system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If the Big Bang happened +/- 13.5B years ago, and if matter - and thus the universe - has been expanding outward ever since, shouldn’t there be a massive void in the center of the universe?
gpt
This is a common misconception. There is no center of the universe, the Big Bang happened everywhere at once. The point is that *everywhere was very close together.* The entire universe was basically in the same place; not that all matter was in the same location, all **locations** were close together.

So the universe expanding is all locations becoming more distant, not mass itself traveling through space. The mass might as well be stationary.