I can understand how fast moving atoms can transfer their kinetic energy to other objects, thus heating them up. But one thing I’ve always wondered is how fast moving atoms can produce infrared energy. How do atoms bouncing into each other produce electromagnetic radiation?
They are jiggling, and they have charge unevenly distributed in space, and it moves around, and the electric field changes in response to the movement in waves that radiate outward at c (or nearly). That is the radiation.
Very interesting. Does that relate to the visible light given off for hot objects? Some hot objects are red. Really, really hot objects can look white. Is that just because the electric field changes are producing light in those ranges? And if so, why don’t hot objects give off all of the colors like blue, green, purple, etc?
Yes, it’s called black-body radiation.
The reason hot objects don’t look other colors is because they don’t emit a single wavelength. When an object is just hot enough to emit visible light, it emits the lowest energy visible light, red, and also infrared. You can’t see the infrared so you just see red. When it’s hotter than that, it emits higher energy light (yellow, green, blue, etc.) but it’s still emitting the low energy red too. The differentcolors of light mix together to form white.
Hot enough objects give off blue light. Look at one through a blue filter and you will see the blue light it gives.