The universal origin story known as the Big Bang postulates that, 13.7 billion years ago, our universe emerged from a singularity — a point of infinite density and gravity
The part you are missing, and it's not possible to picture it, is that that's all there was. There wasn't a point in something. There wasn't something outside the point. It didn't expand into something.
What you said is still there. You said that the universe has a center. I asked for evidence. You said you'd 'read a book'. 'Quote me' You said. So I did.
The Big Bang Theory explains how the universe began.
www.space.com
'Around 13.7 billion years ago, everything in the entire universe was condensed in an infinitesimally small singularity, a point of infinite denseness and heat.'
The Big Bang Theory explains how the universe began.
www.space.com
'Around 13.7 billion years ago, everything in the entire universe was condensed in an infinitesimally small singularity, a point of infinite denseness and heat.'
That is, of course, before the Big Bang and seems to violate the principles of quantum mechanics, so physics makes it really hard to tell what exactly was going on then.