1 00:00:04,120 --> 00:00:07,160 Speaker 1: Get in touch with technology with tech Stuff from how 2 00:00:07,200 --> 00:00:13,960 Speaker 1: stuff works dot Com. Hei there and welcome to tech Stuff. 3 00:00:13,960 --> 00:00:16,439 Speaker 1: I'm your host, Jonathan Strickland. I'm an executive producer and 4 00:00:16,480 --> 00:00:19,119 Speaker 1: I love all things tech and it is time for 5 00:00:19,160 --> 00:00:23,920 Speaker 1: another classic episode of tech Stuff. This episode originally aired 6 00:00:23,960 --> 00:00:28,960 Speaker 1: on November two thousand eleven. And Chris Pallette, my co 7 00:00:29,080 --> 00:00:31,479 Speaker 1: host and editor at the time, and I decided we 8 00:00:31,520 --> 00:00:33,479 Speaker 1: wanted to take a look at something that's kind of 9 00:00:33,520 --> 00:00:38,040 Speaker 1: hard to see, that is when it's actually being used. 10 00:00:38,040 --> 00:00:42,520 Speaker 1: I'm talking about night vision. How does the technology work? Well, 11 00:00:42,640 --> 00:00:44,640 Speaker 1: Chris and I found out and now you will to 12 00:00:45,200 --> 00:00:50,360 Speaker 1: enjoy this classic episode night Vision. The technology dates back 13 00:00:50,800 --> 00:00:54,960 Speaker 1: to the late thirties early forties. It was technology that 14 00:00:55,040 --> 00:00:58,520 Speaker 1: was developed during World War Two and used mainly by 15 00:00:58,560 --> 00:01:03,040 Speaker 1: the American, British, and and Soviet forces during World War Two, 16 00:01:03,120 --> 00:01:08,360 Speaker 1: although other nations began to to develop their own version 17 00:01:08,400 --> 00:01:11,240 Speaker 1: of night vision technology around the same time. Well, yeah, 18 00:01:11,240 --> 00:01:14,520 Speaker 1: the Germans, Uh, A lot of what we had as 19 00:01:14,600 --> 00:01:18,080 Speaker 1: far as our technology in the United States was based 20 00:01:18,120 --> 00:01:22,280 Speaker 1: on some German research that was done in the late thirties. UM. 21 00:01:23,000 --> 00:01:27,480 Speaker 1: And really what it comes down to, UM is the 22 00:01:27,520 --> 00:01:31,399 Speaker 1: spectrum of light that that you're trying to see. Yeah, 23 00:01:31,440 --> 00:01:35,600 Speaker 1: it's it's two different things. It's trying to accept other 24 00:01:35,920 --> 00:01:39,240 Speaker 1: parts of light that human eye is not able to detect, 25 00:01:39,319 --> 00:01:44,640 Speaker 1: and also to uh to amplify whatever little light is there. 26 00:01:44,680 --> 00:01:49,200 Speaker 1: There are two main ways of achieving a night vision 27 00:01:50,000 --> 00:01:54,920 Speaker 1: UH technology. One is called image enhancement, and that's where 28 00:01:54,960 --> 00:01:58,000 Speaker 1: you're taking the little amount of light that's out there 29 00:01:58,560 --> 00:02:01,960 Speaker 1: and UH and trying to amplify it so that you know, 30 00:02:02,040 --> 00:02:04,840 Speaker 1: you're able to see better in that environment. And the 31 00:02:04,880 --> 00:02:08,480 Speaker 1: other is thermal imaging, which is also you know, we 32 00:02:08,600 --> 00:02:11,600 Speaker 1: think of that as being able to see heat. You know, 33 00:02:11,639 --> 00:02:14,000 Speaker 1: the whole idea about like if you've ever seen that 34 00:02:14,080 --> 00:02:19,680 Speaker 1: documentary Predator, Yeah, the Predator actually uses both forms of this, 35 00:02:20,480 --> 00:02:22,799 Speaker 1: but the thermal imaging would be the one where it 36 00:02:22,919 --> 00:02:26,000 Speaker 1: switches and it's that really colorful display where the hotter 37 00:02:26,240 --> 00:02:29,120 Speaker 1: things in the field of vision are a brighter color, 38 00:02:29,280 --> 00:02:32,919 Speaker 1: usually red, uh, and then the cooler things are are 39 00:02:33,480 --> 00:02:35,960 Speaker 1: in the other part of the spectrum of light, so 40 00:02:36,000 --> 00:02:38,600 Speaker 1: they'd be you know, if it's cold, it might be black, 41 00:02:38,680 --> 00:02:41,360 Speaker 1: but if it's cooler, it might be blue or even 42 00:02:41,560 --> 00:02:44,840 Speaker 1: kind of an indigo color. Um. Both of those are 43 00:02:44,880 --> 00:02:48,320 Speaker 1: ways of achieving night vision. The I think the one 44 00:02:48,360 --> 00:02:50,360 Speaker 1: that most people think of when they think of night 45 00:02:50,440 --> 00:02:54,720 Speaker 1: vision is the one where you've got the greenish uh display. 46 00:02:54,840 --> 00:02:59,520 Speaker 1: That's the image enhancement approach, and well, you know that 47 00:02:59,520 --> 00:03:02,400 Speaker 1: that's I think that's the reason people think about it 48 00:03:02,440 --> 00:03:06,520 Speaker 1: is because it's used that way in TV in the movies. Yeah, 49 00:03:06,639 --> 00:03:11,760 Speaker 1: probably so as a visual clue to the viewer that hey, 50 00:03:11,800 --> 00:03:15,320 Speaker 1: we're doing something that you can't normally do, right, Yeah. 51 00:03:15,360 --> 00:03:18,160 Speaker 1: I In fact, I watched a movie just last night 52 00:03:18,320 --> 00:03:23,040 Speaker 1: that involved having a night vision the screen tinged night vision, 53 00:03:23,120 --> 00:03:25,200 Speaker 1: and it was and I'm not going to call it 54 00:03:25,240 --> 00:03:28,519 Speaker 1: the documentary because that's how much of a skeptic I am. 55 00:03:28,680 --> 00:03:31,840 Speaker 1: It was paranormal activity too, and uh, you know in 56 00:03:31,880 --> 00:03:36,720 Speaker 1: paranormal activity those movies, those are done as found footage movies, which, 57 00:03:37,040 --> 00:03:39,040 Speaker 1: in case you're not familiar with the term, that's the 58 00:03:39,080 --> 00:03:41,760 Speaker 1: idea where the film is presented as if it were 59 00:03:42,320 --> 00:03:47,800 Speaker 1: uh collection of clips taken from various cameras. That it 60 00:03:47,880 --> 00:03:50,400 Speaker 1: wasn't meant to be a feature film. It was supposed 61 00:03:50,440 --> 00:03:55,120 Speaker 1: to be actual footage shot of something, right. So clover 62 00:03:55,200 --> 00:03:58,760 Speaker 1: Field is another example, or Blair Witch Project's another example, Yes, 63 00:03:58,800 --> 00:04:00,080 Speaker 1: that's the first time I thought about. Yeah, and that 64 00:04:00,160 --> 00:04:03,400 Speaker 1: it's really popular with the horror crowd. Uh and uh 65 00:04:03,600 --> 00:04:07,360 Speaker 1: so the paranormal activity too. There's one of the cameras 66 00:04:07,400 --> 00:04:09,760 Speaker 1: that is being used in that has a night vision 67 00:04:09,760 --> 00:04:13,640 Speaker 1: setting and it's using the image enhancement approach. By the way, 68 00:04:13,640 --> 00:04:18,080 Speaker 1: in case you're curious about why green, the the answer 69 00:04:18,200 --> 00:04:20,800 Speaker 1: I found through my research was that the reason why 70 00:04:20,800 --> 00:04:26,000 Speaker 1: you get green images is not because of any technological limitation. 71 00:04:26,560 --> 00:04:29,280 Speaker 1: It's because if you're in an environment where you're using 72 00:04:29,400 --> 00:04:31,960 Speaker 1: night vision, you want to be able to switch between 73 00:04:32,040 --> 00:04:35,279 Speaker 1: night vision and your normal vision as quickly as possible. 