Is There a Possibility of Quantum Events Creating Cats?

[clarkvangilder]

Is Quantum Mechanics robust enough to warrant the belief that given enough observations, somewhere in the universe, at least one cat (or anything for that matter) has come into existence via quantum fluctuation?

If so, then P(C) = P(C | N)*P(N), where C = cat, N = # observations. If N = infinity, then it seems that you could get anything that you want, and P(C) = 1. However, if N < infinity, then at what point would P(C) < 1?

This seems wrong to me; but I cannot put my finger on it. I sense that something is wrong in the math, and/or that something is wrong with the Physics. Thoughts?

 

[Nugatory]

This seems wrong to me; but I cannot put my finger on it. I sense that something is wrong in the math, and/or that something is wrong with the Physics.

Vacuum fluctuations aren't what you're thinking they are and they don't do what you're thinking they do. You might give this Insights article a try: https://www.physicsforums.com/insights/vacuum-fluctuation-myth/

 

[clarkvangilder]

Yes. Thank you, that article helps a bit. There does seem to be a persistent belief that quantum mechanical probability waves are real waves delivering real particles that MUST really correspond to physical actualities in time. Is it the case that a probability wave of this sort truly carries the information to convert my mother into a cat? Some think so; but I think that they are bonkers. Even if it did carry that information, it seems that other factors prevent such a transition. Back to the books for me.

 

[ZapperZ]

Yes. Thank you, that article helps a bit. There does seem to be a persistent belief that quantum mechanical probability waves are real waves delivering real particles that MUST really correspond to physical actualities in time.

Whose persistent belief is that?

The wavefunction exists in a configuration (Hilbert) space. What makes you think from such a description that these are "real waves"?

Zz.

 

[clarkvangilder]

I do not think for one second that probability waves are real waves; but I do talk with people who think that they are, and that they actually exist outside of our minds. There seems to be some belief among the experts that the waves are real; but there also seems to be plenty of experts that disagree. I guess this boils down to the the reality of the QM p-wave, and the debate over which of the 8 or 9 interpretations of QM are true, if any. Personally, I think that they are really cognitive things (meaning only that I think of it) that correspond to physical things. Nothing else. They describe particles rather than provide them. I'd like to find a source that says so explicitly.

 

[ZapperZ]

I do not think for one second that probability waves are real waves; but I do talk with people who think that they are,

Who exactly are these "people"?

and that they actually exist outside of our minds.

What in the world does that mean?

There seems to be some belief among the experts that the waves are real;

Can you please provide sources for these "experts"?

Personally, I think that they are really cognitive things (meaning only that I think of it) that correspond to physical things. Nothing else. They describe particles rather than provide them. I'd like to find a source that says so explicitly.

I have no idea what this means, especially when it lacks any reference support.

Zz.

 

[clarkvangilder]

Whose persistent belief is that?
Zz.

http://phys.org/news/2012-04-quantum-function-reality.html

 

[clarkvangilder]

I have no idea what this means, especially when it lacks any reference support.

Zz.

Probability waves are math, not physical reality. Math and Physics are at best, representations of reality.

 

[ZapperZ]

http://phys.org/news/2012-04-quantum-function-reality.html

Then we have a very different interpretation of what is "real".

Please note that when you ask about the quantum mechanical probability WAVES, you are referring to a specific entity in QM. You are not referring to the entire quantum formalism. You asked if these waves are REAL. You are not asking of QM's formalism is real.

We do NOT measure quantum waves. We measure the OBSERVABLES that are described by these wave function. There is a difference.

The reference you referred to is the idea of realism, and whether the classical idea of realism (i.e. a definite value already exists even if we don't measure it) is still valid. This is NOT a question on whether the probability waves are real!

As is the case, what you ask is as important as the answer you seek. Otherwise, confusion and confusing discussion like this will occur. You need to figure out what exactly are you trying to ask here.

Zz.

 

[clarkvangilder]

Whose persistent belief is that?

The wavefunction exists in a configuration (Hilbert) space. What makes you think from such a description that these are "real waves"?

