WEBVTT - TechStuff Gets Meta(material) 0:00:04.200 --> 0:00:07.200 Get in touch with technology with text stuff from how 0:00:07.240 --> 0:00:14.120 stuff works dot Com say they're and welcome to text Stuff. 0:00:14.280 --> 0:00:17.959 I'm Jonathan Strickland and I'm Lauren, And uh, this test, 0:00:17.960 --> 0:00:20.880 we're not doing a listener request, although I would imagine 0:00:20.880 --> 0:00:23.280 a lot of our listeners have heard about the subject 0:00:23.280 --> 0:00:25.320 we're going to be talking about today. But before we 0:00:25.360 --> 0:00:30.600 get into it, Lauren, what is your favorite implementation of 0:00:31.240 --> 0:00:36.080 the concept of invisibility in FICTIONUS? Uh, probably the Ronnie 0:00:36.120 --> 0:00:40.839 Lank cloaking device, Yeah, which the Klingon's managed to get 0:00:40.840 --> 0:00:42.360 their hands on because I was to get the Bird 0:00:42.360 --> 0:00:45.559 of Prey from uh well, they both had Bird of 0:00:45.560 --> 0:00:48.879 Praise that could cloak, and the Star Trek University. Eventually 0:00:48.880 --> 0:00:50.840 the Federation picked it up as well. We could really 0:00:51.120 --> 0:00:53.280 really get into a full thing of us just talking 0:00:53.320 --> 0:00:56.240 about Star Trek and cloaking devices as it turns out. Yeah, No, 0:00:56.320 --> 0:00:59.560 that's a cool, cool implementation. Another one, of course, the 0:00:59.600 --> 0:01:04.880 Predator being able to have that chameleon likability or I guess, 0:01:04.880 --> 0:01:08.919 I guess the halo armor. Yeah, there's of course the 0:01:08.920 --> 0:01:13.760 the Harry Potter invisibility. Yeah, the hay cloak with the 0:01:14.040 --> 0:01:17.280 Marauders invisibility cloaks. So yeah, we've we've got all these 0:01:17.319 --> 0:01:21.839 ideas about invisibility. It's of course been a popular concept 0:01:21.880 --> 0:01:25.280 in fiction, whether it's fantasy or science fiction. In the 0:01:25.280 --> 0:01:27.040 world of science fiction, of course, we have to try 0:01:27.040 --> 0:01:29.600 and come up with a way of how would this work, 0:01:29.680 --> 0:01:32.959 how would we manage to make something invisible? And well, 0:01:33.240 --> 0:01:36.520 some people feel more obligated to do that than others. Well, yeah, 0:01:36.560 --> 0:01:38.600 because some people would argue that if you don't do it, 0:01:38.600 --> 0:01:40.440 you might as well call it science fantasy rather than 0:01:40.480 --> 0:01:43.920 science fiction. But the the concept usually boils down to 0:01:43.959 --> 0:01:47.760 the idea of somehow manipulating light so that bends around 0:01:47.880 --> 0:01:50.960 an object and then continues on as if the object 0:01:51.000 --> 0:01:54.360 were not there. So from an outsider's perspective, it's just 0:01:55.400 --> 0:01:59.520 you know, emptiness or or whatever. It's whatever, see the 0:01:59.520 --> 0:02:04.200 starf behind you or the wallopping willow or whatever. It excellent, 0:02:04.360 --> 0:02:06.080 really well done. I was wondering where you're going to 0:02:06.120 --> 0:02:10.000 go with the Harry Potter one exactly. So the interesting 0:02:10.040 --> 0:02:12.280 thing is that there are people who are really working 0:02:12.320 --> 0:02:15.160 on this technology. You guys out there have probably heard 0:02:15.280 --> 0:02:20.119 about variations on real world cloaking devices, and you may wonder, well, 0:02:20.160 --> 0:02:22.840 how is this even possibly attempted, and there are a 0:02:22.880 --> 0:02:27.040 lot of different approaches, but one emerging field that we 0:02:27.080 --> 0:02:31.320 wanted to talk about is meta materials. Right, because with 0:02:31.480 --> 0:02:35.560 normal materials, perhaps obviously, normal materials do not bend light 0:02:35.600 --> 0:02:37.160 around them so that you can see what's on the 0:02:37.200 --> 0:02:42.560 other side when they're solid and opaque materials. Yeah, yeah, exactly, 0:02:42.600 --> 0:02:46.480 Even a even a transparent window is reflecting some light 0:02:46.560 --> 0:02:49.280 back to you. Right. The idea of a meta material, 0:02:49.520 --> 0:02:52.400 at least in this particular implementation, because there's lots of 0:02:52.400 --> 0:02:55.680 different potential ways to use meta materials, is to bend 0:02:56.040 --> 