Like wars erupting over FTL rather than sharing it, because the country or a corporation who would be the first to have such technology stands to have the potential to colonize distant planets.
Like wars erupting over FTL rather than sharing it, because the country or a corporation who would be the first to have such technology stands to have the potential to colonize distant planets.
There’s no such thing as speeds faster than light—the worldlines of objects with such trajectories are called “spacelike” instead of “timelike” for a reason. “Forward” and “backward” time is only defined for events within your light-cone, and trajectories “faster than light” are outside it. Whether events outside your light-cone are in your future or your past are dependent on your current reference frame, which you can change at will by accelerating—so spacelike trajectories have no intrinsic direction with respect to time.
The thing about “moving with FTL from A to B” is that if B is far away, the event at B simultaneous with your departure from A will be highly dependent on A’s reference frame—a shift in A’s velocity will correspond to a shift in B’s timeline equal to (vx/c2)/√(1-v2/c2) (where v is the change in A’s velocity and x is the distance to B). And things are changing velocities with respect to each other all the time (e.g., for objects on earth due to the planet’s revolution and rotation around the sun), so the point in B’s timeline at which you’d arrive would be constantly swinging backward and forward in time.
And the same is true for the return trip: a minor change in B’s reference frame can put your arrival back in A’s timeline at a point before your original departure.