The discussion centers on the theoretical possibility of wormholes having multiple mouths. Participants agree that a standard wormhole must have at least two mouths, typically defined as a black hole and a white hole. However, some suggest that a network of wormholes could be created where multiple mouths connect to various destinations. The feasibility of such networks remains speculative, with concerns about causality and the physical implications of manipulating wormhole mouths. References to external resources, such as the Wormhole FAQ, provide additional context on constructing multi-mouthed wormholes.
PREREQUISITESThe discussion is beneficial for theoretical physicists, astrophysicists, and students interested in advanced concepts of wormhole physics and their potential applications in space travel and cosmology.
Godspanther said:I have been reading up on wormholes and though I can't claim to understand every thing I've read there is one thing that I have to wonder about. from what I've read I understand that a wormhole has to have at least two mouths and that it is theoretically possible for the multiple mouths to be clustered together. Is it possible however for a single wormhole to have more than two mouths?
Godspanther said:what kind of effects, gravity, radiation, radio waves, distortions etc could one theoretically expect in the vicinity of a wormhole aperture?
HarryRool said:I saw this question and anwer in a http://www.webfilesuci.org/WormholeFAQ.html" . It describes how to a make a 3-mouthed wormhole and asserts that the procedure can be extended to any number of mouths.
Is it possible to create a network of wormholes in which any wormhole mouth could be used to reach multiple destinations directly?
Yes. Assuming that it’s possible to create a single wormhole, the creation of a network of many is not particularly far fetched. You would proceed as follows: 1) Create a wormhole that connects locations A and B. 2) Create another wormhole connecting locations A and C. There are now two wormhole mouths at the location A – one that leads to B and another that leads to C. 3) Move the A mouth of the AC wormhole into the A mouth of the AB wormhole until the A mouth of AC is at the throat of the AB wormhole. 4) You now have a wormhole network in which there is a non-stop connection between any of A, B, and C. Repeat the procedure to add other destinations. 5) Ease congestion at the throat nexus by expanding it (with additional exotic matter) and by adding an automated system that properly routes spacecraft based on their transmitted destination codes.
pseudo said:I don't think that wormholes might be having two mouths ! Basically a wormhole acts as a neck between its front mouth(blackhole) and its rear mouth(white hole). It is very hard to say that wormholes lie between two spaces i.e between two spacetime graphs. so the possibility of the third mouth could be between these two graphs but there exists no spacetime graph between two spaces ! so no possibility of the third mouth.
HarryRool said:I saw this question and anwer in a http://www.webfilesuci.org/WormholeFAQ.html" . It describes how to a make a 3-mouthed wormhole and asserts that the procedure can be extended to any number of mouths.Is it possible to create a network of wormholes in which any wormhole mouth could be used to reach multiple destinations directly?
Yes. Assuming that it’s possible to create a single wormhole, the creation of a network of many is not particularly far fetched. You would proceed as follows: 1) Create a wormhole that connects locations A and B. 2) Create another wormhole connecting locations A and C. There are now two wormhole mouths at the location A – one that leads to B and another that leads to C. 3) Move the A mouth of the AC wormhole into the A mouth of the AB wormhole until the A mouth of AC is at the throat of the AB wormhole. 4) You now have a wormhole network in which there is a non-stop connection between any of A, B, and C. Repeat the procedure to add other destinations. 5) Ease congestion at the throat nexus by expanding it (with additional exotic matter) and by adding an automated system that properly routes spacecraft based on their transmitted destination codes.
HarryRool said:I saw this question and anwer in a http://www.webfilesuci.org/WormholeFAQ.html" . It describes how to a make a 3-mouthed wormhole and asserts that the procedure can be extended to any number of mouths.
Is it possible to create a network of wormholes in which any wormhole mouth could be used to reach multiple destinations directly?
