Metal that’s hot and “cold” at the same time

“Cool” experiment in science grades 6-8: Vince and 6 students took 3 pieces of aluminum, one coated with clear nail polish (A), into the bright sunlight. Of course, the bare metal (B and C) gets hot… but looks quite cold in thermal radiation, which we measured with our FLIR One Pro thermal imaging camera.  The bare metal reflects a lot of “cold” sky radiation, so that it looks cold. The piece with nail polish absorbed as much sunlight but dumped the energy by radiating away a lot of thermal radiation.  We also looked at the radiative temperatures of tall shrubs, the sky itself, hot soil, and an anonymous student.  All the phenomena popped out of Vince’s past scientific research, which he is always eager to share.  Here are three photos, with color-coding for the temperature, from white as high to yellow to red to blue to black as cold.