74 00:04:35,480 --> 00:04:38,760 Speaker 1: But if you use really intense light and and some 75 00:04:38,880 --> 00:04:43,240 Speaker 1: of the brighter lights, your pupils will constrict as you're 76 00:04:43,240 --> 00:04:44,960 Speaker 1: looking at it, which means when you take the night 77 00:04:45,040 --> 00:04:47,039 Speaker 1: vision glasses off, it's going to take more time for 78 00:04:47,080 --> 00:04:50,120 Speaker 1: your eyes to readjust to the darkness around you. But 79 00:04:50,200 --> 00:04:52,800 Speaker 1: the green that is used is a more subtle light, 80 00:04:53,200 --> 00:04:57,760 Speaker 1: and so your your pupils are remain mostly dilated, so 81 00:04:57,800 --> 00:05:00,040 Speaker 1: when you remove the night vision goggles, you don't of 82 00:05:00,120 --> 00:05:02,440 Speaker 1: as long a time to adjust. It doesn't take as 83 00:05:02,440 --> 00:05:04,800 Speaker 1: long for you to adjust to night regular night vision 84 00:05:04,960 --> 00:05:09,560 Speaker 1: like our natural night vision. Uh when you when you 85 00:05:09,640 --> 00:05:11,680 Speaker 1: go back and forth, and that kind of makes sense 86 00:05:11,680 --> 00:05:13,599 Speaker 1: to me. I mean, if you especially when you consider 87 00:05:13,680 --> 00:05:18,320 Speaker 1: that night vision was really originally used as a military technology, 88 00:05:18,600 --> 00:05:20,400 Speaker 1: you would want to be able to have as much 89 00:05:20,520 --> 00:05:23,919 Speaker 1: versatility and flexibility as possible so that you can adapt 90 00:05:23,920 --> 00:05:27,200 Speaker 1: to whatever the situation calls for. Yeah, that makes absolute 91 00:05:27,200 --> 00:05:30,120 Speaker 1: sense to me. So yeah, so at least according to that, 92 00:05:30,440 --> 00:05:34,760 Speaker 1: we could in theory have night vision where it's any color. Uh. 93 00:05:34,839 --> 00:05:39,320 Speaker 1: You know, it probably still probably be monochromatic, but we'll 94 00:05:39,320 --> 00:05:40,880 Speaker 1: get into that when we get into the you know 95 00:05:40,920 --> 00:05:44,480 Speaker 1: exactly what's happening. So so, all the different kinds of 96 00:05:44,560 --> 00:05:48,920 Speaker 1: night vision lie at least somewhat on the infrared, uh, 97 00:05:49,200 --> 00:05:52,120 Speaker 1: part of the spectrum of light, right, and that infrared 98 00:05:52,160 --> 00:05:57,000 Speaker 1: spectrum of light is outside the range of uh, the 99 00:05:57,240 --> 00:06:01,160 Speaker 1: visible light spectrum. UM. In fact, there are three parts 100 00:06:01,279 --> 00:06:05,000 Speaker 1: to the infrared spectrum, which is near infrared, and that's 101 00:06:05,040 --> 00:06:09,640 Speaker 1: the closest one to the visible spectrum spectrum. Yes, I 102 00:06:09,680 --> 00:06:13,920 Speaker 1: can say that word mid infrared um and that has uh. 103 00:06:14,160 --> 00:06:17,440 Speaker 1: I didn't mention the wavelengths. The wavelengths for near infrared 104 00:06:17,480 --> 00:06:21,520 Speaker 1: are from point seven to one point three microns um. 105 00:06:21,720 --> 00:06:25,240 Speaker 1: Mid infrared has wavelengths from one point three to three 106 00:06:25,279 --> 00:06:31,240 Speaker 1: microns um, and then thermal infrared, which is the biggest 107 00:06:31,240 --> 00:06:35,000 Speaker 1: part of the infrared spectrum, and that's from three to 108 00:06:35,320 --> 00:06:38,640 Speaker 1: more than thirty microns. Yeah, and so the the thermal 109 00:06:38,720 --> 00:06:46,440 Speaker 1: infrared you're talking at that point about infrared radiation really yeah, heat, 110 00:06:46,839 --> 00:06:49,320 Speaker 1: in other words, is what's kind of how we perceive 111 00:06:49,400 --> 00:06:53,000 Speaker 1: it usually. But uh, that's something that's actually given off 112 00:06:53,120 --> 00:06:57,240 Speaker 1: by an object itself, Whereas when we're talking about visible light, 113 00:06:57,680 --> 00:07:00,760 Speaker 1: that's something that's reflected off of an object. Right. So 114 00:07:01,120 --> 00:07:04,400 Speaker 1: if if I'm looking at a tree in sunlight, what 115 00:07:04,480 --> 00:07:07,320 Speaker 1: I'm seeing is the light being reflected off of that tree, 116 00:07:07,520 --> 00:07:10,440 Speaker 1: it's that lights hitting my eyes then going through the 117 00:07:10,440 --> 00:07:13,720 Speaker 1: whole focal point getting into my brain and somewhere up 118 00:07:13,720 --> 00:07:16,480 Speaker 1: there in yeah, somewhere up there in the gray matter, 119 00:07:16,840 --> 00:07:21,360 Speaker 1: my brain says, Hello, there's a tree, possibly a large 120 00:07:22,760 --> 00:07:27,560 Speaker 1: a large. Um. I recognize that from very far away. Yes, 121 00:07:28,120 --> 00:07:30,760 Speaker 1: that's how to recognize trees from very far away, quite 122 00:07:30,760 --> 00:07:34,240 Speaker 1: a long way away. Yeah, So that's how that would 123 00:07:34,280 --> 00:07:37,760 Speaker 1: normally work with thermal infrared. If I were to see 124 00:07:37,800 --> 00:07:40,640 Speaker 1: an object using thermal infrared. Let's say that somehow I 125 00:07:40,760 --> 00:07:43,400 Speaker 1: have that ability. You know, we're not talking about technology here, 126 00:07:43,400 --> 00:07:47,280 Speaker 1: but I somehow have the the the natural ability to 127 00:07:47,400 --> 00:07:50,000 Speaker 1: see the thermal infrared. It happened when they shot him 128 00:07:50,000 --> 00:07:52,840 Speaker 1: into space and he was bombarded by cosmic waves while 129 00:07:52,840 --> 00:07:56,240 Speaker 1: we're really just pop culturing this all to heck and back. 130 00:07:56,560 --> 00:07:59,200 Speaker 1: So yeah, with the thermal infrared ability, I would be 131 00:07:59,240 --> 00:08:02,440 Speaker 1: able to see the energy that is being emitted by 132 00:08:02,520 --> 00:08:06,800 Speaker 1: any particular object. Um it's not necessarily light that's reflecting off. 133 00:08:06,880 --> 00:08:08,200 Speaker 1: In fact, there doesn't have to be any sort of 134 00:08:08,240 --> 00:08:11,320 Speaker 1: light source at all. It just so. And if I 135 00:08:11,360 --> 00:08:14,400 Speaker 1: were in a perfectly dark room and there was another 136 00:08:15,240 --> 00:08:19,160 Speaker 1: object there that's giving off heat, essentially, I would be 137 00:08:19,200 --> 00:08:21,480 Speaker 1: able to see it because I would be seeing in 138 00:08:21,520 --> 00:08:25,000 Speaker 1: that range even though there's no other light source coming in. 139 00:08:25,120 --> 00:08:29,320 Speaker 1: It would just be that I'm actually seeing that that energy. 