Are Wormholes Truly Impossible According to Latest Theories?

[nomadreid]

As far as I understand, the latest calculations say that wormholes do not exist. Nonetheless, as a theoretical construction, they would be a "bridge" between two non-contiguous portions of spacetime. At first I thought they might just be a discontinuity in spacetime, but then I read of the metric defined "inside" them. Since they are described as a bridge between two parts of spacetime, any "inside" would be by definition not part of spacetime, which seems odd if a spatiotemporal object (an electron, whatever) could exist in it. So what would they be "made" of, if not spacetime? If they are part of spacetime, then they no longer fit the description of "bridge". Help!

 

[Hertyque]

Possible bridge approach to descibing wormholes...

Wormhole is just a tube connecting two points. This tube since not seen must be extremely small as to not affect the areas of space which it travels through.


The walls would be ultra dense gravitational fields which feed back upon itself on the exterior of the tube so as to limit the effects on its surrounding. The inside of the tube can still be large(relatively speaking) To anyone or thing traveling through the tube.
The inside would be comprised of stretched spacetime such that one foot forward means several light years just outside the tube.

The wormhole mouths are transitional states between the normal densities of spacetime and the "special" conditions on the inside.

Once created the only energy really needed would be to keep the "feed" end open. Though bi-directional travel would be possible you would only need to input energy from one opening to determine its internal characteristics and direction(which point it ties to on other end)

With this said it is entirely possible some big event started a worm hole and one opening tied itself to some form of sustained energy release(Jets from galactic Black hole?) in order to keep the wormhole active..The problem with this is fluctuations in the energy being absorbed by the worm hole, in startrek terms it would have an unstable end point constantly shifting from place to place...Albeit probably predictably.


Hertyque

 

[nomadreid]

Thanks, Hertyque. Very clear answer.

 

[George Jones]

As far as I understand, the latest calculations say that wormholes do not exist. Nonetheless, as a theoretical construction, they would be a "bridge" between two non-contiguous portions of spacetime. At first I thought they might just be a discontinuity in spacetime, but then I read of the metric defined "inside" them. Since they are described as a bridge between two parts of spacetime, any "inside" would be by definition not part of spacetime, which seems odd if a spatiotemporal object (an electron, whatever) could exist in it. So what would they be "made" of, if not spacetime? If they are part of spacetime, then they no longer fit the description of "bridge". Help!

Wormhole are part of spacetime. See

https://www.physicsforums.com/showthread.php?p=1597469#post1597469

 

[humanino]

The problem with this is fluctuations in the energy being absorbed by the worm hole

Can you elaborate on this ? What fluctuations ?

 

[Hertyque]

Fluctuations... Assume we built a device to create a wormhole(Stargate-except they need a gate on the other side) The energy input we give it would be steady. The particles we inject into it would be at very precise intervals, else we may not know where the end opens at or how large the tube would be.

Jets from galactic centers are by far nowhere near contiguous. They fluctuate in particle density as well as types of particles. The same holds true for the electromagnetic radiation streaming through the jet. By no means very steady at all.

Though the source of the energy holding the naturally occurring wormhole open could vary I am not sure of any natural phenomenon which would be precise enough in its energy output to create a very stable wormhole.

Heryque

 

[humanino]

I'm not sure I clearly follow what you refer to.

Quantum fluctuations in a closed timelike curve will amplify like in a laser's resonant cavity except there is no need to pump energy in, there is no way to prevent that. It sucks the energy you developped to create your wormhole. This as far as we know prevents wormhole. It is well-known and Thorne discuss about this at length in "Black Holes and Time Warps", and is even in wikipedia's article on wormhole :

It is thought that it may not be possible to convert a wormhole into a time machine in this manner: some analyses using the semiclassical approach to incorporating quantum effects into general relativity indicate that a feedback loop of virtual particles would circulate through the wormhole with ever-increasing intensity, destroying it before any information could be passed through it, in keeping with the chronology protection conjecture. This has been called into question by the suggestion that radiation would disperse after traveling through the wormhole, therefore preventing infinite accumulation. The debate on this matter is described by Kip S. Thorne in the book Black Holes and Time Warps. There is also the Roman ring, which is a configuration of more than one wormhole. This ring seems to allow a closed time loop with stable wormholes when analyzed using semiclassical gravity, although without a full theory of quantum gravity it is uncertain whether the semiclassical approach is reliable in this case.