 --> 0:11:25.559 Whoa, whoa, whoa, Wait a minute. We can create materials 0:11:25.960 --> 0:11:28.640 or invent materials that don't exist. 0:11:30.120 --> 0:11:31.360 Oh, we do that all the time. 0:11:32.000 --> 0:11:35.680 We can use machine learning techniques and we do these 0:11:35.720 --> 0:11:39.360 things what's called a random property search. So essentially, what 0:11:39.600 --> 0:11:42.640 the modeling people do is they get a whole lot 0:11:42.640 --> 0:11:44.760 of atoms and they put them in a can. Now 0:11:44.800 --> 0:11:47.360 the cans in their computer, but they still call it 0:11:47.360 --> 0:11:51.920 a sample, and they apply various conditions to that sample. 0:11:52.320 --> 0:11:56.400 They might provide a pressure at temperature, they might suddenly 0:11:56.480 --> 0:11:59.760 unload it quickly. They do something to that, and they 0:11:59.800 --> 0:12:03.360 look at what the energy of that system is. And 0:12:03.440 --> 0:12:05.480 if there is a little dip, that means like the 0:12:05.520 --> 0:12:08.079 atoms might be stuck down there. They're all in that 0:12:08.120 --> 0:12:12.400 little configuration. That could indicate that that is a stable structure. 0:12:12.720 --> 0:12:14.959 So then they go, oh, what happened there? And then 0:12:15.000 --> 0:12:18.560 they pull those atoms out at that particular point and 0:12:18.600 --> 0:12:21.319 they look at the structure and they go, oh, this 0:12:21.400 --> 0:12:22.280 is a good structure. 0:12:22.520 --> 0:12:23.000 Uh huh. 0:12:23.120 --> 0:12:25.960 Maybe this is going to be really important in terms 0:12:26.000 --> 0:12:29.679 of a super conducting magnet or it might be really 0:12:29.679 --> 0:12:30.760 really hard. 0:12:32.160 --> 0:12:35.800 Well, this is pretty cool. Scientists can now basically simulate 0:12:35.920 --> 0:12:39.560 nature and basically roll the dice and see if they 0:12:39.600 --> 0:12:43.080 can get atoms to form new kinds of materials that 0:12:43.240 --> 0:12:47.080 maybe we've never seen before. I always thought in movies 0:12:47.120 --> 0:12:51.440 when they mention the fictional material like vibrinium or adamantium 0:12:51.480 --> 0:12:54.000 in the Marvel movies, that it was all made up. 0:12:54.640 --> 0:12:57.559 But there really could be materials out there that can 0:12:57.640 --> 0:13:01.400 do things we can't even imagine right now. Of course, 0:13:01.440 --> 0:13:05.040 though this is all in the computer. The real question is. 0:13:07.120 --> 0:13:10.520 Can we physically create that material, And sometimes the answer 0:13:10.640 --> 0:13:14.040 is no, or can we physically create enough of it 0:13:14.120 --> 0:13:17.360 that we can measure it to actually confirm that it's 0:13:17.400 --> 0:13:21.880 harder than diamond. It's possible, we can never get there physically, 0:13:22.080 --> 0:13:25.320 Like it's just impossible in the terms of pressure, temperature, 0:13:25.320 --> 0:13:27.520 thermodynamics to get to that structure. 0:13:27.640 --> 0:13:30.800 It's impossible to get atoms to make that structure, even 0:13:30.840 --> 0:13:34.600 though it's technically possible. Getting there is a whole different 0:13:34.640 --> 0:13:36.040 thing possible. Yeah. 0:13:36.200 --> 0:13:40.680 Yeah, So there's many, many of these structures proposed. I 0:13:40.679 --> 0:13:45.480 think carbon's got ten or twenty, maybe hundreds of structures 0:13:45.600 --> 0:13:48.040 of carbon that have been proposed to exist. 0:13:48.240 --> 0:13:48.760 Uh huh. 0:13:48.800 --> 0:13:51.800 And this is carbon that's bonded in the same way 0:13:52.040 --> 0:13:56.440 the covalent bond. And we've really only found two that 0:13:56.480 --> 0:13:57.920 we can confirm. 0:13:58.640 --> 0:14:02.960 Okay, there are two materials that scientists think should be 0:14:03.040 --> 0:14:06.680 harder than diamonds. The first one is a material that's 0:14:06.679 --> 0:14:11.760 found in meteorites. Okay, so what are these two materials? 