0:02:59.920 electromagnetic radiation, in this case visible light around it so 0:03:00.080 --> 0:03:02.239 that we wouldn't see it. Now, we're not there yet, 0:03:02.280 --> 0:03:06.680 by the way, spoiler alert, Yes, um, we are working 0:03:06.800 --> 0:03:09.720 slowly towards it. But let's put down a good solid 0:03:09.720 --> 0:03:13.600 definition of meta materials to kind of start the conversation off. Okay, so, 0:03:14.240 --> 0:03:16.799 first thing to keep in mind their artificial These are 0:03:16.840 --> 0:03:20.480 these are materials that are man made, and they are 0:03:20.639 --> 0:03:24.440 very different from natural materials because the properties that you 0:03:24.440 --> 0:03:28.000 would find in any natural material are largely dependent upon 0:03:28.040 --> 0:03:32.760 its chemical composition. So, for example, a bar of gold, 0:03:33.200 --> 0:03:37.720 a bar of gold has the weight, the color, the density, 0:03:37.800 --> 0:03:40.440 it has all of these things because of the nature 0:03:40.520 --> 0:03:43.640 of the atoms of gold. Right. That's if it were 0:03:43.680 --> 0:03:46.640 a different material, it would have very different properties, even 0:03:46.680 --> 0:03:49.880 if you had it at the same physical dimensions, right 0:03:49.920 --> 0:03:52.280 and so, And even though okay, a bar of gold 0:03:52.400 --> 0:03:55.360 is also a man made object, you're rarely going to 0:03:55.400 --> 0:03:58.480 pull a large chunk of gold like that right straight 0:03:58.480 --> 0:04:01.400 out of the ground having minecraft or something without it 0:04:01.440 --> 0:04:03.480 having some kind of impurities that you would have to 0:04:03.880 --> 0:04:06.680 melt out or whatever it is that you do. But 0:04:06.800 --> 0:04:10.800 basically it's all chemical exactly. Now, manty materials they get 0:04:10.840 --> 0:04:15.000 their properties not just from the kind of atoms or 0:04:15.040 --> 0:04:17.719 molecules that make up that mety material. In fact, the 0:04:17.760 --> 0:04:24.320 chemical composition doesn't really ultimately matters they structure exactly. It's 0:04:24.400 --> 0:04:27.599 it's how that material is physically constructed. And when we 0:04:27.600 --> 0:04:30.360 say physical structure, we're not talking about something you can 0:04:30.400 --> 0:04:33.640 see on the macro level. We're talking this is micro 0:04:33.760 --> 0:04:37.080 to nano exactly, to the point where it's so small 0:04:37.160 --> 0:04:40.719 that an optical microscope would not be able to show 0:04:40.800 --> 0:04:44.040 you what that structure is. And a lot of this 0:04:44.240 --> 0:04:46.800 was sort of theoretical. We'll talk about the history of 0:04:46.839 --> 0:04:50.800 it until relatively recently, we've just now started to get 0:04:50.800 --> 0:04:55.200 too sophisticated manufacturing processes that allow us to build these 0:04:55.240 --> 0:05:00.520 super tiny structures that will affect uh well, that will 0:05:00.560 --> 0:05:05.159 interact with electromagnetic radiation and interesting ways. Right. It's sort 0:05:05.200 --> 0:05:08.880 of similar to the way that we've talked about nanostructures 0:05:08.960 --> 0:05:12.279 having different effects on the world around them, then we 0:05:12.320 --> 0:05:17.360 would normally be able to observe larger structures. Meta materials 0:05:17.360 --> 0:05:20.279 are similar and a lot of them will interact specifically 0:05:20.320 --> 0:05:24.000 with electromagnetic radiation in very interesting ways. So if you 0:05:24.000 --> 0:05:26.960 look at electromagnetic radiation, if you were to to just 0:05:27.160 --> 0:05:31.400 be able to stop the whole universe and just look 0:05:31.440 --> 0:05:36.839 at a specific wave of electromagnetic radiation and be able 0:05:36.880 --> 0:05:40.039 to break that apart, conceptually, you'd be able to see 0:05:40.080 --> 0:05:43.240 that there are two major components of it, which are 0:05:43.320 --> 0:05:47.800 electric fields and magnetic fields. Um, there's also the vector, 0:05:47.960 --> 0:05:51.160 which is the wave's magnitude and direction. So all three 0:05:51.200 --> 0:05:54.680 of these things together determine how they interact with any 0:05:54.720 --> 0:05:59.800 given I reject exactly, and so conventional material usually only 0:05:59.800 --> 0:06:03.480 in acts with the electric fields. Usually there are some 0:06:03.560 --> 0:06:07.320 that interact with magnetic fields, but Generally speaking, the electric 0:06:07.320 --> 0:06:11.239 fields are what are interacting with conventional material Many materials 0:06:11.279 --> 0:06:14.440 can also interact with the magnetic fields, which increases the 0:06:14.520 --> 0:06:18.800 number of ways it can interact with any given electromagnetic radiation. 