Whats the difference between warp and subspace? Why do some authors use one and not the other?
Our local universe consists of three main sections. Subspace, normal space and hyperspace. An analogy would be a pond of water (subspace) with air (hyperspace) above it. A small enough object placed upon this pond will create a dent in the water but not sink. This surface tension (normal space) effect is gravity; which is more traditionally modelled by a weight on a rubber sheet. Note that an object existing in normal space (~placed on the surface of the pond) will produce distortions in normal space and subspace and hyperspace. Hence you can detect and describe an object or effect by looking at it from any one of these three points of view. The FTL propulsion in the stories similarly produces effects in normal space, subspace, and hyperspace. For various plot or technology points of view it sometimes makes sense to describe things in terms of just one of these aspects and not the others; even though the other aspects could be used to describe it. For example navigation can be related
