Creation of a wormhole

[Umaxo]

Hi,

if i understood correctly from pop-science literature, there is theoretical possibility of formation of wormholes like in this picture: https://en.wikipedia.org/wiki/File:Wormhole-demo.png
bud you need some exotic particles (i think it means negative energy?).

Now what i really don't understand - how is this possible? General realitivity doesn't describe topology of spacetime, you need to assume it. So why this talk about exotic particles, or quantum foam, or entaglements or whatever they talk in popscience as possibility for creation of wormholes? I would imagine that even in empty space i can decide to identify certain parts of the spacetimes, or insert some (flat) bridge (cylinder) between them and still have flat, minkowski metric that describes whole spacetime with wormhole without need of any particles.

Sorry that i don't have specific quote form those pop-science books. So i would be glad just for some brief words on where the research of wormholes that you know of (those that connect certain part of space otherwise separated by long distance, not wormholes like einstein-rosen bridge in schwarzschild that makes no shortcut between two distant points of spacetime) stands in respect to my objections above.

Thanks

 

[pervect]

Hi,

if i understood correctly from pop-science literature, there is theoretical possibility of formation of wormholes like in this picture: https://en.wikipedia.org/wiki/File:Wormhole-demo.png
bud you need some exotic particles (i think it means negative energy?).

Now what i really don't understand - how is this possible? General realitivity doesn't describe topology of spacetime, you need to assume it. So why this talk about exotic particles, or quantum foam, or entaglements or whatever they talk in popscience as possibility for creation of wormholes? I would imagine that even in empty space i can decide to identify certain parts of the spacetimes, or insert some (flat) bridge (cylinder) between them and still have flat, minkowski metric that describes whole spacetime with wormhole without need of any particles.

Sorry that i don't have specific quote form those pop-science books. So i would be glad just for some brief words on where the research of wormholes that you know of (those that connect certain part of space otherwise separated by long distance, not wormholes like einstein-rosen bridge in schwarzschild that makes no shortcut between two distant points of spacetime) stands in respect to my objections above.

Thanks

Purely classically, I believe it requires a time machine to create a wormhole.

However, there are papers that suggest it'd would be possible to stabilize a wormhole that was created non-classically (say from the 'quantum foam' you menion), via purely classical means. I'd suggest looking at the Moris, Thorne, Yurtserver paper "Wormholes, time machines, and the weak energy condition", <<link>>.

The section where they say "Wormhole creation with such mild space-time curvature that classical general relativity is everywhere, must be accomponied by closed timelike curves and/or noncontinuous choice of future light cone. Which reads as "time machine" in lay terms. In the subsequent section they mention "quantum foam".

There's a popularized discussion in Throne's book, "Einstein's Outrageous Legacy" I believe.