1 00:00:00,280 --> 00:00:02,960 Speaker 1: Brought to you by the reinvented two thousand twelve Camray. 2 00:00:03,160 --> 00:00:08,920 Speaker 1: It's ready. Are you get in touch with technology with 3 00:00:09,000 --> 00:00:17,560 Speaker 1: tech Stuff from how stuff works dot com. Hello everyone, 4 00:00:17,600 --> 00:00:20,279 Speaker 1: welcome to tech Stuff. My name is Chris Poulette, and 5 00:00:20,320 --> 00:00:22,640 Speaker 1: I am an editor at how stuff works dot com. 6 00:00:22,640 --> 00:00:25,280 Speaker 1: Sitting across from me as always, at least as far 7 00:00:25,320 --> 00:00:27,280 Speaker 1: as I can tell, here in the Dark his senior 8 00:00:27,280 --> 00:00:30,400 Speaker 1: writer Jonathan Strickland when the night has come and the 9 00:00:30,520 --> 00:00:33,120 Speaker 1: land is dark and the moon is the only light 10 00:00:33,200 --> 00:00:38,320 Speaker 1: we will see, as an especially good one for today's episode. Yeah, 11 00:00:38,360 --> 00:00:42,280 Speaker 1: I've been trying to theme them a little. Uh. You 12 00:00:42,320 --> 00:00:44,080 Speaker 1: can tell the theme ones because those are the ones 13 00:00:44,120 --> 00:00:48,000 Speaker 1: where I thought about finding the quote before we started recording. 14 00:00:48,560 --> 00:00:50,560 Speaker 1: And most of the time he goes, oh wait, wait, wait, 15 00:00:50,560 --> 00:00:52,839 Speaker 1: I gotta think of a quote. Yeah, exactly, that's that's 16 00:00:52,840 --> 00:00:56,240 Speaker 1: the problem. Usually it's just when we hit record and uh, 17 00:00:56,320 --> 00:00:59,560 Speaker 1: and I strugged. I struggled to find some lyric. But 18 00:00:59,680 --> 00:01:02,360 Speaker 1: any way, let's move on to today's topic, which is 19 00:01:03,080 --> 00:01:05,760 Speaker 1: night vision. And we've had a couple of people asked 20 00:01:05,880 --> 00:01:09,319 Speaker 1: us to cover night vision and people were just curious, 21 00:01:09,400 --> 00:01:12,440 Speaker 1: you know, how does this work? What does how are 22 00:01:12,480 --> 00:01:15,600 Speaker 1: we able to create electronics that allow us to see 23 00:01:15,760 --> 00:01:19,080 Speaker 1: in near perfect darkness, and so we're going to kind 24 00:01:19,080 --> 00:01:23,880 Speaker 1: of cover that. Night vision The technology dates back to 25 00:01:24,160 --> 00:01:28,120 Speaker 1: the late thirties early forties. It was technology that was 26 00:01:28,160 --> 00:01:32,679 Speaker 1: developed during World War Two and used mainly by the American, British, 27 00:01:32,760 --> 00:01:38,080 Speaker 1: and Soviet forces during World War Two, although other nations 28 00:01:38,200 --> 00:01:42,080 Speaker 1: began to to develop their own version of night vision 29 00:01:42,080 --> 00:01:45,640 Speaker 1: technology around the same time. Well, yeah, the Germans, UH. 30 00:01:45,680 --> 00:01:48,840 Speaker 1: A lot of what we had as far as our 31 00:01:48,880 --> 00:01:52,080 Speaker 1: technology in the United States was based on some German 32 00:01:52,120 --> 00:01:56,160 Speaker 1: research that was done in the late thirties. UM. And 33 00:01:56,240 --> 00:02:01,040 Speaker 1: really what it comes down to, UM is the spectrum 34 00:02:01,040 --> 00:02:04,680 Speaker 1: of light that that you're trying to see. Yeah, it's 35 00:02:04,760 --> 00:02:09,280 Speaker 1: it's two different things. It's trying to accept other parts 36 00:02:09,280 --> 00:02:12,280 Speaker 1: of light that human eye is not able to detect, 37 00:02:12,320 --> 00:02:17,640 Speaker 1: and also to uh to amplify whatever little light is there. 38 00:02:17,680 --> 00:02:22,200 Speaker 1: There are two main ways of achieving a night vision 39 00:02:23,000 --> 00:02:27,960 Speaker 1: UH technology. One is called image enhancement, and that's where 40 00:02:28,000 --> 00:02:31,040 Speaker 1: you're taking the little amount of light that's out there 41 00:02:31,560 --> 00:02:35,000 Speaker 1: and UH and trying to amplify it so that you know, 42 00:02:35,080 --> 00:02:37,840 Speaker 1: you're able to see better in that environment. And the 43 00:02:37,919 --> 00:02:41,480 Speaker 1: other is thermal imaging, which is also you know, we 44 00:02:41,600 --> 00:02:44,640 Speaker 1: think of that as being able to see heat. You know, 45 00:02:44,680 --> 00:02:47,040 Speaker 1: the whole idea about like if you've ever seen that 46 00:02:47,120 --> 00:02:52,679 Speaker 1: documentary Predatory, the Predator actually uses both forms of this, 47 00:02:53,480 --> 00:02:55,840 Speaker 1: but the thermal imaging would be the one where it 48 00:02:55,960 --> 00:02:59,040 Speaker 1: switches and it's that really colorful display where the hotter 49 00:02:59,280 --> 00:03:02,120 Speaker 1: things in the field of vision are a brighter color, 50 00:03:02,280 --> 00:03:06,120 Speaker 1: usually red, uh, and then the cooler things are are 51 00:03:06,520 --> 00:03:08,960 Speaker 1: in the other part of the spectrum of light, so 52 00:03:09,040 --> 00:03:11,640 Speaker 1: they'd be you know, if it's cold, it might be black, 53 00:03:11,720 --> 00:03:14,400 Speaker 1: but if it's cooler, it might be blue or even 54 00:03:14,600 --> 00:03:17,840 Speaker 1: kind of an indigo color. Um. Both of those are 55 00:03:17,919 --> 00:03:21,480 Speaker 1: ways of achieving night vision. I think the one that 56 00:03:21,520 --> 00:03:23,720 Speaker 1: most people think of when they think of night vision 57 00:03:23,800 --> 00:03:27,720 Speaker 1: is the one where you've got the greenish uh display. 58 00:03:27,840 --> 00:03:32,560 Speaker 1: That's the image enhancement approach, And well, you know that 59 00:03:32,560 --> 00:03:35,440 Speaker 1: that's I think that's the reason people think about it 60 00:03:35,480 --> 00:03:39,600 Speaker 1: is because it's used that way in TV and the movies. Yeah, 61 00:03:39,680 --> 00:03:44,800 Speaker 1: probably so as a visual clue to the viewer that hey, 62 00:03:44,840 --> 00:03:48,360 Speaker 1: we're doing something that you can't normally do, right. Yeah. 63 00:03:48,400 --> 00:03:51,200 Speaker 1: I In fact, I watched a movie just last night 64 00:03:51,360 --> 00:03:55,680 Speaker 1: that involved having a night vision the screen tinged night 65 00:03:55,760 --> 00:03:58,120 Speaker 1: vision and it was and I'm not going to call 66 00:03:58,160 --> 00:04:01,200 Speaker 1: it a documentary because that's how much of a skeptic 67 00:04:01,240 --> 00:04:04,640 Speaker 1: I am. It was paranormal activity too. And uh, you 68 00:04:04,640 --> 00:04:08,200 Speaker 1: know in paranormal activity those movies, those are done as 69 00:04:08,280 --> 00:04:11,200 Speaker 1: found footage movies, which, in case you're not familiar with 70 00:04:11,240 --> 00:04:13,840 Speaker 1: the term, that's the idea where the film is presented 71 00:04:13,920 --> 00:04:18,520 Speaker 1: as if it were uh collection of clips taken from 72 00:04:18,839 --> 00:04:22,560 Speaker 1: various cameras that it wasn't meant to be a feature 73 00:04:22,600 --> 00:04:26,680 Speaker 1: film is supposed to be actual footage shot of something, right, 74 00:04:27,040 --> 00:04:30,720 Speaker 1: So clover Field is another example, or Blair Witch Project. 