So this would have to be denser than a black hole?
Yeah, this is overly similar to something I seen on TV a while ago... The "we can only travel back the the point where we turned the machine on" was the give away...
You may have seen this, but I thought it might help somewhat... It might get you away from imagining the other dimensions as coordinates...
http://www.tenthdimension.com/medialinks.php
Click on the second option, imagining the tenth dimension...
This is kind of a weird question, so I'll just throw it out there. So I was talking to my mate about BEC a couple of weeks ago and he proposed an interesting idea. I was telling him how BEC was used to slow down light to 38mph, what he suggested was using this concept to move a solar sail. So...