I really enjoy Michio Kaku's presentations on the subject of time, but what I can't understand is his - and science's - generally accepted "truths" about the Big Bang and the ever expanding universe.
It's simple, yet as unanswerable as the original question - because these "answers" aren't really answers at all, just theories that, at least in my opinion, hold no more water then any other theory.
Okay, start with the Big Bang. This theory says there was a moment when it all started. The question that defeats this theory is "what was there before the Big Bang". Absolutely nothing? Nah. There was something. Whether it was God who created the Big Bang or something else, there was something before the Big Bang. Common sense dictates.
And the "ever exanding universe"? Similar thinking applies. What is the ever expanding universe expanding into? Nothing? What does "nothing" look like? Empty space? What is empty space? Or is it a wall? If it's a wall, doesn't the wall have depth? If not, what is behind the wall? Nothing? What does nothing look like? That is, isn't "nothing" something? Of course it is.
So what do these interesting theories really mean? What do they really do for us? They give us something to talk and sound smart about. Not that I would denigrate Michio Kaku, because I really do enjoy his presentations, but it's entertainment, not "science" in the sense of it providing answers to questions, because it doesn't. In fact, it doesn't even raise new questions because the original questions stand as they did - from the beginning of time.
All we really know is that we don't know, that we never knew, and what it seems (at least I think) we'll never know: the meaning of it all. We're not closer today to understanding the meaning of it all then the 1st observers were.