Warp drive

Warp Drive

The warp drive in T-Space is based on the Alcubierre warp, as modified by van den Broek (making it a warp bubble rather than a warp sphere) and others.

(To do: add Technical references, Krasnikov deflection, Finazzi et al. instability, etc. )

Properties

Speed

The earliest (first Alpha Centauri mission) warp drives move a ship at about 200 C. Later (Chinese ships, V-class) this increases to about 300 C. By the Carson & Roberts era, they're up to 500 C. There's some variation on this; a message torpedo goes faster.

In general, speed depends on the number of warp modules. So does power consumption, but it's non-linear. Power consumption goes up faster than speed. (Required power also increases faster than volume of the warp bubble.) Speed goes up as a constant (which depends on the specific design of a given model of warp unit) times the square-root of the number of modules. Eight modules only give you twice the speed of two, but you use fuel faster, so have shorter range.

Thus, with four warp modules, you can go faster than with three, but your range is reduced because you're consuming energy faster. There ain't no such thing as a free lunch. To generate Brenke artificial gravity, you need an odd number of warp modules (or an asymmetric configuration). You can't get the necessary warp field bias with less than three modules. (See the book The Chara Talisman.)

Range

The power/volume limitation puts a practical limit on both the size and range; about 25 light-years, although for some ships that can be extended with drop tanks (they have to fit within the warp field). Since most pilots like to keep a reserve (to allow for variations in efficiency, power use for in-system propulsion, etc), they rarely plan trips longer than 20 light-years between refueling.

Characteristics

Start-up

It takes more power to create the warp field to maintain it, but that is momentary. (It's kind of like the start-up demand surge of an electric motor, or an incandescent light-bulb.) Early-era ships used a "jump capacitor" - a high density power storage device - which was charged (several minutes) to initiate the jump. Later ships had sufficient power output to make than unnecessary, although most designs incorporate such a (lower capacity) device to smooth out transients. Jumps can be made with less than a second between them.

Guidance

There isn't any. A ship goes in a straight line (more or less, see later) in the direction the warp field is pointed when activated. Misalignment of the drive modules or imbalance between them may mean that the warp field is not aligned with the ship. This can be bad. In theory, steering could be accomplished by changing the balance while in flight, but that risks triggering Finazzi instability or getting lost, since there's no way to see where you're going.

If the path of the ship passes close to a large mass, the space-time curvature caused by that mass will also affect the direction of the ship. Usually this effect is minor, given the apparent velocity involved. A neutron star or black hole will have more of a deflection effect. Either way, matter -- such as atmosphere or corona -- is generally the bigger hazard when flying close to a massive object.

The question has been raised as to what happens if a ship is rotating (other than around its longitudinal axis) when it goes into warp. Does it go in a straight line, or corkscrew? The math is indeterminate. If anyone has been silly enough to actually try the experiment at noticeable rotation rates, they've never reported back.

Warp boundary effects

The edges (inner and outer) of the warp bubble are extremely curved space-time. As such, they will exert a strong tidal force on matter, tearing it apart even at the subatomic level. (Gravity is normally a very weak force. The pseudogravity at the edge of a warp bubble rivals the strong force, over atomic distances.) This tends to release energy. Violently.

At larger distances and grazing angles, the field tends to push matter aside. (Krasnikov deflection. Yes, this is a thing.)

Light (radio, etc) waves decohere at the warp boundary. Transmission or reception of EM signals is impossible while in warp. (A really big signal, like a nearby supernova, would be noticed as a brightening of the noise, but about the only information it would carry is "something happened".)