pritty much, but once it starts adding indigo and violet, then ultraviolet to the mix you start seeing a weird 'super white' color, real intense.
If you want a good explanation of EM, NASA has not just
one but
two different pages, and this
cassini page gives a lot of the basic information too.
On different frequencies passing through different matter, in general it has to do with the densities of the mater in question vs the frequency and amplitude of the waves attempting to pass through.
Sometimes structure comes into play too: Sand is almost opaque, while glass made from that same sand is pritty much transparent.
Another big thing is how much of a
refractive index the material has, sometimes it's so high that the waves are reflected right back around.
I hope that helps, I know particle physics isn't exactly the easiest subject to wrap your brain around.
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Sometimes a Hypography Forum Administrator
"With a big enough engine, even a brick will fly." -Law of Aerospace
