🚀 go-pugleaf

andrew@rentec.com (Andrew Mullhaupt) writes...
>>2.  Damnit, the redshift is NOT, NOT, NOT the solution to Olbers'
>>Paradox!  As Scott Chase would say, "Read the FAQ." 
>Now you claim it's OK to ignore this question when explaining the blue sky.
>Not really, it isn't. In physics, you're justified in ignoring things which
>have a _small_ influence on the phenomenon at hand. In this case, the part
>of the phenomenon, (darkness at night) is _not_ a small effect. It is as
>_large_ as the effect (blue sky in the day) itself.

Maybe you think it is interesting to wonder what would the world would be
like if every line from your eye into the heavens ended at the surface of
some star. First of all the thing about everywhere being 6000K is wrong.
The sun's surface is so cool because it is radiating into space. If space
were to reach thermal equilibrium it would be at the core temp of several
million K or higher. Earth would be vaporized along with the atmosphere
which scatters blue light into your eyes. So Andrew is right. This IS a big
effect. :-)

But this is beside the point. Real people who ask why the sky is blue are
taking for granted that the night sky is dark since every child knows this.
There are two naive positions one could take. One might think that the
atmosphere is clear, so the sky should be 'dark as night' except for the
direction of the sun. One also could take the position that scattered light
should have the same color as the sun. Both of these are corrected by the
scientific explanation. And reasonable people are satisfied.

And I claim it is OK to ignore supernovae, even though without them there
would not be an earth.

Dave Ring
dwr2560@zeus.tamu.edu