Ethan, the idea that the expansion happened everywhere at once seems to imply an event that was simultaneous everywhere. But that contradicts relativity…

If there was some “spark” that triggered the expansion, could that spark have began throughout the entire “soccer ball” universe all at once? Or did it start at one point and propagate? If it started at one point, then that is the “center” — but if it started everywhere, that implies a simultaneous change at every point. Usually state changes happen at isolated points and propagate.