in a stable, infinite universe, the night sky should blaze with the light of the stars that lie in all directions, even those far away.
First, realize that each large region of space is very much like any other -- it receives some heat energy, and it radiates some also, and a typical region is in balance with its neighbors -- it radiates just as much energy as it receives.
Therefore, instead of trying to imagine infinity, just imagine a large cube of space with perfect mirrors for walls. The mirrors reflect perfectly, so if you are inside and look in any direction, you see what appears to be an infinite distance.
Energy that reaches an edge of the square "wraps" around to the opposite edge, just as though the square was lined with mirrors. Careful thought will show that this simple method effectively mimics an infinite space.
There's a lot of stars out there, but a whole lot more empty space. There's no real reason to think that just because you could travel infinitely far in a particular direction, you must eventually hit a star. In fact in the case of the mirrored cube, there are quite a few paths for which you could prove that you will never hit a light. Of course the universe isn't so orderly, so it's harder to prove. But consider - even if the path you follow does eventually hit a star, you could then adjust the path by a tiny angle in any direction, and it will miss that star. There are still going to be plenty of paths nearby that miss all the stars in the area.
, doesn't this contradict the 2nd(?) law of thermodynamics stating that the amount of energy remains constant?
In an enclosed space with no avenue of escape for energy, any source of heat, no matter how small, will eventually heat the entire space to its own temperature
Originally posted by Jeroen Wenting:
no it's not
Another avenue of proof is that all celestial objects portray a redshift, meaning they're moving away from us.
Unless the universe is expanding there should be some objects that do not show this redshift because they have nowhere to move to except towards us.
Originally posted by Ashok Mash:
because the universe is in power-save mode??
Originally posted by Jim Yingst:
Evidence of a dark night sky contradicts the thermodynamics laws in space, apparently.
Ummm... how is that? What thermodynamic laws are you talking about? For the ones mentioned so far, a key point is that it still takes a really, really long time. Yes, the stars will eventually burn out (unless the universe collapeses first instead) but that's unlikely to effect most of us in the near future; I'm not terribly concerned. But the fact that the stars haven't burned out yet doesn't mean they won't ever.