0:06:19.120 --> 0:06:23.040 Keep in mind, visible light is electromagnetic radiation. It's part 0:06:23.080 --> 0:06:27.039 of that spectrum. It's a very narrow part of that spectrum, 0:06:27.080 --> 0:06:30.640 which also includes things like ultraviolet light and infrared light, 0:06:30.760 --> 0:06:35.719 but also microwaves and radio waves. Um. So this is 0:06:35.760 --> 0:06:39.280 the stuff that would, at least in theory, if we 0:06:39.279 --> 0:06:42.800 were able to build the right kinds of structures, allow 0:06:42.920 --> 0:06:45.839 us to create an invisibility cloak for real zes or 0:06:45.839 --> 0:06:50.640 at least some sort of of physical object that light 0:06:50.720 --> 0:06:53.080 would bend around so you would not be able to 0:06:53.160 --> 0:06:57.760 see it. And right now we only have invisibility cloaks 0:06:57.800 --> 0:07:01.720 that bend microwaves around. The implementations tend to be very 0:07:01.720 --> 0:07:06.039 specific to very narrow bands in that spectrum, right and 0:07:06.080 --> 0:07:07.719 we'll talk about it. This has to do with the 0:07:07.839 --> 0:07:12.320 specific micro and nanostructures of these objects, which we'll get 0:07:12.320 --> 0:07:15.080 into in a moment um. But while we're talking about waves, 0:07:15.680 --> 0:07:19.640 electromagnetic waves are not the only ones that hypothetically these 0:07:19.680 --> 0:07:23.480 materials can interact with right, absolutely, anything that travels in 0:07:23.560 --> 0:07:28.320 wave form can in theory be uh something that interacts 0:07:28.320 --> 0:07:32.480 in a different way with a meta material. So seismic waves, earthquakes, 0:07:33.120 --> 0:07:36.160 that those it travels in waves, just like you know, 0:07:36.680 --> 0:07:39.160 it's hard for us to imagine in a way things 0:07:39.160 --> 0:07:43.640 like electromagnetic radiation because we can't directly see those waves. Um, 0:07:43.720 --> 0:07:46.720 we also can't well, I guess we can see earthquakes, 0:07:46.880 --> 0:07:49.560 or we can see the effective earthquakes, right, we can 0:07:49.600 --> 0:07:53.400 certainly feel them, certainly, So those those seismic waves that 0:07:53.440 --> 0:07:56.840 travel through the ground, you could in theory create a 0:07:56.960 --> 0:08:00.680 meta material that allows that stuff to just passed through 0:08:00.680 --> 0:08:03.240 it as if it weren't it wasn't there, and then 0:08:03.480 --> 0:08:05.880 imagine making a building out of that stuff. It wouldn't 0:08:05.920 --> 0:08:10.240 even sway when the earthquake moves through. The earthquake would 0:08:10.240 --> 0:08:12.040 just pass through it as if it weren't there. It 0:08:12.040 --> 0:08:15.400 would just redirect. Yeah, it's the same thing with sound waves. 0:08:15.400 --> 0:08:17.960 You could build I mean, I'm I'm picturing our sound 0:08:18.000 --> 0:08:21.320 studio right now without all of this albeit lovely foam 0:08:21.440 --> 0:08:24.000 that that Noll has put up on our walls. Instead 0:08:24.040 --> 0:08:26.120 of that, the walls themselves could just be made of 0:08:26.160 --> 0:08:29.480 a material that redirects the sound waves. They could either 0:08:29.600 --> 0:08:32.680 absorb it or because again it all depends upon the 0:08:32.679 --> 0:08:35.800 physical structure of the material itself. If you were able 0:08:35.840 --> 0:08:38.240 to do that, you could have a perfectly soundproofed room, 0:08:38.640 --> 0:08:40.520 so you would never have to worry about any sort 0:08:40.520 --> 0:08:43.120 of bleed out either going out of the room or 0:08:43.200 --> 0:08:46.600 coming into the room. And we would really like that 0:08:46.679 --> 0:08:49.600 because often we have to stop when there's a siren 0:08:50.480 --> 0:08:54.640 or a drag race or something going on outside, so 0:08:54.640 --> 