Probably everyone has their own idea of a UFT, and mine may be a bit different.  I don't think we will see gravity be successfully treated as a boson momentum exchange (ordinary QFT energy field).  That is the same thing as was said 100 years ago, that gravity is not a force. 

I'll try to avoid the cliche that gravity is geometry however, and instead propose that whatever the relation between gravity and other forces and matter is, it will not tell us much unless it is the long awaited "constructive" theory which Einstein bypassed because not enough was known about the structure of matter at the time.  Or since, apparently.

If one views gravity as geometry, then this "UFT" must be able to construct geometry.  Now there are about three (maybe more) reactions to that:

So, take your pick.

Wormholes exist in reality and in exact solutions of the Einstein eq (for example, "dual-to-Kerr" solutions describe massless wormholes). I have my own UFT based on the idea of  "natural bundles'', which is compatible with Einstein eq and hence, with my UFT.

Some people tried to solve Quantum Entanglement process with help of worm hole.

I solved the same problem with help of Holographic Principle .

One question one should ask , if there exist  a worm hole, matter will be able to retain its state when its out from another end or it will be converted to another form of equivalent energy.

For me, one of the biggest issues with wormholes is the set of associated topographic problems involving fieldline behaviour.

If you take an electron and draw fieldlines radiating away from it to the arbitrary-distant background, and then you push that electron with your finger into the mouth of a wormhole, its fieldlines all still point back out of the mouth. if you push it right //though// the wormhole and out the other side, the wormhole geometry traps the fieldlines so that even when the electron is on the far side, all its fieldlines still point back towards and through the wormhole, and no fieldlines point directly to the region of universe that it now supposedly inhabits.

One interpretation of this is that the electron deposits its charge at the wormhole entrance mouth when it enters - after all, all of the electron's fieldlines point out of the entrance-mouth, which still appears to "own" the electron's charge.

Another interpretation is that if all of the electron's geometry warps in the same way, and the electron in unable to interact - not just electrically but with any type of force or field - with the contents of the new patch of universe (unless something intersects the line-of-sight to the second wormhole mouth), then perhaps it's not meaningful to say that the electron has actually reentered normal space. 

If all it can see is the view back to the wormhole and out of the original mouth, then it might //nominally// have passed though, but from the electron's POV it might be difficult to tell that it wasn't still trapped in the throat. It might be nominally surrounded by stars in the new region of space and unable to see or interact with, or even to identify any spatial position in which those stars might exist, because all of the electron's exterior geometry still points back to and through the wormhole, and out of the original mouth.

So the difficulty of wormholes isn't just whether we're allowed to invoke a discontinuous geometry-change when we create and destroy them, it's also whether we're allowed to invoke a discontinuous geometry-change when matter passes through, so that an object's fields can partially disconnect from the area outside one mouth and then reconnect their geometry to the region on the other side, without the object's fields and geometry getting "snagged" on the geometry of the wormhole.

Of course, it might well be that the fieldline concept and associated geometrical arguments are "naive" and don't hold in this situation, but if we lose those arguments, we lose some valuable tools for consistency-checking.

Once you've tried that "electromagnetic fieldline" exercise, you can repeat it with the electron's gravitational fieldlines ... and if the geometry of its gravitational fieldlines represents the geometry of how the electron interacts with its outside world, then the electron's mass is also being deposited at the first wormhole mouth, and what it sees in all directions is still what it would be seeing in all directions from the vicinity of mouth #1 (perhaps with a bit of extra distance).

So unless we can dismiss the fieldline arguments, the "standard" wormhole – even if it was threaded by an adequately wide region of space and a corresponding quantity of electromagnetic medium – would still seem to be non-traversable by matter. 

You could signal through it and transmit information and energy by waggling the electromagnetic field that threads the hole so that ripples emerged at the other side, but you might not be able to pass any solid matter through it.

... Unless you found way to convert matter to energy as it entered the hole and back to mass again on the far side (at which point, you probably have yourself a Star Trek transporter!) ;)

@Robert and Zafar, thank you for your answers. If you wish, both of you can send your UFT papers to my email: [email protected]. I wil your papers. Thanks

@Eric. I see that you think that wormhole is not traversable by matter or human. But there are some papers discussing Traversable wormholes (see for instance paper by Matt Visser). What do you think onntose papers?

Another question: do you think that wormhole can be triggered by electromagnetic field? Thanks

Worm holes are ruled out by Oppenheimer and Snyder's correct 1939 insight that the in-falling (and return) time for light is infinite from the point of view of the outside world.

it is very strange how the false idea of "equal rights" between infalling proper times and externally valid times could creep into the accepted interpretations.

