Q: How can we see the early universe and the Big Bang? Shouldn’t the light have already passed us?
Physicist: This is a very common question that’s generated (as best I can tell) by a misrepresentation of the Big Bang that you’ll often see repeated in popular media. If the Big Bang and the expansion of the universe were as straightforward as an explosion and things flying away from that explosion, then the earliest light would be on the front of our ever-expanding universe. The view of the universe that physicists work with today involves space itself expanding, as opposed to things in space flying apart. Hot things make lots of light, and the early universe was extremely hot everywhere, so there would have been plenty of light everywhere, shooting in every direction. However, in the open case it’s a touch more difficult to picture how the Big Bang worked.