Forget the Big Bang, we might have had the Big Bounce instead! The Big Bounce hypothesis says that before the universe as we know it today had formed, there was a universe here before us. It disappeared before we arrived in something called the “Big Crunch.” From there it created such an immense amount of density and extreme temperatures that it caused an inversion effect, meaning it went from the big crunch right into expansion, forming the universe as we know it today. No point of singularity, no Big Bang required. This is referred to as the bounce.
If our universe formed through a bounce instead of a Big Bang then maybe some of what exists in the current universe today has already existed in a previous one! The bounce hypothesis arose from our understanding of black holes. It all started in 1968 when physicist James Berdeen modified the equations about black holes in Einstein’s theory of General Relativity.
He stated that the mass of a black hole is not constant but instead a function based off the distance to the center of the black hole. This gave birth to the possibility of a new kind of black hole: named the “regular black hole.” Regular black holes don’t violate general relativity. This idea has been around for decades.