Yes. Assuming that it’s possible to create a single wormhole, the creation of a network of many is not particularly far fetched. You would proceed as follows: 1) Create a wormhole that connects locations A and B. 2) Create another wormhole connecting locations A and C. There are now two wormhole mouths at the location A – one that leads to B and another that leads to C. 3) Move the A mouth of the AC wormhole into the A mouth of the AB wormhole until the A mouth of AC is at the throat of the AB wormhole. 4) You now have a wormhole network in which there is a non-stop connection between any of A, B, and C. Repeat the procedure to add other destinations. 5) Ease congestion at the throat nexus by expanding it (with additional exotic matter) and by adding an automated system that properly routes spacecraft based on their transmitted destination codes.
ryan_m_b said:This is indeed far too speculative. If you could create wormholes then you could not put the mouth of one in the other. If you have two wormhole mouths of 1000kg mass and you sent 100kg through mouth A (so that it came out of mouth B) The mass of A would change to 1100kg and the mass of B to 900kg. If you put wormhole mouth C into A you would change B's mass to 0kg and thus destroy it. There was a thread on here a little while ago talking about this.
The other problem is causality. If you built a wormhole network (not by having the mouths in each other but having B physically close to C) you would have to be very careful not to arrange it so as to allow particles to enter their own past light cone. In theory you would either have just made a time machine or vacuum fluctuations would immediately destroy all the wormholes.
It is not certain whether or not wormholes could even exist however so talking too much about "wormhole physics" is bound to stray into over-speculation
Misericorde said:If you attached both mouths, wouldn't you have something like a Klein Bottle?
ryan_m_b said:What do you mean by attached? The two mouths of wormholes are linked from beginning to end, it is impossible to switch what they are linked to.
mdmaaz said:There's no theory stating that wormholes have more than two mouths. But I think it could be possible. Think about this, there's a network of three black holes, and three white holes, all connected by a single wormhole. kind of like the way many rivers flow into a single big river. That could be possible. If one were to enter anyone of those three black holes, we would randomly come out of anyone of the white holes.
Misericorde said:So are the mouths of a kaluza-klein manifold of the 'bottle' type; I was curious if that was what you were getting at. The mouth at either "end" is the same thing, but the topography is not the usual wormhole because it would feed into itself. I suppose this would be a kind of CTC, but I was asking a question, not posing an answer. I don't know much about this, you see.
ryan_m_b said:You're going to have to provide citations for that idea rather than analogy.
I think you have a misunderstanding though, Schwarzschild wormholes would result in a black hole and white hole. Traversable wormholes such as a Morris-Thorne wormhole link two points in space only requiring no black/white holes.
I don't know too much about it either so I'm not sure what the topography would be like. However if they could be made wormhole mouths would always be attached linking two points in space. Your first comment asking "if you attached them" is what I was replying to as there is no other way they can be. If that makes sense?
ryan_m_b said:This is indeed far too speculative. If you could create wormholes then you could not put the mouth of one in the other. If you have two wormhole mouths of 1000kg mass and you sent 100kg through mouth A (so that it came out of mouth B) The mass of A would change to 1100kg and the mass of B to 900kg. If you put wormhole mouth C into A you would change B's mass to 0kg and thus destroy it. There was a thread on here a little while ago talking about this.
The other problem is causality. If you built a wormhole network (not by having the mouths in each other but having B physically close to C) you would have to be very careful not to arrange it so as to allow particles to enter their own past light cone. In theory you would either have just made a time machine or vacuum fluctuations would immediately destroy all the wormholes.
It is not certain whether or not wormholes could even exist however so talking too much about "wormhole physics" is bound to stray into over-speculation
HarryRool said:Yes it's speculative alright, but only because the entire topic of wormholes is speculative, as was the topic of black holes for most of the 20th century.
The objection that you raise involving excess mass seems to be totally abatable, though. I think that you could compensate for the extra mass by throwing in more exotic matter. And you must assume that that exists, if you have already assumed that it's possible to make a single traversable wormhole.
As to your second point about causality, the same http://www.webfilesuci.org/WormholeFAQ.html" seems to have an answer for that:
Don’t quantum effects prevent wormholes from being turned into time machines?