75 00:04:30,800 --> 00:04:33,040 Speaker 1: There's another example. The first time I thought about yeah, 76 00:04:33,040 --> 00:04:35,840 Speaker 1: and that it's really popular with the horror crowd. Uh 77 00:04:35,880 --> 00:04:39,719 Speaker 1: and uh so the paranormal activity too. There's one of 78 00:04:39,760 --> 00:04:42,159 Speaker 1: the cameras that is being used in that has a 79 00:04:42,240 --> 00:04:46,120 Speaker 1: night vision setting and it's using the image enhancement approach. 80 00:04:46,279 --> 00:04:49,120 Speaker 1: By the way, in case you're curious about why green, 81 00:04:50,000 --> 00:04:53,160 Speaker 1: the the answer I found through my research was that 82 00:04:53,200 --> 00:04:56,600 Speaker 1: the reason why you get green images is not because 83 00:04:56,600 --> 00:05:00,920 Speaker 1: of any technological limitation. It's because does if you're in 84 00:05:00,960 --> 00:05:03,760 Speaker 1: an environment where you're using night vision. You want to 85 00:05:03,800 --> 00:05:06,280 Speaker 1: be able to switch between night vision and your normal 86 00:05:06,360 --> 00:05:10,119 Speaker 1: vision as quickly as possible. But if you use really 87 00:05:10,160 --> 00:05:13,400 Speaker 1: intense light, and in some of the brighter lights, your 88 00:05:13,920 --> 00:05:17,320 Speaker 1: pupils will constrict as you're looking at it, which means 89 00:05:17,320 --> 00:05:19,120 Speaker 1: when you take the night vision glasses off, it's going 90 00:05:19,160 --> 00:05:21,359 Speaker 1: to take more time for your eyes to readjust to 91 00:05:21,400 --> 00:05:24,600 Speaker 1: the darkness around you. But the green that is used 92 00:05:24,680 --> 00:05:27,719 Speaker 1: is a more subtle light, and so your your pupils 93 00:05:27,960 --> 00:05:31,640 Speaker 1: are remain mostly dilated. So when you remove the night 94 00:05:31,720 --> 00:05:34,760 Speaker 1: vision goggles, you don't have as long a time to adjust. 95 00:05:34,800 --> 00:05:36,360 Speaker 1: It doesn't take as long for you to adjust to 96 00:05:36,480 --> 00:05:41,800 Speaker 1: night regular night vision like our natural night vision. Uh, 97 00:05:41,920 --> 00:05:43,960 Speaker 1: when you when you go back and forth, And that 98 00:05:44,040 --> 00:05:45,480 Speaker 1: kind of makes sense to me, I mean, if you 99 00:05:45,600 --> 00:05:48,600 Speaker 1: especially when you consider that night vision was really originally 100 00:05:49,000 --> 00:05:52,600 Speaker 1: used as a military technology, you would want to be 101 00:05:52,680 --> 00:05:55,440 Speaker 1: able to have as much versatility and flexibility as possible 102 00:05:55,480 --> 00:05:59,240 Speaker 1: so that you can adapt to whatever the situation calls for. Yeah, 103 00:05:59,400 --> 00:06:01,560 Speaker 1: that makes sense, Its sense to me. So Yeah, so 104 00:06:01,920 --> 00:06:04,520 Speaker 1: at least according to that, we could in theory have 105 00:06:04,760 --> 00:06:08,240 Speaker 1: night vision where it's any color. Uh, you know, it 106 00:06:08,480 --> 00:06:12,800 Speaker 1: probably still probably be monochromatic, but we'll get into that 107 00:06:12,839 --> 00:06:14,960 Speaker 1: when we get into the you know exactly what's happening. 108 00:06:15,480 --> 00:06:19,159 Speaker 1: So so all the different kinds of night vision lie 109 00:06:19,240 --> 00:06:22,839 Speaker 1: at least somewhat on the infrared, uh, part of the 110 00:06:22,920 --> 00:06:26,039 Speaker 1: spectrum of light, right, and that infrared spectrum of light 111 00:06:26,200 --> 00:06:32,640 Speaker 1: is outside the range of uh, the visible light spectrum. UM. 112 00:06:32,680 --> 00:06:36,000 Speaker 1: In fact, there are three parts to the infrared spectrum, 113 00:06:36,040 --> 00:06:39,200 Speaker 1: which is near infrared, and that's the closest one to 114 00:06:39,560 --> 00:06:43,440 Speaker 1: the visible spectrum spectrum. Yes, I can say that word 115 00:06:43,960 --> 00:06:47,800 Speaker 1: mid infrared um and that has uh oh, I didn't 116 00:06:47,800 --> 00:06:50,960 Speaker 1: mention the wavelengths. The wavelengths for near infrared are from 117 00:06:51,200 --> 00:06:55,520 Speaker 1: point seven to one point three microns um. Mid infrared 118 00:06:55,640 --> 00:07:00,160 Speaker 1: has wavelengths from one point three to three microns um. 119 00:07:00,240 --> 00:07:04,919 Speaker 1: And then thermal infrared, which is the biggest part of 120 00:07:05,000 --> 00:07:08,800 Speaker 1: the infrared spectrum, and that's from three to more than 121 00:07:08,960 --> 00:07:12,960 Speaker 1: thirty microfs. Yeah, and so the the thermal infrared you're 122 00:07:12,960 --> 00:07:19,960 Speaker 1: talking at that point about infrared radiation really heat in 123 00:07:20,000 --> 00:07:22,960 Speaker 1: other words, is what's kind of how we perceive it usually, 124 00:07:23,400 --> 00:07:26,760 Speaker 1: but uh, that's something that's actually given off by an 125 00:07:26,800 --> 00:07:30,920 Speaker 1: object itself, whereas when we're talking about visible light. That's 126 00:07:30,960 --> 00:07:34,480 Speaker 1: something that's reflected off of an object. Right, So if 127 00:07:34,600 --> 00:07:37,680 Speaker 1: if I'm looking at a tree in sunlight, what I'm 128 00:07:37,680 --> 00:07:40,320 Speaker 1: seeing is the light being reflected off of that tree. 129 00:07:40,520 --> 00:07:43,480 Speaker 1: It's that light's hitting my eyes then going through the 130 00:07:43,480 --> 00:07:46,720 Speaker 1: whole focal point, getting into my brain and somewhere up 131 00:07:46,760 --> 00:07:49,520 Speaker 1: there in that Yeah, somewhere up there in the gray matter, 132 00:07:49,840 --> 00:07:54,400 Speaker 1: my brain says, Hello, that's a tree, possibly a large 133 00:07:55,800 --> 00:08:00,600 Speaker 1: a large. Um, I recognize that from very far away. Yes, 134 00:08:01,160 --> 00:08:03,800 Speaker 1: that's how to recognize treats from very far away, quite 135 00:08:03,800 --> 00:08:06,840 Speaker 1: a long way away. Uh. Yeah, So that's how that 136 00:08:07,000 --> 00:08:10,240 Speaker 1: would normally work with thermal infrared. If I were to 137 00:08:10,440 --> 00:08:13,560 Speaker 1: see an object using thermal infrared, Let's say that somehow 138 00:08:13,600 --> 00:08:15,720 Speaker 1: I have that ability. You know, we're not talking about 139 00:08:15,720 --> 00:08:19,640 Speaker 1: technology here, but I somehow have the the the natural 140 00:08:19,680 --> 00:08:22,600 Speaker 1: ability to see the thermal infrared. It happened when they 141 00:08:22,600 --> 00:08:25,240 Speaker 1: shot him into space and he was bombarded by cosmic 142 00:08:25,280 --> 00:08:28,600 Speaker 1: waves while we're really just pop culturing this all to 143 00:08:28,720 --> 00:08:31,800 Speaker 1: heck and back. So yeah, with the thermal infrared ability, 144 00:08:31,840 --> 00:08:34,200 Speaker 1: I would be able to see the energy that is 145 00:08:34,240 --> 00:08:39,000 Speaker 1: being emitted by any particular object. Uh. It's not necessarily light. 