My astrophysics lecturer did Olbers' paradox today in class, and while discussing it, it seemed as if she actually believes that the universe is infinite (infinite amount of space and infinite amount of matter). I came and questioned her about this afterwards, and when I said I had always thought that a finite amount of matter was produced in the Big Bang, she just replied "I'm not sure you're right about that" in a voice that suggested she thought I was flat out wrong. As far as I can see there are two scenarios which would lead to an infinite amount of matter being present in the universe: 1) An infinite amount of matter was created in a process which took a finite time. 2) A matter-creating process has been active for an infinite amount of time. (2) requires an eternal universe and therefore contradicts what we know about the Big Bang. It's reminiscent of the theories espoused by Fred Hoyle and his colleagues in the mid-20th century. (1) is so mind-blowing that if a theory of such a process existed, or even if there was reasonable speculation that such a process had occurred, it would talked about everywhere in pop science, some lecturer or other would have at least mentioned it, and it would form the basis for a revolution in science of similar magnitude to the discovery of relativity or quantum mechanics. In other words I would know about it already. Am I missing anything?