0:14:11.840 --> 0:14:12.120 Okay? 0:14:12.200 --> 0:14:15.560 Some one is a different arrangement which is called Lonsterlight. 0:14:15.960 --> 0:14:19.120 What's it called again, Lonsterlight lines Delight Okay. 0:14:19.320 --> 0:14:23.160 So it's named after Kathleen Lonsdale, who is a carbon 0:14:23.480 --> 0:14:27.680 scientist in the UK. Amazing person, really worth going down 0:14:27.720 --> 0:14:31.560 a rabbit hole with her, and in honor of the 0:14:31.600 --> 0:14:34.760 work that she did in carbon, the lons Light structure 0:14:34.840 --> 0:14:35.640 was named after her. 0:14:36.520 --> 0:14:38.080 So it's also made out of carbon. 0:14:38.240 --> 0:14:40.880 It's made out of carbon. It's also made out of 0:14:40.960 --> 0:14:45.880 convalently bonded carbon. It's also in a continuous three dimension network, 0:14:46.000 --> 0:14:48.960 so it ticks the boxes that we've been talking about. 0:14:49.280 --> 0:14:49.480 Huh. 0:14:49.680 --> 0:14:51.880 But it's got a different structure. 0:14:52.040 --> 0:14:53.280 So the way the. 0:14:53.040 --> 0:14:58.080 Atoms are physically arranged is slightly different. So instead of 0:14:58.160 --> 0:15:03.160 having a repeating box that is a ubique structure. It's 0:15:03.200 --> 0:15:05.600 got a slightly different structure to that, and we call 0:15:05.640 --> 0:15:08.720 it a hexagonal structure. Now that doesn't mean that it's 0:15:08.720 --> 0:15:11.640 sort of arranged in a hexagonal latters. What it means 0:15:11.680 --> 0:15:16.320 is you can create a hexagonal repeating cell within the 0:15:16.360 --> 0:15:21.800 framework of the crystom. It is predicted to be harder 0:15:21.840 --> 0:15:22.440 than diamond. 0:15:24.000 --> 0:15:27.480 Okay, So the first material scientists think could be harder 0:15:27.520 --> 0:15:32.200 than diamonds is called lonstelate, and it's basically a diamond, 0:15:32.440 --> 0:15:36.720 but with its structure tweaked so that overall its grid 0:15:37.160 --> 0:15:41.320 repeats itself in a hexagonal pattern. It actually has been 0:15:41.320 --> 0:15:44.920 found in nature in meteorites that have crashed on Earth. 0:15:45.440 --> 0:15:49.400 Notably who's found in fragments of the Canyon Diablo meteorite, 0:15:49.640 --> 0:15:52.440 which is what made the huge crater at meteor Crater 0:15:52.640 --> 0:15:56.440 landmark in Arizona. It's also been reportedly found in a 0:15:56.560 --> 0:16:01.080 diamond deposit in Kazakhstan. Now, in theory, according to the 0:16:01.120 --> 0:16:05.520 computer simulations, this lancelide should be harder than diamonds. 0:16:06.280 --> 0:16:11.960 But but there's a butt, And usually with all this 0:16:12.080 --> 0:16:14.880 harder than diamond work, there is a butt. And the 0:16:14.920 --> 0:16:19.280 butt is that it is only on one particular poking direction. 0:16:19.760 --> 0:16:21.680 Okay, it's only strong in one direction. 0:16:22.000 --> 0:16:25.880 Yeap, only in one direction, and that is because of 0:16:25.960 --> 0:16:29.720 the way that breaking of bonds, that movement of things, 0:16:30.320 --> 0:16:31.479 how that works. 0:16:32.800 --> 0:16:36.120 What doctor Bradby is saying is that some materials are 0:16:36.160 --> 0:16:40.360 harder or softer depending on which direction you try to 0:16:40.440 --> 0:16:42.760 squeeze them. Sort of like if you had a box 0:16:42.800 --> 0:16:44.840 in front of you and you try to squeeze it 0:16:44.880 --> 0:16:47.960 from top to bottom or from the sides, it might 0:16:48.000 --> 0:16:50.440 feel hard in all of those directions, but if you 0:16:50.480 --> 0:16:53.760 squeeze it at the corners, it might collapse more easily. 0:16:54.120 --> 0:16:57.720 The same thing happens in crystal materials, and in lancelide, 0:16:58.040 --> 0:17:02.160 one of those directions is predicted to be harder than diamonds. 