Will someone please explain how this whole infrared-can-see-through-walls thing got started? It comes up everywhere: James Bond used it, One of the iterations of  CSI used it, then KITT used it on last night’s episode of the New and Improved Knight Rider (now with more humor!). Not that I particularly blame Knight Rider, because it’s such a common meme. So, for the record, infrared cameras cannot see through walls. These cameras, like night vision goggles, pick up lower wavelength electromagnetic signals that we sense as heat. But the insulated walls of buildings are  designed to block heat from escaping, essentially forming a…well, a wall between the camera and person in the building. Luckily, there are many excellent real ways for KITT to see through walls.

The Lobster-Eye X-Ray Device (LEXID)  uses X-rays (like Superman!) to see through walls. The LEXID looks like a flashlight, but it uses  X-ray emissions to see through up to three inches of steel. It’s actually pretty neat, the designers modelled it on the vision system used by lobsters and other crustaceans. Where the human eye uses a lens to refract light onto the optic nerve, a lobster uses a series of tiny biological “mirrors” to project disparate light beams onto a single focal point. The LEXID collects X-rays in the same way.

Or how about a little mini-radar type system? The Xaver 800 can see into a room, map it onto a screen, and maintain real-time, three dimensional updates on the locations of people within the room. The system relies on Ultra Wide Bandwidth signals, a method that relies on timing and and a large selection of radio wavelengths, rather than sheer power (Traditional uses of radiowaves use a narrower part of the spectrum but are higher power).  The system can see through concrete, reinforced concrete, wood, brick, and pretty much anything except a continuous sheet of metal.

So there’s plenty of ways for futuristic soliders and talking cars to see through walls. I just wish I could figure out how we got to thinking that infrared was one of them.

January 29th, 2009 Tags: CSI, infra red, James Bond, Knight Rider, remote sensing
by Eric Wolff in Physics, TV | 5 comments | RSS feed | Trackback >