Why does anything exist? Why isn't there nothing?

A deep question into the very nature of existence.
To answer this question you’d have to get to the very heart of astrophysics.
What happened? How did everything that be come to be? Was it a big bang? Or something else?
We don’t know for sure. The one thing we know is that things do exist. Why they exist – how they came to exist – will they exist in the future – that we don’t know.
These are the questions scientists are asking and the reason for their research and theories.