Physics
Thermal Emission
Quick fact
The Sun's surface temperature of about 5500°C makes its thermal emission peak in visible light, while a human body at 37°C emits mostly infrared radiation, invisible to our eyes.
Why this is interesting
You've seen a hot stove glow red and felt warmth from a campfire, but did you know that even cold objects like ice emit radiation? Why does this happen, and what determines the color and amount of the emitted energy?