Wormholes in Space

[Sindri]

Originally Posted by lwcamp

Note that the diametric drive has net zero mass, so is probably prohibited by the quantum limits that prohibit other forms of negative mass without even more positive mass around to balance it. It is also unstable in many ways.

There are Krasnikov tubes, something like FTL railways in space, but if you have wormholes then Krasnikov tubes don't get you anything you don't already have and probably cost a lot more.

There are Alcubierre style warp drives. But the more we look at these, the more we realize how problematic they are (you can't turn them off, they destroy their destination, they destroy the traveler, and in an asymptotically flat space-time like ours you probably can't turn them on, either).

The diametric drive did sound problematic. How solid is this requirement for negative mass to be surrounded by positive mass?

Yeah Oh I should have mentioned Krasnikov tubes and Alcubierre drives too. I was actually considering the Krasnikov tube first and just checking wormholes out to see if they would be an alternative. However I thought Krasnikov tubes required less then a wormhole? I had a concern that since a Krasnikov tube is a warping of space the relative motions of the places you wanted to get to would leave it steadily farther away.

Originally Posted by lwcamp

Also, on another note, I just want to make sure that you are aware that wormholes conserve all the usual conserved quantities (energy, momentum, angular momentum, electric charge, and in non-relativistic cases, mass) and do so locally. So a wormhole mouth gains the mass of anything that goes through it (and momentum, electric charge, etc.) and loses the mass (& etc) of everything that comes out of it. Thus, if you find a wormhole out to the middle of intergalactic space where the far end has a mass of only a few hundred hydrogen atoms, you can't put anything through the wormhole with a mass of more than a few hundred hydrogen atoms before the mass at the far end goes negative and the whole structure probably collapses. Preferably, your wormhole ends up inside a massive object so you can grab some mass from outside and stuff the wormhole with it to bulk it up.

Luke

That's odd, I would have thought that it didn't work that way since it would require colonists to work a bit for their supplies.