# Effects on area outside the mouth of the wormhole

Michael Chase
Supposing it were possible to open a stable wormhole close to a planets surface, what could the effects to the immediate area outside the mouth of the wormhole be? Such as radiation, atmospheric anomalies, changes to the planets magnetic field, etc. Thank you for any assistance

Michael Chase
Perhaps this wikipedia article will introduce you to wormhole theory

https://en.wikipedia.org/wiki/Wormhole

Have you found other wormhole info in your research?

And here's a NOVA show on it:

http://www.pbs.org/wgbh/nova/next/physics/are-wormholes-everywhere/

There may be some content on Youtube by well known science organizations that could help too
Thank you for your response. I grasp the concepts of the creation of the wormhole, along with forces at work inside the wormhole. What I seem to be having trouble with is what the possible effects might be outside the mouth of the wormhole when it opens. In other words, what would it look like on the surrounding terrain if one opened on the surface of a planet.

Mentor
Supposing it were possible to open a stable wormhole close to a planets surface, what could the effects to the immediate area outside the mouth of the wormhole be?

There is more than one proposed spacetime geometry for wormholes, but the simplest that I've seen is the Morris-Thorne wormhole, discussed in this previous thread:

Based on the Christoffel symbols I calculated in that thread, this wormhole does not have any gravity--in the sense that you can stay at the same "radius" outside the wormhole and feel no pull towards it (or "push" away from it). So at least to a first approximation, it should not have any effect on the area outside it.

Staff Emeritus
Supposing it were possible to open a stable wormhole close to a planets surface, what could the effects to the immediate area outside the mouth of the wormhole be? Such as radiation, atmospheric anomalies, changes to the planets magnetic field, etc. Thank you for any assistance

Let's start with a wormhole in empty space. Then the gravitational effects of the wormhole can be roughly modeled by thinking of the womrhole mouth as having a mass. (The ADM mass, to be specific and technical).

The situation near a planet's mouth is similar, though it gets complicated by the non-linearity of gravity. Modulo those complications though, it's reasonable to just think of the mouth of the wormhole as having some mass.

The main issue is - how big is this mass? That's unclear, without more information about the wormhole. What we can say is that as objects transverse the wormhole, the mass of the entrance and exit mouth will change. A reasonable way of describing it in words would be to say that when an object enters the wormhole, its mas gets added to the entrance wormhole, and subtracted from the exit wormhole.

Cramer had some pop-sci articles on how objects in Analog that were fairly well written (I could come up with a few links if there was some specific interest, though we tend to avoid pop-sci here.). For a better soucre, I'd recommend Visser's book, "Lorentzian wormholes", if you can find a copy. I believe it's out of print , at least last time I checked, so you'd probably need to get it from a library. It's not terribly technical as such things go, if you're interested in wormholes it'd be a good read if you could find it.

There are three cases I can think of. The first is that the wormhole mass is "small", that has the drawback of the exit wormhole mass possibly becoming negative. This turns out to be a bit unpleasant for reasons of stability, though perhaps it's possible.

THe second is that the mass of the wormhole mouth is "medium". This avoids having to deal with the physics of negative masses, as the "medium" mass of the wormhole is presumed to be much larger than the traffic going through it. The medium mass has to be low enough to not serioudly endanger the planet, but still large enough to avoid the negative mass issue.

The last possibility is that the mass of the wormhole mouth is "large". Large in this context means multiple stellar masses. It's difficult to see how a planet could survive this case.

Orodruin
Mentor
Let's start with a wormhole in empty space. Then the gravitational effects of the wormhole can be roughly modeled by thinking of the womrhole mouth as having a mass. (The ADM mass, to be specific and technical).

At least for the Morris-Thorne wormhole, this can't be right as it stands, because, as I noted before, observers near the wormhole do not have their worldlines bent towards the wormhole. For example, as I pointed out in the previous thread I linked to, a worldline of constant ##l## in this wormhole (i.e., at a constant "radial distance" from the wormhole throat) is a geodesic. (Compare with a worldline of constant ##r## in Schwarzschild spacetime.)