Imagine this scenario: It’s 110°F in Phoenix; the asphalt has apparently become molten lava, and somewhere up on a roof, a small piece of plain white paint is sitting cool as cucumbers at 10.8°F (6°C) below the ambient temperature, using no power source, no compressor, and relying on passive radiative cooling rather than mechanical refrigeration. This isn’t science fiction; it’s an actual achievement accomplished by a group of researchers at Columbia University.
