eli5:How come one end of light wavelengths is red and one violet, not black and white?

Question

eli5:How come one end of light wavelengths is red and one violet, not black and white?

In: Physics

Answer 1

White isn’t a single color, it’s what we see when red, green and blue (the primary spectral colors that our eyes detect) are mixed together. 

Now off the red end of the spectrum is infrared, and off the violet end is ultraviolet. Our eyes can’t see those wavelengths of light, so you could argue that the visible spectrum actually starts and ends with black…