h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

You missed one of the theoretical possibilities of timetravel using a black hole. This one does not include stopping you from being crushed by it, but at least there is no chance the thing will collapse on you.

You mentioned Einstein's relativity, well part of that theory is that gravity affects time. And as black holes have one of the largest gravitational pull known to man, you could travel through time with it.

In fact, if I were to watch, say George Bush fall into a black hole, I would never fully see him disappear in my lifetime. This is because time is that much slower around the black hole than my timeperception.

Logical assumptions are as followed: Astronauts travel in time every time they go into space, as they have less gravitational pull as on Earth. This has actually been measured by NASA.
Someone who works in a skyscraper experiences time faster than someone who lives on the ground. Not enough to be noticeable, but still.

To conclude, timetravel to the future is possible, just not as flashy as we're made to believe in the movies. To succesfully pull this off, we need to know exactly how much time differs in a black hole and we need to think of a safe way to get in and out of it, not to mention some device that makes sure our timetraveler does not get ripped apart by the violent gravity.

You're right. A black hole could be used to time travel to the future. So could a fast spaceship, for that matter. If all you want is to travel into the future, there are plenty of options open for you. It's only if you want to travel into the past that you run into problems.

I just like to mention briefly, and I shall ellaborate further another time, that modern mans contemporary school of thought regarding time travel(is in my humble opinion)linear thinking.I have a theory that time is neither past or future, and that it is mathematically and quantum mechanically possible to exist in different states, ie: different possible out-comes. I realize that I'am being very vague and presumptious, nevertheless I just wanted to throw the "concept" out there.

My personal quantum-mechanical view of the universe is that whenever a quantum superposition is broken, a number of new universes are created to compensate for the probilities of which way the superposition could break. But I don't think that one can ever easily access any of those other universes, so we can't really use them for any practical time machine. They do, however, make theorizing about a hypothetical time machine easier.