0:08:56.240 that you guys, I mean, I'm sure a couple of 0:08:56.240 --> 0:08:58.199 them have snuck through anyway, but we try to limit 0:08:58.240 --> 0:09:03.319 them also at will. Waves like ocean waves, those are 0:09:03.360 --> 0:09:07.440 another form that I've seen. I've seen the Navy looking 0:09:07.480 --> 0:09:11.480 into a strategy where they would have a special meta 0:09:11.520 --> 0:09:14.760 material on the outside of the whole of ships to 0:09:14.840 --> 0:09:17.240 make them more efficient in moving through the water, exactly 0:09:17.280 --> 0:09:20.000 releasing all that drags so that you don't have to 0:09:20.040 --> 0:09:21.920 worry about that. It doesn't have to do as much 0:09:21.920 --> 0:09:25.600 work to move a huge vessel through the water because 0:09:25.679 --> 0:09:29.040 you have redirected the waves as if you're not there. Also, 0:09:29.640 --> 0:09:32.840 you could in theory, reduce the wake of a vehicle 0:09:33.240 --> 0:09:36.120 moving through the water, so that the ocean itself does 0:09:36.160 --> 0:09:40.320 not reveal the fact that an enormous like aircraft carrier 0:09:40.480 --> 0:09:43.880 just bustled through. You wouldn't have a wake, it would 0:09:44.800 --> 0:09:49.360 This to me is hard to imagine. It's hard for 0:09:49.360 --> 0:09:54.720 me to imagine. Yeah, going all, you know, Scutty said 0:09:54.760 --> 0:09:57.160 you cannot break the laws of physics, and I think 0:09:57.520 --> 0:10:00.839 I think it was a little shortsighted. Actually, I think 0:10:00.920 --> 0:10:03.680 mento materials kind of prove them wrong. But I mean, 0:10:03.800 --> 0:10:05.959 clearly we're still working within the laws of physics. It's 0:10:06.000 --> 0:10:09.719 just we're expanding our our knowledge of how they how 0:10:09.760 --> 0:10:12.000 they work. We're just tweaking them a little bit, you know, 0:10:12.120 --> 0:10:13.760 kind of you know, just a little thumb of the 0:10:13.800 --> 0:10:17.280 nose at the laws of physics. So, alright, what is 0:10:17.320 --> 0:10:20.199 actually going on here? How you know, we've talked about 0:10:20.240 --> 0:10:22.520 what they are and what they do in general, and 0:10:22.559 --> 0:10:25.360 we've talked about this structure issue. But let's let's get 0:10:25.440 --> 0:10:28.640 down into it. Yeah, So, if you were able to 0:10:28.880 --> 0:10:32.360 shrink down to a teeny tiny size and observe this 0:10:32.480 --> 0:10:36.560 material on the nano scale, what you would notice is 0:10:36.600 --> 0:10:39.840 that the actual physical structure of that material would be 0:10:39.880 --> 0:10:42.880 made up of repeated patterns. They would be kind of 0:10:42.920 --> 0:10:46.720 like a repeated scaffolding in a way. And think, again, 0:10:46.760 --> 0:10:49.280 this is on the nano scale. You to to us 0:10:49.280 --> 0:10:51.400 on the macro scale, it would just look like stuff. 0:10:51.920 --> 0:10:54.560 Whatever it happened to be made out of. We went 0:10:54.760 --> 0:10:57.760 notice that structure because it's far too too tiny for 0:10:57.800 --> 0:11:00.760 us to see. But you would see these repeated patterns, 0:11:00.800 --> 0:11:04.720 and those repeated patterns would be specific to whatever wave 0:11:05.080 --> 0:11:07.520 it was supposed to interact with. Because here's the thing. 0:11:08.480 --> 0:11:13.040 For meta materials to be effective, generally speaking, those structures 0:11:13.400 --> 0:11:17.400 need to be smaller than whatever the wavelength is of 0:11:17.520 --> 0:11:20.080 the whatever it's going to interact with. Right. This is 0:11:20.080 --> 0:11:23.280 why we've had better success with microwaves than anything else, 0:11:23.320 --> 0:11:27.400 because microwaves are very long wavelength as well, I mean 0:11:27.840 --> 0:11:32.000 compared to light. Absolutely. If for red's the same way 0:11:32.000 --> 0:11:35.320 and for red is a longer wavelength and say red, Yeah, 0:11:35.559 --> 0:11:38.360 so you run into a building problem, just just a 0:11:38.440 --> 0:11:42.080 structural issue here. Exactly how do you build something tiny 0:11:42.160 --> 0:11:45.120 enough to interact with these very tiny wavelengths? Yeah, so 0:11:45.160 --> 0:11:47.600 in order for you to have something that would be 0:11:47.720 --> 0:11:50.920 able to shield an object from visible light, you would 0:11:50.920 --> 0:11:55.160 have to make uh structures with such precision that those 0:11:55.200 --> 0:11:59.880 repeating patterns would be just teeny teeny tiny, like yeah, 0:12:00.000 --> 0:12:02.160 as building blocks would have to be like no bigger 0:12:02.200 --> 0:12:05.920 than ten to twenty nanometers. Yeah, that's really super small. 