In reply to the recent time travel articles, time travel definitely IS possible, in fact we have ALL ridden in time machines and travelled through time!!!

I think time definitely is a very physical thing, a in built property of our four dimensional universe. Sure we have developed our own unique measurement units, based on the workings of our own solar system, and Mr Alien bloke probably uses a totally different system. But then he's hardly going to measure his dick in inches either is he?

The problem is that if time is just another dimension, then the maths says we should be able to move backwards and forwards in time as easily as we do in the other 3 dimensions.

At the moment though it only seems feasible to travel forwards in time, I think reversing the direction of the passage of time and going into the past may be the stuff of science fiction. It is mathematically possible, but it involves a lot of waffle about worm holes and such like, and considering we haven't even found any worm holes or proof for their existence, then I think we can forget about travelling into the past for now.

This seems to make sense as one of the main and most valid criticisms about time travel concerns the many paradoxes that arise. If time travel is a one way system, however, then there are no problems. You cannot meet yourself in the future either, or go and find out what happens to you in the future, because there is still only one of you.

So you might well be wondering how you go about time travelling on a limited budget. Well you can simply go for a walk. Or better still, take a ride in a car!

The most important concept to grasp is that there is not one big clock ticking away which covers the whole universe ("absolute" time), as was thought by Issac Newton and his chums. Einstein said, and it has since been proved, that we all carry our own independent measure of time, relative to everyone else. In fact this is what his theory of relativity tends to waffle on about a lot.

Right, so how does this turn your car into a time machine then? Well, the faster you travel, the slower your personal clock runs relative to every one else's. Honest!

So if you go for a ride in the car, while you mate stays sat on his arse, he will have aged more than you by the time you both meet up again.

Okay! I admit, the difference between you and your mate will be immeasurable, but the effect has been measured, and Einstein's theories proved accurate, by comparing the time shown by atomic clocks carried on space craft and fast jets, with stationary clocks on the ground.

If you want to go further than a few millionths of a nanosecond into the future, then you're going to need a slightly bigger budget. Often quoted in text books is the trip to Alpha Centuri at near light speed.

You see the closer you get to light speed, the slower your own clock ticks, until at the speed of light, your clock stops. Of course you can't do this coz Einstein also reckons that the more energy you get, the heavier you get. At light speed you will be infinitely heavy, so it takes infinite energy to get there. Erm. I think.

So anyway, the end result is that you go on your 2 week round trip to Alpha Centuri, but when you get back everyone else is five years older than when you left.

There is another way of travelling into the future, which is happening now, and is less complicated and easier to visualise. You don't actually physically travel through time, you just alter your perception of time.

How? Sit in a freezer for 500 years! When the men in white coats work out how thaw you out, you will have no recollection of the past 500 years, and will have effectively travelled into the future.

The only problem is that people tend to go a bit mushy when you thaw then out, but the cryogenics dudes are working on it.

Anyway, who wants to go into the dismal archaic past? Lottery cheats! That's who! I'd go into the future any day!