Zz.

http://www.nature.com/news/quantum-physics-what-is-really-real-1.17585

 

[ZapperZ]

http://www.nature.com/news/quantum-physics-what-is-really-real-1.17585

The tests being used to work that out are extremely subtle, and have yet to produce a definitive answer. But researchers are optimistic that a resolution is close. If so, they will finally be able to answer questions that have lingered for decades. Can a particle really be in many places at the same time? Is the Universe continually dividing itself into parallel worlds, each with an alternative version of ourselves? Is there such a thing as an objective reality at all?

OBSERVABLES and classical realism!

https://www.physicsforums.com/threads/possibility-of-quantum-event.898501/#post-5653332

Zz.

 

[clarkvangilder]

I am not trying to confuse anyone ZapperZ ... just trying to come to a better understanding, and therefore give a better response to the persons that I am referring to. I am not sure why you are upset with me, but it is becoming quite a bother. If you could just answer my questions without chastising me, that would be appreciated; otherwise, please move on and let someone else help me out.

 

[clarkvangilder]

I started this topic with a question about can QM provide us with warrant for a belief that a thing can spontaneously transition into another thing. I DO NOT think that it can; but others claim that this is so. They are convinced that QM can somehow do this. I have no idea why; but would like to offer more than what I have done so far, which is to point out that p-waves do not do this. Is there something else in QM that would warrant such a ridiculous belief?

 

[ZapperZ]

I am not trying to confuse anyone ZapperZ ... just trying to come to a better understanding, and therefore give a better response to the persons that I am referring to. I am not sure why you are upset with me, but it is becoming quite a bother. If you could just answer my questions without chastising me, that would be appreciated; otherwise, please move on and let someone else help me out.

The problem here is that YOU are the one who is confused. I spent time and effort in my previous post trying to untangle this confusion. You seem to have ignored it.

Please do not provide me anymore references, because none of these are addressing what I was asking for. You are confusing the idea of non-classical quantum realism, with the idea that people are actually measuring these "probability WAVES". We do not measure these waves. We measure these "observables", such as position, energy, momentum, etc...

I would think that you want to understand this first. If you do not, then you may ignore all of my posts here.

Zz.

 

[secur]

Is Quantum Mechanics robust enough to warrant the belief that given enough observations, somewhere in the universe, at least one cat (or anything for that matter) has come into existence via quantum fluctuation?

It may be worthwhile to point out that "Boltzmann brains" is a similar idea, although it's about thermodynamics not QM. Google it if interested.

 

[clarkvangilder]

It may be worthwhile to point out that "Boltzmann brains" is a similar idea, although it's about thermodynamics not QM. Google it if interested.

True. Isn't the Boltzmann Brain thing more of a reduction ad absurdism against what I am inquiring about. At least that is my current understanding of that idea.

I am looking for a set of reasons to deny that QM can provide warrant for the belief that anything, such as a rock or planet can either pop into existence from "nothing" (so to speak), or that a rock or planet could transition to something else, like a cat. I keep running into people who are or have been convinced that QM provides a warrant for such belief, and it seem outrageous to me.

 

[Jilang]

Well, cats do appear from planets don't they? It just takes some time.

 

[Nugatory]

I am looking for a set of reasons to deny that QM can provide warrant for the belief that anything, such as a rock or planet can either pop into existence from "nothing" (so to speak), or that a rock or planet could transition to something else, like a cat.

That's easy... Pick up any first year textbook, see if it says anything even remotely like that. It won't.

I keep running into people who are or have been convinced that QM provides a warrant for such belief, and it seem outrageous to me.

Many misconceptions about quantum mechanics have been passed down from one popular science writer to another. This happens with just about any technical subject, of course, but QM does attract an unusual number of distortions.

 

[clarkvangilder]

I have looked at a few introductory textbooks on the matter, and YES ... they DO NOT give any warrant for what I am asking about. It's the writing that comes higher in the food chain that worries me, such as the popular writers who are sometimes experts in the field.

