Your Eyes Are Nearly Blind

The electromagnetic spectrum spans from radio waves with wavelengths of kilometers to gamma rays smaller than an atom. Visible light — the only part your eyes detect — occupies a sliver between 380 and 700 nanometers.

Every color you have ever seen, every sunset, every painting — all of it comes from a microscopic slice of the spectrum. Red has the longest visible wavelength, violet the shortest. Beyond violet lies ultraviolet and X-rays. Below red lies infrared and radio waves.