[House Atreides]

“ …My “time” machine is a stationary mass, temporal displacement unit manufactured by General Electric….”
********************************************
It his time machine is stationary after his trip back to our time he will have arrive at a place, in our expanding universe, in space where the Earth will be at the future time he left. His arrival location will likely be a cold empty space. From where we are at now, our planet will move through space as it rotates and orbits our Sun. And, of course, our Sun will continue in its orbit around the center of our Milky Way galaxy which itself is moving through space.

[monkeyshine]

“ …My “time” machine is a stationary mass, temporal displacement unit manufactured by General Electric….” ******************************************** It his time machine is stationary after his trip back to our time he will have arrive at a place, in our expanding universe, in space where the Earth will be at the future time he left. His arrival location will likely be a cold empty space. From where we are at now, our planet will move through space as it rotates and orbits our Sun. And, of course, our Sun will continue in its orbit around the center of our Milky Way galaxy which itself is moving through space.

Well, presuming time and space are two different dimensions in a universe of possible dimensions, in theory you could calculate the exact position of this spatial universe (in this case, the earth as we know it) at any given time in the past or future and dial in for that location. Of course, if you go back in time (or forwards for that matter) you'd need to bring the machine with you. Otherwise you could be stuck for good.

[Blood of Tyrants]

Exactly. At a particular time, the earth will be at a particular place and you will have to calculate that place to the nth degree or you will end up inside the earth or millions of miles away in space. And the further away from the present time you get, the more imprecise your calculations will be. For this reason, any time machine would also need to be a spacecraft unless there was some way of fixing the time machine to a place on earth.

[cgbg]

It his time machine is stationary after his trip back to our time he will have arrive at a place, in our expanding universe, in space where the Earth will be at the future time he left. His arrival location will likely be a cold empty space.

I see you are doing some of that racist math again....time travel is about "feelings".

;-)