Time Travel brain-ache thoughts

"Anything is possible" I always say - how about this:-

The giant atom-smasher being built at the European centre for nuclear research, Cern, near Geneva, could create the conditions where it might be possible to travel backwards or forwards in time. If true, this would mark the first time in human history that a time machine has been created. If travelling back in time is possible at all, it should in theory be only possible to travel back to the point when the first time machine was created and so this would mean that time travellers from the future would be able to visit us. As an article in this week's New Scientist suggests, this year – 2008 – could become "year zero" for time travel.

Is this really a serious proposition?
The New Scientist article points out that there are many practical problems and theoretical paradoxes to time travel. "Nevertheless, the slim possibility remains that we will see visitors from the future in the next year," says the magazine says, rather provocatively. Apart from the practicalities, what's to stop time travel?

The biggest theoretical problem is known as the time-travel paradox. If someone travels back in time and does something to prevent their own existence, then how can time travel be possible? The classic example is the time traveller who kills his grandfather before his own father is conceived. Cosmologists, renowned for their imaginative ingenuity, have come up with a way round this paradox. They have suggested that there is not one universe but many – so many that every possible outcome of any event actually takes place. In this multiple universe, or "multiverse" model, a woman who goes back in time to murder her own granny can get way with it because in the universe next door the granny lives to have the daughter who becomes the murderer's mother.

So will we one day be able to travel into the future?

Yes...

* There is nothing in the laws of physics to prohibit it, and events in Geneva are pointing the way and could be a first step

* In physics, so the saying goes, if nothing is prohibited, it must happen at some point

* All we need to do is to work out how to manipulate black holes and wormholes, and away we go