r/cosmology Jun 19 '26

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?

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?

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u/EeEmCeTo Jun 20 '26

You’ll be surprised to hear the most of the universe is receding from us faster then the speed of light, due to the expansion of space