… because the universe is expanding.

The Blue Sky Theory and Entothopter ideas both formed in my mind within the same two minutes. I was now emboldened to ask, simply ‘what other question can I figure out?’ The redness of the moon during an eclipse seemed like a good prospect, especially after the errors of Lord Rayleigh that I had certainly unveiled in the blue sky phenomenon.

I searched the web, and it was amusing to find that the official answer was held by Lord Rayleigh. His strange notion was that all interesting color effects must be caused by refraction. (With as much scientific sounding waffle as possible)

This time, the theory leads us to believe that refraction causes the red of sunsets; which are supposedly in turn responsible for the redness of the moon during a lunar eclipse. This seemed viable to Lord Rayleigh, despite relatively few sunsets being red. And of course Lord Rayleigh would not have known that this tiny flash of seldom seen red color is not at all visible from space. And the sun is not white.

If refraction was responsible, once more we would not see a flat monotone color, but a rainbow. So where was the red coming from? My Science fiction writing research had led me to realize that the majority of nearby stars are red dwarves, too dim to be seen individually by the naked eye. Could they accumulatively cause this redness? It seemed too little, but still much more red light than from the occasional sunset! And it was constant light as well. Never mind that the shape of a circular red ring of light from the Earth’s circumference would produce a ring shape on the moon with an empty center! Not, a smooth monotone crimson color.

After much deliberation, it suddenly hit me that the Red Shift (or Doppler Affect) stretches the light from distant galaxies, making the wavelength longer, and therefore: Red. This stretching is due to the universe expanding. In fact it is this observable redness of the Red Shift that leads us to the conclusion that the universe is expanding. But once more, was there enough to make the moon glow?

Light from each star diminishes in magnitude to the inverse of the square by distance. So that light twice as far away is four times less brilliant. However the sheer number of celestial bodies in three dimensions of space increases to the power 3 with distance.