140 00:08:29,360 --> 00:08:32,800 Speaker 1: Because we'll get into why, it's kind of interesting. Has 141 00:08:32,840 --> 00:08:39,320 Speaker 1: to do with excitation, but not good vibrations. Yeah, although 142 00:08:39,440 --> 00:08:42,760 Speaker 1: perhaps that lady was able. Never mind, So moving on, 143 00:08:43,600 --> 00:08:46,320 Speaker 1: I hope you guys are enjoying this classic episode so far. 144 00:08:46,480 --> 00:08:48,840 Speaker 1: We've got more to talk about, but first, let's take 145 00:08:48,880 --> 00:08:59,000 Speaker 1: a quick break to thank our sponsor. Before we get 146 00:08:59,040 --> 00:09:01,839 Speaker 1: into the whole atoms and thermal infrared, let's let's talk 147 00:09:01,880 --> 00:09:06,440 Speaker 1: about the image enhancement approach first, because that's the one 148 00:09:06,480 --> 00:09:11,400 Speaker 1: that's the most familiar and uh and it's kind of interesting. Um. 149 00:09:11,440 --> 00:09:15,320 Speaker 1: The way that it works currently is that you've got 150 00:09:15,360 --> 00:09:18,800 Speaker 1: you've got very basic parts to a particular kind of 151 00:09:18,920 --> 00:09:21,200 Speaker 1: night vision. You've got you've got your lens. That's where 152 00:09:21,240 --> 00:09:25,240 Speaker 1: the light is going through. The objective lens. Just a 153 00:09:25,800 --> 00:09:28,719 Speaker 1: lens that catches it's a lens. Yeah, it catches ambient light, 154 00:09:28,840 --> 00:09:32,800 Speaker 1: catches near infrared light. So this is the near infrared spectrum, 155 00:09:32,800 --> 00:09:37,319 Speaker 1: the light that's closest to the visible spectrum. Now that 156 00:09:37,440 --> 00:09:41,080 Speaker 1: light is sent to a tube, and that tube is 157 00:09:41,080 --> 00:09:46,000 Speaker 1: called the image intensive fire tube intense. Yeah, and the 158 00:09:46,160 --> 00:09:48,880 Speaker 1: drinking energy drinks all day and yeah. So you can 159 00:09:48,880 --> 00:09:50,800 Speaker 1: think of this tube. It's almost like a vacuum tube. 160 00:09:50,840 --> 00:09:52,559 Speaker 1: In fact, there it is, There is a vacuum in 161 00:09:52,640 --> 00:09:54,560 Speaker 1: side of it. So you think of this sort of 162 00:09:55,040 --> 00:09:58,560 Speaker 1: imagine a glass vial all right in the middle of 163 00:09:58,559 --> 00:10:01,000 Speaker 1: this glass vial or on one end of the class file, 164 00:10:01,000 --> 00:10:04,280 Speaker 1: you've got something called a photo cathode. Now, the photo 165 00:10:04,360 --> 00:10:09,240 Speaker 1: cathode takes photons. Those are those individual elements of energy 166 00:10:09,320 --> 00:10:12,680 Speaker 1: for light. Yes, and and those come in the entire 167 00:10:12,760 --> 00:10:16,800 Speaker 1: spectrum of light um so infrared. They're infrared photons, just 168 00:10:16,880 --> 00:10:21,600 Speaker 1: as there are visible light photons. So the photo cathode 169 00:10:22,320 --> 00:10:26,640 Speaker 1: converts photons into electrons. It's it's one of those. Uh 170 00:10:26,800 --> 00:10:30,079 Speaker 1: So it changes light into electricity essentially. Yeah, And if 171 00:10:30,080 --> 00:10:32,839 Speaker 1: you listen to our episode about high speed and low 172 00:10:32,840 --> 00:10:38,040 Speaker 1: speed photography, we talked about how there are certain types 173 00:10:38,120 --> 00:10:44,040 Speaker 1: of materials that when a photon strikes it, it causes 174 00:10:44,080 --> 00:10:47,840 Speaker 1: a reaction. That's the case here a photocathode. It's that's 175 00:10:47,880 --> 00:10:50,640 Speaker 1: the and that's how it behaves when a photon hits it. 176 00:10:50,640 --> 00:10:53,560 Speaker 1: It gives off an electron. Uh So, You've got the 177 00:10:53,559 --> 00:10:55,679 Speaker 1: photo cathode at one end of this tube, and that's 178 00:10:55,720 --> 00:10:58,040 Speaker 1: where the light that's being captured by the lens is 179 00:10:58,040 --> 00:11:01,560 Speaker 1: directed to the photo cathode. The electrons emitted by the 180 00:11:01,559 --> 00:11:04,199 Speaker 1: photo cathode then have to pass through what is called 181 00:11:04,280 --> 00:11:09,240 Speaker 1: a micro channel plate or m c P. That's a 182 00:11:09,240 --> 00:11:12,560 Speaker 1: little glass disc. Yeah, I see. I thought MCP was 183 00:11:12,600 --> 00:11:17,840 Speaker 1: the master control program. End of line. It is. Okay, However, 184 00:11:18,000 --> 00:11:20,839 Speaker 1: two different mcps well it was until Tron got hold 185 00:11:20,840 --> 00:11:24,520 Speaker 1: of it. That's right. So glass disc Tron m c P. 186 00:11:25,320 --> 00:11:28,600 Speaker 1: I'm sensing some convergence here as we Mentionedron again. Ye. 187 00:11:28,920 --> 00:11:31,720 Speaker 1: So anyway, you've got this glass little tiny glass disc 188 00:11:31,760 --> 00:11:34,920 Speaker 1: called a micro channel plate and has lots and lots 189 00:11:35,000 --> 00:11:37,480 Speaker 1: of channels. That's why it's called a micro channel plate. 190 00:11:37,520 --> 00:11:40,320 Speaker 1: Lots of channels that go through this plate. Okay, So 191 00:11:40,400 --> 00:11:42,840 Speaker 1: think of the plate. Think of it like a dish. 192 00:11:43,200 --> 00:11:45,520 Speaker 1: You got a dish, put it up on its side, 193 00:11:45,880 --> 00:11:47,720 Speaker 1: and it has a whole bunch of little holes drilled 194 00:11:47,720 --> 00:11:51,080 Speaker 1: in it. Now, those holes are what allow electrons to 195 00:11:51,120 --> 00:11:55,040 Speaker 1: pass through. But there's also an electrode on either side 196 00:11:55,080 --> 00:12:00,000 Speaker 1: of the dish. So electrons coming from the photo cathodes 197 00:12:00,120 --> 00:12:03,760 Speaker 1: strike one side of this micro channel plate and start 198 00:12:03,840 --> 00:12:06,280 Speaker 1: to go through one of the channels. And they're going 199 00:12:06,800 --> 00:12:10,240 Speaker 1: through in the same direction they came from the the 200 00:12:10,240 --> 00:12:15,559 Speaker 1: from the photo cathode uh section of this this uh 201 00:12:15,679 --> 00:12:21,120 Speaker 1: this image intensive ire tube. So the photon converts to electron. 202 00:12:21,160 --> 00:12:23,560 Speaker 1: Electron goes through this channel. As it goes through the channel, 203 00:12:23,840 --> 00:12:30,560 Speaker 1: it starts to actually set off a well a reaction. Yeah, 204 00:12:30,720 --> 00:12:34,559 Speaker 1: and it basically functions as a multiplier for the electrons. 205 00:12:34,559 --> 00:12:38,760 Speaker 1: It's called a cascaded secondary emission. So this is where 206 00:12:38,880 --> 00:12:42,440 Speaker 1: when electron collide collides with something inside that that channel, 207 00:12:42,720 --> 00:12:45,920 Speaker 1: it starts to set off other electrons, uh, down that 208 00:12:46,040 --> 00:12:49,079 Speaker 1: same pathway, And there's a voltage applied to those electrodes 209 00:12:49,080 --> 00:12:52,439 Speaker 1: that's channeling the electrons through that pathway, like that's why 210 00:12:52,480 --> 00:12:56,360 Speaker 1: they're going in that direction. So you've got more and 211 00:12:56,400 --> 00:12:59,880 Speaker 1: more electrons bouncing off of each other through these channels, 212 00:13:00,480 --> 00:13:04,319 Speaker 1: which means that you've you've created an amplifier. And uh, 213 00:13:04,679 --> 00:13:06,800 Speaker 1: if you guys want to know kind of like a 214 00:13:06,880 --> 00:13:10,199 Speaker 1: big picture way of what this might look like, imagine 215 00:13:10,360 --> 00:13:13,680 Speaker 1: having a h