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I am working on a story which is based on space time hacking and moderation. While researching I found that a wormhole is simply a Folded time-space-as shown in demonstration below (Image credits: shutterStock-taken from here):

Wormhole

However, what happens to the "space" (place) which is left when space gets folded (as shown using red arrows)? I tried searching a lot but I could not find any real fact or science based theory.

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    $\begingroup$ You'd probably be better off asking this question in Physics $\endgroup$ – nzaman Feb 25 '17 at 9:22
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    $\begingroup$ @nzaman I changed it to science-based, and that works fine here as we can suggest thihgs that would work to make a good story, not only interpreting GR as with (e.g.) Kip Thorne’s ideas. $\endgroup$ – JDługosz Feb 25 '17 at 13:22
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No new space is created (outside of the wormhole) by the wormhole.

The curvature depicted in the image is just to portray the idea that a traveler going from one side of the wormhole to the other will take a longer path. That is, that we can understand the wormhole as a shortcut.

The background of the image is unfortunate, you should disregard it.


The wormhole is about the topology (read: connectivity) of the universe. If you can have an otherwise mostly "flat" universe where two distant points are connected, so that you can travel from one to the other, you have a wormhole.

Now, how do we show that to kids?

Well, we can have a sheet of paper that represents the space-time, curve in such way that it touches itself and go "look, if you create a shortcut you can travel the vast distances of space in an instant".

paper folded in two with a pen going through

but the wormhole is not about curving the whole universe to make two points meet. Well, maybe it is, we can't create these things, you know? - It is about two distant points connected, just because it is possible the universe have those (the equations of general relativity can be solved for a topology like that).


It is probably better to represent the wormhole like this (except now it doesn't look like a shorter path):

wormhole on a flat 2d space-time

People not to scale


Besides the representation of the curvature as a surface is misleading...

Space time curvature 2D

It is better to visualize it as space becoming "denser":

Space time curvature 3D

At its core, this is intended to show that distances nearby the object (earth in the pictures) are shorter. But we don't have a good way to show wormholes in this representation.


Addendum: In case it wasn't clear, I'm saying that the "created space" is an artifact of the representation, and there is no new space created at all.

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    $\begingroup$ Bravo! A well explained answer, and nicely illustrated too. Plus one. $\endgroup$ – a4android Feb 25 '17 at 12:24
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    $\begingroup$ "People not to scale" - Are you sure it's the people that aren't to scale? I think the people are to scale and it's everything else that isn't. $\endgroup$ – Pharap Feb 25 '17 at 17:56
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    $\begingroup$ You should use the 2047 Playboy for your pen demo, more authentic. $\endgroup$ – Nick T Feb 25 '17 at 20:11
  • $\begingroup$ "may disregard" May I recommend changing that to, "should disregard"? $\endgroup$ – jpmc26 Feb 26 '17 at 8:11
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    $\begingroup$ @jpmc26 agreed. $\endgroup$ – Theraot Feb 26 '17 at 8:12
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The grid in the picture is a representation of a two-dimensional universe. This universe is shown from the outside.

We can draw such a picture because our universe is three-dimensional, and we can imagine the two-dimensional space 'floating' in our three-dimensional space.

This three-dimensional space is not part of the two-dimensional universe: Beings living on the surface cannot perceive or interact with the ambient space.

The tunnel represents what a wormhole would look like viewed from outside the two-dimensional universe. If there was no tunnel the inhabitants of the surface would have to travel a long distance to get from the yellow place to the blue place.

The inhabitants would have no way to know their universe is 'curved' because they cannot perceive the space it is curved in.

It is impossible to 'scale up' the picture to represent a wormhole in three-dimensional space, because we would have to either have it floating in four-dimensional space, or somehow put the perspective outside our universe.

A wormhole in our three dimensional universe can only be perceived through strange relative distances between things. On a good day we can get to the moon by going straight up for 360,000 km. If you find you can also get to the same moon by walking straight through the secret portal in your wardrobe, then that's what a wormhole looks like.

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    $\begingroup$ There are some interesting simulations available on the WWW of what Ellis wormholes look like from a distance and when traversed by a 3-D observer, by Corvin Zahn and by Thomas Müller. $\endgroup$ – JdeBP Feb 26 '17 at 8:20

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