The short answer: nothing, nada, zip. But scientists still wonder if something existed before all the nothing. One theory: Our universe is caught in an endless loop of explosions and crunches. Eventually, in billions and billions of years, the iron grip of gravity will slow the growth of the universe, stall it, and then pull everything back toward its center – a process that astrophysicists call the ‘’big crunch.’’ Planets, stars, and galaxies will slowly collapse back into the singularity that started it all, kicking off another big bang and a brand-new universe.
According to another theory, our universe is just one of many, many, many alternate universes just like it in a vast ‘’multiverse.’’ When two of these universes interact at the quantum level (a level smaller than an atom), it kicks off a big bang and the birth of yet another alternate universe.
Picture Credit : Google