Changes

Debate over whether light was a wave, or consists of particles was finally solved when [[quantum physics]] revealed all particles have wavelengths, but this is not generally noticeable in normal matter.  

Debate over whether light was a wave, or consists of particles was finally solved when [[quantum physics]] revealed all particles have wavelengths, but this is not generally noticeable in normal matter.  

The EM spectrum consists of the following types of photon radiation (in order of increasing wavelength): cosmic rays, gamma rays, x-rays, ultraviolet light, visible light, infrared light and radio waves.

The EM spectrum consists of the following types of photon radiation (in order of increasing wavelength): microwaves, gamma rays, x-rays, ultraviolet light, visible light, infrared light and radio waves.

The speed of light is the same in every frame of reference, no matter how fast the source or the observer are moving, this gives rise to the [[theory of relativity]].

The speed of light is the same in every frame of reference, no matter how fast the source or the observer are moving, this gives rise to the [[theory of relativity]].