ENTRY 182: Relativistic Time Travel
Not everyone groks the full physics, but this much has percolated through to the bulk of transhumanity: while no one can travel back in time (yet), if you accelerate up to a reasonable portion of the speed of light and back down again, you can travel into the future, while not personally experiencing the same passage of time. Relativistic time travel is then is theoretically available with current technology; just strap yourself in to a ship with enough fuel and supplies, set a round-trip course, and accelerate up to around 10% of the speed of light and back again, to return to a solar system decades or centuries later than the one you had left, but having subjectively experienced only a fraction of that time passing within the craft. It’s all about frames of reference.
Realistically, efforts at relativistic time travel remain rare. The calculations are precise, the amount of fuel involved often immense (barring some of the more unusual schemes), and under current technologies even approaching relativistic velocities in an acceptable period of subjective time is problematic—most current efforts at building vessels capable of relativistic speeds center around antimatter drives. Still, there have been experiments. Zooming around beyond the Outer Rim is the Undiscovered Country, a small vessel with a crew of six infomorphs still accelerating up toward relativistic velocities since it was launched six years ago; if the ship holds and the calculations are correct it should return to the solar system somewhere around AF 150.
Using Relativistic Time Travel
There are two main uses of relativistic time travel: visitors from the past, or diving headlong into the future. In the former case, the assumption is that at some point a ship or other vessel was shot into space, attained relativistic speed, and then came back, decelerated, and re-entered the solar system’s frame of reference. To say this is unlikely given pre-Fall technology is putting it mildly, but for the sake of including forward-time travelers the gamemaster should consider it. The return of such a vessel is likely to be a momentous occasion, akin to opening a time capsule from another century—as given earlier technologies, it is unlikely that the original pilots of such ships are still alive; if they did somehow avoid perishing of old age, they have a lot of catching up to do… Time travelers from the past are especially likely to have the Old Age and Immortality Blues traits.
On the other hand, PCs or NPCs may look to travel into the future of the Eclipse Phase setting using relativistic time travel. At worst, their efforts are doomed to failure—the vessel they select simply isn’t able to achieve relativistic speeds. At best, the gamemaster is stuck with how (or whether) to present a setting even farther in the future than Eclipse Phase already is. If the GM is willing to bend the rules of physics a bit more, then Pandora’s Gate-derived wormhole-generation technology in a future Eclipse Phase setting might permit the PCs to travel back after being stranded in a strange future by relativistic time travel…but at that point, it might be easier just to have the PCs be reconstituted in the present-Eclipse Phase from forks left behind before their trip.