Let's suppose that time travel is possible, achieved by whatever timemachine of H.G.Wells, or by the magnetic hyperfield of Dr.Longstreet's generator.

In all these non-space-traveling time-machine techniques, i wonder what happens to the space coordinates.

Will timetravel happen according to absolute universe coordinates, means that the HG Wells machine or the "Eldridge" is somewhere in outer space or caught in the Earth magma, after the travel, due to universe expansion and moving of the galaxies, suns and planets... ?

Or can these devices have an integrated space coordinates regulation, so they stay in the same relative position on earth surface, during the travel?

I've been expirimenting wiht it but eth short-term isdlexia effects force em ot post.

If we're supposing time travel is possible, then we can suppose whatever capabilities of the device that we see fit. It's not much of a stretch to suppose that a device that can freely travel through time can just as easily travel through space (can anyone say TARDIS?)

Perhaps a default scenario if no space-travel capability is added would be for the device to follow a space-time geodesic. This would mean that an Earth-originating device would orbit the Earth's core in an ellipse, returning to the surface once each orbit but spending most of the time inside. If that were the case, the issue could be resolved by having the device in a nice orbit to begin with.

Of course, it seems most likely that any time-travel device would not travel in time itself, but only allow time travel inside it.

I copied and pasted this from a post I made a few days ago.. I'm too lazy to retype it :)

Now, for my view on time travel If I were to be completely logical I would have to say it would be nearly impossible to get a signal to the past and target the Earth to receive the signal. I'll use Back to the Future as an example.. When Marty took the Delorean from 1985 to 1955 and traveled in time but not in space he appeared in the field where the mall parking lot would be 30 years later, sounds reasonable right? This was the first movie that actually made me think about time travel and I came to the conclusion that if one were to travel 30 years into the past, wormhole style, like the Prof's Delorean then Marty would have had about 5 seconds to get an explitive out before he died in the hard vacuum of space and the Earth would eventually get to his location in 30 years what with the rotation of the Galaxy and the movement of all objects in space the Earth shouldn't be in exactly the same fixed point in space even in every orbit around Sol.