Someday's a question simply arises. I will often pump the question straight into the Google search engine and see what happens. Today I asked, "Why is the sky blue?". The question brought me to Yahoo! Answers.com. I quite often land on this site. I like the way people tend to speak a bit more plainly about physics, and such stuff. It's easy to verify what someone is saying with a little research. Today, I found that someone's answer to the question really struck a bell with me:
Tyndall and Rayleigh thought that the blue colour of the sky must be due to small particles of dust and droplets of water vapour in the atmosphere. Even today, people sometimes incorrectly say that this is the case. Later scientists realised that if this were true, there would be more variation of sky colour with humidity or haze conditions than was actually observed, so they supposed correctly that the molecules of oxygen and nitrogen in the air are sufficient to account for the scattering. The case was finally settled by Einstein in 1911, who calculated the detailed formula for the scattering of light from molecules; and this was found to be in agreement with experiment. He was even able to use the calculation as a further verification of Avogadro's number when compared with observation. The molecules are able to scatter light because the electromagnetic field of the light waves induces electric dipole moments in the molecules.
I've come to a few conclusions about light. Light is emitted by matter, as is all electromagnetic radiation. If there is no matter, you will not find EMR being emitted by anything else. EMR can travel through a vacuum, but it lacks any kind of "punch" until it reacts with a reciever. This reciever has to take the form of matter. Therefore, EMR is acting much more like a signal which tells the reciever how to behave. I don't think EMR is a form of energy transfer, because I think the energy belongs to the medium in-which light propagates - the aether. The behaviour of atoms dictates how they react to the aether field. ALL energy - potential, kinetic, or otherwise - belongs to the aether.
So there's a special relationship between light and matter. The way in which the atomic structure of matter is made-up, and how it induces the aether, shall directly affect the wavelength of EMR being emitted. If Einstein was able to calculate the formula for the scattering of light from molecules - does this then open the way for calculating how, and why, the wavelengths of the visible spectrum are the size they are?