0:17:02.720 --> 0:17:05.560 The reason for that is a little technical, but basically, 0:17:05.720 --> 0:17:08.480 when you press down on a material and it yields 0:17:08.560 --> 0:17:11.960 or it gives, the atoms tend to rearrange themselves a 0:17:12.000 --> 0:17:15.080 little bit. And in lons oflide, because of its tweak 0:17:15.200 --> 0:17:19.760 diamond structure, the crystal has to rearrange itself twice, which 0:17:19.800 --> 0:17:23.360 is what makes it a harder material. Okay, you might 0:17:23.359 --> 0:17:26.000 have noticed that we keep saying loss of lighte might 0:17:26.080 --> 0:17:29.919 be harder than diamonds. You're probably thinking, if we found 0:17:29.960 --> 0:17:32.560 lons of light in meteorites here on Earth, why can't 0:17:32.600 --> 0:17:35.640 we just test it, you know, smash it against diamonds 0:17:35.640 --> 0:17:38.439 and see which one survives. But the problem is that 0:17:38.480 --> 0:17:41.800 lonz of lte has only been found as tiny, little 0:17:41.840 --> 0:17:45.159 microscopic crystals that are too small to put in a 0:17:45.200 --> 0:17:48.680 machine to test, and also no one's quite been able 0:17:48.720 --> 0:17:50.240 to make it in the lab. 0:17:52.200 --> 0:17:54.840 There is definitely a crystal structure called lonster light that 0:17:54.960 --> 0:17:58.920 is definitely different to the cubic structure. But whether the 0:17:59.080 --> 0:18:03.440 diamond can form enough of this material to be perfect 0:18:03.840 --> 0:18:07.200 and be in a bulk like structure, we have never 0:18:07.240 --> 0:18:08.760 been able to successfully make that. 0:18:08.840 --> 0:18:09.000 Yet. 0:18:09.040 --> 0:18:12.960 We've made tiny amounts of the lunsterlite. You could imagine 0:18:13.000 --> 0:18:17.200 a little one centimeter rock of this stuff, but each 0:18:17.359 --> 0:18:22.399 individual crystal is still really small, like it's not a 0:18:22.440 --> 0:18:25.720 perfect single crystal. It would be lovely if we could 0:18:25.720 --> 0:18:28.359 make a perfect single crystal of this material that was 0:18:28.640 --> 0:18:30.840 about a centimeter, because then we could put it in 0:18:30.880 --> 0:18:33.560 all our machines, we could look at it from every 0:18:33.600 --> 0:18:36.919 direction and we could confirm that is, yes, this is 0:18:36.960 --> 0:18:42.040 exactly that structure. And more importantly, we could actually measure 0:18:42.400 --> 0:18:44.920 and see if it was indeed harder than diamond. 0:18:45.600 --> 0:18:48.159 I see, but we can't because the sample that you 0:18:48.200 --> 0:18:50.200 have created is really small. 0:18:50.480 --> 0:18:52.679 And of course then we get to the thorny question 0:18:52.800 --> 0:18:56.080 of what do you poke it with? Because at the 0:18:56.119 --> 0:18:59.280 moment all our pokey tools are made of diamond. 0:18:59.359 --> 0:19:02.440 Of course, So this is a. 0:19:02.359 --> 0:19:05.520 Problem I pose to every first year class that I think, 0:19:06.000 --> 0:19:08.840 I am trying to measure something harder than diamond, but 0:19:08.920 --> 0:19:10.880 the only thing I have to measure with is diamond. 0:19:11.280 --> 0:19:13.000 If you want to come and talk. 0:19:12.840 --> 0:19:15.679 To me about the solution to this, please how work. 0:19:15.600 --> 0:19:16.120 In my lab? 0:19:18.119 --> 0:19:20.400 All right, when we come back, we're going to learn 0:19:20.400 --> 0:19:24.119 about another material scientist think might be harder than diamonds. 0:19:24.480 --> 0:19:26.679 And then we're going to talk about two things that 0:19:26.720 --> 0:19:31.439 are definitely harder than diamonds. Don't go anywhere. You're listening 0:19:31.480 --> 0:19:47.159 to sign stuff, Welcome back. So then this long slight 0:19:47.280 --> 0:19:49.399 would be stronger, but only in certain directions. In the 0:19:49.440 --> 0:19:51.639 other directions, it wouldn't be stronger than diamond. 0:19:51.840 --> 0:19:52.520 Correct, Ye? 0:19:53.240 --> 0:19:55.080 Now, is that the only one that we know about 0:19:55.080 --> 0:19:56.040 that might be harder? 