This will be a riddle to future generations.

Thank you for your answer, Dr. Rossler. Best wishes

I completely agree with Otto as long as the theory in use is GR.

If we suspend disbelief, Eric Baird gives a fascinating picture of an electron going through a wormhole and leaving its field lines behind. 

In QFT, a field line is not really different from a particle.  You could say the field line is a region where virtual particles behave in a certain way.  So I don't see the difference between a field line going through a wormhole and a particle going through.

Gravity is a bigger problem.  I imagine an electron has more than enough positive mass to close any practical wormhole, since we don't really have a way of making negative mass (energy) to enlarge the ones spontaneously occurring in the quantum foam.

I thank Victor and I thank Robert. 

And I dare reiterate that any talking about something going on at the horizon or beyond the horizon is as unphysical as talking about any other event that will occur in the universe after more than an infinity of our outside time has passed. There is not a sigle finished black hole in the universe. Right?

Dear Dr. Rossler, i agree that there is no black hole in our universe, it is only a mathematical artefact. Best wishes

Dear Dr. Otto E. Rossler

I just learned your public call for convene in order to stop CERN's blackhole experiment. You argued in favor of blackhole stability (see http://www.wissensnavigator.com/documents/cerntrigger.pdf). 

Allow me to ask you: what happened since then? Did they listen to you and make a convene eventually.? Your comments will be highly apreciated. Thanks

Hi Robert!

The fieldline problem is a topological one - an electron can't obviously "withdraw" a fieldline that connects to one region of space and extend a replacement to connect through the wormhole to a different region of space without cutting whatever the fieldline was connected to, and leaving a severed end flapping about. Part of the value of the fieldline concept was that it took a vague idea (the field) and made it subject to a set of restrictive topological rules. Those rules don't appear to be compatible with the idea of a traversable wormhole.

Of course the fieldline rules are artificial and abstract and may well be too naive for this sort of problem (perhaps fieldlines can have unterminated "fuzzy ends")... but it's difficult to throw away a logical framework used for consistency-testing because it disagrees with some cool idea that we're fond of, without having at least a suggestion of what sort of framework might replace it.

----

The idea of trapped electric fieldlines was used by Wheeler when he described a doubly-connected space containing a wormhole threaded by parallel lines of electric force ("Charge without Charge", eg MTW, page 1200) – to a distant observer, one mouth would appear positively charged and the other negatively-charged, even though observers diving into either mouth to find the source of the charge would find themselves emerging somewhat confused back into normal space at the other side without the wormhole-trapped lines actually terminating anywhere ("sourceless charge").

The idea that an electron passing through a wormhole deposits its electric charge at the mouth is probably already in a few published papers, but I don't have any references. It sounds to me like one of Wheeler's ideas, but it might have been someone else's. If the same topological arguments also apply to the particle's "gravitational" charge, then its not obvious how much of the particle could actually be said to be successfully passing through the hole (if its charge and gravitational mass, and presumably also its associated inertial mass, are all left behind).

Otto,

   Wormhole theory doesn't always start with black holes. In Visser's "Spacetime Surgery" scenario, we surgically (magically!) remove two spherical regions of space and associate (short-circuit) the two "bleeding" surfaces directly together outside normal space. The spatial density in the resulting otherwise-flat short-circuited regions is then lower than in the surrounding regions of normal space, which suggests a negative gravitational field rather than a positive one, and this idea is strengthened if we plot a set of parallel light-beams through the short-circuit ... they diverge at the other side, suggesting that the "seam" may be associated with negative gravitation (if you allow it to smudge out a little).

Optically, a simple spherical surgical hole would look like a pair of mirrored spheres, except that light falling on one surface would emerge from the other - your "reflection" on one surface would appear at the other, but the geometry of the distorted images seen through the wormhole would basically be the same as the distortion of a mirrored spherical reflector.

It's a pretty result. Not much obvious use for anything, but pretty nonetheless

Eric, I understand what you are saying, but basically I don't buy the field line argument.  I have too much experience with electrical engineering, and we cut field lines all the time.  This causes a big release of the energy in the field, some radiation to reconfigure the field, and then everything is settled into the new configuration.  It can happen gradually as you move a charge about, or all at once if you flip a switch.

However, I do not think wormholes are compatible with currently accepted theories.  GR is derived from SR and equivalence.  I am not sure that the field equation limits the solutions sufficiently to the postulates.  Someone more familiar with it can address this.  But consider the situation of a usable, practical wormhole.  Then there would be two straight line paths between a pair of points A and B.  If the distances are exactly equal, it is not a practical wormhole, as there is no advantage to using it.

