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As far as I understand, it is understood that throughout the universe there exists, what is known as, a quantum field from which, due to its fluctuations, temporary (pairs of) virtual particles continuously appear in a random, unpredictable (or should I say probabilistic?) fashion.

For my idea to have any viability, I am assuming that this quantum field is an intrinsic part of reality, that existed "before" or rather at the time of the Big Bang already. Is this a correct assumption? Or is it believed that this quantum field was "formed" at the time, or perhaps even later than, the moment of the Big Bang? I hope not.

Assuming the former, and also understanding that those pairs of virtual particles typically annihilate each other almost instantaneously, but sometimes actually create real particles — for instance in Hawking radiation — is it a far stretch to think that the Big Bang was possibly started by the highly improbable (but in an "infinite" timespan of underlying reality, likely to occur), cataclysmic event of a huge amount of virtual particle all appearing, either "at the same time", or in such a sequential manner, that they couldn't annihilate each other anymore and were destined to actually form large quantities of real particles?

David Z
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Decent Dabbler
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  • I tried really hard to understand what you're asking and what's going on in your mind in general. I have no chance. First, a quantum field is a description of natural phenomena, the basic object in a theory, and of course it exists everywhere and since the beginning if the theory is right. The quantum field theory was ultimately invalid too early after the Big Bang, for a short time, and had to be replaced by string theory whose basic blocks aren't quantum fields, at least not when you calculate it exactly. – Luboš Motl Dec 09 '12 at 05:59
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    Now, virtual particles aren't real particles, that's why we call them virtual, which is why it makes no sense to talk about their presence in the spacetime at a given moment. One may only talk about the presence of the real particles. A virtual particle is a part of a history in the middle of it, when it's not measured, and it contributes to the evolution of real particles, but one can't associate them with any "objective state" of the system or with any measurement. – Luboš Motl Dec 09 '12 at 06:01
  • Otherwise there have been many severe, extreme, and even cataclysmic events in the history of the Universe, lots of particles almost entirely annihilated, and so on, and so on, but why do you need to mix these things with notions - such as quantum fields and virtual particles - whose meaning is totally clearly completely incomprehensible to you? Isn't it a better idea to only use words whose meaning is actually clear to you? – Luboš Motl Dec 09 '12 at 06:03
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    @LubošMotl Perhaps I'm in over my head here, but, concerning your first response: are you saying that quantum field theory is not a viable theory (anymore?) and that it is replaced by string theory? (I'm not following what you are trying to say here.) Secondly: I think I understand your remark about virtual particles vs. spacetime. But, if it is believed that virtual particles can account for the loss of mass of black holes (due to Hawking radiation) by creating real particles, why wouldn't virtual particles also be able to create real particles at the time of the Big Bang? – Decent Dabbler Dec 09 '12 at 06:23
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    @fireeyedboy What Luboš means is run-of-the-mill, vanilla QFT is not the end-all, be-all of physics, and it is commonly accepted that it, like most of our theories, fails to be an accurate description of nature too close to the Big Bang; string theory may very well do better. That said, I think this is a valid question despite any potential misconceptions, though maybe it takes one person who's used to having misconceptions to understand another :) –  Dec 09 '12 at 07:30
  • @ChrisWhite Seeing you know a heck of a lot more about physics than I do, and still think my question is a valid one, that is reassuring! :) Thank you. And thank you for clarifying further. – Decent Dabbler Dec 09 '12 at 08:19
  • @fireeyedboy, virtual particles indeed account for many observations and important mechanisms but their becoming real is a very special thing that only happens near event horizons. There are event horizons in black holes; there may also be event horizons in cosmology and the "virtual to real" process is a reason behind the non-uniformity of the temperature of the cosmic microwave background explained by cosmic inflation. Your suggestion is somewhat similar to cosmic inflation but is too vague and maybe you should find and learn what cosmic inflation is. – Luboš Motl Dec 09 '12 at 09:19
  • @fireeyedboy The Big Bang Theory accounts for the origin of spacetime and energy and matter. For virtual particles to appear from no spacetime should not be possible, so I think the answer to your question is no. – resgh Dec 09 '12 at 09:32
  • @fireeyedboy And the fact that we still do not have a theory of quantum gravity, which should be significant in situations such as at or near the Big Bang, limits our ability to answer your question. – resgh Dec 09 '12 at 09:36
  • @LubošMotl "Your suggestion [...] is too vague" - Fair enough, I understand. Thank you for getting back at me and pointing me to cosmic inflation. That theory indeed sounds very similar to what I had in mind. – Decent Dabbler Dec 09 '12 at 18:37
  • @namehere "For virtual particles to appear from no spacetime should not be possible" Is that indeed the general consensus? Because the possibility of it would indeed be the premise for my idea to even begin to have any sort of merit. And so, if what you are saying is indeed the case, does that also imply that the quantum field and quantum fluctuations are part of spacetime, and not "outside" of spacetime, as an intrinsic part of underlying reality, so to speak? (Please excuse my rather clumsy terminology.) – Decent Dabbler Dec 09 '12 at 18:54
  • @fireeyedboy Well, quantum states are in the Hilbert space, not spacetime. But to predict something not in spacetime, I would consider highly unphysical. – resgh Dec 10 '12 at 01:16
  • @namehere But quantum states are constantly inferred from empirical observation, are they not? And just about any theory in physics is first hypothesized before either being empirically observed directly or inferred from empirical observation, no? I don't see the problem here. Could you expand on what you mean? Are you suggesting quantum states ought to be considered metaphysical mumbo-jumbo? Or am I completely misunderstanding you? I'm sorry if I appear to be way in over my head here. If I do, it's likely because I probably am. But I really like to understand what you are trying to say here. – Decent Dabbler Dec 11 '12 at 05:14
  • @fireeyedboy If a theory describes something independent with spacetime, would you consider it unphysical? That's what I mean. – resgh Dec 11 '12 at 06:01
  • @namehere No, not necessarily; unless I'm still completely missing your point. At the risk of sounding like some new-age fool, I guess the thing that I got out of reading about quantum fluctuations and virtual particles, is that this could very well be considered an intrinsic part of the unstable and probabilistic nature of reality, that we consequently are currently still witnessing inside spacetime. In other words, that spacetime is merely a result of this unstable reality. (Cont.) – Decent Dabbler Dec 11 '12 at 07:51
  • @namehere (Cont.) And so this, at least in my mind, wouldn't necessarily make this hypothetical state of quantum fluctuations "before" spacetime "unphysical". Hard to empirically test, because in the past, at the start of the Planck epoch? Sure. But not "unphysical" by definition. I would argue that without spacetime, a virtual particle popping in and out of existence, can still be considered a, ever so short (less than one Planck time), physical event. (I hope I've hereby properly understood what you were trying to get accross.) – Decent Dabbler Dec 11 '12 at 07:53
  • @fireeyedboy QFT doesn't explain spacetime. – resgh Dec 11 '12 at 08:02
  • @namehere So to conclude: if your argument is that without the existence of spacetime, there cannot be the event of virtual particles popping in and out of existence, than I'd have to agree with you. But I'm not convinced that that is the case. But I certainly can't back this up with anything concrete, as I simply don't have the underpinnings in physics, or mathematics. I was just curious whether my ideas made any sense at all in the field of physics, and if so, whether these possibilities are being studied by physicists. – Decent Dabbler Dec 11 '12 at 08:05
  • @namehere OK, I was not aware of this. Is this because it doesn't make any effort, or that it's outside of its scope, or that it simply can't (currently, or perhaps ever)? – Decent Dabbler Dec 11 '12 at 08:12
  • @fireeyedboy QFT describes the phase space, not spacetime. Thus, I do not think QFT can actually somehow 'create' spacetimes. – resgh Dec 11 '12 at 08:30