This entire thread has been quite helpful though in exposing how the technical jargon gets muddled by semantic interpretations that do not correspond to the math. That is a tough thing to unravel, indeed.

 

[bhobba]

Probability waves are math, not physical reality. Math and Physics are at best, representations of reality.

Physics is written in the language of math but is not math.

II don't know what you mean by just math, in fact I see that written quite often and have zero idea what is meant. Math is a language. It's like saying Shakespeare is just English - you go - huh.

The question is are quantum states real like a table is real. That is very interpretation dependent. Without specifying an interpretation its an unanswerable question.

Thanks
Bill

 

[bhobba]

I am looking for a set of reasons to deny that QM can provide warrant for the belief that anything, such as a rock or planet can either pop into existence from "nothing" (so to speak), or that a rock or planet could transition to something else, like a cat. I keep running into people who are or have been convinced that QM provides a warrant for such belief, and it seem outrageous to me.

That's because you are asking the wrong questions. Of course things can pop into existence from 'nothing' so to speak eg photon number are not conserved. All of a sudden an atom can spontaneously emit a photon that was not there before. The reason lies in Quantum Field Theory where the electron is coupled to the quantum EM field that permeates all space. Work through the math and there is a definite chance this will happen - in fact 100% for sure it will definitely happen - its just a matter of when.

Can cats pop into existence like a photon? Maybe - but with a probability so close to zero you can forget it. Even in classical physics there is a chance all the atoms in the air will travel in the same direction and lift you up - the chance though is so negligible you can forget it.

In physics there are quantities so close to zero it is for all practical purposes zero. Don't be too worried if you don't get it yet, some for some reason never seem to get that one even though its used in applied math (not just physics but many area where math is used) all the time - and some (admittedly very few) are highly qualified professionals who argue since its not exactly zero you can't assume it is so your explanation where its a very small value so is taken as zero is wrong.

Thanks
Bill

 

[clarkvangilder]

I don't know what you mean by just math, in fact I see that written quite often and have zero idea what is meant. Math is a language. It's like saying Shakespeare is just English - you go - huh.

I agree that math is just a language...one of many representational systems. It does not exist like objects do. We think of ways to describe objects, motion of objects, etc. Math is just one way to do that.

 

[clarkvangilder]

That's because you are asking the wrong questions.

OK...then what are the right questions that I should be asking then?

While I wait, how about these?

1. Is it true that the likelihood of virtual particles popping into and out of existence is 1 since it happens all of the time? Casimir Effect? Based on experiments, it seems silly to question that empirical fact that conforms perfectly well to theory.

2. Some macroscopic object popping into existence is nonsense because the quantum foam does not produce such things? You would need the quantum foam to give you everything that is needed for magic to happen elsewhere?

 

[weirdoguy]

virtual particles

Virtual particles do not exist, there are plenty of threads about that issue.

 

[Jilang]

Ask yourself this. When you watch the television are they the same photons hitting your retina as the ones that were bouncing off the actors?
If you would like to stick to a particle model entirely I can't see how one could dispense with virtual particles..for how likely is it that a detected electron is the one you started with?

 

[clarkvangilder]

That's easy... Pick up any first year textbook, see if it says anything even remotely like that. It won't.

I started looking into that, and am curious what piece(s) of math in particular represents (or is) a quantum fluctuation.

I have been reading and re-reading the quantum fluctuation myth thread; but do not recall anything specific about the actual math that a fluctuation is, or is referring to. In first-year-textbook context, is it in the wave function, the probability function, the Fourier functions, all the above, etc?

 

[clarkvangilder]

I stumbled onto this article [http://physics.aps.org/articles/pdf/10.1103/Physics.8.6] in an effort to revisit first-course level Quantum Physics by looking at the basic rules, and in particular, inequalities like Bell and Leggett-Garg. The Leggett-Garg test really grabbed my attention relative to the way that I started this thread with a question about macroscopic objects popping into existence due to a quantum fluctuation, and thus led me to this article.

