h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

if white light is made up from the colours of the rainbow, are there 7 coloured photons or are they just pimary colours???

Taff
agent of kaos

Neither. Colour is dependent on the wavelength of light. Therefore it is impossible to describe the colour of a photon, only the wavelength of the photon that is received by our retinas.

B

does that mean wevelength = colour and vicki vercki

More or less, yes.

B

so there are different coloured photons

No. There is a single photon that can travel in many different wave formations.

B

Are there any circumstances under which a photon might bounces off of another photon at a visible light wavelength?

and at each different wave length it is a different colour????

First, there aren't really seven colours in the rainbow. There is a continuous smear from violet all the way to red. Different cultures assign different names to different parts of that smear. Western civilisation sees it as six colours, but due to the Ancient Greeks' preoccupation with the mystical number 7, we've invented a seventh colour so that there would be seven colours. WHo really knows the difference between Blue and Indigo?

Rainbow colours corespond to wavelengths of light. But there are other colours such as Magenta which don't correspond to any single wavelength. Instead, they are a combination of two different wavelengths in a particular proportion. ANd there can be a few different combinations of wavelength that will appear the same colour to us. "Yellow" can be light of a single particular wavelenght, or it can be a mixture of equal parts of "red" light and "green" light. So the colours don't really exist in nature, they are in our brain. The only thing there is in the real world is wavelenghts of light.

so when light is split by a prism the photons are sorted out into wavelengths??

Yes, basically.

Yes.