“I am he as you are he as you are me and we are all together.” – John Lennon, I Am The Walrus.
When discussing the nature of what each and everyone of us is – i.e. the undivided, eternal, infinite universe – people sometimes ask me “but what happened before the Big Bang?”
It’s a great question and something physicists would love to understand as well. But for our purposes, it’s actually a nonsensical question. The reason is that asking “before” is asking a question about time. And before this universe existed, there was no time. Remember, space and time are the same structure, which is why physicists refer to it often as “space-time” (blame Einstein). So asking what came before the universe is like asking what came before time – and there can be no “before” time.
It’s hard for us to get our mammalian brains around, because they evolved over millions of years to help us deal with shorter-term issues – like how to catch our food or how to hide from a lion. However I find it helps if you ask a similar question but taking the ‘space’ angle – as in, “Where came before the universe?” It is easier to grasp the idea that before the universe there was no space, therefore no ‘where’. As we can’t see time, it makes it a little trickier to conceive, but, again, we have to remember that space and time are the same structure.
Therefore… if the history of our universe encompasses all of time, it is eternal. And so are you, because you are the entire universe.
According to this Stephen Hawking book I’m reading at the moment, The Grand Design, it’s quite likely that the universe doesn’t even have a past at all – until we observe it, it’s past is just a probability containing all possible pasts. Once we observe it, we lock in a particular history. The only reality seems to be ‘right now’.