Though I am not yet fully understanding why that is not only false; but NOT what fluctuations even do; and though I believe as stated elsewhere that fluctuations happen in the math rather than in quantum reality (hope I got that right finally), I am still curious how one could refute the proposal that "the probability of a cat popping into existence from the quantum foam is 1" using only only introductory Quantum Physics ideas/rules/methods.

 

[bhobba]

I am still curious how one could refute the proposal that "the probability of a cat popping into existence from the quantum foam is 1" using only only introductory Quantum Physics ideas/rules/methods.

I don't know what you mean by quantum foam, but as I mentioned before it is possible that there is a very very small probability of a cat popping into existence. That being the case if you wait long enough then yes there is a dead cert it will happen. Note the - use of possible here and the maybe I used before - by this is meant we do not yet know the complete laws of nature - to be specific we do not know what's going on below the Plank scale - above it - yes - below it is a mystery - for now. We need to know those before deciding if things like cats can suddenly pop into existence - maybe - maybe not.

I will state it plainly. YOU CAN"T REFUTE THE IDEA OF A CAT JUST POPPING INTO EXISTENCE. Its just very unlikely or it maybe impossible. We don't know.

Again I think you are contused a bit by it being just math. In physics there is no thing as just math. Math is a language. In that language certain lines in a Feynman Diagram which is the pictorial representation of a mathematical series, called a Dyson series, are called virtual particles. They could have just as easily been called Jaberwocky's - it makes no difference - its just a name. They are not what we usually call particles ie they do not register on particle detectors. However the name is a suggestive aid to intuition in solving certain problems. For example thinking of them as popping into and out of existence in positron electron pairs around an electron means they exert a screening effect on the electrons charge explaining why as you get closer to an electron its charge increases. Its a wrong intuitive answer - meaning the reasoning is incorrect but the result is right - the real reason is due to the cutoff in re-normalization. John Baez is fond of saying you learn the intuitive reason, then the real reason, then when you are very experienced you understand they are the same - that is when you are at the advanced level.

Thanks
Bill

 

[durant35]

I don't know what you mean by quantum foam, but as I mentioned before it is possible that there is a very very small probability of a cat popping into existence. That being the case if you wait long enough then yes there is a dead cert it will happen. Note the - use of possible here and the maybe I used before - by this is meant we do not yet know the complete laws of nature - to be specific we do not know what's going on below the Plank scale - above it - yes - below it is a mystery - for now. We need to know those before deciding if things like cats can suddenly pop into existence - maybe - maybe not.

I will state it plainly. YOU CAN"T REFUTE THE IDEA OF A CAT JUST POPPING INTO EXISTENCE. Its just very unlikely or it maybe impossible. We don't know.

Again I think you are contused a bit by it being just math. In physics there is no thing as just math. Math is a language. In that language certain lines in a Feynman Diagram which is the pictorial representation of a mathematical series, called a Dyson series, are called virtual particles. They could have just as easily been called Jaberwocky's - it makes no difference - its just a name. They are not what we usually call particles ie they do not register on particle detectors. However the name is a suggestive aid to intuition in solving certain problems. For example thinking of them as popping into and out of existence in positron electron pairs around an electron means they exert a screening effect on the electrons charge explaining why as you get closer to an electron its charge increases. Its a wrong intuitive answer - meaning the reasoning is incorrect but the result is right - the real reason is due to the cutoff in re-normalization. John Baez is fond of saying you learn the intuitive reason, then the real reason, then when you are very experienced you understand they are the same - that is when you are at the advanced level.

Thanks
Bill

As a scientific possibility, how would the things happening on the Planck scale have anything to do with fluctuations?

 

[bhobba]

As a scientific possibility, how would the things happening on the Planck scale have anything to do with fluctuations?

But that's not what was said.

The query was is it possible for a cat to pop into existence. Some particle numbers are conserved, some not. If what's going on below the Planck scale allows particle numbers of the particles that make up a cat to not be conserved then it may (emphasis may) be possible for things like a cat to pop into existence.

Basically we do not know.

