Aaswath Raman, a material scientist at UCLA, has looked into the past to solve today’s problems. He has led a team that’s created an impressive device that uses radiative cooling to help cool anything by sending heat into outer space. This sounds like it’s right out of science fiction, but it is very real and is based on sound science that’s been ignored for decades. A basic example of radiative cooling is how temperatures drop on buildings overnight due to the lack of sunlight, in this case the heat just goes into the atmosphere. Using Raman’s new device the heat can get transferred into outer space because the material used reflects a very particular wavelength which won’t get trapped in the atmosphere.
In a few years the Stanford group had its first prototype. Placed outside in the hot California sun, it felt cold to the touch. It was a giddy, counterintuitive sensation, even to Raman.
Yet even after he convinced himself that daytime radiative cooling was possible, it wasn’t until a trip to visit his grandmother in Mumbai that Raman started to see how it could also be useful.
A growing number of homes in Mumbai had air conditioners in their windows, something he rarely saw during childhood visits. That’s an unqualified victory for people’s health, Raman said; exposure to extreme heat can lead to a range of illnesses, from respiratory illness to psychological distress.