Question

If there was nothing before the Big Bang occurred, then in theory there was nothing to cause it to expande/explode. How do scientists explain this phenomenon?

Answer 1

The basics of the Big Bang theory are fairly simple. In short, the Big Bang hypothesis states that all of the current and past matter in the Universe came into existence at the same time, roughly 13.8 billion years ago. ... Suddenly, the Singularity began expanding, and the universe as we know it began.