User blog comment:Mr.Robbo/On 'Superluminal Inductors'/@comment-4068313-20130315142516/@comment-5135903-20130316105703

The warp 'bubble' (region in which the starship is) would end up being spherical. The starship doesn't need to be spherical, but if it wasn't there would be a lot of wasted space within the warp bubble, the problem being that it would take a lot of energy to create a warp bubble.

Here's an example. The Cylindrions of Hypothetica Prime build cylindrical starships 1000 metres long and 100 metres wide (volume = 7,853,982 m^3), so they need warp bubbles at least 1000 metres across to contain their starships. Meanwhile, the Spheriads of Imaginum-1 build spherical starships with exactly the same volume, so their diameter is only 247 metres.

The Spheriads therefore have warp bubbles less than a quarter of the diameter of Cylindrion warp bubbles for the same volume of starships (since they do not waste any space within the warp bubble) and therefore require less energy to generate their warp bubbles (even though they would go at the same speed and have the same sized starship).

I made a diagram to add but couldn't import it for some reason, so I hope I explained well enough here.