and you can see play of videos 216 00:13:13,679 --> 00:13:17,000 Speaker 1: of this on YouTube, But imagine having a big glass 217 00:13:17,000 --> 00:13:20,679 Speaker 1: container filled with mouse traps, and each mouse trap has 218 00:13:20,720 --> 00:13:23,280 Speaker 1: a ping pong ball set on it, and then you 219 00:13:23,360 --> 00:13:27,560 Speaker 1: drop a ping pong ball into the glass chamber and 220 00:13:27,640 --> 00:13:29,960 Speaker 1: that will set off a mouse trap, and as the 221 00:13:29,960 --> 00:13:32,120 Speaker 1: ping pong balls bounce around, they set off more and 222 00:13:32,160 --> 00:13:35,200 Speaker 1: more mouse traps, so soon the glass case, like within 223 00:13:35,240 --> 00:13:39,080 Speaker 1: a fraction of a second ball, the balls are bouncing everywhere. Right, 224 00:13:39,600 --> 00:13:42,040 Speaker 1: same sort of idea here with the micro channel plate, 225 00:13:42,040 --> 00:13:44,800 Speaker 1: except that we're talking on a sub atomic level, and 226 00:13:45,080 --> 00:13:48,839 Speaker 1: we're talking about something that's really channeled, really has a 227 00:13:48,960 --> 00:13:51,960 Speaker 1: firm direction. So instead of the electrons bouncing everywhere, they're 228 00:13:51,960 --> 00:13:55,280 Speaker 1: going in a very specific direction. Right now, when they 229 00:13:55,280 --> 00:13:57,560 Speaker 1: get to the other side of that micro channel plate, 230 00:13:57,840 --> 00:14:00,520 Speaker 1: you've got the electrons still traveling in this ame direction 231 00:14:00,559 --> 00:14:02,480 Speaker 1: they were when they came in on the front side, 232 00:14:02,960 --> 00:14:06,280 Speaker 1: but now there are way more electrons, right, just amplified 233 00:14:06,320 --> 00:14:11,840 Speaker 1: the number. The electrons then hit a screen that's coated 234 00:14:11,880 --> 00:14:16,840 Speaker 1: with phosphors. Now phosphors pos phosphors do the they're kind 235 00:14:16,840 --> 00:14:19,640 Speaker 1: of like the opposite of the photo cathode, right. They 236 00:14:19,680 --> 00:14:22,640 Speaker 1: take When the electron strikes the phosphor, they give off light. 237 00:14:23,280 --> 00:14:26,080 Speaker 1: So you're changing the electron back to a photo photon. Right. 238 00:14:26,120 --> 00:14:29,440 Speaker 1: But now, because there are more electrons coming through hitting 239 00:14:29,440 --> 00:14:32,200 Speaker 1: that phosphoor than they were coming in, the light that's 240 00:14:32,240 --> 00:14:35,960 Speaker 1: generated is much greater in intensity than the light that 241 00:14:36,080 --> 00:14:40,400 Speaker 1: was coming in. So you've amplified the light. Now that 242 00:14:40,760 --> 00:14:44,600 Speaker 1: information that light is sent to a viewer of some type. 243 00:14:44,720 --> 00:14:47,200 Speaker 1: It could just be a regular lens, which is usually 244 00:14:47,240 --> 00:14:50,000 Speaker 1: called the ocular lens, or it could be sent to 245 00:14:50,040 --> 00:14:53,360 Speaker 1: a monitor. So if you have a pair of night 246 00:14:53,440 --> 00:14:57,520 Speaker 1: vision goggles or a night vision scope. That's what you're seeing. 247 00:14:57,560 --> 00:15:01,520 Speaker 1: You're seeing that amplified light hitting the lens or the 248 00:15:01,920 --> 00:15:06,840 Speaker 1: Monitor's cool, it's pretty awesome, right, And again, this isn't 249 00:15:06,960 --> 00:15:10,360 Speaker 1: just the the visible light, the ambient visible light that's 250 00:15:10,400 --> 00:15:14,480 Speaker 1: out there, but also the infrared light. So um, because 251 00:15:14,480 --> 00:15:16,720 Speaker 1: those photons, you know it doesn't you know, the photons, 252 00:15:16,760 --> 00:15:21,040 Speaker 1: It doesn't matter if it's visible or not. UM. And uh, 253 00:15:21,440 --> 00:15:24,680 Speaker 1: the more light that's hitting certain areas, that the brighter 254 00:15:24,720 --> 00:15:27,800 Speaker 1: it's going to be for whatever it is you're looking at. 255 00:15:27,800 --> 00:15:31,480 Speaker 1: So if you're looking at something that's that's fairly reflective, um, 256 00:15:31,560 --> 00:15:35,320 Speaker 1: you're gonna be able to see it in higher definition 257 00:15:35,360 --> 00:15:39,080 Speaker 1: than you could with something that is not as reflective. Now, 258 00:15:39,120 --> 00:15:42,400 Speaker 1: there are different ways of actually achieving this too. You 259 00:15:42,440 --> 00:15:48,720 Speaker 1: can have a various they're various generations of this technology, 260 00:15:48,760 --> 00:15:53,600 Speaker 1: all right. So the earliest generation of this technology actually 261 00:15:53,680 --> 00:15:59,120 Speaker 1: involved shining infrared light at the objects you're looking at 262 00:15:59,200 --> 00:16:02,200 Speaker 1: through the through the night vision goggles, right, So when 263 00:16:02,240 --> 00:16:05,360 Speaker 1: that that infrared light was reflected, then you would be 264 00:16:05,400 --> 00:16:08,880 Speaker 1: able to see it, right, because these goggles were not 265 00:16:09,000 --> 00:16:11,520 Speaker 1: so sensitive as to be able to take just the 266 00:16:11,600 --> 00:16:14,480 Speaker 1: ambient light. Right, if you did that, you would probably 267 00:16:14,480 --> 00:16:17,080 Speaker 1: get you you might be able to see marginally better 268 00:16:17,160 --> 00:16:20,360 Speaker 1: than you would if you had just use your regular vision. 269 00:16:20,760 --> 00:16:26,120 Speaker 1: But using this infrared flashlight, essentially you could illuminate the 270 00:16:27,080 --> 00:16:28,920 Speaker 1: scene and be able to see it through the night 271 00:16:28,960 --> 00:16:31,320 Speaker 1: vision goggles. But if you did not have the goggles, 272 00:16:31,360 --> 00:16:35,760 Speaker 1: because infrared light falls outside the visible spectrum, any independent 273 00:16:35,800 --> 00:16:40,000 Speaker 1: observer wouldn't be able to tell what you were doing. Yeah, now, 274 00:16:40,440 --> 00:16:43,400 Speaker 1: I UM I did some research on the the US 275 00:16:43,800 --> 00:16:49,680 Speaker 1: military website about the history of of night vision and apparently, 276 00:16:50,200 --> 00:16:54,400 Speaker 1: um they sent about three hundred sniper scopes over to 277 00:16:54,440 --> 00:16:56,720 Speaker 1: be used in the Pacific theater during World War Two, 278 00:16:56,720 --> 00:16:59,960 Speaker 1: but they didn't get used very much because of the 279 00:17:00,040 --> 00:17:03,600 Speaker 1: way that the technology worked. Um they really could see 280 00:17:04,119 --> 00:17:07,239 Speaker 1: less than a hundred yards. Yeah, they weren't very effective, right, 281 00:17:07,280 --> 00:17:13,480 Speaker 1: because again, since it's dependent upon a reflected ray of 282 00:17:13,720 --> 00:17:17,080 Speaker 1: infrared light, if it's you know, the rays starting to 283 00:17:17,320 --> 00:17:19,960 Speaker 1: dispersees as it goes out, Right, it's not not a 284 00:17:20,119 --> 00:17:23,000 Speaker 1: not a concentrated like a laser beam. Yeah, it's not 285 00:17:23,040 --> 00:17:26,240 Speaker 1: a beam. It does disperse and