Speaker 1: Welcome to brain Stuff production of iHeart Radio. Hey brain Stuff,
Speaker 1: I'm Lauren Bokelbaum, and this is a classic episode from
Speaker 1: our erstwhile host, Christian Sagar. This one concerns a favorite
Speaker 1: technological trope of spy and action movies, night vision goggles.
Speaker 1: How do they really work? Hey, brain stuff? This is
Speaker 1: Christian Sager. So night vision seems like a pretty cool idea, right,
Speaker 1: I mean, you see it all the time in movies.
Speaker 1: Some secret agent type straps on a pair of goggles,
Speaker 1: sneaks into a luxurious supervillain compound and mose down enemies
Speaker 1: under the cover of darkness, or the predator stalks Arnold
Speaker 1: Schwarzenegger killing his platoon one by one by one. And
Speaker 1: as you're watching all this, you may occasionally ask yourself, Hey,
Speaker 1: do those goofy looking goggles really work? Well? The answer
Speaker 1: is yes, absolutely. With a good night vision device or
Speaker 1: n v D, you can see a person standing over
Speaker 1: two hundred yards or a hun driden eighty three meters
Speaker 1: away on a moonless, cloudy night. And whether we're talking goggles, scopes,
Speaker 1: or cameras, most of these devices rely on one or
Speaker 1: two types of night vision image enhancement. That's the green
Speaker 1: looking one, and thermal imaging, which is the bluish gray stuff.
Speaker 1: They both produce results, but work in different ways. Thermal
Speaker 1: imaging captures the upper portion of the infrared light spectrum.
Speaker 1: Objects emit this as heat rather than reflecting it as light.
Speaker 1: Hotter objects, such as the bodies of secret agents, emit
Speaker 1: more of this light than cooler objects like buildings, trees,
Speaker 1: or you know, dead bodies, and that's what you're seeing
Speaker 1: when you use thermal imaging, essentially a measure of temperature
Speaker 1: from negative four degrees fahrenheit to three thousand and six
Speaker 1: hundred degrees fahrenheit. The magic or well you know, the
Speaker 1: science starts at the lens, which focuses the infrared light
Speaker 1: emitted by all of the objects in view and uses
Speaker 1: a phased array of infrared detector elements to create a
Speaker 1: temperature pattern called a thermogram, which is translated first into
Speaker 1: electric impulses and then into data for the display, where
Speaker 1: it appears as various colors depending on the intensity of
Speaker 1: the infrared. Then there's image enhancement. This collects tiny amounts
Speaker 1: of light, including the lower portion of the infrared light spectrum,
Speaker 1: and amplifies it devices using this approach rely on an
Speaker 1: image intensifier tube to collect and amplify light, both the
Speaker 1: infrared kind and the visible stuff. Image enhancers use a
Speaker 1: photo cathode to convert photons into electrons and high voltage
Speaker 1: to amplify those electrons in a micro channel plate or
Speaker 1: an m c P before they hit a screen that's
Speaker 1: coated with phosphors. Here's the crazy part. These electrons maintain
Speaker 1: their position in relation to the micro channel they passed through,
Speaker 1: which provides a perfect image, and the electrons stay in
Speaker 1: the same alignment as the original photons. When they hit
Speaker 1: the screen, their energy excites the phosphors, releasing photons. Those
Speaker 1: phosphors create the green image you see when you look
Speaker 1: through a night vision scope. Today's episode was written by
Speaker 1: Ben Bollen and produced by Tyler Clang. For more on
Speaker 1: this and lots of other insightful topics, visit hous toff
Speaker 1: works dot com. Brain Stuff is production of I Heart Radio.
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Speaker 1: favorite shows.