Thanks
Bill

 

[durant35]

But that's not what was said.

The query was is it possible for a cat to pop into existence. Some particle numbers are conserved, some not. If what's going on below the Planck scale allows particle numbers of the particles that make up a cat to not be conserved then it may (emphasis may) be possible for things like a cat to pop into existence.

Basically we do not know.

Thanks
Bill

Yes, I understand that was the query. I mentioned fluctuations because that is the word used most oftenly for "thing coming into existence from nothing", like the cat in the example you said.

Unfortunately, I don't understand what you mean by 'particle numbers of the particles'. So going with this conclusion it might be possible that micro-stuff can pop into existence, but macro stuff like a cat cannot? Could you elaborate?

 

[bhobba]

Yes, I understand that was the query. I mentioned fluctuations because that is the word used most oftenly for "thing coming into existence from nothing", like the cat in the example you said.

Unfortunately, I don't understand what you mean by 'particle numbers of the particles'. So going with this conclusion it might be possible that micro-stuff can pop into existence, but macro stuff like a cat cannot? Could you elaborate?

Some particles like photons pop in and out of existence. Their total number is not conserved. As far as we can tell that does not apply to say electrons - their number is fixed. Now for a cat to pop into existence electrons need to pop into existence which is not possible since their number is conserved. But that is as far as we can tell today. Their may be something going on below the Planck scale that means its not exactly conserved so it may be possible.

Its that simple.

Thanks
Bill

 

[durant35]

Some particles like photons pop in and out of existence. Their total number is not conserved. As far as we can tell that does not apply to say electrons - their number is fixed. Now for a cat to pop into existence electrons need to pop into existence which is not possible since their number is conserved. But that is as far as we can tell today. Their may be something going on below the Planck scale that means its not exactly conserved so it may be possible.

Its that simple.

Thanks
Bill

When you say it that way it really seems simple.

But why do cosmologists like Sean Carroll consider any type of particle popping into existence like a real possibility when considering Boltzmann brains and other macroscopic objects? Is it because the possibility you mentioned which depends on Planck scale?

And what about cats popping into existence from a bunch of disorganized atoms? For instance in the far future there may be bunch of atoms colliding in a high entropical state, can similar reasoning be applied to forming of cats and other structured objects (either by quantum or thermal fluctuations) from a bunch of atoms?

 

[bhobba]

But why do cosmologists like Sean Carroll consider any type of particle popping into existence like a real possibility when considering Boltzmann brains and other macroscopic objects?

Beats me. I don't read that sort of stuff. Sounds like misuse of virtual particles to me.

And what about cats popping into existence from a bunch of disorganized atoms? For instance in the far future there may be bunch of atoms colliding in a high entropical state, can similar reasoning be applied to forming of cats and other structured objects (either by quantum or thermal fluctuations) from a bunch of atoms?

Well that may be possible under known laws.

Added later
Did a bit of reading. Here is what was said 'And he closes by noting that our understanding of the early universe will have to improve before we can answer these questions.' Understanding the early universe means understanding the Planck scale - we don't - yet.

Thanks
Bill

 

[mikeyork]

Things don't "pop into existence" except in certain very special cases called transitions. And these have to obey certain rules such as conservation of energy, momentum, angular momentum, charge and a host of other quantum numbers. Whatever then "pops into existence" is accompanied by an appropriate change in the quantum numbers of whatever else is left behind in order to obey those conservation rules. Examples are radio-active decay and particle collisions. Even chemical reactions fall into this category. Cats (kittens) "pop into existence" through a complex chain of chemical reactions called conception and birth with conservation rules applying at every link in the chain.

 

[clarkvangilder]

Things don't "pop into existence" except in certain very special cases called transitions. And these have to obey certain rules such as conservation of energy, momentum, angular momentum, charge and a host of other quantum numbers. Whatever then "pops into existence" is accompanied by an appropriate change in the quantum numbers of whatever else is left behind in order to obey those conservation rules. Examples are radio-active decay and particle collisions. Even chemical reactions fall into this category. Cats (kittens) "pop into existence" through a complex chain of chemical reactions called conception and birth with conservation rules applying at every link in the chain.