Given that the two distances between A and B are inequal, then the shorter path may be used to examine the SR clock synchronization along the longer path, without the synchronization losses from relative motion.  From this observation, a preferred reference frame can be deduced.  This violates SR.  Therefore, the supposition that a practical wormhole exists leads to a contradiction of the postulates, and so the practical wormhole cannot exist within GR. 

It might exist within some other theory.  For example, if you had a preferred reference frame to begin with, then this would not be a contradiction.  Those space travel enthusiasts who wish to get somewhere faster than light traveling through normal space should look first to finding a preferred frame.  Otherwise, shortcuts will always lead to contradictions.

Hi Victor!

As far as I know, the fieldline problem seems to be geometrically insoluble, unless you discard or modify the fieldline concept or add dimensions. It's a matter of topology. Of course, a unified field theory may add dimensions that allow a length of fieldline to be pushed out of normal space and reemerge threading the wormhole throat. However, solutions based on this idea might be specific to a particular theory, and if we were able to manipulate space and geometry to //that// extent, we might not need wormholes!

Regarding the existing papers on traversable wormholes, many of them strike the attitude of e "Okay, we don't know if these objects are possible, but if they are, this is what their properties would seem to have to be". I think that that's an entirely correct attitude, but the existence of the papers doesn't necessarily suggest that the objects being discussed are more than fascinating mathematical objects for study.  IMO they are worth exploring mathematically regardless of whether or not they are physically allowed in our universe.

I went through a phase a few years ago of reading every paper I could find on the subject, and even dabbled a little in what you might loosely call relevant research.  I thought it was a wonderful topic, great fun, well worth studying and and a great limbering-up exercise for other things. However, I never felt the need to consider the subject as more than a (very fun!) brain-stretching exercise.

(Visser's great on this stuff, BTW. I got his book when it came out in paperback)

Hi Robert!

Re: cutting fieldlines:

Really? Oh. Okay.

Re: Wormholes breaking SR clock-synch,

I don't think the SR community would lose much sleep over it. They've dealt with much worse breakdowns in the past.

In this case, I think they'd just shrug and say, “for more complex geometries you need to use GR, not SR” and refer you to their GR colleague, who'd say “Nowadays, we appreciate that SR is only a local theory. How big is local? In this case. .. if your region of space includes both wormhole mouths, and that would break the theory, then that's obviously too big … “

Eric you are quite right about what they would say.  I think, and I suspect you do too, that it is b.s.  I have begun to realize in the last few weeks that

• curved spacetime gravity can be derived from SR and equivalence
• the necessary parts of equivalence probably can be derived from energy conservation
• the necessary parts of SR might even be derivable from energy conservation

The only thing one really needs is that gravity affects everything.  This however follows from the idea that it affects "mass" and that E=mc2.  Relating energy to mass. 

So GR is not actually a separate theory from SR.  And if you accept for the sake of this discussion that SR might be implied by energy conservation, then "practical usable" wormholes violate energy conservation.  This is actually much less likely than violating SR.  I should have thought of this in the first place.

In fact, we can make the argument directly.  Suppose points A and B are connected through normal space, and through a wormhole.  If the gravitational potential difference from traveling one path is greater than another, then we can choose a direction that allows an excess of energy to be siphoned off.

OK, I suppose whatever powers the wormhole could provide that energy.  But then I think the universe would work to close it pretty quickly.  : )

Robert, yep, I think that that's one of the big questions in wormhole theory, whether a gravitational field acts through a wormhole or not ... whether a wormhole can short-circuit a field differential, or whether the differential between the two linked regions in normal space also exists though the wormhole connection.

If the wormhole bypasses the normal field differential then there are energy-conservation questions, and also issues of what happens when the two wormhole mouths have different local rates of timeflow.

On the other hand, if the same field differential existed //through// the wormhole mouth, then you might have to be careful about what regions of space you connected to. And sometimes the gravitational field differential between two locations can be route-dependent , and I don't know how a wormhole could equilibrate to match that.

@Eric and Robert: yes i also think that almost all discussions of wormhole in literature are impractical, at least for now. The only exception is perhaps the concept of electromagnetic cloaking as suggested by Greenleaf et al. What do you think on that?

@Robert: your remark that it is possible to find curved spacetime using special relativity is very interesting. Where do you read that? Or perhaps you wrote a paper on this issue? If yes, please kindly share. Thanks

Victor, the paper is linked below.