146 00:08:39,040 --> 00:08:40,719 Speaker 1: That's reflecting off. In fact, there doesn't have to be 147 00:08:40,800 --> 00:08:43,560 Speaker 1: any sort of light source at all. It just so. 148 00:08:43,679 --> 00:08:46,160 Speaker 1: And if I were in a perfectly dark room and 149 00:08:46,160 --> 00:08:51,360 Speaker 1: there was another object there that's giving off heat, essentially, 150 00:08:51,840 --> 00:08:53,920 Speaker 1: I would be able to see it because I would 151 00:08:53,960 --> 00:08:56,200 Speaker 1: be seeing in that range even though there's no other 152 00:08:56,559 --> 00:08:59,320 Speaker 1: light source coming in. It would just be that I've 153 00:08:59,320 --> 00:09:04,240 Speaker 1: actually seeing that that energy. Because we'll get into why 154 00:09:04,559 --> 00:09:08,680 Speaker 1: it's kind of interesting. Has to do with excitation, but 155 00:09:08,800 --> 00:09:13,800 Speaker 1: not good vibrations. Yeah, although perhaps that lady was a 156 00:09:13,920 --> 00:09:18,240 Speaker 1: will never mind, so moving on. She was made up 157 00:09:18,280 --> 00:09:21,160 Speaker 1: of atoms, that's true. But before we get into the 158 00:09:21,160 --> 00:09:24,160 Speaker 1: whole atoms and thermal infrared, let's let's talk about the 159 00:09:24,160 --> 00:09:28,600 Speaker 1: image enhancement approach first because that's the one that's the 160 00:09:28,600 --> 00:09:33,240 Speaker 1: most familiar and uh, it's kind of uh interesting. Um. 161 00:09:33,280 --> 00:09:37,160 Speaker 1: The way that it works currently is that you've got 162 00:09:37,200 --> 00:09:40,640 Speaker 1: you've got very basic parts to a particular kind of 163 00:09:40,760 --> 00:09:43,040 Speaker 1: night vision. You've got you've got your lens. That's where 164 00:09:43,080 --> 00:09:47,079 Speaker 1: the light is going through. The objective lens. Just a 165 00:09:47,679 --> 00:09:50,560 Speaker 1: lens that catches a lens. Yeah, it catches ambient light, 166 00:09:50,600 --> 00:09:53,480 Speaker 1: it catches near infrared light. So this is the near 167 00:09:53,600 --> 00:09:58,200 Speaker 1: infrared spectrum, the light that's closest to the visible spectrum. 168 00:09:58,480 --> 00:10:02,560 Speaker 1: Now that light is sent to a tube, and that 169 00:10:02,600 --> 00:10:07,239 Speaker 1: tube is called the image intensive fire tube tense. Yeah, 170 00:10:07,320 --> 00:10:10,480 Speaker 1: and the drinking energy drinks all day and yeah. So 171 00:10:10,520 --> 00:10:11,839 Speaker 1: you can think of this tube. It's almost like a 172 00:10:11,920 --> 00:10:13,880 Speaker 1: vacuum tube. In fact, there it is, There is a 173 00:10:13,960 --> 00:10:16,000 Speaker 1: vacuum in side of it. So you think of this 174 00:10:16,120 --> 00:10:19,880 Speaker 1: sort of a imagine a glass vial all right. In 175 00:10:19,960 --> 00:10:22,240 Speaker 1: the middle of this glass vial or on one end 176 00:10:22,280 --> 00:10:25,679 Speaker 1: of the glass vile, you've got something called a photo cathode. Now, 177 00:10:25,720 --> 00:10:30,280 Speaker 1: the photo cathode takes photons. Those are those individual elements 178 00:10:30,400 --> 00:10:33,320 Speaker 1: of energy for light, yes, and and those come in 179 00:10:33,480 --> 00:10:37,440 Speaker 1: the entire spectrum of light um, so infrared. There are 180 00:10:37,480 --> 00:10:41,440 Speaker 1: infrared photons just as there are visible light photons. So 181 00:10:42,400 --> 00:10:47,840 Speaker 1: the photo cathode converts photons into electrons. It's it's one 182 00:10:47,880 --> 00:10:51,520 Speaker 1: of those, uh so it changes light into electricity essentially. Yeah. 183 00:10:51,679 --> 00:10:54,400 Speaker 1: And if you listen to our episode about high speed 184 00:10:54,400 --> 00:10:58,679 Speaker 1: and low speed photography, we talked about how there are 185 00:10:58,840 --> 00:11:05,120 Speaker 1: certain types of materials that when a photon strikes it, 186 00:11:05,120 --> 00:11:09,120 Speaker 1: it causes a reaction. That's the case here a photocathode. 187 00:11:09,200 --> 00:11:11,280 Speaker 1: It's that's the and that's how it behaves. When a 188 00:11:11,320 --> 00:11:14,760 Speaker 1: photon hits it, it gives off an electron. Uh. So 189 00:11:14,840 --> 00:11:17,240 Speaker 1: you've got the photocathode at one end of this tube, 190 00:11:17,240 --> 00:11:19,439 Speaker 1: and that's where the light that's being captured by the 191 00:11:19,520 --> 00:11:23,200 Speaker 1: lens is directed to the photo cathode. The electrons emitted 192 00:11:23,200 --> 00:11:25,440 Speaker 1: by the photo cathode then have to pass through what 193 00:11:25,679 --> 00:11:30,360 Speaker 1: is called a micro channel plate or or m c P. 194 00:11:30,840 --> 00:11:33,600 Speaker 1: That's a little glass disc. Yeah, I see, I thought 195 00:11:33,720 --> 00:11:39,680 Speaker 1: MCP was the master control program end of line is Okay, However, 196 00:11:39,840 --> 00:11:42,520 Speaker 1: two different mcps. Well, it was until Tron got a 197 00:11:42,520 --> 00:11:46,120 Speaker 1: hold of it, that's right. So glass disc Tron, m 198 00:11:46,160 --> 00:11:51,360 Speaker 1: c P. I'm sensing some convergence here again. Ye. So anyway, 199 00:11:51,400 --> 00:11:53,840 Speaker 1: you've got this glass, little tiny glass disc called a 200 00:11:53,880 --> 00:11:57,600 Speaker 1: micro channel plate and has lots and lots of channels. 201 00:11:57,679 --> 00:11:59,599 Speaker 1: That's why it's called a micro channel plate. Lots of 202 00:11:59,679 --> 00:12:02,520 Speaker 1: channels that go through this plate. Okay, So think of 203 00:12:02,520 --> 00:12:05,440 Speaker 1: the plate. Think of it like a dish. You got 204 00:12:05,440 --> 00:12:07,960 Speaker 1: a dish, put it up on its side, and it 205 00:12:08,000 --> 00:12:10,679 Speaker 1: has a whole bunch of holes drilled in it. Now, 206 00:12:10,679 --> 00:12:13,760 Speaker 1: those holes are what allow electrons to pass through. But 207 00:12:13,800 --> 00:12:18,240 Speaker 1: there's also an electrode on either side of the dish. 208 00:12:18,640 --> 00:12:23,160 Speaker 1: So electrons coming from the photo cathode strike one side 209 00:12:23,240 --> 00:12:26,319 Speaker 1: of this micro channel plate and start to go through 210 00:12:26,520 --> 00:12:29,200 Speaker 1: one of the channels, and they're going through in the 211 00:12:29,240 --> 00:12:32,680 Speaker 1: same direction they came from the the from the photo 212 00:12:32,720 --> 00:12:38,520 Speaker 1: cathode UH section of this this UH this image intensive 213 00:12:38,559 --> 00:12:43,600 Speaker 1: ire tube. So the photon converts to electron. Electron goes 214 00:12:43,640 --> 00:12:45,800 Speaker 1: through this channel. As it goes to the channel, it 215 00:12:45,880 --> 00:12:52,680 Speaker 1: starts to actually set off a well a reaction and 216 00:12:53,120 --> 00:12:56,560 Speaker 1: it basically functions as a multiplier for the electrons. It's 217 00:12:56,600 --> 00:13:00,840 Speaker 1: called a cascaded secondary emission. So this is where when 218 00:13:00,920 --> 00:13:04,640 Speaker 1: electron collie collides with something inside that that channel, it 219 00:13:04,720 --> 00:13:08,640 Speaker 1: starts to set off other electrons uh down that same pathway. 