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Originally Posted by tw
Correct. The moon would be completely dark. But sunlight passing through the earth's atmosphere is refracted.
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Correct.
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Originally Posted by tw
Lowest frequency light is bent most which is why the moon glows red.
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Not so. Although the redder frequencies of the visible portion of the spectrum of light
are refracted more than the bluer frequencies, this has nothing to do with the percieved color of the moon in this example. The red of the moon and the blue of the sky are what they are for the same reason: scattering. The gasses that compose our atmosphere scatter light at different rates, and blue light is scattered about four times more than red light. Consequently, of all the light that manages to reach the observer standing on the surface of the earth, much more of the blue has been removed leaving a greater proportion of red, hence the reddish moon.
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Originally Posted by tw
Intensity of that light measures atmosphere clarity. This intensity must be compensated for by adjustments in the moon's orbit (apogee and perigee, etc), variation in sun's intensity, how the light is measured, etc. These experiments have been ongoing for decades. I thought I had posted a description previously in The Cellar. Apparently not.
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The "intensity of that light measures atmospheric clarity" but it is an
extremely coarse measurement indeed, having precisely five stops on the scale. And while it is influenced by the current atmospheric conditions, including cloud cover, its intended purpose is to describe the brightness of the moon during and eclipse, not atmospheric clarity.
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The French astronomer A. Danjon proposed a useful five point scale for evaluating the visual appearance and brightness of the Moon during total lunar eclipses. 'L' values for various luminosities are defined as follows:
L = 0 Very dark eclipse.
Moon almost invisible, especially at mid-totality.
L = 1 Dark Eclipse, gray or brownish in coloration.
Details distinguishable only with difficulty.
L = 2 Deep red or rust-colored eclipse.
Very dark central shadow, while outer edge of umbra
is relatively bright.
L = 3 Brick-red eclipse.
Umbral shadow usually has a bright or yellow rim.
L = 4 Very bright copper-red or orange eclipse.
Umbral shadow has a bluish, very bright rim.
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From the earlier post...
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Research has suggested a substancial decrease in light absorbing materials in earths atmosphere. If air is dirtier, then global warming has occurred slower.
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This sounds like nonsense. Do you care to explain it in more detail?