2 Answers2

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The idea that the universe is a vacuum flucuation has been around a long time. The first public mention of the idea I know of is from Edward Tryon in 1973, but I bet it had been discussed long before that. Do you have access to old copies of Nature? If so have a look at "Is the Universe a Vacuum Fluctuation?" by Edward Tryon, Nature 246, 396 - 397 (14 December 1973).

Alexander Vilenkin developed the idea further in 1982, and his paper is available online at http://mukto-mona.net/science/physics/a_vilinkin/universe_from_nothing.pdf.

The bottom line is that we don't understand the physics well enough to know if there is any foundation to these ideas, and no-one has come up with any experimental way to test them. I should note that the various theories of quantum gravity have come up with scenarios in which the universe wasn't created at the Big Bang but has existed (potentially at least) forever. From String Theory we have the ekpyrotic universe, and from loop quantum cosmology the idea that there might have been a Big Bounce.

I suspect most physicists would regard the question as philosophy rather than physics.

John Rennie
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    Thank you — very interesting. This got me thinking: how does Lawrence Krauss' idea, of a universe from nothing, stack up against Tryon/Vilenkin's ideas? Are Krauss' ideas also rooted in quantum-field theory? And are they approached from a similar angle as Tryon and Vilenkin's ideas? Or is Krauss coming at it from a whole other angle? – Decent Dabbler Dec 09 '12 at 20:57
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    I actually found the answers in this talk by Lawrence Krauss already. – Decent Dabbler Dec 10 '12 at 00:00
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The thing that appeals to me about this idea is , if there is some theoretical way the virtual pair can be kept apart, then we might assume an identical anti-universe was created. This would neatly explain why we don't observe equal quantities of matter and anti- matter in our universe. All the anti-matter is in the other universe outside of our observable event horizon.

The Big Bang and inflation result from the supermassive universe particle decaying/condensing/phase changing into the zoo of particles we observe today.

Ronald Swager
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  • I agree that the question of baryon asymmetry is far from being resolved, and that the principle of your solution would be a basis for a consistent explanation. Moreover, a sort of "second universe" is in view if one would admit that antimatter is simply moving backwards in time, i.e. in the opposite direction of our time arrow. However, the solution is not so simple, because apparently antimatter has been experimentally observed as moving in our direction of the time arrow. – Moonraker Jul 05 '16 at 19:27
  • Nevertheless, some solution according to the principle of your idea would encounter much less consistency problems than the current attempts for a solution. – Moonraker Jul 05 '16 at 19:27
  • The Rishon Model (https://en.wikipedia.org/wiki/Rishon_model) says there are equal amounts of matter and anti-matter in our Universe. Maybe there exists another Universe with the anti-particles of our Universe (anti-quarks, anti-leptons) present, which are also composed of equal amounts of matter and anti-matter (rishons and anti-rishons, just as in our Universe). I think rishons have no point structure (though not string-like) and maybe the Universe was so small (Planck scale, like the size of rishons), that the vacuum energy was that negative to cause inflation, and two Universes emerged. – Deschele Schilder Dec 22 '17 at 02:41