220 00:13:08,840 --> 00:13:12,040 Speaker 1: And there's a voltage applied to those electrodes that's channeling 221 00:13:12,080 --> 00:13:14,800 Speaker 1: the electrons through that pathway, like that's why they're going 222 00:13:14,920 --> 00:13:19,240 Speaker 1: in that direction. So you've got more and more electrons 223 00:13:19,280 --> 00:13:22,760 Speaker 1: bouncing off of each other through these channels, which means 224 00:13:22,800 --> 00:13:26,800 Speaker 1: that you've you've created an amplifier and UH, if you 225 00:13:26,840 --> 00:13:29,320 Speaker 1: guys want to know kind of like a big picture 226 00:13:29,360 --> 00:13:33,720 Speaker 1: way of what this might look like. Imagine having a 227 00:13:32,960 --> 00:13:35,720 Speaker 1: h and you can see play of videos of this 228 00:13:35,800 --> 00:13:39,800 Speaker 1: on YouTube. But imagine having a big glass container filled 229 00:13:39,800 --> 00:13:43,000 Speaker 1: with mouse traps, and each mouse trap has a ping 230 00:13:43,080 --> 00:13:45,640 Speaker 1: pong ball set on it, and then you drop a 231 00:13:45,679 --> 00:13:49,560 Speaker 1: ping pong ball into the the glass chamber and that 232 00:13:49,600 --> 00:13:52,000 Speaker 1: will set off a mouse trap, And as the ping 233 00:13:52,040 --> 00:13:54,200 Speaker 1: pong balls bounce around, they set off more and more 234 00:13:54,280 --> 00:13:57,440 Speaker 1: mouse traps, so soon the glass case like within a 235 00:13:57,480 --> 00:14:00,880 Speaker 1: fraction of the second ball. The balls are bouncing everywhere, right, 236 00:14:01,440 --> 00:14:04,160 Speaker 1: same sort of idea here with the microchannel plate, except 237 00:14:04,160 --> 00:14:07,120 Speaker 1: that we're talking on a sub atomic level, and we're 238 00:14:07,120 --> 00:14:11,439 Speaker 1: talking about something that's really channeled, really has a firm direction. 239 00:14:11,480 --> 00:14:14,080 Speaker 1: So instead of the electrons bouncing everywhere, they're going in 240 00:14:14,080 --> 00:14:17,319 Speaker 1: a very specific direction. Right now, when they get to 241 00:14:17,400 --> 00:14:20,120 Speaker 1: the other side of that micro channel plate, you've got 242 00:14:20,120 --> 00:14:22,720 Speaker 1: the electron still traveling in the same direction they were 243 00:14:22,760 --> 00:14:25,200 Speaker 1: when they came in on the front side, but now 244 00:14:25,200 --> 00:14:28,560 Speaker 1: there are way more electrons, right, just amplified the number. 245 00:14:29,040 --> 00:14:34,760 Speaker 1: The electrons then hit a screen that's coated with phosphors. Now, 246 00:14:34,840 --> 00:14:39,440 Speaker 1: phosphors phosphors do there, they're kind of like the opposite 247 00:14:39,480 --> 00:14:42,520 Speaker 1: of the photo cathode. Right, they take when the electron 248 00:14:42,560 --> 00:14:45,800 Speaker 1: strikes the phosphoor, they give off light, So you're changing 249 00:14:45,800 --> 00:14:48,440 Speaker 1: the electron back to a pot photon. Right. But now, 250 00:14:48,480 --> 00:14:51,920 Speaker 1: because there are more electrons coming through hitting that phosphoor 251 00:14:51,960 --> 00:14:55,120 Speaker 1: than they were coming in, the light that's generated is 252 00:14:55,240 --> 00:14:58,440 Speaker 1: much greater in intensity than the light that was coming in. 253 00:14:59,160 --> 00:15:03,400 Speaker 1: So you've ample vide the light. Now that information that 254 00:15:03,520 --> 00:15:06,640 Speaker 1: light is sent to a viewer of some type. It 255 00:15:06,640 --> 00:15:09,280 Speaker 1: could just be a regular lens, which is usually called 256 00:15:09,320 --> 00:15:12,520 Speaker 1: the ocular lens, or it could be sent to a monitor. 257 00:15:13,280 --> 00:15:15,200 Speaker 1: So if you have a night a pair of night 258 00:15:15,280 --> 00:15:19,400 Speaker 1: vision goggles or a night vision scope, that's what you're seeing. 259 00:15:19,400 --> 00:15:23,720 Speaker 1: You're seeing that amplified light hitting the lens or the 260 00:15:23,760 --> 00:15:28,400 Speaker 1: Monitor's pretty cool, it's pretty awesome. Right. And again, this 261 00:15:28,480 --> 00:15:32,040 Speaker 1: isn't just the the visible light, the ambient visible light 262 00:15:32,080 --> 00:15:35,640 Speaker 1: that's out there, but also the infrared light so um 263 00:15:36,000 --> 00:15:38,560 Speaker 1: because those photons, you know, it doesn't you know, the photons, 264 00:15:38,600 --> 00:15:42,880 Speaker 1: It doesn't matter if it's visible or not. Um. And uh, 265 00:15:43,280 --> 00:15:46,520 Speaker 1: the more light that's hitting certain areas, that the brighter 266 00:15:46,560 --> 00:15:49,640 Speaker 1: it's going to be for whatever it is you're looking at. 267 00:15:49,640 --> 00:15:52,479 Speaker 1: So if you're looking at something that's that's fairly reflective. 268 00:15:53,160 --> 00:15:56,680 Speaker 1: Um you're gonna be able to see it in higher 269 00:15:56,680 --> 00:16:00,920 Speaker 1: definition than you could with something that is not as reflective. Uh. Now, 270 00:16:00,960 --> 00:16:04,240 Speaker 1: there are different ways of actually achieving this too. You 271 00:16:04,320 --> 00:16:10,400 Speaker 1: can have a various there are various generations of this technology, 272 00:16:10,600 --> 00:16:15,480 Speaker 1: all right, So the earliest generation of this technology actually 273 00:16:15,520 --> 00:16:20,960 Speaker 1: involved shining infrared light at the objects you're looking at 274 00:16:21,040 --> 00:16:24,080 Speaker 1: through the through the night vision goggles. Right, So when 275 00:16:24,080 --> 00:16:27,200 Speaker 1: that that infrared light was reflected, then you would be 276 00:16:27,240 --> 00:16:30,720 Speaker 1: able to see it, right, because these goggles were not 277 00:16:30,880 --> 00:16:33,400 Speaker 1: so sensitive as to be able to take just the 278 00:16:33,440 --> 00:16:36,560 Speaker 1: ambient light. If you did that, you would probably get 279 00:16:36,600 --> 00:16:39,200 Speaker 1: you you might be able to see marginally better than 280 00:16:39,240 --> 00:16:42,200 Speaker 1: you would if you had just use your regular vision. 281 00:16:42,600 --> 00:16:47,960 Speaker 1: But using this infrared flashlight, essentially you could illuminate the 282 00:16:48,920 --> 00:16:50,760 Speaker 1: scene and be able to see it through the night 283 00:16:50,840 --> 00:16:53,200 Speaker 1: vision goggles. But if you did not have the goggles, 284 00:16:53,200 --> 00:16:57,640 Speaker 1: because infrared light falls outside the visible spectrum, any independent 285 00:16:57,640 --> 00:17:01,840 Speaker 1: observer wouldn't be able to tell you were doing Yeah, now, 286 00:17:01,960 --> 00:17:04,879 Speaker 1: uh I UM I did some research on the the 287 00:17:04,960 --> 00:17:10,520 Speaker 1: US military website about the history of of night vision, 288 00:17:10,640 --> 00:17:15,560 Speaker 1: and apparently UM they sent about three hundred sniper scopes 289 00:17:15,840 --> 00:17:18,160 Speaker 1: over to be used in the Pacific theater during World 290 00:17:18,160 --> 00:17:21,600 Speaker 1: War Two, but they didn't get used very much because 291 00:17:21,600 --> 00:17:24,680 Speaker 1: of the way that the technology worked. Um they really 292 00:17:24,680 --> 00:17:28,160 Speaker 1: could see less than a hundred yards, so they weren't 293 00:17:28,240 --> 00:17:33,520 Speaker 1: very effective, right because again, since it's dependent upon a 294 00:17:33,680 --> 00:17:38,199 Speaker 1: reflected ray of infrared