Quote:
Originally Posted by xelasnave
... and as I say the sums tell us that in a black hole time stops GR either says it stops or not.. I am sure that is what is says so either I have it wrong or that is the way of it... I have seen comentary from true believers that one can expect to be able to time travell using the science relating to black holes... ticks me off but that sort of stuff is out there and not on crack pot sites but put forward by legit folks..have a look around the science daily site or the like and you will find an article along those lines... fits into the same box as worm holes..crap from extrapolation of the sums I feel.
alex  |
Alex,
I agree, using Black Holes to travel back in time is pure fantasy.
However, in a sense, you can go forward in time (i.e. lose time). Basically, special relativity says that time can slow down for one observer moving relative to another. If I was away for 20 years, travelling around at a speed of 4c/5 during this time, this would be equivalent to about 33 years for an observer B on Earth. When I got back, I would have skipped 13 years of normal Earth time.
General relativity says this same effect can be achieved by gravitation. For a Black Hole, the higher gravity would result in a slower time for observer A near the Event Horizon relative to distant observer B. If it were possible for them to meet up later, observer A would have aged less than observer B.
Rob