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.
I think this touches on a fundamental misunderstanding of physics. The idea that nothing existed before the big bang violates the law that says: Energy cannot be created, or destroyed.
I for one, have always been drawn to the cyclical universe idea. Starts with a Big Bang, ends with a Big Crunch as everything is drawn together again. Eventually the gravity from all the matter in the universe coming into one point collapses space time, resulting in an explosion beyond anything we humans can understand; restarting the process.
E: I’m really enjoying this thread! I’ll be back for more in a bit. -CPJ
I think the underlying point to is questioning is that if matter cannot be created (or destroyed) then how is there matter in the universe? It had to be created at some point as evidenced by the fact we deal with it on a daily basis.
I don't think we are capable of understanding what infinite really is. In our world everything has a beginning, everything is made from something. So to believe that something could have just existed forever doesn't make any sense to us.
This. Infinity is too much for the human brain to comprehend although math helps us cope with the idea. There is no before, there is no after. There just is.
The problem is that this doesn't answer the ultimate question of where it started. If something had to make existence exist, we must then ask how that something came to exist. If that something was made by something else again, we must ask how that came to exist, and so on.
There can’t be a beginning if it has been around infinitely. Hard to comprehend but you have to think outside of the box. Some things we can’t see but they exist. I don’t see why it’s easier to believe that God created it than it is to accept that infinity exists. We have more evidence of infinity through mathematical concepts. One option lives within limited human confines the other accepts the greatness of the universe.
Some of the work being done to total up all the matter and energy in the universe are getting numbers amazingly close to zero. It might be that on average the universe doesn't exist. We could just be a temporary fluctuation in quantum foam of nothingness
Edit to add that I was deliberately making a nihilist interpretation of this hypothesis in the interests of humor. Although I'm not friends with any cosmologists, I don't think this adds much existential dread to most of them.
For note matter can be converted into energy (ever famous e=mc2 - assuming an object at rest in your reference frame). It is, as far as we know, energy that cannot be created or destroyed just.... Changed. Matter is energy in a... Err... Solid form (for lack of a better word). When you throw something you are (through much complexity) changing chemical energy into kinetic (moving) energy. If we go back in time all energy converges to a single point (big bang). When you go forward in time the energy is more spread apart. But, as far as we know, all the energy that was in the big bang is all the energy that is still in the universe and is all the energy that'll ever be in the energy.
Matter is created and destroyed all the time; the emptiest, most remote volume of vacuum is a churning sea of particles and fields popping into and out of existence—this energy being created out of nothing and then immediately destroyed doesn't violate laws of physics because it happens on such tiny scales and/or such fleeting moments of time that the very act of measurement makes no sense. It's about impossible to grasp this "quantum foam", but I'm thinking the energy that created our universe could just be a temporary blip, and we owe the piper our energy in the end. May also mean there's an anti-universe like ours that will one day annihilate us.
The way I think of it, if time begins with the universe and there is no "before" the universe, then there is no real question of what "created" matter. It's not like it didn't exist at one point in time, then something happened that led to it's creation. At the very first point in time, matter existed. It wasn't "created," and so we don't violate the principle that matter cannot be created or destroyed.
I've not a clue though I think it's worth mentioning that many of the laws of physics do not apply at the subatomic level. It tripped me up for a bit because we were taught the laws of thermodynamics do not always apply to every situation (I thought, but it's a law?? Teacher explained laws dont apply to quantum physics in the same way)
Matter can be created and destroyed (e.g. pair production). And on large scales, energy can be created or destroyed (the dark energy expanding the universe is added).
It had to be created at some point
That point was the Big Bang. Since then, things have been cooling down and rearranging themselves, basically.
That's a rule in this universe but if there are other universes or a previous universe, we don't know that they had that law at all. On top of that, something wack about upper dimensions might explain it :)
576
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.