light, if it's you know, the 295 00:17:38,280 --> 00:17:41,320 Speaker 1: rays starting to dispersees as it goes out, Right, it's 296 00:17:41,320 --> 00:17:44,600 Speaker 1: not not a not a concentrated like a laser beam. Yeah, 297 00:17:44,600 --> 00:17:47,520 Speaker 1: it's not a beam. It does disperse and diffuse as 298 00:17:47,520 --> 00:17:50,840 Speaker 1: it goes out. So the further away your target, the 299 00:17:50,960 --> 00:17:52,840 Speaker 1: less likely you're going to be able to see it. 300 00:17:53,119 --> 00:17:55,879 Speaker 1: And even with a really really advanced version. That's by 301 00:17:55,880 --> 00:17:59,880 Speaker 1: the way, it's called active infrared because you're actively beam 302 00:18:00,119 --> 00:18:03,719 Speaker 1: infrared radiation out in order to try and see uh, 303 00:18:03,920 --> 00:18:10,320 Speaker 1: stuff coming back through the monitors. Um if because because 304 00:18:10,359 --> 00:18:12,880 Speaker 1: you're relying on that reflection, if it's too far away, 305 00:18:12,920 --> 00:18:14,800 Speaker 1: you're not gonna be all se very well. So obviously 306 00:18:14,920 --> 00:18:18,440 Speaker 1: a sniper rifle where at least in theory, you want 307 00:18:18,440 --> 00:18:20,600 Speaker 1: to be able to put your snipers at a good 308 00:18:20,680 --> 00:18:23,879 Speaker 1: distance away from the targets to maximize their effectiveness and 309 00:18:23,920 --> 00:18:27,720 Speaker 1: minimize the chance that they will be targeted. Um, it doesn't. 310 00:18:27,760 --> 00:18:30,360 Speaker 1: It's not so effective if you know your your distance 311 00:18:30,440 --> 00:18:34,520 Speaker 1: is cut down that dramatically. Yeah. Plus, the first generation 312 00:18:34,680 --> 00:18:38,880 Speaker 1: wasn't exactly um useful for someone like a sniper, considering 313 00:18:38,920 --> 00:18:42,720 Speaker 1: the batteries were huge and the I R emitters had 314 00:18:42,760 --> 00:18:46,080 Speaker 1: to be carried on flatbed trucks. It's hard to put 315 00:18:46,080 --> 00:18:48,000 Speaker 1: one of those up in a tree. Yeah. Yeah, it 316 00:18:48,040 --> 00:18:51,199 Speaker 1: turns out that also all of these are going to 317 00:18:51,480 --> 00:18:54,919 Speaker 1: involve having a power supply of some sort. But for 318 00:18:54,960 --> 00:18:58,240 Speaker 1: the active infrared it requires even lot more energy because 319 00:18:58,240 --> 00:19:01,120 Speaker 1: you're not you're not just for your your actual night 320 00:19:01,240 --> 00:19:03,840 Speaker 1: vision device, whether it's a scope or goggles or whatever, 321 00:19:03,880 --> 00:19:07,240 Speaker 1: but also for the emitter. By the way, that generation 322 00:19:07,400 --> 00:19:11,480 Speaker 1: is normally referred to as generation zero for a night vision. 323 00:19:12,000 --> 00:19:18,080 Speaker 1: Generation one was the first generation using passive infrared system. Now, 324 00:19:18,119 --> 00:19:21,320 Speaker 1: this was the kind of of night vision goggles or 325 00:19:21,640 --> 00:19:25,080 Speaker 1: scope that could just use the ambient light in the area, 326 00:19:25,160 --> 00:19:28,320 Speaker 1: although it needed a good amount of the ambient light. 327 00:19:28,400 --> 00:19:33,280 Speaker 1: So moonlight or starlight should say starlight, Yeah, that's what 328 00:19:33,320 --> 00:19:36,920 Speaker 1: it was. Yeah, the U. S Army they called it starlight. Uh, 329 00:19:37,080 --> 00:19:41,040 Speaker 1: the without the moon or stars you wouldn't be able 330 00:19:41,080 --> 00:19:43,320 Speaker 1: to see very much, so on an overcast night it 331 00:19:43,320 --> 00:19:46,040 Speaker 1: would not be terribly useful. But on a clear day, 332 00:19:46,080 --> 00:19:48,960 Speaker 1: you could see forever. You're got a clear day, you 333 00:19:49,000 --> 00:19:54,960 Speaker 1: don't need night vision. Okay, starlight first star I see tonight. Um, 334 00:19:55,119 --> 00:20:00,240 Speaker 1: So yeah, it was better than generation zero. Still still 335 00:20:00,359 --> 00:20:03,840 Speaker 1: pretty far acry from what we have today. Although interestingly, 336 00:20:04,440 --> 00:20:06,440 Speaker 1: if you were to go out and buy a pair 337 00:20:06,600 --> 00:20:10,320 Speaker 1: of night vision goggles, you know, a consumer brand version 338 00:20:10,480 --> 00:20:14,960 Speaker 1: would probably be Generation one. I guess you know. That's 339 00:20:15,720 --> 00:20:19,440 Speaker 1: the military tends to reserve the more the more advanced 340 00:20:19,480 --> 00:20:22,520 Speaker 1: forms UH generation too, it's possible that they could be 341 00:20:22,560 --> 00:20:26,720 Speaker 1: generation two as well. Generation two where they had better 342 00:20:27,400 --> 00:20:29,800 Speaker 1: UH image in tensi fire tubes, which meant that they 343 00:20:29,800 --> 00:20:34,000 Speaker 1: could use them in extreme low light conditions. So on 344 00:20:34,040 --> 00:20:36,560 Speaker 1: a moonless night, you could use these and it would 345 00:20:36,560 --> 00:20:39,520 Speaker 1: be UH strong enough to be able to to amplify 346 00:20:39,560 --> 00:20:42,320 Speaker 1: that light so you can see. Generation three is what 347 00:20:42,520 --> 00:20:46,160 Speaker 1: you can find in the US military now. Um. And 348 00:20:46,240 --> 00:20:49,960 Speaker 1: that is they used a new kind of photo cathode 349 00:20:50,000 --> 00:20:52,920 Speaker 1: called gallium marsonite, so it's even more sensitive than the 350 00:20:52,960 --> 00:20:55,600 Speaker 1: previous ones, which means that you know, it's it's not 351 00:20:55,680 --> 00:20:59,320 Speaker 1: that the Uh, they've really advanced the technology that much. 352 00:20:59,320 --> 00:21:03,360 Speaker 1: They just found them material that that emits electrons much 353 00:21:03,400 --> 00:21:06,120 Speaker 1: more readily than others. Yeah. As a matter of fact, 354 00:21:06,119 --> 00:21:07,960 Speaker 1: I believe we talked about gallium arson and when we 355 00:21:07,960 --> 00:21:11,480 Speaker 1: talked about transistors, I believe we did back. Yeah, and 356 00:21:11,520 --> 00:21:17,399 Speaker 1: then we have generation four, which is yet more improvements. Uh. 357 00:21:17,440 --> 00:21:20,879 Speaker 1: And it works both in in low and high level 358 00:21:21,560 --> 00:21:25,440 Speaker 1: light environments. Which that's important too, because some sometimes you're 359 00:21:25,440 --> 00:21:27,680 Speaker 1: in an environment where you're gonna have more light than 360 00:21:28,359 --> 00:21:31,560 Speaker 1: uh than Well, let's take two separate nights. Okay, we 361 00:21:31,640 --> 00:21:34,360 Speaker 1: have one night where let's say there's a lot of moonlight, Uh, 362 00:21:34,400 --> 00:21:37,800 Speaker 1: there's starlight. There might even be some some lights set 363 00:21:37,880 --> 00:21:40,640 Speaker 1: up in whatever it is you're looking at, Like let's 364 00:21:40,640 --> 00:21:43,000 Speaker 1: say it's an enemy encampment. Let's say you're sniper looking 365 00:21:43,040 --> 00:21:46,560 Speaker 1: at an enemy encampment. Uh. If you're using a device 366 00:21:46,640 --> 00:21:50,439 Speaker 1: that's meant for low light environments, you might not be 367 00:21:50,480 --> 00:21:53,280 Speaker 1: able to see anything anyway because all of that light 368 00:21:53,359 --> 00:21:56,200 Speaker 1: just overwhelms the device, and so you all you see 369 00:21:56,240 --> 00:22:00,160 Speaker 1: is just a big green screen. Uh. So you need 370 00:22:00,200 --> 00:22:02,640 Speaker 1: to have one that can work in both kinds of situations. 