0:19:56.359 --> 0:19:59.879 No, there's another few. So there is more on nitri 0:20:00.640 --> 0:20:02.639 that you can get a cubic structure of that or 0:20:02.760 --> 0:20:03.840 hexagonal structure. 0:20:04.119 --> 0:20:08.000 Okay, so that one's not just pure carbon atoms. It's different. 0:20:08.240 --> 0:20:11.639 No, it's got nitrogen in it as well, so it's hydrogen, helium, 0:20:11.680 --> 0:20:16.000 lithium boron. So we're still talking about a low atomic number. 0:20:16.400 --> 0:20:17.200 And this does. 0:20:17.040 --> 0:20:19.960 Seem to be the case that all the harder elements 0:20:19.960 --> 0:20:22.119 are low atomic numbers. They're high up there on the 0:20:22.119 --> 0:20:22.960 periodic table. 0:20:24.760 --> 0:20:27.800 You might not remember this from high school chemistry. I 0:20:27.920 --> 0:20:31.920 certainly didn't, but atoms high on the periodic table are 0:20:32.119 --> 0:20:36.840 smaller and lighter, and it means that electrons are closer 0:20:36.960 --> 0:20:40.399 to their nuclei, which means the bonds they form with 0:20:40.520 --> 0:20:45.440 other atoms are shorter, which makes them stronger. It's also 0:20:45.520 --> 0:20:49.159 no coincidence that boron and nitrogen, the main components of 0:20:49.440 --> 0:20:52.119 or nitrite, are just to the rate and just to 0:20:52.200 --> 0:20:56.080 the left of carbon in the periodic table, so they're 0:20:56.240 --> 0:20:59.960 kind of the closest you can get to a carbon bond. 0:21:00.480 --> 0:21:04.119 But now the question is is this boron nitride harder 0:21:04.160 --> 0:21:05.360 than diamonds? 0:21:07.240 --> 0:21:11.240 That's also predicted to be a super hard material, perhaps 0:21:11.280 --> 0:21:14.440 harder than diamond, but it's not really, I'm not convinced. 0:21:14.480 --> 0:21:15.080 Put it that way. 0:21:15.640 --> 0:21:17.480 Okay, So why are you not convinced? 0:21:17.760 --> 0:21:23.040 Because I am an experimental scientist and one of the 0:21:23.080 --> 0:21:25.920 sayings in my lab is nice story, Now show. 0:21:25.760 --> 0:21:30.560 Me the data. So there's no data for this material 0:21:30.720 --> 0:21:34.320 not convincing no meaning like people have made it, but 0:21:34.359 --> 0:21:36.280 they haven't tested it. What does it mean? 0:21:36.520 --> 0:21:40.439 Yes, well, if you test it using a diamond and 0:21:40.480 --> 0:21:44.320 you poke it, if you're approaching the hardness of the 0:21:44.320 --> 0:21:47.600 diamond and you push them together, you can imagine that 0:21:47.600 --> 0:21:50.040 there's going to be some sort of giving in the 0:21:50.080 --> 0:21:51.680 tip in the diamond. 0:21:51.400 --> 0:21:52.520 As well as the sample. 0:21:53.400 --> 0:21:56.840 And currently that's not accounted for in many of the measurements. 0:21:57.040 --> 0:21:59.159 But the diamond makes a whole a divid in the 0:21:59.240 --> 0:22:00.800 boron like yeah. 0:22:00.720 --> 0:22:02.800 Yeah, I mean the diamond can make a divot in 0:22:02.840 --> 0:22:05.639 other diamond. But that doesn't mean that diamond is harder 0:22:05.680 --> 0:22:06.880 than the tip diamond. 0:22:07.280 --> 0:22:11.720 H What is it? Because if it is harder that 0:22:11.800 --> 0:22:12.639 it's hard to tell. 0:22:13.400 --> 0:22:17.200 Yeah, I would say the evidence that it's harder has 0:22:17.240 --> 0:22:18.919 not been compelling. 0:22:19.240 --> 0:22:21.439 So what would it take to convince you if we 0:22:21.520 --> 0:22:22.040 switched it? 0:22:22.359 --> 0:22:26.439 If somebody made an indented tip from oron nitride and 0:22:26.640 --> 0:22:30.879 use that to indented diamonds surface. And there was just 0:22:30.920 --> 0:22:33.560 an indent in the diamond surface. And we looked at 0:22:33.560 --> 0:22:36.679 the tip before and after, and we analyzed it, and 0:22:36.720 --> 0:22:39.200 we looked down with an electron microscope, and we saw 0:22:39.240 --> 0:22:42.000 that there was no defects in that tip. 0:22:42.680 --> 0:22:43.240 That might be a. 0:22:43.240 --> 0:22:45.680