Alcubierre warp-lanes, what is the most stable way to create them?

Question

2 informational references for Alcubierre fields can be found at the end of this question.

Warp-lanes aren't a novelty in science-fiction. Space ships can use a specific route to go through a Galaxy at often superluminal speeds. Alcubierre found a way to use current physics of relativity by Einstein and create a possibility for FTL travel in the Alcubierre drive. One of the disadvantages of this drive is that you lose the negative mass that you require for the field. The solution to this is to send a subluminal ship with the negative mass and this ship creates a lane of negative mass that can be used and re-used by ships afterwards to travel faster than light.

A problem that I expect to occur is that everything is spinning. Mass of a planet spins around an axis, the axis spins and wobbles around a sun, the sun spins around the center of the universe. Building a warp-lane from one solar system to another could simply have "seasons", where during a certain season the enter/exit point of the warp-lane is farther or closer to the solarsystem's center. But it could also mean that you need to build and re-build warp-lanes every so many years to keep a proper lane open.

My question is: What is the most efficient way to lay down a warp-lane in a way that it requires the least amount of new warp-lanes for a given time? Say 1 Galactic rotation.

If necessary, two scenario's are considered:

• A warp-lane from Earth to Alpha-centauri.
• A warp-lane from Earth to a system at 50.000 lightyears from earth, at the other end of the Galaxy (Earth is approximately 25.000 lightyears from the Galactic center).

For an answer, it is allowed to simply keep extending the warp-lane if it drifts off, so long as it does not extend the warp-lane length more than 20% of the original length.

For some background information you can watch this: https://www.youtube.com/watch?v=94ed4v_T6YM

More information can be found here: https://www.researchgate.net/publication/258317793_The_Status_of_the_Warp_Drive

Notable are the advantages in this paper:

• Benefit 1: Removal of interstellar distance barrier, as no longer restricted to subluminal speed limitations. Get faster than light travel, as measured by distant observer outside of disturbed region. This will allow missions to the nearby stars and closer examination of astrophysical phenomena than is possible today.

• Benefit 2:
  It is a conventional transport scheme, in that it requires no ‘tearing’ of space or non-trivial topologies (i.e. wormholes) and does not require the transmission of copies of objects across space as a means of getting to the destination (i.e. teleportation).Warp drive is a simple transport from origin to destination through space.

• Benefit 3:
  No time dilation effects, as usually expected with other space propulsion schemes due to special relativity. This is because the vehicle could be moving at subluminal speeds so that clocks on board would remain synchronized with the origin and destination.

• Benefit 4:
  No relativistic mass increase of vehicle, since ship is at the centre of warp bubble is at rest with respect to locally flat space.

• Benefit 5:
  No requirement for rocket type propulsion to achieve near light speed, which usually restricts the maximum speed attainable due to special relativistic effects such as infinite thrust for infinite masses.

• Benefit 6:
  Technological and economic benefits to mankind.

(1) (PDF) The Status of the Warp Drive. Available from: https://www.researchgate.net/publication/258317793_The_Status_of_the_Warp_Drive [accessed Jan 29 2019].

Answer 1

If the lanes themselves don't move through space along with the galaxy they're in, then the whole system is a wash. But if they do (and from your description, it sounds like they do), then under the parameters you've laid out, you may not actually have the issues you're imagining you might have.

Remember that a galaxy doesn't just rotate, but moves through the universe, as well. As you describe them, your warp lanes are fixed with regards to the galactic center. If this is so then that means they are traveling along with the galaxy at large; if not, then they'll be sitting alone in deep space as the rest of the galaxy quickly leaves them behind. So, if they're traveling along with the galaxy, why can they not also orbit the galaxy just like every other occupant?

Now, at first glance, that may not seem to solve your problem entirely, since star systems all orbit a galaxy at different rates. But, since you mention leeway of up to 20%, you probably don't have to worry about this at all, since it would take many thousands of years of relative drift between systems for a warp lane to "stretch" past this limit. Alternatively (or additionally), you could set up multiple endpoints in advance to supercede older ones as planetary systems shift in distance to each other, but that would be planning way in the future.

Also, as a much more minor concern, keep in mind that a solar system's orbital plane doesn't necessarily line up with it's parent galaxy's plane. Our own solar system's orbital plane is at roughly a 60 degree angle to the Milky Way's orbital plane. As you design your warp lane systems, angles more favorable or more extreme to each other may have some impact on the ideal/optimal endpoints for your lanes on a case by case basis. (E.g., one lane might be able to line up essentially connecting one inner planet to another inner planet, whereas in another case, a lane is better suited exiting on the outskirts of the system.) But even then, the angle between systems would need to be quite close to 90 degrees for this to be an issue.

Update in response to comment concerning "twisting and turning" of the warp lane:

Such a twisting motion doesn't need to occur. The factors affecting an object's position don't equally influence its orientation. To use a very simplistic analogy: if your warp lanes are like "tubes" through space, they don't need to be tied down at their endpoints, they just need to reside (orbit) at their desired positions.

Theoretical warp lane constructs like you're describing would have, by necessity, some measure of "tension" to them. So, continuing with my extremely simplistic analogy: imagine a hose dipped into a basin of water (on the surface of the Earth). If you let a hose sink down partway into the water, and then you start rotating the basin, then sure, that hose will be subject to the influence of turbulence you've just created, but the dominant forces affecting it's position will be hydrostatics and gravity, same as if the basin were at rest. If we performed this experiment at the scales you're concerned with, the effects would comparatively be even more negligible.

It's not a perfect analogy, of course, but this is a lot like how the dominant gravitational forces affecting the endpoints of your warp lanes would exert themselves. The endpoints aren't relatively "glued" to their locations, they're in orbit at their locations. The rotational influence of nearby bodies (i.e., the "turbulance") won't be enough to disrupt the stability of your warp lane so that they'd start to twist in disruptive ways. Rather, it's the overall gravitational influence of the nearby objects (i.e., the "hydrostatic equilibrium") interacting with the mass of the lane itself that exerts the most influence.

Granted, these descriptions are relative depending on the perspective of an observer. But the overall notion that stable warp lanes don't necessarily exhibit catastrophically destructive twisting effects is maintained, regardless. The simple reason for this is, if they were so easily affected by such forces, they wouldn't be stable enough to exist in the first place.

Answer 2

Construct a web of warp-lanes with fixed points in space relative to a predetermined galactic "center of commerce". So, with respect to that point in the universe, the warp gates are immobile (not spinning with the rest of the universe). Arrange the network so that there will always be a way to get somewhere close to where you want to go, granting that some places will (with the seasons) be more or less difficult to reach. In this scenario, the "seasons" won't require rebuilding the warp-lanes, but will require travelers to pick different routes through space in order to get where they want to go.

Economically, this implies that whoever owns the center of the web has an advantage over the whole network of warp gates. But there can be more than one web of warp-gates, with different relative-centers. This means that routing of traffic between two far-removed places in the universe can get very complex, but not infeasible at all. If your ship-computer has all the information it needs to simulate the motion of these webs, then it can generate the best path between any two points on-the-fly.

So, you'll need a lot of warp gates to start, but changing distances between two gates won't be a factor affecting gate maintenance.