371 00:22:03,200 --> 00:22:09,240 Speaker 1: UM So, Yeah, that's your basic that's your basic uh 372 00:22:09,480 --> 00:22:14,080 Speaker 1: image enhancement style night vision. Now, I guess we can 373 00:22:14,119 --> 00:22:20,440 Speaker 1: move on to the the thermal devices, which again can 374 00:22:20,640 --> 00:22:23,840 Speaker 1: look at you can look at stuff and see the 375 00:22:23,960 --> 00:22:27,120 Speaker 1: energy it's giving off, the light it's giving off even 376 00:22:27,160 --> 00:22:30,800 Speaker 1: though light, uh, an outside source of light isn't necessarily 377 00:22:30,840 --> 00:22:34,679 Speaker 1: present m and this has to and this involves the 378 00:22:34,720 --> 00:22:38,639 Speaker 1: whole concept of excitation. Yeah. Yeah, Now you have to 379 00:22:38,680 --> 00:22:42,880 Speaker 1: have a special type of lens to use when you're 380 00:22:42,880 --> 00:22:47,200 Speaker 1: working with thermal imaging, basically to identify the infrared light. 381 00:22:47,240 --> 00:22:49,920 Speaker 1: And you've got to uh, what happens is once the 382 00:22:50,000 --> 00:22:53,359 Speaker 1: light is focused through the lens um, a phased array 383 00:22:53,440 --> 00:22:58,639 Speaker 1: of infrared detector elements scans it um basically trying to 384 00:22:58,680 --> 00:23:02,159 Speaker 1: create a dn called a thermogram, which shows you the 385 00:23:02,200 --> 00:23:06,600 Speaker 1: different ranges in temperature um. And this can be done 386 00:23:06,640 --> 00:23:13,159 Speaker 1: pretty quickly, about on a second, So like okays a 387 00:23:13,240 --> 00:23:16,480 Speaker 1: second essentially, yeah, and concerning that film is twenty four 388 00:23:16,560 --> 00:23:18,960 Speaker 1: frames a second. That is that's fast. Yeah, It's fast 389 00:23:19,040 --> 00:23:21,119 Speaker 1: enough so that you can get a good view. So 390 00:23:21,160 --> 00:23:23,920 Speaker 1: even if something's in motion, you should be able to 391 00:23:23,960 --> 00:23:26,560 Speaker 1: get a pretty good view of it. Yeah. And then 392 00:23:26,640 --> 00:23:30,320 Speaker 1: and then very much like the other style. It creates 393 00:23:30,600 --> 00:23:34,680 Speaker 1: a thermogram UH and then translates it into UH an 394 00:23:34,680 --> 00:23:38,160 Speaker 1: electric impulse UM just like that, and then it's sent 395 00:23:38,200 --> 00:23:43,280 Speaker 1: to a signal processing unit which is basically UH electronic 396 00:23:43,880 --> 00:23:50,160 Speaker 1: circuit board UM, and UH. Instead of converting electrons to photons, 397 00:23:50,240 --> 00:23:56,160 Speaker 1: it actually creates display of information UM. So it's more 398 00:23:56,200 --> 00:23:59,560 Speaker 1: like a computer than it is UH. An ocular system 399 00:23:59,600 --> 00:24:01,520 Speaker 1: with the Yeah, you wouldn't have a lens. You would 400 00:24:01,520 --> 00:24:03,520 Speaker 1: have a monitor of some site, some type. Now that 401 00:24:03,600 --> 00:24:08,040 Speaker 1: monitor might be small, so it could be a monitory. Yeah, 402 00:24:08,040 --> 00:24:12,480 Speaker 1: it could even fit into a headset or or binoculars 403 00:24:12,520 --> 00:24:15,320 Speaker 1: or whatever. Um. Yeah, this is the what I was 404 00:24:15,359 --> 00:24:18,120 Speaker 1: talking about with the the documentary Predator, where you've got 405 00:24:18,160 --> 00:24:22,640 Speaker 1: the different colors representing different temperatures. So if you've ever 406 00:24:22,680 --> 00:24:28,679 Speaker 1: watched any ghost hunting shows where they use thermal detectors 407 00:24:28,680 --> 00:24:32,040 Speaker 1: to try and see if there are cold or warm spots, 408 00:24:32,520 --> 00:24:35,359 Speaker 1: that's what they're using. By the way, just so just 409 00:24:35,680 --> 00:24:39,639 Speaker 1: side note, the air can actually retain heat for a 410 00:24:39,680 --> 00:24:42,119 Speaker 1: good amount of time. So let's say that you're with 411 00:24:42,160 --> 00:24:44,760 Speaker 1: a big crew of people down in a cold basement 412 00:24:44,800 --> 00:24:46,760 Speaker 1: and you've set up a bunch of lights and stuff, 413 00:24:47,160 --> 00:24:49,040 Speaker 1: and you're filming some things, and then you turn the 414 00:24:49,119 --> 00:24:51,399 Speaker 1: lights off and you go and you turn on the 415 00:24:51,400 --> 00:24:54,840 Speaker 1: thermal imaging detector and you see this hot spot in 416 00:24:54,880 --> 00:24:58,360 Speaker 1: the air that could possibly be generated by someone who 417 00:24:58,359 --> 00:25:00,520 Speaker 1: had been standing there for about five or ten minutes, 418 00:25:00,600 --> 00:25:02,880 Speaker 1: or even a light that have been turned on, not 419 00:25:02,960 --> 00:25:09,199 Speaker 1: necessarily a paranormal, uh ghostly presence. Okay, rent Over, I 420 00:25:09,280 --> 00:25:12,320 Speaker 1: was actually going to use Blue Thunder as an example. 421 00:25:12,840 --> 00:25:15,720 Speaker 1: Like they used to they would fly outside and hover 422 00:25:15,760 --> 00:25:18,560 Speaker 1: outside the window and they could see the shapes where 423 00:25:18,560 --> 00:25:21,159 Speaker 1: people were, Which is funny because when you when you 424 00:25:21,200 --> 00:25:24,960 Speaker 1: mentioned it like that and the movies and TV uh, 425 00:25:25,080 --> 00:25:28,040 Speaker 1: when a person moves across the room, the heat stay, 426 00:25:28,200 --> 00:25:31,080 Speaker 1: you know, stays with the person. It makes very identifiable 427 00:25:31,200 --> 00:25:36,119 Speaker 1: human shape. It's very very much defined to that particular shape. 428 00:25:36,160 --> 00:25:39,640 Speaker 1: It seems like in the case of since the air 429 00:25:39,720 --> 00:25:41,480 Speaker 1: can retain heat, it seems like they would leave a 430 00:25:41,520 --> 00:25:45,719 Speaker 1: trail of some Yeah, depending on how residual pattern as 431 00:25:45,800 --> 00:25:48,040 Speaker 1: much as the roadrunner does with a little cloud of 432 00:25:48,119 --> 00:25:50,479 Speaker 1: dust when it takes off. Well, if you're if you're moving, 433 00:25:50,600 --> 00:25:54,160 Speaker 1: if you're moving steadily through the environment, you're probably not 434 00:25:54,520 --> 00:25:57,120 Speaker 1: leaving much of a trail. But if you have been 435 00:25:57,200 --> 00:26:01,199 Speaker 1: staying in a position and then start moving, then it 436 00:26:01,200 --> 00:26:03,560 Speaker 1: wouldn't be so quick as to you wouldn't see like 437 00:26:03,640 --> 00:26:08,680 Speaker 1: a clearly human defined red shape, uh move from uh 438 00:26:08,840 --> 00:26:11,639 Speaker 1: from a position that had been standing in for like 439 00:26:12,040 --> 00:26:14,920 Speaker 1: twenty minutes and then move across the room. It wouldn't 440 00:26:15,760 --> 00:26:18,240 Speaker 1: you know, it wouldn't be in an immediate effect. You 441 00:26:18,240 --> 00:26:20,280 Speaker 1: would still be able to see at least the residual 442 00:26:20,320 --> 00:26:22,760 Speaker 1: heat that was left behind. Now it might be enough 443 00:26:22,800 --> 00:26:24,760 Speaker 1: so that you can clearly tell which one is the 444 00:26:24,840 --> 00:26:27,400 Speaker 1: human and which one's just the space that the human 445 00:26:27,520 --> 00:26:30,280 Speaker 1: was in, but it's not gonna be you know, just 446 00:26:30,640 --> 00:26:35,159 Speaker 1: totally clear cut. Um. So I'm sorry. I was just 447 00:26:35,200 --> 00:26:38,320 Speaker 1: gonna say. So if you're if you're looking at a 448 00:26:38,400 --> 00:26:42,480 Speaker 1: show and they're showing a colored image of you know, 449 00:26:42,760 --> 00:26:45,920 Speaker 1: night vision, basically that's thermal imaging. And if you're looking 450 00:26:45,960 --> 00:26:49,200 Speaker 1: at the monochromatic green screen version, that would be the image. 