0:12:05.960 --> 0:12:09.240 And we've managed to do that kind of thing with microprocessors, 0:12:09.320 --> 0:12:12.200 but we're talking about expanding that out potentially to a 0:12:12.360 --> 0:12:16.880 three dimensional object. Ultimately, when you're looking at microprocessors, you're 0:12:16.920 --> 0:12:19.880 really talking about two dimensions. You're talking about the height 0:12:19.920 --> 0:12:23.200 and the width. There's no real Yeah, it's to the 0:12:23.200 --> 0:12:25.200 point where you might as well say it's two dimensional. 0:12:25.640 --> 0:12:28.000 So when you're talking about three dimensional object and building 0:12:28.040 --> 0:12:34.320 that outward volumetrically, especially to cover say a car or yeah, 0:12:34.440 --> 0:12:38.360 oh yeah, or an aircraft carrier or whatever. Obviously the 0:12:38.400 --> 0:12:43.560 military carrier whatever, the military applications for this are obvious, right, 0:12:43.600 --> 0:12:46.800 I mean any kind of cloaking device. So yeah, being 0:12:46.840 --> 0:12:49.000 able to manufacture that out in a way that it 0:12:49.000 --> 0:12:53.120 has a practical effect is an enormous undertaking. It's something 0:12:53.120 --> 0:12:57.920 that is, uh, we're years beyond that, like or no, 0:12:58.080 --> 0:13:00.959 that's years beyond us, I should say we we and 0:13:01.120 --> 0:13:05.199 it not close together. As my point, we're kind of 0:13:05.200 --> 0:13:09.040 shouting at each other exactly through the future exactly, so 0:13:09.679 --> 0:13:12.240 although we can't see them because when they're in the 0:13:12.240 --> 0:13:15.280 future in two they're invisible. But uh yeah, that's the 0:13:15.280 --> 0:13:17.480 thing is that you have to have these super super small, 0:13:17.559 --> 0:13:20.240 small small structures. And not only that, but visible light 0:13:20.880 --> 0:13:23.600 takes up a spectrum. You know, we say the visible spectrum, 0:13:24.000 --> 0:13:25.800 and you know the easy way of saying that as 0:13:25.880 --> 0:13:28.679 the Roy G. Biv Right, You've got from red on 0:13:28.679 --> 0:13:30.800 one end to violet on the other end, and that 0:13:30.960 --> 0:13:33.400 and everything in between. And that's what makes a visible 0:13:33.480 --> 0:13:36.280 light for us. Well, in order to be able to 0:13:36.320 --> 0:13:39.800 shield something from visible light, you would have to somehow 0:13:39.920 --> 0:13:43.160 engineer a meta material that would be effective for that 0:13:43.360 --> 0:13:48.080 entire range of those wavelengths. That's really tricky. It's one 0:13:48.160 --> 0:13:51.200 thing to design a meta material that works for a 0:13:51.400 --> 0:13:57.200 narrow range of wavelengths. That is, it's I hesitate to 0:13:57.240 --> 0:14:01.559 use the word easier. It's more realistic than effect creating 0:14:01.600 --> 0:14:04.960 a material that would be effective across an entire spectrum 0:14:05.240 --> 0:14:08.640 of wavelengths. So it may be that we never get 0:14:08.679 --> 0:14:12.360 to a point where, using meta materials we create a 0:14:12.400 --> 0:14:15.760 cloaking device that's effective for visible light. That doesn't mean 0:14:15.800 --> 0:14:18.280 we won't create cloaking devices. We may do it through 0:14:18.320 --> 0:14:21.920 a totally different technology, or we may have cloaking devices 0:14:21.960 --> 0:14:26.040 that are cloaking devices for specific wavelengths like microwaves, because 0:14:26.680 --> 0:14:31.480 radar uses microwaves. Right, So, a stealth bomber that has 0:14:31.720 --> 0:14:36.200 meta material surfaces which means that the radar waves will 0:14:36.240 --> 0:14:39.040 go straight through it and not bounce back, you wouldn't 0:14:39.080 --> 0:14:41.880 have to have those super funky uh the panels that 0:14:41.880 --> 0:14:45.040 are all at weird angles. Yeah, that whole episode right right. 