Colour is caused by the eye interpreting the spin rate of a Photon.
A Photon is a ballistic particle, and as with a bullet richcheting off of a hard object, its spin rate is modified. A bullet makes that classic richochet sound which is dependant on what it hits. Bullets bouncing off nickel based armour sound different to brick, concrete or stone.
Anyone who was schooled in and/or understands the physics ballistics will understand that the energy expended by a ballistic object on a target is G=MV(Squared) + spin rate. For those confused by this, try to push a drill bit through wood without turning the drill on.
Unlike a drill, where the source of spin rate energy is supplied, a bullet or Photon is more akin to a spinning top whereby the spin rate is pre-determined from initialisation.
Any contact with another object will "scrub off" some of the spin energy.
In the case with Photons, this change of spin rate is directly related to the colour we see.
The rate of spin of an object can also be described as its frequency and this led to the false belief that light was a wave rather than a particle. However, a recreation of the grating experiment with a jet of fine sand finally nailed the "wave theory" argument firmly into its coffin.
Eyes are marvelous pieces of kit, being able to interpret the spin rate energy of a stream of Photons and convert them into electro-chemical signals to the brain of a creature.
Topic: Science quiz for the American public. (Read 10547 times)