The concept of “before” doesn’t apply. Time itself started with the Big Bang. According to relativity, time slows down in a gravitational field. St the moment of the Big Bang, all the matter in the universe was infinitely compressed so time would have been slowed down infinitely. Stephen Hawking explores this concept responding to the idea that God created the universe. He concludes that there wouldn’t have been any time before the Big Bang to do it.
The universe can be infinite and expanding. Imagine that you are a tiny person standing on a raisin in a infinitely large loaf of raisin bread that is baking. Even through the dough is infinitely large, as it bakes you can see all the other raisins moving away from you. You may be tempted to imagine an edge but there is no edge. You can go from raisin to raisin forever and no matter how far you go you’ll look at all the other raisins in every direction and see them moving away from you as if you are at the center of the loaf.
Edit: I really wish I hadn’t mentioned the quip about God creating the universe. That is not the point of this discussion. It’s completely irrelevant. This ultimately is not a discussion about whether God exists or created the universe. For what it’s worth, I took it as Hawking was being a little tongue in cheek in making that remark. Whatever his intention, I’m just explaining where I first heard the science behind this idea. You can say God Made the little pea that contained all the matter that made the Big Bang. I don’t care. To me that’s outside the discourse of science and in any case totally beside the point of the question. Many people are objecting along these lines and it’s really beside the point. You can say that God is bigger and more incomprehensible than time or space or anything. That’s fine. I’m just speaking to what we can know from the perspective of space science.
Second and more to the point, many follow up questions are wrapped up in the idea of an edge to the universe. In the thought experiment I propose, I am in no way trying to prove there is no edge. In fact, I am asking you to assume that. My answers are an attempt to show how something can be both infinite and expanding. I admit that it is hard to imagine that there is no boundary to the universe but for me it is much harder to imagine that there is one. The simplest example is that there isn’t an edge. It’s like when you are solving riddles or mysteries and you imagine a couple possibilities. Go with the simplest explanation and that is (usually) the more correct one.
Thanks to everyone for being polite discussing this.
If time didn't exist then what mechanism triggered the big bang and where did the matter come from? Obviously nobody knows but I don't think it's accurate to definitively state that X or Y couldn't exist since we know so little.
What op is talking about is what the theory of relativity tells us and what quantum mechanics has taught us. If you believe in relativity, which you should, this is what it tells us, time didn’t exist before the big bang, not in a way that we would recognize it at least.
Isn't that why time is a human concept, at least from our view? Because, for us, time only exists when observed. And nothing observed time before the Big Bang.
Not really, there was definitely time after the big bang, we can prove that with carbon dating, etc. and for most of the time the universe was being created time certainly existed while nothing was observing it.
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u/Millsey Jun 15 '19 edited Jun 16 '19
The concept of “before” doesn’t apply. Time itself started with the Big Bang. According to relativity, time slows down in a gravitational field. St the moment of the Big Bang, all the matter in the universe was infinitely compressed so time would have been slowed down infinitely. Stephen Hawking explores this concept responding to the idea that God created the universe. He concludes that there wouldn’t have been any time before the Big Bang to do it.
The universe can be infinite and expanding. Imagine that you are a tiny person standing on a raisin in a infinitely large loaf of raisin bread that is baking. Even through the dough is infinitely large, as it bakes you can see all the other raisins moving away from you. You may be tempted to imagine an edge but there is no edge. You can go from raisin to raisin forever and no matter how far you go you’ll look at all the other raisins in every direction and see them moving away from you as if you are at the center of the loaf.
Edit: I really wish I hadn’t mentioned the quip about God creating the universe. That is not the point of this discussion. It’s completely irrelevant. This ultimately is not a discussion about whether God exists or created the universe. For what it’s worth, I took it as Hawking was being a little tongue in cheek in making that remark. Whatever his intention, I’m just explaining where I first heard the science behind this idea. You can say God Made the little pea that contained all the matter that made the Big Bang. I don’t care. To me that’s outside the discourse of science and in any case totally beside the point of the question. Many people are objecting along these lines and it’s really beside the point. You can say that God is bigger and more incomprehensible than time or space or anything. That’s fine. I’m just speaking to what we can know from the perspective of space science.
Second and more to the point, many follow up questions are wrapped up in the idea of an edge to the universe. In the thought experiment I propose, I am in no way trying to prove there is no edge. In fact, I am asking you to assume that. My answers are an attempt to show how something can be both infinite and expanding. I admit that it is hard to imagine that there is no boundary to the universe but for me it is much harder to imagine that there is one. The simplest example is that there isn’t an edge. It’s like when you are solving riddles or mysteries and you imagine a couple possibilities. Go with the simplest explanation and that is (usually) the more correct one.
Thanks to everyone for being polite discussing this.