What is INSIDE a Wormhole?

Question

IF they were real, would wormholes work in the way that they do in sci-fi (for all intents and purposes "teleportation", travel without movement, FTL, immediately "appearing" at the other location), OR is there space, time, matter inside a wormhole?

If a wormhole is meant to circumvent light speed by practically "teleporting" mass from one place to another then there should not be a passage of time and space inside it. One should step into the wormhole and at the other location an observer would see your leg instantaneously coming out of another wormhole, right?

Or is there a "place and time" in between, where one could potentially hang out for a while, before stepping out to another place, or even back where you came from?

In short I'm trying to create a place that is outside of reality from which one could then step back into reality at any point (not time travel, just space travel). What do you think?

Sub-question for extra xoxo: If you could hang out inside the wormhole could you somehow "decide" in there where to come out, or is the exit of a wormhole predetermined upon its creation?

EDIT: This is an August 2015 article. First step towards creating a real wormhole?

Wormhole created in lab creates magnetic field https://www.livescience.com/51925-magnetic-wormhole-created.html

Answer 1

I found the same image used by ESL, but in English. See below:

In such diagrams, a 4D (3 spatial dimensions + time) universe is "compressed" into two dimensions. Any lines over such a diagram will look like straight lines to observers within that universe. In fact, those lines are paths of light rays.

So if you want to picture what a wormhole would look like, simply draw lines over the diagram that connect an observer to visible objects while passing through the wormhole. The wormhole would seem like a very powerful fisheye lens with whatever is around it seeming to be inside it. There is an artistic rendition in Wikipedia.

As for how it would feel, going down through one. You would be utterly f... Destroyed.

Going through a wormhole would be like traveling over a line that goes through the wormhole. The universe is very curved but it would seem like a straight line to the traveller. The real problem is gravity.

Wormholes have mass. You may imagine them as just a topological feature of the universe, but that topological feature requires exotic matter to be stable. So the mass of the wormhole is the energy-mass of that exotic matter. We could talk a whole about how that energy mass is perceived, but it suffices to say that even if the exotic matter in use would the the kind to produce "negative mass", there would still be forces pulling it towards regular, positive mass. For all practical purposes, the energy mass would be positive.

So how massive would a wormhole feel? If it is one-meter wide and very flat, it will have the approximate equivalent mass of Jupiter, or close to 318 Earths. In another post I describe what would happen should the Earth ever come close to something like that.

Should a spaceship come close to that, it would face dire tidal forces. It would be akin to approaching a black hole. You would be broken apart as you fell into the throat. The difference is that instead of going into a region of space with practically infinite gravity, your particles would be spread out with great force somewhere else in the universe.

If you handwave the monstrous gravity and manage to survive, though, it should feel like the ultimate roller coaster.

Last but not least, as for how long it would take to cross the wormhole... I'll refer to this post in Physics:

There's a recent popularization of wormhole physics that nicely lists the properties of the four wormhole examples that Morris and Thorne considered in their 1988 paper. These properties include traversal times. Here's a summary

1. Infinite-Exotic-Region Wormhole (exotic matter distributed throughout space) ~ 1 hour

2. Large-Exotic-Region Wormhole (exotic matter confined to large finite radius) >= 7 days

3. Medium-Exotic-Region Wormhole (exotic matter loosely restricted to throat) ~ 200 days

4. Small-Exotic-Region Wormhole (exotic matter closely restricted to throat) >= 0.7 seconds

(...)
These times are completely independent of the distances between the mouths of each wormhole in normal space

Suggested theme song for wormhole traversal: Shooting Stars, by the Bag Raiders.

Answer 2

As I understand, technically there is not inside, but practically what is in reality the sorounds of the wormhole.

The wormholes are, theoretically, created when a portion of space-time us curved enough to touch any other portion (maybe in same time another coords, same cords and another time, all different, etc.).

How do you bend space-time? With gigantic amounts of energy/mass. It is speculated that too make it stable you need exotic matter (and I think it is necessary to create a wormhole with a diameter that allows you to cross without crush).

_{(source: wikimedia.org)}

So, in a strict definition, the wormhole is the point where ever two portions touch. And there is no meaning of "inside" if you talk about a point.

But, in a practical way, you'll perceive anomalies in the proximity of the worm hole. Because the space-time around it would be so much bended. But that space-time is the same that was before the wormhole exists. And it is filled originally with the same things that were before, and later with that plus what enters, minus what exists, cross what to mate in the proximity (that depends on the theory and the characteristics is the wormhole).

See this simulation for a possibility: https://m.youtube.com/watch?v=SZDOKtT_QZE