diffuse as it goes out. 286 00:17:26,560 --> 00:17:29,840 Speaker 1: So the further away your target the less likely you're 287 00:17:29,880 --> 00:17:32,080 Speaker 1: going to be able to see it, and even with 288 00:17:32,160 --> 00:17:34,359 Speaker 1: a really really advanced version. That's, by the way, it's 289 00:17:34,400 --> 00:17:39,600 Speaker 1: called active infrared because you're actively beaming infrared radiation out 290 00:17:39,680 --> 00:17:43,200 Speaker 1: in order to try and see stuff coming back through 291 00:17:43,280 --> 00:17:50,160 Speaker 1: the monitors. Um if because because you're relying on that reflection, 292 00:17:50,200 --> 00:17:51,679 Speaker 1: if it's too far away, you're not gonna be all 293 00:17:51,720 --> 00:17:55,479 Speaker 1: se very well. So obviously a sniper rifle, where at 294 00:17:55,560 --> 00:17:57,480 Speaker 1: least in theory, you want to be able to put 295 00:17:57,520 --> 00:18:00,400 Speaker 1: your snipers at a good distance away from the targets 296 00:18:00,440 --> 00:18:03,480 Speaker 1: to maximize their effectiveness and minimize the chance that they 297 00:18:03,520 --> 00:18:06,960 Speaker 1: will be targeted. Um it doesn't. It's not so effective 298 00:18:07,000 --> 00:18:11,399 Speaker 1: if you know your your distance is cut down that dramatically. Yeah. Plus, 299 00:18:11,440 --> 00:18:15,960 Speaker 1: the first generation wasn't exactly um useful for someone like 300 00:18:16,000 --> 00:18:19,560 Speaker 1: a sniper, considering the batteries were huge and the i 301 00:18:19,760 --> 00:18:23,760 Speaker 1: R emitters had to be carried on flatbed trucks. It's 302 00:18:23,760 --> 00:18:26,000 Speaker 1: hard to put one of those up in a tree. Yeah. Yeah, 303 00:18:26,040 --> 00:18:29,240 Speaker 1: it turns out that also all of these are going 304 00:18:29,280 --> 00:18:32,320 Speaker 1: to involve having a power supply of some sort. But 305 00:18:33,000 --> 00:18:36,080 Speaker 1: for the active infrared it requires either more more energy 306 00:18:36,119 --> 00:18:38,960 Speaker 1: because you're not you're not just for your your actual 307 00:18:39,119 --> 00:18:41,960 Speaker 1: night vision device, whether it's a scope or goggles or whatever, 308 00:18:42,040 --> 00:18:45,399 Speaker 1: but also for the emitter. By the way, that generation 309 00:18:45,560 --> 00:18:49,639 Speaker 1: is normally referred to as generation zero for a night vision. 310 00:18:50,160 --> 00:18:56,240 Speaker 1: Generation one was the first generation using passive infrared system. Now, 311 00:18:56,280 --> 00:18:59,480 Speaker 1: this was the kind of of night vision goggles or 312 00:18:59,720 --> 00:19:03,240 Speaker 1: scope that could just use the ambient light in the area, 313 00:19:03,280 --> 00:19:06,439 Speaker 1: although it needed a good amount of the ambient light. 314 00:19:06,560 --> 00:19:11,160 Speaker 1: So moonlight or starlight. It's funny you should say starlight. Yeah, 315 00:19:11,200 --> 00:19:12,560 Speaker 1: that's what it was called. Yea in the U. S. 316 00:19:12,680 --> 00:19:17,760 Speaker 1: Army they called it starlight. Uh, the without the moon 317 00:19:17,920 --> 00:19:19,880 Speaker 1: or stars, you wouldn't be able to see very much. 318 00:19:19,880 --> 00:19:23,440 Speaker 1: So on an overcast night it would not be terribly useful. Yeah, 319 00:19:23,480 --> 00:19:25,680 Speaker 1: but on a clear day you could see forever. You 320 00:19:26,080 --> 00:19:29,520 Speaker 1: got a clear day, you don't need night vision. Okay, 321 00:19:29,840 --> 00:19:35,639 Speaker 1: starlight first star I see tonight. Um, so yeah, it 322 00:19:35,720 --> 00:19:39,359 Speaker 1: was better than Generation zero. Still still pretty far acry 323 00:19:39,400 --> 00:19:43,240 Speaker 1: from what we have today. Although interestingly, if you were 324 00:19:43,320 --> 00:19:45,960 Speaker 1: to go out and buy a pair of night vision goggles, 325 00:19:46,000 --> 00:19:51,520 Speaker 1: you know, a consumer brand version would probably be Generation one, 326 00:19:51,760 --> 00:19:54,840 Speaker 1: I would guess, you know that's the military tends to 327 00:19:54,880 --> 00:20:00,399 Speaker 1: reserve the more the more advanced forms generations. It's they 328 00:20:00,400 --> 00:20:03,760 Speaker 1: could be generation two as well. Generation two where they 329 00:20:04,359 --> 00:20:07,800 Speaker 1: had better UH image intensive fire tubes, which meant that 330 00:20:07,840 --> 00:20:11,840 Speaker 1: they could use them in extreme low light conditions. So 331 00:20:12,080 --> 00:20:14,440 Speaker 1: on a moonless night, you could use these and it 332 00:20:14,480 --> 00:20:17,680 Speaker 1: would be strong enough to be able to to amplify 333 00:20:17,720 --> 00:20:20,440 Speaker 1: that light. So you can see. Generation three is what 334 00:20:20,680 --> 00:20:24,120 Speaker 1: you can find in the U. S Military now, UM, 335 00:20:24,160 --> 00:20:27,639 Speaker 1: and that is they used a new kind of photo 336 00:20:27,680 --> 00:20:30,840 Speaker 1: cathode called gallium arsenide, so it's even more sensitive than 337 00:20:30,880 --> 00:20:33,560 Speaker 1: the previous ones, which means that you know, it's it's 338 00:20:33,600 --> 00:20:37,480 Speaker 1: not that the UH they've really advanced the technology that much. 339 00:20:37,520 --> 00:20:41,520 Speaker 1: They just found a material that that emits electrons much 340 00:20:41,520 --> 00:20:44,240 Speaker 1: more readily than others. Yeah. As a matter of fact, 341 00:20:44,280 --> 00:20:46,320 Speaker 1: I believe we talked about gallium arsenid when we talked 342 00:20:46,320 --> 00:20:49,359 Speaker 1: about transistors. I believe we did some months back. Yeah, 343 00:20:49,520 --> 00:20:54,000 Speaker 1: and then we have generation four, which is yet more 344 00:20:54,080 --> 00:20:58,200 Speaker 1: improvements UH and it works both in UH in low 345 00:20:58,280 --> 00:21:02,200 Speaker 1: and high level light environments, which that's important too, because 346 00:21:02,200 --> 00:21:05,040 Speaker 1: some sometimes you're in an environment where you're gonna have 347 00:21:05,119 --> 00:21:09,000 Speaker 1: more light than UH than well, let's take two separate 348 00:21:09,119 --> 00:21:11,160 Speaker 1: nights Okay, we have one night where let's say there's 349 00:21:11,160 --> 00:21:13,880 Speaker 1: a lot of moonlight, Uh, there's starlight. There might even 350 00:21:13,880 --> 00:21:17,200 Speaker 1: be some some lights set up in whatever it is 351 00:21:17,240 --> 00:21:20,000 Speaker 1: you're looking at, Like let's say it's an enemy encampment. 