0:14:45.040 --> 0:14:49.320 The surface of stealth bombers right now operate by redirecting 0:14:49.680 --> 0:14:53.440 those waves exactly. It's kind of like the idea of 0:14:53.800 --> 0:14:59.840 just uh, deflecting the wave to some other direction ap 0:15:00.200 --> 0:15:03.200 from the receiving station. Right. So, as long as the 0:15:03.240 --> 0:15:06.480 receiving station never gets the waves back, it doesn't know 0:15:06.920 --> 0:15:08.480 that there's an object. So you can you could go 0:15:08.480 --> 0:15:10.720 on and make those things more aerodynamic at that point, yeah, 0:15:10.800 --> 0:15:15.160 you could. You could completely redesign the self the weird 0:15:15.280 --> 0:15:19.239 bulky looking thing. Yeah, I mean sure they were ridiculously 0:15:19.320 --> 0:15:24.120 expensive and inefficient ultimately, but hey, they look cool. I 0:15:24.160 --> 0:15:29.720 also like the Deloreans, so same. I mean, Deloreans show 0:15:29.760 --> 0:15:32.880 up on radar like crazy, but that's that's that's another episode. Now, 0:15:32.920 --> 0:15:36.880 there are different types of meta materials. There's there are 0:15:36.920 --> 0:15:41.520 different ways of building meta materials to interact with various 0:15:41.560 --> 0:15:45.240 types of wave links. So I'm going to go ahead 0:15:45.240 --> 0:15:48.760 and preface this part of the podcast by saying, neither 0:15:48.840 --> 0:15:54.800 of us are physicists, and electromagnetic radiation is a difficult 0:15:55.040 --> 0:15:57.840 topic to wrap your head around when you haven't had 0:15:57.920 --> 0:16:02.520 that as as your continual background for say thirty years. Yeah. 0:16:02.720 --> 0:16:06.320 So if there are any physicists out there who cringe 0:16:06.520 --> 0:16:12.120 as we start to oversimplify what's happening, I apologize to you. Now. 0:16:12.240 --> 0:16:14.600 I am doing the best of my ability to explain 0:16:14.680 --> 0:16:17.040 what's going on. Yes, and if we get anything wrong, 0:16:17.080 --> 0:16:20.080 please do be gentle with us, but let us know, Yes, 0:16:20.200 --> 0:16:22.120 please do, because then we can always do a follow 0:16:22.200 --> 0:16:24.960 up and say, you know what, we were doing this 0:16:25.000 --> 0:16:26.840 based on our understanding, and as it turns out, our 0:16:26.920 --> 0:16:30.280 understanding was flawed, and here's how it really works. We 0:16:30.320 --> 0:16:34.120 appreciate that. Yes, please be gentle. Alright, So starting off, 0:16:34.160 --> 0:16:37.960 we have the electro magnetic band gap meta materials or 0:16:38.080 --> 0:16:40.760 also known as e b M meta materials or just 0:16:40.840 --> 0:16:42.840 a b M, because that's what the m stands for 0:16:43.440 --> 0:16:46.640 So these manipulate light propagation, and they are either made 0:16:47.080 --> 0:16:51.760 from left handed materials or photonic crystals left handed materials. 0:16:52.440 --> 0:16:55.880 That means they're more creative, it means they're sinister. So 0:16:55.880 --> 0:16:58.960 when you go to the old French being a left hander, 0:16:59.000 --> 0:17:03.280 I consider myself sinister. Now, left handedness and electromagnetic radiation 0:17:03.720 --> 0:17:07.119 is um a very particular thing and you've got to 0:17:07.160 --> 0:17:10.240 be careful on how you define it. So with electromagnetic radiation, 0:17:10.320 --> 0:17:12.879 like we said earlier, you've got the electric field, the 0:17:12.880 --> 0:17:16.399 magnetic field, and the wave vector, which is that magnitude 0:17:16.400 --> 0:17:21.200 and direction combo. Right, So you also have physical material. 0:17:21.440 --> 0:17:25.120 So any given physical material has a couple of different features, 0:17:25.240 --> 0:17:29.239 one called permitivity and one called permeability, and those are 0:17:29.240 --> 0:17:31.280 the ways in which it's going to interact with any 0:17:31.400 --> 0:17:36.800 given wavelength of electromagnetic radiation. Right, Yeah, Because your permitivity 0:17:36.960 --> 0:17:40.240 is how it interacts with electric fields. Your permeability is 0:17:40.280 --> 0:17:43.960 how it interacts with magnetic fields. And a positive number 0:17:44.040 --> 0:17:48.199 essentially says that it has this kind of interaction. But 0:17:48.320 --> 0:17:51.280 here's the thing you can actually have. You