Expert: Steve Nelson - 12/7/2010

Question
How much light is there available in great distance from any star, outside any galaxy? If I would be there (theoretically), would I be able to read, or even see anything? Of course inside a galaxy, I would see something, like under a starry night. But what if I were in intergalactic space, maybe even away from any galaxy cluster or supercluster. Like somewhere in the middle of one of those colossal voids that were detected in the structure of the universe. How much light is there? Would I be able to see the distant galaxy clusters, at least vaguely, with just the naked eye? Or everything would be just totally dark and I would'n see even my own hand in front of my face?

Answer
You see more than stars when you look up, or you'd only see a thin band of stars in the Milky Way.  The other directions in the sky you mostly see galaxies and such, so it would still look like a starry sky, but you'd be in a very dark place where the temperature is only ~3K (3 degrees Celsius above absolute zero, the temperature of the cosmic background radiation).  You wouldn't likely be able to read by it,  Or maybe even see your hand except as a shadow, but the sky would appear basically as it does from Earth, minus the stars that are actually in the Milky Way.