Yes! This seems to me to be closer to the truth about the chances of obtaining a cat from the quantum _____________. There seems to be NO doubt that ALL of the particles needed can come from the quantum ___________; however, a complex macroscopic structure like a cat comes about through a longer and more complicated series of thermal fluctuations that would be understood classically.

BTW ... I am using "the quantum ____________" as a placeholder for what I do not understand. In NO way am I wanting to promote the fluctuation myth that has been so eloquently debunked in another discussion in the PF.

Also, I DO NOT dispute that when it comes down to it, we simply DO NOT, as Bill said, know.

 

[StandardsGuy]

Vacuum fluctuations aren't what you're thinking they are and they don't do what you're thinking they do. You might give this Insights article a try: https://www.physicsforums.com/insights/vacuum-fluctuation-myth/

So I take it that you don't think the universe came about from a quantum fluctuation. I was led to believe that this was a popular belief, though not one of mine.

 

[bhobba]

So I take it that you don't think the universe came about from a quantum fluctuation.

Its exactly as he said.

The theory you are thinking of is tunneling in the false vacuum:
https://en.wikipedia.org/wiki/False_vacuum

It is often said to be caused by quantum fluctuations but that is just loose terminology often found in popularization's and even otherwise good articles like the above.

Thanks
Bill

 

[StandardsGuy]

Its exactly as he said.

The theory you are thinking of is tunneling in the false vacuum:
https://en.wikipedia.org/wiki/False_vacuum

It is often said to be caused by quantum fluctuations but that is just loose terminology often found in popularization's and even otherwise good articles like the above.

Thanks
Bill

I was looking for clarification on what he said. Your link talks about the universe disappearing, not coming into existence. So I take it that YOU think it is more likely that the universe will disappear than a cat will pop into existence. Am I correct?

 

[bhobba]

I was looking for clarification on what he said. Your link talks about the universe disappearing, not coming into existence. So I take it that YOU think it is more likely that the universe will disappear than a cat will pop into existence. Am I correct?

From the link:
Expansion of bubble
Any increase in size of the bubble will decrease its potential energy, as the energy of the wall increases as the surface area of a sphere {\displaystyle 4\pi r^{2}} but the negative contribution of the interior increases more quickly, as the volume of a sphere {\displaystyle \textstyle {\frac {4}{3}}\pi r^{3}}Therefore, after the bubble is nucleated, it quickly begins expanding at very nearly the speed of light. The excess energy contributes to the very large kinetic energy of the walls. If two bubbles are nucleated and they eventually collide, it is thought that particle production would occur where the walls collide. The tunnelling rate is increased by increasing the energy difference between the two vacua and decreased by increasing the height or width of the barrier.

It doesn't explicicitly state this is how the universe was born the following makes it explicit:
https://ned.ipac.caltech.edu/level5/Guth/Guth3.html

'Once a patch of the early Universe is in the false vacuum state, the repulsive gravitational effect drives the patch into an inflationary period of exponential expansion. To produce a universe with the special features of the Big Bang discussed above, the expansion factor must be at least about 1025. There is no upper limit to the amount of expansion. Eventually the false vacuum decays, and the energy that had been locked in it is released. This energy produces a hot, uniform, soup of particles, which is exactly the assumed starting point of the traditional Big Bang theory. At this point the inflationary theory joins onto the older theory, maintaining all the successes for which the Big Bang theory is believed.'

It is how the big bang started and the mechanism of the so called 'universe from a fluctuation'. It leads more naturally to continuing inflation type theories where universes are being born all the time.

The point is while loose terminology like quantum fluctuation is used its really well known quantum tunneling type effects.