352 00:21:20,040 --> 00:21:23,359 Speaker 1: Let's say you're sniper looking at an enemy encampment. Uh. 353 00:21:23,480 --> 00:21:27,880 Speaker 1: If you're using a device that's meant for low light environments, 354 00:21:28,080 --> 00:21:30,520 Speaker 1: you might not be able to see anything anyway, because 355 00:21:30,560 --> 00:21:33,560 Speaker 1: all of that light just overwhelms the device, and so 356 00:21:33,640 --> 00:21:35,239 Speaker 1: you all you see is just a big, you know, 357 00:21:35,440 --> 00:21:38,840 Speaker 1: green screen. Uh. So you need to have one that 358 00:21:38,880 --> 00:21:42,960 Speaker 1: can work in both kinds of situations. Um. So yeah, 359 00:21:43,000 --> 00:21:49,080 Speaker 1: that's your basic that's your basic. Uh. Image enhancement style 360 00:21:49,320 --> 00:21:52,360 Speaker 1: night vision. Chris and I are about to wrap up 361 00:21:52,400 --> 00:21:54,919 Speaker 1: this discussion about night vision, but before we get to that, 362 00:21:55,000 --> 00:22:05,880 Speaker 1: let's take another quick break to thank our sponsor. Now, 363 00:22:06,160 --> 00:22:11,399 Speaker 1: I guess we can move on to the the thermal devices, 364 00:22:11,440 --> 00:22:15,159 Speaker 1: which again can look at you can look at stuff 365 00:22:15,880 --> 00:22:18,560 Speaker 1: and see the energy it's giving off, the light it's 366 00:22:18,600 --> 00:22:22,000 Speaker 1: giving off even though light uh, an outside source of 367 00:22:22,080 --> 00:22:26,800 Speaker 1: light isn't necessarily present. M And this has to this 368 00:22:26,880 --> 00:22:31,040 Speaker 1: involves the whole concept of excitation. Yeah, yeah, Now, you 369 00:22:31,080 --> 00:22:34,080 Speaker 1: have to have a special type of lens to use 370 00:22:35,200 --> 00:22:39,160 Speaker 1: when you're working with thermal imaging basically to identify the 371 00:22:39,200 --> 00:22:42,520 Speaker 1: infrared light. And you've got to what happens is once 372 00:22:42,560 --> 00:22:45,640 Speaker 1: the light is focused through the lens, UM I phased 373 00:22:45,800 --> 00:22:51,200 Speaker 1: array of infrared detector elements scans it UM basically trying 374 00:22:51,240 --> 00:22:54,719 Speaker 1: to create a pattern called a thermogram, which shows you 375 00:22:54,800 --> 00:22:59,040 Speaker 1: the different ranges in temperature UM. And this can be 376 00:22:59,080 --> 00:23:02,800 Speaker 1: done pretty quickly, about one of a second. Yeah, so 377 00:23:03,600 --> 00:23:07,760 Speaker 1: like okay, thirty frames a second essentially, so yeah, and 378 00:23:07,760 --> 00:23:09,960 Speaker 1: considering that film is twenty four frames a second, that 379 00:23:10,080 --> 00:23:12,440 Speaker 1: is that's Yeah, it's fast enough so that you can 380 00:23:12,480 --> 00:23:15,200 Speaker 1: get a good view. So even if something's in motion, 381 00:23:15,920 --> 00:23:17,720 Speaker 1: you should be able to get a pretty good view 382 00:23:17,760 --> 00:23:20,520 Speaker 1: of it. Yeah. And then and then, very much like 383 00:23:21,000 --> 00:23:25,200 Speaker 1: the other style, it creates a thermogram UH and then 384 00:23:25,240 --> 00:23:30,000 Speaker 1: translates it into an electric impulse UM just like that, 385 00:23:30,080 --> 00:23:33,000 Speaker 1: and then it's sent to a signal processing unit which 386 00:23:33,040 --> 00:23:39,840 Speaker 1: is basically UH electronic circuit board UM and UH. Instead 387 00:23:39,960 --> 00:23:45,760 Speaker 1: of converting electrons to photons, it actually creates a display 388 00:23:45,920 --> 00:23:50,160 Speaker 1: of information UM. So it's more like a computer than 389 00:23:50,200 --> 00:23:53,120 Speaker 1: it is an ocular system with the other one. Yeah, 390 00:23:53,080 --> 00:23:54,760 Speaker 1: you wouldn't have a lens. You would have a monitor 391 00:23:54,800 --> 00:23:57,920 Speaker 1: of some site, some type. Now that motor might be small, Yeah, 392 00:23:58,160 --> 00:24:00,760 Speaker 1: so it could be a motor they then probably Yeah, 393 00:24:00,760 --> 00:24:05,160 Speaker 1: it could even fit into a headset or or binoculars 394 00:24:05,240 --> 00:24:08,000 Speaker 1: or whatever. Um. Yeah, this is the what I was 395 00:24:08,040 --> 00:24:10,800 Speaker 1: talking about with the the documentary Predator, where you've got 396 00:24:10,880 --> 00:24:15,360 Speaker 1: the different colors representing different temperatures. So if you've ever 397 00:24:15,359 --> 00:24:21,359 Speaker 1: watched any ghost hunting shows where they use thermal detectors 398 00:24:21,400 --> 00:24:24,720 Speaker 1: to try and see if there are cold or warm spots, 399 00:24:25,200 --> 00:24:28,080 Speaker 1: that's what they're using. By the way, just so just 400 00:24:28,359 --> 00:24:32,359 Speaker 1: side note, the air can actually retain heat for a 401 00:24:32,359 --> 00:24:34,800 Speaker 1: good amount of time. So let's say that you're with 402 00:24:34,880 --> 00:24:37,480 Speaker 1: a big crew of people down in a cold basement 403 00:24:37,480 --> 00:24:39,480 Speaker 1: and you've set up a bunch of lights and stuff, 404 00:24:39,880 --> 00:24:41,720 Speaker 1: and you're filming some things, and then you turn the 405 00:24:41,800 --> 00:24:44,119 Speaker 1: lights off and you go and you turn on the 406 00:24:44,119 --> 00:24:47,520 Speaker 1: thermal imaging detector and you see this hot spot in 407 00:24:47,560 --> 00:24:51,000 Speaker 1: the air that could possibly be generated by someone who 408 00:24:51,080 --> 00:24:53,200 Speaker 1: had been standing there for about five or ten minutes, 409 00:24:53,320 --> 00:24:55,560 Speaker 1: or even a light that had been turned on. Not 410 00:24:55,640 --> 00:25:01,879 Speaker 1: necessarily a paranormal, uh ghostly presence Okay, rant Over, I 411 00:25:01,960 --> 00:25:05,000 Speaker 1: was actually going to use blue Thunder as an example. 412 00:25:05,560 --> 00:25:08,400 Speaker 1: Like they used to they would fly outside and hover 413 00:25:08,480 --> 00:25:11,280 Speaker 1: outside the window and they could see the shapes where 414 00:25:11,280 --> 00:25:13,840 Speaker 1: people were. Which is funny because when you when you 415 00:25:13,880 --> 00:25:17,680 Speaker 1: mentioned it like that and the movies and tv uh, 416 00:25:17,760 --> 00:25:20,720 Speaker 1: when a person moves across the room, the heat stay, 417 00:25:20,880 --> 00:25:24,639 Speaker 1: you know, stays with the person. It's identifiable human shape. 418 00:25:24,840 --> 00:25:28,919 Speaker 1: It's very very much defined to that particular shape. It 419 00:25:28,960 --> 00:25:32,560 Speaker 1: seems like in the case of since the air can 420 00:25:32,600 --> 00:25:34,520 Speaker 1: retain heat, it seems like they would leave a trail 421 00:25:34,840 --> 00:25:38,399 Speaker 1: of some Yeah, depending on how where residual pattern as 422 00:25:38,480 --> 00:25:41,080 Speaker 1: much as the roadrunner does with a little cloud of dust. 423 00:25:41,320 --> 00:25:43,399 Speaker 1: It takes off well if you're if you're moving, if 424 00:25:43,400 --> 00:25:47,480 Speaker 1: you're moving steadily through the environment, you're probably not leaving 425 00:25:47,560 --> 00:25:50,320 Speaker 1: much of a trail. But if you have been staying 426 00:25:50,359 --> 00:25:54,320 Speaker 1: in a position and then start moving, then it wouldn't 427 00:25:54,359 --> 00:25:56,359 Speaker 1: be so quick as to you wouldn't see like a 428 00:25:56,960 --> 00:26:01,760 Speaker 1: clearly human defined red shape. Um move from h from 429 00:26:02,240 --> 