Quote:
Originally Posted by xtgold
Somebody once said the higher the frequency,the more the signal takes on the characteristics of light.Since the roof and shingles block light,you will get nothing.A closed window will cut the signal quality by 25 or 30%
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It is true that the higher the freq of the rf, the more similar it is to light, but it's not nearly as simple as this when it comes to blocking a signal.
The above comparison doesn't get very far when you look at the highest end of the electromagnetic spectrum, ie X-rays and Gamma-rays, both of which go through things that visible light doesn't appear to penetrate.
Think about an old wide mesh
C-band dish, which completely blocks low frequency C-band, but Ku goes through.
Also, if you think about what windows are made out of... ie materials like sand... silica... you don't think of a beach as being invisible.
Also, think of all the birds that run into windows, because at certain angles they become almost perfect mirrors. Or run a sander over your window, and it is no longer transparent.
Another example is the various medical imaging methods, like magnetic resonance and X-ray, one of which is lower freq than visible light and the other higher freq. So transparency really doesn't have a direct relationship with frequency. It's more a case that different materials have very specific frequencies that they interact with, which is responsible for colors, etc, since certain freqs are absorbed and others aren't, etc.
Most of the materials that things like asphalt shingles are made of are all things that visible light could go through in some other configuration.
Really, much of the electromagnetic spectrum will go through most materials, partly because all matter is predominantly space. Think of the atoms and molecules in solids as similar to the galaxies and solar systems in the universe, ie mostly space.
There are several mechanisms whereby solid and liquid materials interact with electromagnetic waves. There is absorption, reflection, refraction, diffraction, scattering, etc, etc, many of which are related.
But the bottom line is that much of what people consider to be materials that "block" light is really a complicated combination of these various interactions, and has more to do with scattering than blocking the light.
Anyway, it's not that simple.