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Mathematical Proof That the Universe Could Come From Nothing
TaleSlinger writes: One of the great theories of modern cosmology is that the universe began in a "Big Bang", but the mathematical mechanism by which this occurred has been lacking. Cosmologists at the Wuhan Institute have published a proof that the Big Bang could indeed have occurred spontaneously because of quantum fluctuations. "The new proof is based on a special set of solutions to a mathematical entity known as the Wheeler-DeWitt equation. In the first half of the 20th century, cosmologists struggled to combine the two pillars of modern physics— quantum mechanics and general relativity—in a way that reasonably described the universe. As far as they could tell, these theories were entirely at odds with each other.
At the heart of their thinking is Heisenberg's uncertainty principle. This allows a small empty space to come into existence probabilistically due to fluctuations in what physicists call the metastable false vacuum. When this happens, there are two possibilities. If this bubble of space does not expand rapidly, it disappears again almost instantly. But if the bubble can expand to a large enough size, then a universe is created in a way that is irreversible. The question is: does the Wheeler-DeWitt equation allow this? "We prove that once a small true vacuum bubble is created, it has the chance to expand exponentially," say the researchers.
At the heart of their thinking is Heisenberg's uncertainty principle. This allows a small empty space to come into existence probabilistically due to fluctuations in what physicists call the metastable false vacuum. When this happens, there are two possibilities. If this bubble of space does not expand rapidly, it disappears again almost instantly. But if the bubble can expand to a large enough size, then a universe is created in a way that is irreversible. The question is: does the Wheeler-DeWitt equation allow this? "We prove that once a small true vacuum bubble is created, it has the chance to expand exponentially," say the researchers.
The nothing they are referring to is mass-energy. I think that basically they have mathematically confirmed the theory that a cold, empty false-vacuum universe could spontaneously spawn a bubble of stable true vacuum filled with the seething energy that eventually cooled to become the universe we see today.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Our brains were made for the 4 F's: fighting, fleeing, foraging and reproducing. Understanding of quantum mechanics was not a driving factor, so we just have to accept that we don't understand.
there is always the question 'but what caused that'? really? there is "always" this question only if you continue to think about the world in the same mindset.
you don't have to search for an answer in the world through Newtonian glasses. "caused" implies causation. causation implies a before, and an after. first there is the cause, then there is its effects. abstract ideas like before and after are looking at the world from a point of view of LINEAR time.
if you truly study relativity
If you truly study relativity, you'll see the words "causality" and "causal" used. It's not a strictly Newtonian idea. As long as there's no faster-than-light travel, "X happens before Y" is an invariant - it's true in all reference frames.
At least mathematically speaking, there are solutions to the equation of general relativity that have "closed timelike curves", so you could get causality violations, although those solutions might not be realistic (e.g., infinite rotating cylinders). See, for example, the Wikipedia page on Tipler cylinders, and the references to which it links.
In our experience, there's always a next question. I wouldn't call that a paradox. That's like saying driving down the road is a paradox because once you finish a mile, there's another mile.
If we can say for certainty that our universe was created in this quantum fluctuation we answered a question. It raised another question about what is fluctuating, but that question doesn't invalidate the first. We moved ahead.
Depends what you mean by nothing. by standard measures of "mass" or "energy" quantum fluctuations are pretty much nothing. In fact I'm pretty sure virtual particle pairs are *exactly* nothing if measured from a sufficient distance.
There's a joke attributed to Abraham Lincoln: Q: If you call a tail a leg, how many legs does a dog have? A: Four. Calling a tail a leg does not make it one.
Nothing in ordinary parlance (headlines, say) means an absolute absence, which is an empty concept, like the Philosopher's Stone or an honest politician. You don't get to decide for the sake a headline that it means something else. Only grasping little scumbag shills do that, people who are so fundamentally and thoroughly debased that they turn everything they touch--even language--into garbage.
"Pretty much nothing" is not "nothing". "In terms of mass and energy" is not a relevant restriction. The quantum vacuum is rich in properties. There is absolutely no basis to ignore those properties for the sake of a dishonest, misleading and confusing headline. It's like people who say "Before Europeans arrived North America had no people in it!" Which is true, for a certain value of "people". This is why precision in language matters, because there are people who actually say things like that to the considerable detriment of their fellow-humans.
"From a sufficient distance" would mean "infinity" if you want to talk about asymptotically vanishing properties of the vacuum, which would still leave all the other properties, so again: it isn't clear why anyone would dishonestly and stupidly restrict the discussion to one particular set of properties unless they wanted to dishonestly and stupidly made a false, dishonest and stupid claim that "the universe came from nothing!"
So other than being dishonest, stupid and wrong, there is nothing at all dishonest, stupid and wrong abut the claim "the universe came from nothing."
Blasphemy is a human right. Blasphemophobia kills.
There was no before. Time was created with the Big Bang. Otherwise you are saying the Big Bang occured in a pre-existing universe, which is not the case. Then you have to ask yourself about this pre-existing universe and how it was created and so on. The before question is pointless.
Achille Talon
Hop!
And that's the paradox. There is ALWAYS the question "but what caused THAT?" with no ultimate answer more satisfactory than a meta-physicist can come up with.
See, you're thinking classically. Causality must be maintained. But causality is an artifact of the existence of time. The big bang created time as well.
It would be like a stick figure on a piece of paper saying "Ok, so I was drawn by a giant pencil. But where IS the pencil?!? I can look to the top and bottom of the paper... to the right and left... there is no giant pencil! Therefor it cannot exist."
There actually *is* a real problem here. At least if you consider space and time as parts of the universe. If there is no space and no time, then you can't have quantum fluctuations.
My guess is that the actual universe is eternal, and that space and time exist without (most?) of the other features of the universe. But that they can be distorted by mass and energy. This essentially solves the problem as I understand it. There is the question of size in the absence of matter and a few other problems.
If my guess is correct, any "universe" that's created by this process is temporary. (What are a few billion years to eternity?) What's not clear is what the constraints are. Can a new universe be caused (or happen) to erupt within an existing universe? The probability of each eruption at any one point would necessarily be extremely small (or it wouldn't match observations)...but this doesn't mean it couldn't happen, or that it couldn't be caused. What the effects would be are difficult to contemplate. Does the eruption cause new space and time to be created, pushing pre-existing stuff out of the way, or does it occur within the same space-time? Etc.
P.S.: Whenever you get a singularity you get the laws of physics breaking down because division by zero is an invalid operation. But if Heisenberg's uncertainty rules, then you will never actually get exactly onto the singularity, so the laws don't break down. (You can divide by arbitrarily small numbers, as long as they aren't actually zero.) Sometimes other tricks are used to avoid this problem (see renormalization), but that's the simple way to say it.
P.P.S.: If you actually read and understand Einstein's work you don't realize that ordinary linear time is an illusion, you realize instead that it's a pretty precise statement of the way things work at low energy levels. It just doesn't work as you approach certain boundaries (like the speed of light, Schwartzhild boundary strength gravity, etc.). This is predictable because we never experience those boundaries. If you want an actual illusion, think about the way electromagnetic waves are translated into color sensations.
P.P.S.: To reiterate, the laws of physics do not break down near the Big Bang, only *AT* it. And Heisenberg uncertainty offers a way to finesse that problem.
I think we've pushed this "anyone can grow up to be president" thing too far.