00:26:05,080 Speaker 1: a position that had been standing in for like twenty 430 00:26:05,119 --> 00:26:08,639 Speaker 1: minutes and then move across the room. It wouldn't you know, 431 00:26:08,760 --> 00:26:11,400 Speaker 1: it wouldn't be in an immediate effect you would still 432 00:26:11,400 --> 00:26:13,240 Speaker 1: be able to see at least the residual heat that 433 00:26:13,320 --> 00:26:15,840 Speaker 1: was left behind. Now, it might be enough so that 434 00:26:16,080 --> 00:26:17,879 Speaker 1: you can clearly tell which one is the human and 435 00:26:17,920 --> 00:26:20,439 Speaker 1: which one's just the space that the human was in, 436 00:26:21,000 --> 00:26:26,200 Speaker 1: but it's not gonna be, you know, just totally clear cut. Um. 437 00:26:26,280 --> 00:26:28,679 Speaker 1: So I'm sorry. I was just gonna say. So if 438 00:26:28,680 --> 00:26:32,520 Speaker 1: you're if you're looking at a show and they're showing 439 00:26:32,560 --> 00:26:36,960 Speaker 1: a colored image of you know, night vision, basically that's 440 00:26:37,119 --> 00:26:40,320 Speaker 1: thermal image and if you're looking at the monochromatic green 441 00:26:40,400 --> 00:26:42,760 Speaker 1: screen version, that would be the image ence, So you 442 00:26:42,800 --> 00:26:45,400 Speaker 1: know now which one is which, right, So let's why 443 00:26:45,560 --> 00:26:48,920 Speaker 1: are you able to see the heat? That's the question. Well, 444 00:26:49,600 --> 00:26:52,720 Speaker 1: let me let me talk about some atoms here. Now 445 00:26:52,960 --> 00:26:56,720 Speaker 1: you've probably heard us talk about how atoms are. Uh, 446 00:26:56,960 --> 00:26:59,520 Speaker 1: normally they're moving. Yes, it's really only if you're at 447 00:26:59,600 --> 00:27:02,760 Speaker 1: zero kelvin, when you have no molecular movement, when you 448 00:27:02,800 --> 00:27:06,760 Speaker 1: have no movement on the atomic scale, absolutely, thank you, 449 00:27:06,880 --> 00:27:12,480 Speaker 1: absolute zero. Yes, uh, Because you know, atoms are always moving, 450 00:27:12,520 --> 00:27:16,960 Speaker 1: even in in solid material like a block of marble. 451 00:27:17,359 --> 00:27:21,320 Speaker 1: The atoms within that block of marble are moving. They're 452 00:27:21,320 --> 00:27:25,400 Speaker 1: not moving necessarily at the same speed as say, uh, 453 00:27:25,400 --> 00:27:31,080 Speaker 1: oxygen gas is moving, but they are moving, and atoms 454 00:27:31,119 --> 00:27:35,240 Speaker 1: have a specific state, an energy state that they are 455 00:27:35,920 --> 00:27:39,280 Speaker 1: naturally found in the ground state. No, no, not that 456 00:27:39,400 --> 00:27:42,840 Speaker 1: kind of state. The ground state is what we call it. 457 00:27:42,840 --> 00:27:44,920 Speaker 1: That's the ground state energy level. That's the amount of 458 00:27:45,000 --> 00:27:50,360 Speaker 1: energy and atom has normally if no other outside forces 459 00:27:50,480 --> 00:27:53,600 Speaker 1: or energies are acting upon it. Okay, so you've got 460 00:27:53,600 --> 00:27:56,080 Speaker 1: the ground state energy level. That's when all the electrons 461 00:27:56,119 --> 00:28:00,600 Speaker 1: are at their normal electron shell. This is from the 462 00:28:00,680 --> 00:28:05,160 Speaker 1: nucleus of the atom. When you add energy to an atom, 463 00:28:05,240 --> 00:28:08,800 Speaker 1: then you excite the electrons until they start to have 464 00:28:08,840 --> 00:28:12,880 Speaker 1: so much energy that they'll pop into outer electron shells 465 00:28:13,320 --> 00:28:16,399 Speaker 1: further out from the nucleus, and the more energy you 466 00:28:16,400 --> 00:28:20,760 Speaker 1: pour in, the further out they get. Okay, So when 467 00:28:21,080 --> 00:28:25,080 Speaker 1: you remove that energy, when that energy is when the 468 00:28:25,119 --> 00:28:28,359 Speaker 1: electrons get to a point where the energy is as 469 00:28:28,400 --> 00:28:30,720 Speaker 1: decreased enough so that the the electrons are going to 470 00:28:30,760 --> 00:28:34,720 Speaker 1: go back toward the nucleus. They have to give off 471 00:28:35,200 --> 00:28:37,719 Speaker 1: some kind of energy for that to happen. You all right, 472 00:28:37,760 --> 00:28:40,320 Speaker 1: So you think of it almost like you have a 473 00:28:40,040 --> 00:28:44,720 Speaker 1: a balloon and you over inflate that balloon. When you 474 00:28:45,200 --> 00:28:48,120 Speaker 1: let out the uh, the air, than that balloon is 475 00:28:48,160 --> 00:28:50,680 Speaker 1: gonna deflate some. Right, it's gonna come back down to 476 00:28:51,480 --> 00:28:53,479 Speaker 1: a smaller size, and if you keep it open, it's 477 00:28:53,480 --> 00:28:56,440 Speaker 1: gonna go all the way down to flat. Well, the 478 00:28:56,480 --> 00:28:59,080 Speaker 1: electrons are gonna start moving back towards the nucleus. They 479 00:28:59,120 --> 00:29:03,280 Speaker 1: give off photons when they do this, and depending upon 480 00:29:03,320 --> 00:29:08,640 Speaker 1: the material uh that in question, you'll get different different 481 00:29:08,720 --> 00:29:11,960 Speaker 1: kinds of photons within the spectrum of light. So some 482 00:29:12,040 --> 00:29:15,200 Speaker 1: things are going to give off light that is actually visible, 483 00:29:15,280 --> 00:29:17,880 Speaker 1: especially if you pour enough energy into it. That's why 484 00:29:18,240 --> 00:29:21,440 Speaker 1: Let's say you've got a toaster oven and you've got 485 00:29:21,480 --> 00:29:23,480 Speaker 1: a toaster oven going on full blast, and you look 486 00:29:23,520 --> 00:29:26,200 Speaker 1: in and you see the little toaster oven coils have 487 00:29:26,320 --> 00:29:30,560 Speaker 1: turned red. That's actually photons being given off by these atoms. 488 00:29:30,920 --> 00:29:33,000 Speaker 1: And uh, if you were to pour even more energy 489 00:29:33,000 --> 00:29:35,240 Speaker 1: into it, if you were to crank it up a notch, 490 00:29:35,760 --> 00:29:40,480 Speaker 1: those coils might start to glow even brighter and different colors. 