>>13579756Someone noticed a lot more galaxies are moving away (red shifted) than coming towards us (blue shifted). The assumption was that the universe was static back then, but once this observation was made, it was induced that everything must have been way closer to each other at some point and that that light from the early universe must have been red shifted so much, it ends up being microwave. So we looked for it and found the cosmic microwave background.
Scientists who were still in the static universe mindset poked fun of the theory saying
>everything must have come from a big bang then if it all started from a single point.And the name stuck.
What was there before the singularity when everything was in a single point is still unknown. The theory of relativity predicts time and space started at that moment, and every time we rewind the math to before the big bang, it breaks. So there could be more that we don’t know that would fix this issue, or some explanation we are yet to know. We need more evidence (observations) to come up with a better theory.
For now, what was before the singularity expanding or why it expanded is unknown. There are a lot of ideas, some wacky, some weird.
I think that the universe could be infinite and that the laws of nature are on some gradients and change across mass distances that at some points, it can form a pinch where mass collects and when the stress and forces from subtle small changes of laws of nature across “observable universes” in size and distance have enough force to untangle the pinch of mass, it makes a “big bang” but that is just random thoughts. There is not enough evidence to prove or falsify this idea
