Warppunk Setting

[linkhyrule5]

In that case, I think I can reasonably rule that it doesn't work because matter tends to resist warping of the space that it occupies. (Warp drive and shields only warp space around the ship. A ship using warp drive passes through warped space, but that space is already warped before the ship enters it.) You could, in theory, use the warp device to navigate within a system by adjusting your distance from (and therefore attraction to) the star, but this is usually not cost-effective in comparison to conventional reaction-mass engines.

Matter's mostly empty space, though.

[jalapeno_dude]

In that case, I think I can reasonably rule that it doesn't work because matter tends to resist warping of the space that it occupies. (Warp drive and shields only warp space around the ship. A ship using warp drive passes through warped space, but that space is already warped before the ship enters it.) You could, in theory, use the warp device to navigate within a system by adjusting your distance from (and therefore attraction to) the star, but this is usually not cost-effective in comparison to conventional reaction-mass engines.

Matter's mostly empty space, though.

And, more importantly, the vast majority of a stellar system is empty space even by standards where a planet isn't.

[Lambda]

The important thing is the internal forces that most matter has. If you try to warp space that has matter in it, you have to pull against things like molecular bonds or the strong nuclear force, and the warp device's ability to overcome those things is grossly energy-inefficient.

[jalapeno_dude]

The important thing is the internal forces that most matter has. If you try to warp space that has matter in it, you have to pull against things like molecular bonds or the strong nuclear force, and the warp device's ability to overcome those things is grossly energy-inefficient.

The density of space is *very* low. (Wikipedia says that it's around 5 particles per cubic centimeter, which if anything seems high to me (in the universe as a whole it's of order 1 proton per cubic *meter*, but it's higher within galaxies).)

As for the strong nuclear force: this is only relevant if you're warping space with a radius of curvature that's of order the size of a nucleus (~1 fm = 10^-15 m). If you're creating a bubble to transport something macroscopically large, you are not going to be creating any warp worth mentioning on the scale of atomic nuclei. (Think about zooming in on the surface of a sphere: the further and further in you zoom, the more it'll look like a flat plane.) Same for molecular bonds (now we're talking angstroms or nanometers, but that's still far from macroscopic).

[Lambda]

It still seems to me that if you're causing a mass to accelerate, then you're exerting a force. Space warping is generally an inefficient means of exerting a force.

[jalapeno_dude]

It still seems to me that if you're causing a mass to accelerate, then you're exerting a force. Space warping is generally an inefficient means of exerting a force.

Careful, you're applying a fundamentally Newtonian concept (forces, acceleration) to something intrinsically general-relativistic (warping space). But I'd tend to agree with you. :p

[linkhyrule5]

At any rate - in order for an Alcubierre drive to work on any reasonable timeframe, you're going to need rather impressive gravitational gradients anyway, I'm pretty sure.

Also, in an Alcubierre bubble, the ship never passes through warped space - the space around it is flat. Just outside that area is the sharp gradient of the bubble, which carries the ship along. How to actually achieve that with purely local means is one of the remaining problems with the Alcubierre drive.

Honestly, this is a rather fundamental consequence of having warp drives - you really can't have an Alcubierre drive achieved through direct gravitic manipulation without also having things like gravitic shields and slower-than-light engines.

(Also, establishing a field against an opposing force doesn't take energy. It's not going to be any harder to establish the field, the ship will just "fall" back towards a new equilibrium.)