1 00:00:01,920 --> 00:00:07,120 Speaker 1: Welcome to brain Stuff production of iHeart Radio. Hey brain Stuff, 2 00:00:07,120 --> 00:00:09,959 Speaker 1: I'm Lauren Bokelbaum, and this is a classic episode from 3 00:00:09,960 --> 00:00:13,920 Speaker 1: our erstwhile host, Christian Sagar. This one concerns a favorite 4 00:00:14,040 --> 00:00:18,160 Speaker 1: technological trope of spy and action movies, night vision goggles. 5 00:00:18,520 --> 00:00:23,960 Speaker 1: How do they really work? Hey, brain stuff? This is 6 00:00:24,040 --> 00:00:27,760 Speaker 1: Christian Sager. So night vision seems like a pretty cool idea, right, 7 00:00:27,800 --> 00:00:29,840 Speaker 1: I mean, you see it all the time in movies. 8 00:00:30,080 --> 00:00:32,640 Speaker 1: Some secret agent type straps on a pair of goggles, 9 00:00:32,680 --> 00:00:36,879 Speaker 1: sneaks into a luxurious supervillain compound and mose down enemies 10 00:00:37,159 --> 00:00:41,000 Speaker 1: under the cover of darkness, or the predator stalks Arnold 11 00:00:41,000 --> 00:00:44,920 Speaker 1: Schwarzenegger killing his platoon one by one by one. And 12 00:00:44,960 --> 00:00:48,360 Speaker 1: as you're watching all this, you may occasionally ask yourself, Hey, 13 00:00:48,400 --> 00:00:52,000 Speaker 1: do those goofy looking goggles really work? Well? The answer 14 00:00:52,080 --> 00:00:55,600 Speaker 1: is yes, absolutely. With a good night vision device or 15 00:00:55,760 --> 00:00:58,360 Speaker 1: n v D, you can see a person standing over 16 00:00:58,400 --> 00:01:01,200 Speaker 1: two hundred yards or a hun driden eighty three meters 17 00:01:01,280 --> 00:01:06,400 Speaker 1: away on a moonless, cloudy night. And whether we're talking goggles, scopes, 18 00:01:06,600 --> 00:01:09,680 Speaker 1: or cameras, most of these devices rely on one or 19 00:01:09,720 --> 00:01:12,959 Speaker 1: two types of night vision image enhancement. That's the green 20 00:01:13,000 --> 00:01:16,720 Speaker 1: looking one, and thermal imaging, which is the bluish gray stuff. 21 00:01:17,040 --> 00:01:21,200 Speaker 1: They both produce results, but work in different ways. Thermal 22 00:01:21,240 --> 00:01:24,720 Speaker 1: imaging captures the upper portion of the infrared light spectrum. 23 00:01:25,040 --> 00:01:29,000 Speaker 1: Objects emit this as heat rather than reflecting it as light. 24 00:01:29,400 --> 00:01:32,560 Speaker 1: Hotter objects, such as the bodies of secret agents, emit 25 00:01:32,640 --> 00:01:35,679 Speaker 1: more of this light than cooler objects like buildings, trees, 26 00:01:35,800 --> 00:01:39,440 Speaker 1: or you know, dead bodies, and that's what you're seeing 27 00:01:39,480 --> 00:01:43,280 Speaker 1: when you use thermal imaging, essentially a measure of temperature 28 00:01:43,319 --> 00:01:46,720 Speaker 1: from negative four degrees fahrenheit to three thousand and six 29 00:01:46,800 --> 00:01:51,560 Speaker 1: hundred degrees fahrenheit. The magic or well you know, the 30 00:01:51,600 --> 00:01:55,360 Speaker 1: science starts at the lens, which focuses the infrared light 31 00:01:55,440 --> 00:01:58,800 Speaker 1: emitted by all of the objects in view and uses 32 00:01:58,840 --> 00:02:02,520 Speaker 1: a phased array of infrared detector elements to create a 33 00:02:02,560 --> 00:02:07,280 Speaker 1: temperature pattern called a thermogram, which is translated first into 34 00:02:07,280 --> 00:02:11,640 Speaker 1: electric impulses and then into data for the display, where 35 00:02:11,639 --> 00:02:14,880 Speaker 1: it appears as various colors depending on the intensity of 36 00:02:14,919 --> 00:02:20,120 Speaker 1: the infrared. Then there's image enhancement. This collects tiny amounts 37 00:02:20,120 --> 00:02:23,800 Speaker 1: of light, including the lower portion of the infrared light spectrum, 38 00:02:24,080 --> 00:02:27,880 Speaker 1: and amplifies it devices using this approach rely on an 39 00:02:27,919 --> 00:02:32,480 Speaker 1: image intensifier tube to collect and amplify light, both the 40 00:02:32,520 --> 00:02:37,120 Speaker 1: infrared kind and the visible stuff. Image enhancers use a 41 00:02:37,200 --> 00:02:42,280 Speaker 1: photo cathode to convert photons into electrons and high voltage 42 00:02:42,560 --> 00:02:46,519 Speaker 1: to amplify those electrons in a micro channel plate or 43 00:02:46,560 --> 00:02:49,440 Speaker 1: an m c P before they hit a screen that's 44 00:02:49,480 --> 00:02:53,720 Speaker 1: coated with phosphors. Here's the crazy part. These electrons maintain 45 00:02:53,800 --> 00:02:57,120 Speaker 1: their position in relation to the micro channel they passed through, 46 00:02:57,320 --> 00:03:01,280 Speaker 1: which provides a perfect image, and the electrons stay in 47 00:03:01,320 --> 00:03:05,160 Speaker 1: the same alignment as the original photons. When they hit 48 00:03:05,240 --> 00:03:10,200 Speaker 1: the screen, their energy excites the phosphors, releasing photons. Those 49 00:03:10,200 --> 00:03:13,679 Speaker 1: phosphors create the green image you see when you look 50 00:03:13,720 --> 00:03:22,080 Speaker 1: through a night vision scope. Today's episode was written by 51 00:03:22,080 --> 00:03:24,840 Speaker 1: Ben Bollen and produced by Tyler Clang. For more on 52 00:03:24,880 --> 00:03:27,639 Speaker 1: this and lots of other insightful topics, visit hous toff 53 00:03:27,639 --> 00:03:30,720 Speaker 1: works dot com. Brain Stuff is production of I Heart Radio. 54 00:03:31,000 --> 00:03:33,280 Speaker 1: For more podcasts for my heart Radio, visit the iHeart 55 00:03:33,360 --> 00:03:36,080 Speaker 1: Radio app, Apple Podcasts, or wherever you listen to your 56 00:03:36,080 --> 00:03:36,800 Speaker 1: favorite shows.