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

As a personal view on Time Travel, I am of the belief that while it may be possible, the methods are not very conventional. Firstly, if you are going to create a wormhole or a neutron star, how are you going to control how far back it takes you? I very much doubt that either of those two have a control panel like in the science fiction films where you simply punch in the year you want to go to and you are off. For the first example the rotating black hole, if you were to go through the "ring" of the quantum singularity, how are you to control how far back it takes you. An only slightly more possibly controlable method would be the massively dense column of matter which you fly around. No one has any idea what the time differential per orbit would be, so for all we know one orbit is equal to one second's difference in time. to go back or forward several years or several hundred years would be difficult to say the least, and it would sure as hell make you dizzy. Or, perhaps on the opposite end of the spectrum, one orbit is equivalent to 1,000 years time, which means it would be very hard to pinpoint the exact year you were aiming for and were likely to be decades off.

Furthermore, perhaps getting to the past is all very well, but how are you going to get back? there doesnt seem to be a 100% reliable answer to that question.

Before discussing things such as the Grandfather Paradox, I believe it would be much more prudent to discuss the more basic problems presented by Time Travel, such as how you are going to go back to, relatively speaking, so narrow a length of time as the lifespan of a human.