491 00:29:40,520 --> 00:29:42,480 Speaker 1: So if they went from red to orange, that would 492 00:29:42,480 --> 00:29:45,959 Speaker 1: mean that you have even more energy that's being given off, right, 493 00:29:46,360 --> 00:29:48,320 Speaker 1: that you've you've poured more into it and it's and 494 00:29:48,360 --> 00:29:54,600 Speaker 1: it's giving off higher energy photons. So, uh, all materials, 495 00:29:54,640 --> 00:29:57,880 Speaker 1: all all things are giving off at least some kind 496 00:29:58,120 --> 00:30:01,800 Speaker 1: of photon energy when the because the whole idea of 497 00:30:01,800 --> 00:30:05,040 Speaker 1: movement and excitation, and the more it gives off, the 498 00:30:05,080 --> 00:30:09,280 Speaker 1: brighter it's going to be. So that's that's what the 499 00:30:09,280 --> 00:30:12,760 Speaker 1: thermal night vision goggles are detecting. When when they're going 500 00:30:12,800 --> 00:30:14,840 Speaker 1: when the lights being pulled through that lens, when the 501 00:30:14,920 --> 00:30:19,040 Speaker 1: lens is directing that light to the the sensors, it's 502 00:30:19,080 --> 00:30:22,600 Speaker 1: detecting the the photons that are given off, the thermal 503 00:30:22,760 --> 00:30:26,120 Speaker 1: infrared photons that are given off by things just because 504 00:30:26,120 --> 00:30:30,280 Speaker 1: of the excitation of atoms. So that's what we're actually 505 00:30:30,280 --> 00:30:32,760 Speaker 1: looking at. That's why you can be in a completely 506 00:30:33,240 --> 00:30:37,240 Speaker 1: isolated room. You could be in a cave deep below 507 00:30:37,280 --> 00:30:40,600 Speaker 1: the Earth's surface where there's there's no ambient light whatsoever, 508 00:30:40,640 --> 00:30:45,400 Speaker 1: and still be able to see based upon the what's 509 00:30:45,400 --> 00:30:50,440 Speaker 1: around you. Now, the less the less stuff gives off heat, 510 00:30:50,520 --> 00:30:52,440 Speaker 1: then the less you're gonna be able to see, the 511 00:30:52,520 --> 00:30:54,600 Speaker 1: less the less excitation is there. So if you're in 512 00:30:54,600 --> 00:30:57,360 Speaker 1: a cave where there's nothing else living in there, it 513 00:30:57,440 --> 00:31:00,360 Speaker 1: may you know, the thermal the thermal gogs may not 514 00:31:00,440 --> 00:31:02,440 Speaker 1: do you any good except to let you see where 515 00:31:02,520 --> 00:31:04,719 Speaker 1: your feet are in relation to the rest of you. 516 00:31:05,040 --> 00:31:09,160 Speaker 1: So that might be more useful to carry, say a flashlight. Yes, yes, 517 00:31:09,240 --> 00:31:12,400 Speaker 1: that might be a good idea to carry a flashlight 518 00:31:12,480 --> 00:31:17,480 Speaker 1: or a headlamp even better. And um, yeah, so that's 519 00:31:17,560 --> 00:31:21,640 Speaker 1: kind of the basics of night vision. It's pretty cool stuff. 520 00:31:21,640 --> 00:31:23,960 Speaker 1: I don't know, have you ever had an opportunity to 521 00:31:23,960 --> 00:31:26,840 Speaker 1: actually look through any sort of night vision stuff? No, 522 00:31:26,960 --> 00:31:29,480 Speaker 1: not really, I just haven't been exposed to it. Um. 523 00:31:30,040 --> 00:31:31,800 Speaker 1: But you can use it for all kinds of different things. 524 00:31:31,840 --> 00:31:35,640 Speaker 1: Of course, the military applications are obvious, um. But you 525 00:31:35,680 --> 00:31:40,520 Speaker 1: can use it for uh, you know, photography, um, for spelunking. 526 00:31:40,680 --> 00:31:44,600 Speaker 1: You know, that was an excellent uh suggestion, you know, 527 00:31:44,760 --> 00:31:46,600 Speaker 1: all kinds of sports and things where you might be 528 00:31:46,600 --> 00:31:48,880 Speaker 1: out on hunting, you know, out in the woods. There 529 00:31:48,920 --> 00:31:51,040 Speaker 1: are a lot of cam quarters out there that have it. Now, 530 00:31:51,240 --> 00:31:56,760 Speaker 1: there's also cars that have displays that include night vision 531 00:31:57,280 --> 00:32:01,200 Speaker 1: uh a night vision elements so that you see better 532 00:32:01,240 --> 00:32:03,640 Speaker 1: when you're driving a night and and they're in fact 533 00:32:03,800 --> 00:32:06,800 Speaker 1: cars that use different versions of it. There's some that 534 00:32:06,880 --> 00:32:10,360 Speaker 1: use the thermal version where they're really detecting the heat 535 00:32:10,440 --> 00:32:13,040 Speaker 1: of things, so that you can get an idea if 536 00:32:13,040 --> 00:32:15,200 Speaker 1: there's something in the road, like a person or an animal, 537 00:32:15,680 --> 00:32:18,920 Speaker 1: but those are only gonna show you things that are 538 00:32:18,960 --> 00:32:22,719 Speaker 1: again active. Really Uh. Then there are other kinds that 539 00:32:22,920 --> 00:32:27,920 Speaker 1: use the the the image enhancement style. Um. And there 540 00:32:27,920 --> 00:32:30,560 Speaker 1: are even some that use the active image enhancement. So 541 00:32:30,600 --> 00:32:33,120 Speaker 1: when you turn on your head lights, you're actually beaming 542 00:32:33,160 --> 00:32:37,800 Speaker 1: not just visible light, but infrared rays as well, infrared radiation. 543 00:32:38,280 --> 00:32:41,959 Speaker 1: So uh, the the system and those cars picks up 544 00:32:41,960 --> 00:32:44,360 Speaker 1: the reflection, just like we were talking about in the 545 00:32:44,440 --> 00:32:49,520 Speaker 1: generation zero image enhancement. Night vision he uses that same principle. 546 00:32:50,200 --> 00:32:52,640 Speaker 1: And now that of course means that the range is limited, 547 00:32:52,880 --> 00:32:55,680 Speaker 1: just as we were talking about earlier. And if it's 548 00:32:55,720 --> 00:32:58,600 Speaker 1: a foggy night, it doesn't work so well because the 549 00:32:58,600 --> 00:33:03,520 Speaker 1: fog will reflect that h that radiation back before it 550 00:33:03,600 --> 00:33:06,520 Speaker 1: can hit something more substantial, so you'll just end up 551 00:33:06,880 --> 00:33:09,200 Speaker 1: It's just like fog, right, It's just like if you 552 00:33:09,240 --> 00:33:14,760 Speaker 1: were to put your high beams on the fog bank there. Yeah, 553 00:33:14,920 --> 00:33:17,680 Speaker 1: and and in that case, the night vision might not 554 00:33:17,760 --> 00:33:19,280 Speaker 1: help you out unless you have well, if you have 555 00:33:19,320 --> 00:33:23,760 Speaker 1: the thermal one it might, but the the the image 556 00:33:23,800 --> 00:33:26,880 Speaker 1: enhancement style not so not so useful in that situation. 557 00:33:27,520 --> 00:33:30,400 Speaker 1: And that's it for another classic episode of tech Stuff. 558 00:33:30,400 --> 00:33:32,800 Speaker 1: I hope you guys enjoyed this. It's always fun to 559 00:33:33,440 --> 00:33:36,840 Speaker 1: look back in the stretches of time and revisit some 560 00:33:36,880 --> 00:33:39,160 Speaker 1: of these topics that I've talked about in the past. 561 00:33:39,360 --> 00:33:42,960 Speaker 1: I occasionally take these and make new episodes out of them, 562 00:33:43,040 --> 00:33:46,040 Speaker 1: so you never know when I might revisit this topic 563 00:33:46,160 --> 00:33:48,360 Speaker 1: and talk about the advances that have been made since 564 00:33:48,400 --> 00:33:52,200 Speaker 1: two thousand eleven. If you have any suggestions for future episodes, 565 00:33:52,480 --> 00:33:55,920 Speaker 1: why not go to tech Stuff podcast dot com. That 566 00:33:56,040 --> 00:33:59,320 Speaker 1: website has all the different ways to contact us. Remember 567 00:33:59,360 --> 00:34:02,000 Speaker 1: to check out our merchandise store over at t public 568 00:34:02,120 --> 00:34:04,800 Speaker 1: dot com slash tech stuff for all your tech stuff 569 00:34:04,840 --> 00:34:07,440 Speaker 1: merchandise needs. Every purchase goes to help the show and 570 00:34:07,480 --> 00:34:11,200 Speaker 1: we greatly appreciate it. And uh, that's it for me. 571 00:34:11,600 --> 00:34:20,160 Speaker 1: I'll talk to you again really soon for more on 572 00:34:20,239 --> 00:34:23,000 Speaker 1: this and thousands of other topics because it how stuff works. 573 00:34:23,000 --> 00:34:33,279 Speaker 1: Dot com