Thanks
Bill

 

[StandardsGuy]

From the link:
Expansion of bubble
Any increase in size of the bubble will decrease its potential energy, as the energy of the wall increases as the surface area of a sphere {\displaystyle 4\pi r^{2}} but the negative contribution of the interior increases more quickly, as the volume of a sphere {\displaystyle \textstyle {\frac {4}{3}}\pi r^{3}}Therefore, after the bubble is nucleated, it quickly begins expanding at very nearly the speed of light. The excess energy contributes to the very large kinetic energy of the walls. If two bubbles are nucleated and they eventually collide, it is thought that particle production would occur where the walls collide. The tunnelling rate is increased by increasing the energy difference between the two vacua and decreased by increasing the height or width of the barrier.

It doesn't explicicitly state this is how the universe was born the following makes it explicit:
https://ned.ipac.caltech.edu/level5/Guth/Guth3.html

'Once a patch of the early Universe is in the false vacuum state, the repulsive gravitational effect drives the patch into an inflationary period of exponential expansion. To produce a universe with the special features of the Big Bang discussed above, the expansion factor must be at least about 1025. There is no upper limit to the amount of expansion. Eventually the false vacuum decays, and the energy that had been locked in it is released. This energy produces a hot, uniform, soup of particles, which is exactly the assumed starting point of the traditional Big Bang theory. At this point the inflationary theory joins onto the older theory, maintaining all the successes for which the Big Bang theory is believed.'

It is how the big bang started and the mechanism of the so called 'universe from a fluctuation'. It leads more naturally to continuing inflation type theories where universes are being born all the time.

The point is while loose terminology like quantum fluctuation is used its really well known quantum tunneling type effects.

Thanks
Bill

Thanks, Bill. I didn't read that far. I read:

"In a 2005 paper published in Nature, as part of their investigation into global catastrophic risks, MIT physicist Max Tegmark and Oxford philosopher Nick Bostrom calculate the natural risks of the destruction of the Earth at less than 1 per giga year from all events, including a transition to a lower vacuum state. They argue that due to observer selection effects, we might underestimate the chances of being destroyed by vacuum decay because any information about this event would reach us only at the instant when we too were destroyed...
If measurements of these particles suggests that our universe lies within a false vacuum of this kind, then it would imply—more than likely in many billions of years[16][Note 1]—that it could cease to exist as we know it, if a true vacuum happened to nucleate.[16]"

So the universe would cease to exist as we know it. 'Disappeared' may not have been good terminology on my part. I'm less concerned about loose terminology than on the assumptions that people spit off as fact. An example would be the first sentence in your quote about repulsive gravity. It may be so, but it's not so just because a person with a phd proposed it. People want citations, but how good are they?

As you pointed out, it takes an initial vacuum before the tunneling can occur. Logically, that would have to have been in a prior universe, since there wasn't any vacuum here until it was created by the Big Bang. That prior universe would have its own time, so there WAS something before time in this universe. Would you be open to a Feynman Cat (a cat going backwards in time)? (Joking) Maybe a false cat?

Another quote from your link:
"In general, gravitation makes the probability of vacuum decay smaller; in the extreme case of very small energy-density difference, it can even stabilize the false vacuum, preventing vacuum decay altogether. We believe we understand this. For the vacuum to decay, it must be possible to build a bubble of total energy zero. In the absence of gravitation, this is no problem, no matter how small the energy-density difference; all one has to do is make the bubble big enough, and the volume/surface ratio will do the job..."

 

[bhobba]

Would you be open to a Feynman Cat (a cat going backwards in time)? (Joking) Maybe a false cat?

No. Particles or cats do not go backwards in time.

This idea of positrons being electrons going back in time is obvious nonsense as can be seen by the argument being reversible - an electron is a positron going backwards in time. Its another of those heuristic falsehoods the bedevil QFT.

And yes there was something before time in most modern cosmological theories - if before is appropriate without time. That's why when I hear this something from nothing nonsense then some philosophical mumbo jumbo either for or against it I sort of go - sigh. I remember one guy who constantly harped on you can't get something from nothing - its impossible and obviously so. I had to carefully explain modern theories but also just because in everyday life we don't see something from nothing it doesn't mean its not possible. He never got it.

Thanks
Bill