Time can also be used dramatically in a longer term view in science fiction. Where will we be in so many years? Time travel is another way, and then there are the books that stitch together star systems with relativistic travel, decades long travel between stars and everybody that you knew when you headed out is long dead and hundreds of years have passed. To me it is depressing, or rather actually scary. When we travel on Earth we get those same affects, but since we are no where close to the speed of light we don't notice that those people sitting still are relatively older than us.
So most science fiction that isn't diligently exploring what life would be like without a go-faster-than-light card creates a way to travel faster than light without the time dilation problem. However, they try to limit themselves with problems such as gravity wells and where and how the drive works. So let me introduce an idea for FTL drive that is limited in its own way, I might have equations...
First, the BasicsDiscovery of a universe "below" ours that our universe is wrapped around. It is smaller in the fact that things can move much faster through it. The main feature of the neighbor universe, sub-space, is that it has no electromagnetic force, but it does show the effects of our universe in terms of gravity. A ship going in unprotected would just fall apart as all the electromagnetic forces holding atoms and molecules together would collapse.
Also gravity wells are a major player, essentially entering and leaving the sub-verse must be done at a similar gravitational potential energy. Coming in at higher potential energies cause major power stripping coming in, lower potential energies means the possibility of overwhelming systems with incoming energy. There is no limit to how far inside or outside a gravity well a ship must be however, orbital and absolute velocity relative to mass and proximity affect the velocity in the sub-verse.
What do I want my timelines to be in the universe? Do I want to make it such that we are retelling old sailing tails and battles on the high-ocean? Or skipping across the universe seemingly unfettered? I think I have enough restrictions to play with both logically and dramatically, but I also want a bit of down-time, unable-to-do-anything time that my characters might need to experience. I think reasonable speeds would be about two light-years in and hour, meaning about 8760 times the speed of light. Of course that is highly variable due to the gravity well that you are exiting.
One of the major problems with early travel using this drive was pointing and timing. Hitting a star's or planet's same orbital potential in such a way that you weren't just plummeting toward its surface but instead tangent and able to establish an orbit was extremely hard, however the first wave of extra-solar colonists risked it.
I will continue these thoughts in the next installment.