The Electromagnetic Spectrum
Electromagnetic waves can have any wavelengths at all: anywhere from picometres to light-years.
- These are all basically the same things: waves of entwined electricity and magnetism flying through space: the only thing that’s different is the wavelength. You also get waves longer than radio and shorter than Gamma Rays - but these are very rare, and as far as we know useless (at present). Our eyes are only sensitive to visible light.