Torpedo, Torpedo

[Crazy Eddie]

The spatial distortions required to make warp-drive work would be such that they would make most gravitational fields look miniscule (in terms of the distortion relative to the area of space distorted) and would not be effected much by most gravitational fields (except like a neutron-star or a black hole or something).

In terms of raw power, this is mostly true. On the other hand, a car with a 250hp engine fares little better than a bicycle on an icy road.

In this case, you could describe it as a matter of "traction." The same distortion produces less movement when other gravity fields--which may themselves by greater sources of SUBSPACE distortion--are in the area. Especially considering that in terms of mass-energy equivalent, a planet or an asteroid has ALOT more energy than a starship's warp engine.

The difference in how much distance the ship covers has to do with something called a plot-device. If the episode calls for the ship to be really fast, the ship magically covers more distance. If the episode calls for the ship to lumber along, it does.

Right, exactly. My original objective was to try and generate an IN UNIVERSE rule for that plot device so it could be applied consistently. This way it could be invoked with a repeatable and recognizable line of dialog, something like "space-energy density is increasing" or "we're making good time, Sir. Subspace conditions are as good as I've ever seen them."

I honestly think it's much more practical at least for TOS to assume a maximum ship speed of 0.73 LY/Hr which Gene Roddenberry wrote about in a proposal named something like "Star Trek Is..." or something like that. It would yield a speed of 6,400c at full-throttle and would match similar speeds to that shown in the episode with the USS Constellation and the Planet Killer.

Sure, but there's gotta be a reason why they can't ALWAYS go that fast, and why they can sometimes go faster. I'm just thinking if you're going to invoke the plot device anyway, you might as well do it in a way that it seems (to the uninformed reader) to be intentional and not just you screwing around with physics to make the story run better.