451 00:26:49,880 --> 00:26:51,960 Speaker 1: So you know now which one is which? Right, So 452 00:26:52,119 --> 00:26:55,400 Speaker 1: let's why are you able to see the heat? That's 453 00:26:55,440 --> 00:26:58,800 Speaker 1: the question. Well, let me let me talk about some 454 00:26:58,880 --> 00:27:01,640 Speaker 1: atoms here. Now you've probably heard us talk about how 455 00:27:01,680 --> 00:27:06,560 Speaker 1: atoms are uh normally they're moving. It's really only if 456 00:27:06,560 --> 00:27:09,840 Speaker 1: you're at zero kelvin when you have no molecular movement, 457 00:27:09,840 --> 00:27:13,120 Speaker 1: when you have no movement on the atomic scale, absolutely, 458 00:27:13,680 --> 00:27:19,800 Speaker 1: thank you, absolute zero. Yes, uh, Because atoms are always moving, 459 00:27:19,840 --> 00:27:24,080 Speaker 1: even in in solid material like a block of marble. 460 00:27:24,640 --> 00:27:28,600 Speaker 1: The atoms within that block of marble are moving. They're 461 00:27:28,640 --> 00:27:32,720 Speaker 1: not moving necessarily at the same speed as say, uh, 462 00:27:32,720 --> 00:27:38,400 Speaker 1: oxygen gas is moving, but they are moving. And atoms 463 00:27:38,440 --> 00:27:42,560 Speaker 1: have a specific state, an energy state that they are 464 00:27:43,240 --> 00:27:46,600 Speaker 1: naturally found in the ground state. No, no, not that 465 00:27:46,680 --> 00:27:50,119 Speaker 1: kind of state. The ground state is what we call it. 466 00:27:50,160 --> 00:27:52,240 Speaker 1: That's the ground state energy level. That's the amount of 467 00:27:52,280 --> 00:27:57,640 Speaker 1: energy and atom has normally if no other outside forces 468 00:27:57,800 --> 00:28:01,000 Speaker 1: or energies are acting upon it. So you've got the 469 00:28:01,000 --> 00:28:03,520 Speaker 1: ground state energy level. That's when all the electrons are 470 00:28:03,520 --> 00:28:08,600 Speaker 1: at their normal electron shell distances from the nucleus of 471 00:28:08,640 --> 00:28:12,720 Speaker 1: the atom. When you add energy to an atom, then 472 00:28:12,760 --> 00:28:16,200 Speaker 1: you excite the electrons until they start to have so 473 00:28:16,280 --> 00:28:20,919 Speaker 1: much energy that they'll pop into outer electron shells further 474 00:28:21,000 --> 00:28:24,119 Speaker 1: out from the nucleus, and the more energy you pour in, 475 00:28:24,240 --> 00:28:29,280 Speaker 1: the further out they get. Okay, so when you remove 476 00:28:29,440 --> 00:28:33,400 Speaker 1: that energy, when that energy is when the electrons get 477 00:28:33,400 --> 00:28:36,280 Speaker 1: to a point where the energy is is decreased enough 478 00:28:36,320 --> 00:28:39,120 Speaker 1: so that the electrons are going to go back toward 479 00:28:39,280 --> 00:28:43,160 Speaker 1: the nucleus. They have to give off some kind of 480 00:28:43,240 --> 00:28:45,920 Speaker 1: energy for that to happen, all right, So you think 481 00:28:45,920 --> 00:28:48,760 Speaker 1: of it almost like you have a a balloon and 482 00:28:48,880 --> 00:28:54,200 Speaker 1: you over inflate that balloon when you let out the uh, 483 00:28:54,320 --> 00:28:56,840 Speaker 1: the air, than that balloon is gonna deflate some. Right, 484 00:28:56,840 --> 00:28:59,720 Speaker 1: it's gonna come back down to a smaller size, and 485 00:28:59,720 --> 00:29:01,320 Speaker 1: if you keep it open, it's gonna go all the 486 00:29:01,360 --> 00:29:04,840 Speaker 1: way down to flat. Well, the electrons are gonna start 487 00:29:04,840 --> 00:29:08,400 Speaker 1: moving back towards the nucleus. They give off photons when 488 00:29:08,440 --> 00:29:12,360 Speaker 1: they do this, and depending upon the material uh that 489 00:29:12,600 --> 00:29:17,040 Speaker 1: in question, you'll get different different kinds of photons within 490 00:29:17,080 --> 00:29:19,960 Speaker 1: the spectrum of light. So some things are going to 491 00:29:20,000 --> 00:29:23,160 Speaker 1: give off light that is actually visible, especially if you 492 00:29:23,200 --> 00:29:26,160 Speaker 1: pour enough energy into it. That's why Let's say you've 493 00:29:26,160 --> 00:29:29,400 Speaker 1: got a toaster oven, and you got the toaster oven 494 00:29:29,440 --> 00:29:31,160 Speaker 1: going on full blast, and you look in and you 495 00:29:31,200 --> 00:29:35,200 Speaker 1: see the little toaster oven coils have turned red. That's 496 00:29:35,240 --> 00:29:38,560 Speaker 1: actually photons being given off by these atoms. And uh, 497 00:29:38,640 --> 00:29:40,680 Speaker 1: if you were to pour even more energy into it. 498 00:29:41,000 --> 00:29:43,520 Speaker 1: If you were to crank it up a notch, those 499 00:29:43,560 --> 00:29:47,800 Speaker 1: coils might start to glow even brighter and different colors. 500 00:29:47,800 --> 00:29:49,760 Speaker 1: So if they went from red to orange, that would 501 00:29:49,800 --> 00:29:52,720 Speaker 1: mean that you have even more energy that's being given off, 502 00:29:53,120 --> 00:29:55,480 Speaker 1: right that you've you've poured more into it, and it's 503 00:29:55,560 --> 00:30:01,880 Speaker 1: and it's giving off higher energy photons. So, uh, all materials, 504 00:30:01,920 --> 00:30:05,200 Speaker 1: all all things are giving off at least some kind 505 00:30:05,400 --> 00:30:09,000 Speaker 1: of photon energy when they because of the whole idea 506 00:30:09,000 --> 00:30:12,240 Speaker 1: of movement and excitation, and the more it gives off, 507 00:30:12,280 --> 00:30:16,120 Speaker 1: the brighter it's going to be. So that's that's what 508 00:30:16,360 --> 00:30:19,920 Speaker 1: the thermal night vision goggles are detecting when when they're 509 00:30:19,920 --> 00:30:21,960 Speaker 1: going when the lights being pulled through that lens, when 510 00:30:22,080 --> 00:30:25,280 Speaker 1: the lens is directing that light to the the sensors, 511 00:30:26,120 --> 00:30:29,440 Speaker 1: it's detecting the the photons that are given off, the 512 00:30:29,440 --> 00:30:33,080 Speaker 1: thermal infrared photons that are given off by things just 513 00:30:33,120 --> 00:30:37,160 Speaker 1: because of the excitation of atoms. So that's what we're 514 00:30:37,200 --> 00:30:39,240 Speaker 1: actually looking at. That's why you can be in a 515 00:30:39,320 --> 00:30:44,200 Speaker 1: completely isolated room. You could be in a cave deep 516 00:30:44,240 --> 00:30:47,920 Speaker 