No. It’s true that calculations seem to show that a wormhole-destroying feedback loop of virtual particles appears whenever a wormhole is configured as a time machine. But these calculations don’t assume the existence of the parallel universes that would have prevented the feedback. Even without this assumption, it’s possible to make the feedback arbitrarily small by replacing the single wormhole with a Roman ring of wormholes.
What is a Roman ring?
An arrangement of several wormholes that functions collectively as a time machine, even though no subset of the wormholes functions as one.
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This FAQ is an excerpt from a book that explains this in detail and cites the corresponding references in the physics literature.
This is based on calculations in semiclassical gravity though, and many physicists would argue they just suggest that semiclassical gravity is probably no longer a good approximation to quantum gravity in situations involving wormholes. For example, see this paper on Roman rings by wormhole expert Matt Visser (author of the textbook Lorentzian Wormholes: From Einstein to Hawking), where in the conclusion on p. 4 he writes: "My interpretation is perhaps a little different: I view this not as a vindication for time travel enthusiasts but rather as an indication that resolving issues of chronology protection requires a fully developed theory of quantum gravity [5]."HarryRool said:As to your second point about causality, the same http://www.webfilesuci.org/WormholeFAQ.html" seems to have an answer for that:
Don’t quantum effects prevent wormholes from being turned into time machines?
No. It’s true that calculations seem to show that a wormhole-destroying feedback loop of virtual particles appears whenever a wormhole is configured as a time machine. But these calculations don’t assume the existence of the parallel universes that would have prevented the feedback. Even without this assumption, it’s possible to make the feedback arbitrarily small by replacing the single wormhole with a Roman ring of wormholes.
What is a Roman ring?
An arrangement of several wormholes that functions collectively as a time machine, even though no subset of the wormholes functions as one.
ryan_m_b said:I really don't get the parallel universe thing and how that would help. If the wormhole connects to another universe then time travel won't apply.
If quantum fluctuations or even real particles would cause a wormhole to collapse then a roman ring wouldn't help, no matter how you do it when the QFs or real particles enter their own past light cone the wormholes will collapse.
HarryRool said:Yeah, there's a FAQ (answer) for that:
Isn’t time travel by wormhole or any other means impossible due to the paradoxes that it implies?
Not necessarily. Dealing with time travel paradoxes by conjecturing the impossibility of time travel is only one of three ways of resolving the issue. The other ways are:
1) Impose self consistency on classical physics: A time traveler cannot change the past because he was always part of it. When he attempts to change the past, his efforts will be thwarted by an apparent conspiracy of events. 2) Impose self consistency on quantum physics: A time traveler cannot change the past because all possible pasts have already occurred in parallel universes. When he attempts to change the past, his efforts will not seem to him to be thwarted. This is because he will have entered the past of a preexisting parallel universe in which he has already made the changes that he seeks to effect.
http://arxiv.org/abs/gr-qc/9702043" that the semi-classical calculation of the wormhole destroying feedback loop of virtual particles is unrealiable, because semi-classical calculations also show that these effects can be made arbitrarily small with a Roman ring. Here's the abstract for his 1997 paper entitled, "Traversable wormholes: the Roman ring":
"In this brief report I introduce a yet another class of geometries for which semi-classical chronology protection theorems are of dubious physical reliability. I consider a ``Roman ring'' of traversable wormholes, wherein a number of wormholes are arranged in a ring in such a manner that no subset of wormholes is near to chronology violation, though the combined system can be arbitrarily close to chronology violation. I show that (with enough wormholes in the ring) the gravitational vacuum polarization (the expectation value of the quantum stress-energy tensor) can be made arbitrarily small. In particular the back-reaction can be kept arbitrarily small all the way to the ``reliability horizon''---so that semi-classical quantum gravity becomes unreliable before the gravitational back reaction becomes large."
I view this not as a vindication for time travel enthusiasts but rather as an indication that resolving issues of chronology protection requires a fully developed theory of quantum gravity