can create 0:17:51.320 --> 0:17:56.320 a material that has negative permitivity and negative permeability. You 0:17:56.359 --> 0:17:58.520 won't find it in the nature, or at least we 0:17:58.560 --> 0:18:01.680 haven't found anything in nature so far that has both 0:18:01.760 --> 0:18:08.240 negative permeability and permitivity simultaneously. We have made stuff that does, 0:18:08.680 --> 0:18:11.560 and that stuff is called left handed yes and h. 0:18:11.680 --> 0:18:15.800 So it's really interesting concept that you are able to 0:18:15.840 --> 0:18:19.879 create something that has this negative permitivity and permeability. What 0:18:20.000 --> 0:18:23.760 it ultimately means is that you could create a material 0:18:24.240 --> 0:18:30.320 that resists waves as they impact that material. So imagine 0:18:30.400 --> 0:18:34.840 creating a military vehicle out of this stuff and there's 0:18:34.840 --> 0:18:40.080 an electromagnetic burst. This thing would actually effectively the material 0:18:40.080 --> 0:18:45.840 itself would push back against that oncoming electromagnetic wave, leaving 0:18:46.080 --> 0:18:49.680 the vehicle fine. So you could imagine that being really 0:18:49.720 --> 0:18:53.240 effective for something like an electromagnetic pulse weapon that wipes 0:18:53.240 --> 0:18:56.639 out electronics. Otherwise, if you're if you have it shielded 0:18:56.680 --> 0:18:59.320 with this stuff, it's like the ultimate Faraday cage. Yeah, 0:18:59.400 --> 0:19:02.520 it's like a field almost, but it's because of again 0:19:02.680 --> 0:19:07.560 the physical structure of the structure of the material. Yeah, 0:19:07.600 --> 0:19:11.240 there's there's no energy thing going on here. It has 0:19:11.280 --> 0:19:13.080 nothing to do like you don't have to turn off, 0:19:13.200 --> 0:19:17.600 switch off exactly. It's just the way the stuff is 0:19:17.800 --> 0:19:23.919 physically built. It's it's unbelievable to me. It's amazing to 0:19:24.000 --> 0:19:28.600 me that just by uh, specifically designing the structure, you 0:19:28.680 --> 0:19:33.280 can dictate how electromagnetic radiation is going to interact with something. 0:19:33.800 --> 0:19:37.400 And now there's also single negative meta materials, which would 0:19:37.440 --> 0:19:41.639 have one of those two things, primitivity or permeability, be negative, 0:19:41.680 --> 0:19:44.200 but the other one would be positive. Then you have 0:19:44.720 --> 0:19:47.800 natural materials that have like the double positive, which means 0:19:47.840 --> 0:19:51.199 the permitivity and permit permeability are both positive. You can 0:19:51.240 --> 0:19:54.080 make meta materials that have that same stuff. Uh, I mean, 0:19:54.080 --> 0:19:56.199 it all depends on what you want the meta material 0:19:56.280 --> 0:19:59.640 to do obviously. Uh. Then there are others that get 0:20:00.040 --> 0:20:03.120 restively more difficult for me to describe. So I'm not 0:20:03.200 --> 0:20:07.119 gonna try because I know at that point I would 0:20:07.160 --> 0:20:11.560 just be giving misinformation. But uh, that's the basic ideas, 0:20:11.760 --> 0:20:15.399 the the idea of interacting with either the electric field 0:20:15.480 --> 0:20:18.120 or the magnetic field or both in a way that's 0:20:18.240 --> 0:20:22.399 different from your general natural materials out there. So this 0:20:22.480 --> 0:20:26.479 all sounds like incredible science fiction technology to me. This 0:20:26.520 --> 0:20:31.120 is all probably really recent research, right, Well, how about 0:20:32.400 --> 0:20:36.320 late nineteenth century is that still recent? I mean, overall 0:20:36.920 --> 0:20:39.320 from a geological time scale, it's like no time at 0:20:39.320 --> 0:20:42.640 all has passed, but for for humans. Yeah, this this 0:20:42.720 --> 0:20:47.320 is actually the whole concept is built upon observations that 0:20:47.400 --> 0:20:50.200 were starting to come out of the scientific world in 0:20:50.240 --> 0:20:56.160 the late nineteenth century. Back in a scientist named Jagaudie 0:20:56.600 --> 0:21:01.560 chunder Bows experimented with microwaves and twisted structures that today 0:21:01.600 --> 0:21:04.919 we would call artificial chirals. Chiral, by the way, is 0:21:05.000 --> 0:21:08.040 essentially