This is

This is Scientific American 60 Second Science.

I'm Christopher Intagiyata.

You've probably seen pictures of Greek villages

where every house is painted bright white.

The paint reflects the intense sunlight of the Mediterranean,

and it works pretty well to keep the houses from heating up in the sun, but it doesn't actively

cool them.

To understand why, consider what the white paint does.

Here's how optical scientists Shaubo Yin of the University of Colorado describes it.

It's a mirror for the sunlight, it's also a mirror for the radiation as well.

And it might seem like reflecting all those incoming rays would be a good thing,

but the benefit is limited because what it really means,

Ian says, is that the houses, well,

they don't release much energy.

Release more energy, again in the form of infrared radiation,

aka heat, and you effectively get free AC.

So Yin and his colleagues built a material that does exactly that.

It reflects visible light, but it also emits infrared wavelengths, which gives it the power to

actually cool.

It's two layers, a top layer of polymer packed with glass beads just

eight microns across so they can absorb and then emit infrared radiation and it has a silver

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