Easy-to-make thermal chameleon fades into the background

Easy-to-make thermal chameleon fades into the background

Enlarge / This story isn’t really about this kind of chameleon. Sorry. (credit: Renee Grayson / Flickr)

Chameleons, unlike bowties, are cool. The chameleon is most famous for its ability to blend with its surroundings (I’m just as impressed with the acrobatic tongue), something we’d often like to do ourselves. Doing something similar with heat would be exciting. Imagine a camouflage suit that blended in with its background in both the visible and the infrared.

Three researchers suggest they’ve done exactly that in a recent paper on a thermal cloaking demonstration. Unfortunately, their cloak doesn’t so much blend with the surroundings as become completely transparent. This is still remarkable, and, at least when cloaking in two dimensions, it’s surprisingly simple to make.

Hiding in plain sight

Before we get to how the cloak works, let me take you through what the thermal chameleon is trying to hide. Let’s

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Study says ancient Romans may have built “invisibility cloaks” into structures

Study says ancient Romans may have built “invisibility cloaks” into structures

Enlarge / The Roman Colosseum is an oval amphitheatre in the center of the city of Rome. French scientists suggest its structure might have helped protect it from earthquake damage. (credit: Alex Livesey/Danehouse/Getty Images))

Scientists are hard at work developing real-world “invisibility cloaks” thanks to a special class of exotic manmade “metamaterials.” Now a team of French scientists has suggested in a recent preprint on the physics arXiv that certain ancient Roman structures, like the famous Roman Colosseum, have very similar structural patterns, which may have protected them from damage from earthquakes over the millennia.

Falling within the broader class of photonic band gap materials, a “metamaterial” is technically defined as any material whose microscopic structure can bend light in ways it doesn’t normally bend. That property is called an index of refraction, i.e., the ratio between the speed of light in a vacuum and how

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