an asymmetric shape. It's one that if you were 0:21:08.080 --> 0:21:11.520 to superimpose a reverse of its image, it would not 0:21:12.160 --> 0:21:17.240 fit onto itself. Um. He found that by introducing randomly 0:21:17.280 --> 0:21:21.800 oriented wire helisses as in the plural of helix uh 0:21:21.840 --> 0:21:25.640 in a host medium, he could create a microwave lens. Essentially, 0:21:25.840 --> 0:21:28.760 he was bombarding stuff with microwaves and he had these 0:21:28.840 --> 0:21:34.200 little wire helix structures embedded into that material, and then 0:21:34.240 --> 0:21:38.320 he would move the little helix helis sees around, changing 0:21:38.320 --> 0:21:41.760 their orientation, changing their their layout, and he discovered that 0:21:41.760 --> 0:21:45.280 that was changing the the effect of those microwaves. He 0:21:45.320 --> 0:21:49.919 could focus it exactly, so he's like, huh, something to 0:21:50.000 --> 0:21:53.320 do with the physical structure is affecting the way the 0:21:53.359 --> 0:21:57.439 microwaves are behaving with this material, and that was the 0:21:57.640 --> 0:22:01.080 very beginning. Some say, because there are people who argue 0:22:01.080 --> 0:22:03.360 about whether or not this is in fact the origin. 0:22:04.920 --> 0:22:08.399 But by the nineteen sixties you had scientists hypothesizing that 0:22:08.880 --> 0:22:11.680 if we were in fact able to build stuff with 0:22:12.040 --> 0:22:16.480 incredible nano precision, we could do so and make it 0:22:16.640 --> 0:22:20.320 so that it behaves in a specific way when introduced 0:22:20.359 --> 0:22:24.159 to electromagnetic radiation. There wasn't any way we could actually 0:22:24.200 --> 0:22:26.520 do it at that time. Yeah, we wouldn't actually get 0:22:26.560 --> 0:22:30.640 into that kind of production technology until the nineteen nineties. Yeah, 0:22:30.720 --> 0:22:33.440 And in fact, really it wasn't until the two thousands 0:22:33.520 --> 0:22:38.919 that you started seeing the first real forays into the 0:22:38.960 --> 0:22:43.160 microwave world, where we were trying to uh specifically create 0:22:43.160 --> 0:22:46.560 a meta material that would allow microwaves to pass straight 0:22:46.600 --> 0:22:48.760 through it as if nothing were there at all, and 0:22:49.160 --> 0:22:51.240 kind of around it. But yeah, kind of around it. Yeah. 0:22:51.240 --> 0:22:54.120 When I say through it, over it, I guess technically, yeah, 0:22:54.160 --> 0:22:56.879 imagine that the light like think of it almost like water, 0:22:57.359 --> 0:22:59.439 you know how water. If you put a stone in 0:22:59.560 --> 0:23:02.520 an in flowing water, the water will just flow around 0:23:02.520 --> 0:23:05.359 the stone and then continue on as if nothing were there. 0:23:05.880 --> 0:23:07.639 It's the same sort of things. In this case, we're 0:23:07.640 --> 0:23:10.760 talking about light. It actually bends around the object and 0:23:10.760 --> 0:23:13.400 then continues on not to us, it's as if light 0:23:13.520 --> 0:23:16.199 is just passing straight through it, right, That's that's an 0:23:16.200 --> 0:23:19.400 optical illusion. So if we were able to see in microwaves, 0:23:19.640 --> 0:23:22.480 we would not see that object. It would just be 0:23:22.520 --> 0:23:25.399 as if there was nothing there at all. So that was, 0:23:25.760 --> 0:23:28.679 you know, kind of the beginning of it. But as 0:23:28.720 --> 0:23:32.440 far as where we are now, we're really seeing lots 0:23:32.520 --> 0:23:37.159 of effort going into making this technology more sophisticated. Uh, 0:23:37.160 --> 0:23:41.280 And we're able to create much more precise meta materials 0:23:41.320 --> 0:23:44.200 than we ever have been before. Oh yeah, A lot 0:23:44.200 --> 0:23:46.920 of that has to do with three D printing. Talk 0:23:46.960 --> 0:23:49.440 about that a lot on this show. We do. Uh. 0:23:49.480 --> 0:23:52.480 For example, that microwave invisibility click that we were that 0:23:52.920 --> 0:23:56.080 we've been talking about involved printing wires and patterns on 0:23:56.160 --> 0:23:59.520 too circuit boards in order to create this this shield. Yeah, yeah, 0:23:59.520 --> 0:24:03.760 that's pretty cool. So this whole microwave shield thing, it's 0:24:03.760 --> 0:24:06.239