Scientists believe that in the beginning there was the singularity. It was the entire universe as we know it, condensed into a point that has 0 length, width, height, and time.
Meaning that, in the beginning, the universe was everything and nothing.
What was before that? Well there wasn’t any before, time didn’t exist.
Then scientists believe that for whatever reason, this nothing exploded. Out of this nothing came everything.
Here the story usually goes into the everything, the atoms and molecules.
But what happened to the nothing? The nothing was still there, but now it had to share “space” in the universe with everything, conceptually. But literally, nothing exists where everything doesn’t exist. They share the universe together, in fact they are the universe together.
Before the big bang, the universe, which in fact is a misnomer if used in this context because the universe is wherever everything exists and before the big bang nothing existed. But we have to give some sort of identity to this non-thing that non-existed before the big bang so that our human brains can understand it. So before the big bang, the “universe” didn’t even have nothing. The concept of nothing didn’t exist without its counterpart, everything.
After the big bang, there were now two things, everything and nothing, a duality. There are lots of very fundamental dualities in our conception of the world. There are dualities of right and wrong, good and bad, true and untrue, positive negative, etc. A key attribute of a duality is that without one, the other doesn’t exist. All dualities are linked in some way, they aren’t just important in our society and our reality, but are in fact just shadows of the larger duality, everything and nothing.
Thus even the fabric of our day to day lives are tied in with the universe in such a deep level. When you try to think about what the right thing to do is, you are participating in a dance that reality is participating in, from every single particle of your own body, all the way up to the galaxies whipping each other about in the halls of our universe.