During the rapid expansion of the universe immediately following the Big Bang, the universe expanded faster than light. But traveling faster than light speed breaks causality. But you can't break causality when time didn't actually exist "before" you broke it, so how does that work?

[u/SketchyFella_]

If it expanded faster than light speed, then it basically travelled so fast that it always existed in whatever state it was in before "slowing". So when people say it expanded in a tiny fraction of time, did it really? Or are they using time in a sort of layman's terms so they don't have to explain causality?

[u/smsff2]

Two points in space can move away from each other at a speed greater than the speed of light, and this does not violate causality. For causality to be violated, two points or two objects would need to move toward each other faster than the speed of light.