Time travel is feat thought by most to be impossible. After all time travel is what many science fiction movies are made of. Let us not forget such movies as "Back to the Future" or "The Time Machine." Yet unlike those movies time travel is not necessarily fiction. "We are in our own time machines, our hearts are pumping blood, we " re breathing, we are existing through time (at least until our own personal time machines seriously malfunction)." (Need help citing this! ) Still surrounding this topic is a series of theories, and surrounding these series is a number of flaws. Theories and flaws that need to be explained to fully understand the idea of time travel. First things first we must state the basics.

To begin with throw away whatever you thought you ever knew about time travel. There is no such thing as working time machines, you can't go back in time by falling into a black hole, and sitting in a tub of water is not going to change you molecular structure and send it back in time by having you float through a wormhole. Time travel is achieved through speed; theoretically you must reach close to light speeds to go forward in time and faster than light speed to go back in time, according to Einstein's theory of relativity mind you. Einstein's theory of relativity is the basis of all time travel theories (Davies 1), "The essence of his prediction is that time is not absolute and universal but depends on the observer's state of motion." (Davies 1) States Paul Davies of the University of Adelaide in Australia, and writer for Sky & Telescope Magazine. "This implies that two observers moving at different speeds, say, will measure different time intervals between the same two events." (Davies 1) For example say there are two people, Bob and Bobette, if Bob is traveling at x speed and Bobette is traveling at a speed of 2 x, the amount of time passing would differ between Bob and Bobette. So what does this have to do with anything? Well I'll tell you.

Now this is pure fiction it is being used to show a point. Say we are traveling to Andromeda, which is 2. 2 million light years away (help). We first set the acceleration to 1 g (the gravitational field of the earth) because if we could accelerate to infinity we would be smashed to the size of an atom (help).

So at 1 g we should reach our maximum speed (the speed of light) in 354 days (help). After that it would take no time to get there at all since the time to get there would have shrunk to zero (help). So assuming we go there just to come back, it should take us a little under two years to get there and back. So we would have only aged two years, while the earth would have aged 2.

2 million years. Thus us theoretically we would have travelled to the future. Here's where it gets complicated. Travelling back in time requires faster than light speeds. But that is impossible you can't go faster than light, otherwise you would be flattened to an infinitely thin film.

Yet there are ways around the light barrier. Worm holes. Wormholes don't allow you to travel at speeds faster than light. What they do is shorten the distance needed to travel from one point to another so in theory you are getting there faster then light would, thus travelling faster than light. Since we said close to light speed slows down time, faster than light speeds slow down time so much, it reverses time! Yet there are consequences of travelling back in time, paradoxes. Say get mad at your self, and think it would be a creative way of committing suicide by killing you grandpa before he met your grandma.

So you go back in time and kill you grandpa, thus your dad would have never been born, and then you would have never been born. Well if you were never born, how could you have gone back in time to kill your grandpa? So your grandpa lives, your dad gets born, and so do you, just to grow up and kill your grandpa. And this goes on and on for infinity. This is a paradox. One of the many consequences of backward time travel, and this applies to almost anything, that's why physics believe if there is time travellers they are discrete about who they are, and don't show them selves.

Then there are the ones that say time travel is impossible. If time travel is possible why are we not crowed with time travellers? Some think that if someone was to go back in time the entire universe would be thrown off balance and everyone would cease to exist. Think about it the death of one person can affect the lives off millions of people, if someone went back in time and killed off some of the first humans we would all be dead, terrorist time travellers. Also if we travel back in time we will be adding our mass to whatever universe we travel to, throwing off the delicate equilibrium of the universe and dooming that time and the future. The list goes on and on. In conclusion, time travel is a complicated thing.

There is a lot more to it. However a heated debate it is. The future, the past, and more importantly the present. If we can change the future from the past, why can't we change the future from the present? Bibliography. 1.

) Davies, Paul. "Wormholes and Time Machines." Sky & Telescope Jan. 1992: 20-33: SIRS Researcher. CD-ROM. 2001 SIRS Mandarin, Inc.

Fall 2001 2. ) Freedman H. David. "Time Travel Redux." DISCOVER Apr. 1992, pp. 54-61: SIRS Researcher.

CD-ROM. SIRS Mandarin, Inc. Fall 2001. web.