Why does hot metal and glass change colors? What causes the progression of red – orange – yellow -white?

Question

Why does hot metal and glass change colors? What causes the progression of red – orange – yellow -white?

In: Physics

Answer 1

All materials above absolute zero give off some amount of electromagnetic radiation. The wavelength of that radiation shortens as the temperature increases, along with the amount increasing.

When they reach around 600F, that wavelength starts to get into the visible spectrum, and you see a dull red. A little hotter, and orange and yellow start to be made. Hotter still, and blue is made, but there is still the other wavelengths so it all combines to white.