can of wormhole

[moth]

If you could make a "u" shape wormhole and mount it so both ends of the wormhole are side by side at one end of a tube,
and then accelerate a mass from  the other end of the tube through the wormhole so it comes right back to where it started...
Does conservation of momentum still hold?
When the projectile is launched, the tube gets accelerated opposite the projectile, and when the projectile lands the tube gets accelerated in the same direction as the projectile so all the forces act together to accelerate the tube without reaction mass.  

Or...

Edited April 29, 2021 by moth
needed more ellipses

[moth]

Is it possible to violate conservation laws with wormholes (i don't think so), or would a violation mean wormholes are purely sci-fi?
If you could put one end of a wormhole at the bottom of a lake and the other end on top of a nearby mountain you could generate electricity using the water flowing back down the mountain to power the wormhole  generator.
In the inertial drive setup, I'm assuming an object traversing a wormhole doesn't give up all it's momentum to the wormhole. If objects did lose all their momentum to the wormhole, that might restore conservation of momentum but then how can you move through a wormhole when you have zero momentum?

[beecee]

1 minute ago, moth said:

Is it possible to violate conservation laws with wormholes (i don't think so), or would a violation mean wormholes are purely sci-fi?

We have never seen or detected any wormhole, but it is a solution to GR equations.

[moth]

23 minutes ago, beecee said:

We have never seen or detected any wormhole, but it is a solution to GR equations.

You never played Portal? In Portal 2 the machine gun turrets all serenade you at the end, it's great.

I know there's no way to test these ideas without a wormhole to experiment with, that's why i put this in speculations.
I don't think the lack of an observable worm hole should stop us from trying to build a model of how they could exist and be consistent with the rest of physics.
It was the same with Black holes at one time, they were consistent with GR theory so people made models of how black holes could be consistent with physical laws.

[MigL]

If the wormhole allows for violation of spatial translation symmetry, that is, if the laws of physics distinguish between different points in space ( external and internal to the wormhole ), then conservation of momentum is not required.

[beecee]

3 minutes ago, moth said:

I don't think the lack of an observable worm hole should stop us from trying to build a model of how they could exist and be consistent with the rest of physics.
It was the same with Black holes at one time, they were consistent with GR theory so people made models of how black holes could be consistent with physical laws.

I am not actually disagreeing with you just confirming that as yet, they are only a prediction of GR, which as we know, has a pretty good track record. With BH's of course, we had observational data of there existence in the early seventies with Cygnus X1.

[moth]

1 hour ago, MigL said:

... if the laws of physics distinguish between different points in space ( external and internal to the wormhole )...

Could it be something like a black hole's event horizon making the distinction? 

[MigL]

No, the EH is not a 'separator' for all rames.
And there is no variance to the laws of physics on either side.

[moth]

4 hours ago, MigL said:

...if the laws of physics distinguish between different points in space ( external and internal to the wormhole ), then conservation of momentum is not required.

Does that mean a properly configured wormhole can be a free energy device?

[MigL]

depends on what you mean by 'free'.
A Black Hole can supply energy, which might seem free, but it is at the expense of the BH's mass-energy, or size of EH.

[moth]

Maybe some arrangement where an excited atom emits a photon then goes through a wormhole back in time to emit the same photon over and over, or dropping an electric charge through a field and wormholing it back out to be dropped again. Like a wormhole current source. 

[MigL]

Closed timelike curves don't work that way, not even with stable ( ? ) wormholes.

Take a look at these lecture notes from K Thorne ( he gets to wormhole time travel near the end )

II-121.pdf (caltech.edu)

[moth]

Thanks MigL I'm reading the paper tonight. looks like it will give me some help with my questions. 
I read (in WIkipedia i think) that accelerating one end of a stable wormhole near c and then returning to the other end resulted in a wormhole version of the twin paradox. If you go through one way you age, if you go the other way you're younger. That is the type of wormhole I was using in my atom emits a photon example I don't think it's a CTC.

[MigL]

12 hours ago, moth said:

If you go through one way you age, if you go the other way you're younger.

If you read the .pdf you should have realized that 'wormholes-as-time-machines' don't work that way.

[moth]

Still struggling with the .pdf. Is it a multi-worlds thing like after the atom goes through the wormhole each copy of the emission event is in a different universe?