[Prince Charon]

Originally Posted by maximara

There are ways around the "can't exceed the speed of light in a vacuum" aspect of Relativity. Isaac Arthur's FTL03: Alcubierre Warp Drives goes into this.

The Science of Star Trek - Warp Drive gives the cliff notes on the process,

The way it works is spacetime itself can move FTL. So a "bubble" of spacetime is formed around the ship and that piece of spacetime (with the ship inside) is moved through universe spacetime. Yes it requires some exotic things (like negative mass) that haven't been discovered but per our current models they could exist.

I have found that many articles, even by scientists, over look this method of FTL and over focus on the ship itself going FTL. But from the standpoint of it own little bubble of spacetime the ship doesn't move at all. It is the bubble of spacetime with the ship inside of it that is going FTL.

I'm aware of that, I've seen arguments like that before, but I've also seen scientists claim that it won't work/isn't that simple. It's something modern science is still struggling with, hence the decision I made to include both sub-light warp drives, and in one of the five worldlines (the Earth-1 universe), eventual FTL warp drive. The different worldlines have differing spacial conditions in the local interstellar area, and thus different FTL types are more or less efficient in each worldline.

Originally Posted by maximara

This differs from hyperdrive FTL which is basically a way to create wormholes allowing one to bypass normal spacetime.

That depends on which version of 'hyperdrive' you're using (speaking of fiction, not physics). While the wormhole version is common to some settings (e.g. Stargate, I think), hyperdrive in a lot of fiction involves crossing into another dimension called 'hyperspace,' and coming out some time later (whether instantly or after noticeable travel time) at one's destination... or at some place that isn't one's intended destination, but is interesting for storytelling purposes. That's the form of hyperdrive established for the Earth-2 universe (or the parts of it near enough to Earth-2 to matter in-story).

Originally Posted by maximara

As side note I have added Isaac Arthur's channel as an additional material option for ''GURPS Space'' in the GURPSwiki article.

OK, cool.

EDIT:

Originally Posted by maximara

There is so much variety that I doubt that Infopunk Earth would have anything even remotely resembling consistency of their sublight travel design.

There would be Flash Gordon/Buck Rodgers/Atompunk inspired atomic drives seen in the 1930s-1970s, the old round tubs forming the bottom par of an "A" seen in TOS, as well as the TNG inspired Warp coils.

The warp coil design becomes common because that's what DARPA ends up reverse-engineering from various shuttlecraft mockups and things like that, and spreading around due to tech-sharing agreements. That doesn't mean that the others don't exist, just that they tend to be less common than warp coils.