Welcome to brain Stuff production of iHeart Radio. Hey brain Stuff, I'm Lauren Bokelbaum, and this is a classic episode from our erstwhile host, Christian Sagar. This one concerns a favorite technological trope of spy and action movies, night vision goggles. How do they really work? Hey, brain stuff? This is Christian Sager. So night vision seems like a pretty cool idea, right, I mean, you see it all the time in movies.
Some secret agent type straps on a pair of goggles, sneaks into a luxurious supervillain compound and mose down enemies under the cover of darkness, or the predator stalks Arnold Schwarzenegger killing his platoon one by one by one. And as you're watching all this, you may occasionally ask yourself, Hey, do those goofy looking goggles really work? Well? The answer
is yes, absolutely. With a good night vision device or n v D, you can see a person standing over two hundred yards or a hun driden eighty three meters away on a moonless, cloudy night. And whether we're talking goggles, scopes, or cameras, most of these devices rely on one or two types of night vision image enhancement. That's the green looking one, and thermal imaging, which is the bluish gray stuff.
They both produce results, but work in different ways. Thermal imaging captures the upper portion of the infrared light spectrum. Objects emit this as heat rather than reflecting it as light. Hotter objects, such as the bodies of secret agents, emit more of this light than cooler objects like buildings, trees, or you know, dead bodies, and that's what you're seeing when you use thermal imaging, essentially a measure of temperature from negative four degrees fahrenheit to three thousand and six
hundred degrees fahrenheit. The magic or well you know, the science starts at the lens, which focuses the infrared light emitted by all of the objects in view and uses a phased array of infrared detector elements to create a temperature pattern called a thermogram, which is translated first into electric impulses and then into data for the display, where it appears as various colors depending on the intensity of
the infrared. Then there's image enhancement. This collects tiny amounts of light, including the lower portion of the infrared light spectrum, and amplifies it devices using this approach rely on an image intensifier tube to collect and amplify light, both the infrared kind and the visible stuff. Image enhancers use a photo cathode to convert photons into electrons and high voltage to amplify those electrons in a micro channel plate or an m c P before they hit a screen that's
coated with phosphors. Here's the crazy part. These electrons maintain their position in relation to the micro channel they passed through, which provides a perfect image, and the electrons stay in the same alignment as the original photons. When they hit the screen, their energy excites the phosphors, releasing photons. Those phosphors create the green image you see when you look through a night vision scope. Today's episode was written by
Ben Bollen and produced by Tyler Clang. For more on this and lots of other insightful topics, visit hous toff works dot com. Brain Stuff is production of I Heart Radio. For more podcasts for my heart Radio, visit the iHeart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.