1: below the Earth's surface where there's there's no ambient light whatsoever, 517 00:30:47,960 --> 00:30:52,680 Speaker 1: and still be able to see based upon the what's 518 00:30:52,720 --> 00:30:57,720 Speaker 1: around you. Now, the less the less stuff gives off heat, 519 00:30:57,800 --> 00:30:59,720 Speaker 1: then the less you're gonna be able to see, the 520 00:30:59,800 --> 00:31:01,880 Speaker 1: less the less excitation is there. So if you're in 521 00:31:01,920 --> 00:31:04,640 Speaker 1: a cave where there's nothing else living in there, it 522 00:31:04,720 --> 00:31:07,640 Speaker 1: may you know, the thermal the thermal goggles may not 523 00:31:07,720 --> 00:31:09,760 Speaker 1: do you any good except to let you see where 524 00:31:09,800 --> 00:31:12,040 Speaker 1: your feet are in relation to the rest of you. 525 00:31:12,360 --> 00:31:16,480 Speaker 1: So that might be more useful to carry, say a flashlight. Yes, yes, 526 00:31:16,560 --> 00:31:19,720 Speaker 1: that might be a good idea. To carry a flashlight 527 00:31:19,760 --> 00:31:24,320 Speaker 1: or a head lamp even better. And um, yeah, so 528 00:31:24,560 --> 00:31:28,280 Speaker 1: that's kind of the basics of night vision. It's pretty 529 00:31:28,280 --> 00:31:30,520 Speaker 1: cool stuff. I don't know, have you ever had an 530 00:31:30,520 --> 00:31:34,120 Speaker 1: opportunity to actually look through any sort of night vision stuff? No, 531 00:31:34,240 --> 00:31:36,760 Speaker 1: not really, I just haven't been exposed to it. Um. 532 00:31:37,360 --> 00:31:39,080 Speaker 1: But you can use it for all kinds of different things. 533 00:31:39,120 --> 00:31:42,960 Speaker 1: Of course, the military applications are obvious. Um. But you 534 00:31:42,960 --> 00:31:47,800 Speaker 1: can use it for uh, you know, photography, Um, for spelunking. 535 00:31:48,000 --> 00:31:51,920 Speaker 1: You know, that was an excellent uh suggestion, you know, 536 00:31:52,040 --> 00:31:53,880 Speaker 1: all kinds of sports and things where you might be 537 00:31:53,920 --> 00:31:56,320 Speaker 1: out hunting, you know, out in the woods. There are 538 00:31:56,320 --> 00:31:58,320 Speaker 1: a lot of cam quarters out there that have it. Now, 539 00:31:58,520 --> 00:32:03,560 Speaker 1: there's also cars that have UH displays that include night 540 00:32:03,720 --> 00:32:07,480 Speaker 1: vision UH a night vision element so that you can 541 00:32:07,880 --> 00:32:10,520 Speaker 1: see better when you're driving a night and and they're 542 00:32:10,560 --> 00:32:13,800 Speaker 1: in fact cars that use different versions of it. There's 543 00:32:13,840 --> 00:32:17,280 Speaker 1: some that use the thermal version where they're really detecting 544 00:32:17,320 --> 00:32:19,920 Speaker 1: the heat of things so that you can get an 545 00:32:19,960 --> 00:32:21,840 Speaker 1: idea if there's something in the road like a person 546 00:32:21,960 --> 00:32:25,280 Speaker 1: or an animal, but those are only gonna show you 547 00:32:25,360 --> 00:32:29,360 Speaker 1: things that are again active really uh. Then there are 548 00:32:29,400 --> 00:32:34,960 Speaker 1: other kinds that use the the the image enhancement style UM. 549 00:32:35,000 --> 00:32:37,200 Speaker 1: And there are even some that use the active image 550 00:32:37,280 --> 00:32:39,680 Speaker 1: enhancement so when you turn on your head lights, you're 551 00:32:39,680 --> 00:32:43,320 Speaker 1: actually beaming not just visible light, but infrared rays as well, 552 00:32:43,720 --> 00:32:48,760 Speaker 1: infrared radiation. So uh, the the system and those cars 553 00:32:48,800 --> 00:32:51,280 Speaker 1: picks up the reflection just like we were talking about 554 00:32:51,360 --> 00:32:55,160 Speaker 1: in the generation zero image enhancement night vision. He uses 555 00:32:55,200 --> 00:32:59,000 Speaker 1: that same principle. Now that of course means that the 556 00:32:59,120 --> 00:33:01,480 Speaker 1: range is limited, just as we were talking about earlier, 557 00:33:02,000 --> 00:33:05,280 Speaker 1: and if it's a foggy night, it doesn't work so 558 00:33:05,320 --> 00:33:09,240 Speaker 1: well because the fog will reflect that the that radiation 559 00:33:09,280 --> 00:33:13,200 Speaker 1: back before it can hit something more substantial, so you'll 560 00:33:13,240 --> 00:33:15,720 Speaker 1: just end up it's just like fog. Right, It's just 561 00:33:15,800 --> 00:33:18,760 Speaker 1: like if you were to put your high beams on 562 00:33:18,840 --> 00:33:22,680 Speaker 1: the fog bank, it's like out there. Yeah. Yeah, And 563 00:33:22,680 --> 00:33:25,240 Speaker 1: and in that case, the night vision might not help 564 00:33:25,280 --> 00:33:26,680 Speaker 1: you out unless you have well, if you have a 565 00:33:26,720 --> 00:33:31,040 Speaker 1: thermal one it it might, but the the the image 566 00:33:31,120 --> 00:33:35,120 Speaker 1: enhancement style not so not so useful in that situation. Yeah. 567 00:33:35,200 --> 00:33:38,320 Speaker 1: I've also read that they're looking into the possibility of 568 00:33:38,360 --> 00:33:42,960 Speaker 1: adding it to some smartphones, which would be interesting. Um. 569 00:33:43,080 --> 00:33:47,600 Speaker 1: I've definitely seen the overlays where it's not it's not 570 00:33:47,760 --> 00:33:51,280 Speaker 1: actual thermal imaging, but it is. Yeah, it's the it's 571 00:33:51,320 --> 00:33:53,360 Speaker 1: just the you know, all it does is all it 572 00:33:53,400 --> 00:33:56,160 Speaker 1: does is simulate thermal imaging so that it overlays all 573 00:33:56,160 --> 00:34:00,280 Speaker 1: these bright hypercolors on top of an image. Still have 574 00:34:00,280 --> 00:34:03,480 Speaker 1: a hypercolor shirt? Do you? Does it work? Not anymore? 575 00:34:03,480 --> 00:34:06,760 Speaker 1: I don't think So that's for another podcast. We'll have 576 00:34:06,800 --> 00:34:10,799 Speaker 1: to do a whole podcast just on hypercolor. I've got 577 00:34:10,800 --> 00:34:14,160 Speaker 1: I've written an article about it. All right, guys, we're 578 00:34:14,160 --> 00:34:17,480 Speaker 1: gonna wrap this up. If you have suggestions for particular 579 00:34:17,600 --> 00:34:19,879 Speaker 1: kinds of technology that you would like us to tackle, 580 00:34:20,000 --> 00:34:23,239 Speaker 1: let us know. You can email us our addresses tex 581 00:34:23,320 --> 00:34:26,480 Speaker 1: stuff at how stuff works dot com, or drop us 582 00:34:26,480 --> 00:34:29,840 Speaker 1: a line on Facebook or Twitter. Are handle there is 583 00:34:29,960 --> 00:34:33,160 Speaker 1: tech Stuff hs W. Chris and I will talk to 584 00:34:33,200 --> 00:34:38,200 Speaker 1: you again really soon. Be sure to check out our 585 00:34:38,239 --> 00:34:41,600 Speaker 1: new video podcast, Stuff from the Future. Join how Stuff 586 00:34:41,600 --> 00:34:44,560 Speaker 1: Work staff as we explore the most promising and perplexing 587 00:34:44,600 --> 00:34:48,600 Speaker 1: possibilities of tomorrow. The house stuff Works. I fine app 588 00:34:48,640 --> 00:34:56,279 Speaker 1: has arrived. Download it today on iTunes, brought to you 589 00:34:56,320 --> 00:34:59,680 Speaker 1: by the reinvented two thousand twelve camera. It's ready. Are 590 00:34:59,719 --> 00:34:59,879 Speaker 1: you