You might remember that we looked at some paradoxes when we studied special relativity earlier this term. Here is another situation where a paradox can arise. The German astronomer Heinrich Olbers (1758–1840) asked why the night sky was dark. At the time, astronomers believed that the Universe was both infinite and steady state (unchanging), so it seemed like a good question.
- Wouldn’t there be a star in any direction you chose to look?
- Shouldn’t the light from that star prevent the night sky from looking dark?
Well, the problem is that the Universe is not infinite because it is still expanding. The Universe also isn’t steady state because it is… expanding. It turns out that a question posed by a follower of the infinite, steady state model of the Universe is actually a decent piece of evidence in support of the Big Bang model of the Universe.
Watch these two videos and see how they chip away at the paradox and show how the answers to the question turn out to support the expanding Universe model.