Why shouldn't the original singularity of the big bang happen to be the centre of the Universe? Assume that the universe is expanding isotropically with a constant speed.
1$\begingroup$ Hi Jack and welcome to Astronomy on StackExchange. Your question will likely be flagged as a 'duplicate' question (and closed.) I can appreciate your curiosity... and that's a good thing. I would encourage you to use the StackExchange search feature and enter 'center of the universe' to find many excellent answers as this question has been asked and answered several times. $\endgroup$– Tim CampbellNov 30, 2020 at 4:45
(I can't comment)- See https://physics.stackexchange.com/questions/136860/did-the-big-bang-happen-at-a-point
TLDR, The big bang happened everywhere in the universe at the same time, because it was the universe. The top answer goes more in depth.