Time travel

One thing that I have always wondered about is whether it is possible for us to travel back in time. Wouldn't it be just wonderful to be back in the days when you were just a little kid, oblivious to all the problems haunting you? I have wished I had a 'Time Machine' of my own, something I could use to go back and undo all the mistakes I have done in my life as a child. Is it really possible?

Einstein says it is. If we can manage to travel faster than light, beating the mind-boggling speed of 3 * 10^8 metres per second, we really could go back to yesterday. It has not been experimentally proven though, for beating that speed will take something really special than jet propulsion and rocket engines.

But suppose you do manage to travel faster than light, what would happen? Would you go back to yesterday and see yourself or would you experience yesterday all over again? The former case will create two of you, and in the latter, you wouldn't even know that you had travelled back in time. Or would you? It really gets confusing over there.

Another phenomenon that is associated with time travel is what is known as the 'Grandfather Paradox.' Suppose you travel back in time to the childhood days of your grandfather. You take a gun and kill him. Now, obviously he died before your father was conceived. That would mean you wouldn't exist. So who killed your grandfather anyway?

There are a couple of arguments against the 'Grandfather Paradox'. The first says that you just wouldn't be able to go back in time. As plain as that. Another one says that even if you do go back to your grandfather's childhood days, you wouldn't be able to affect it in anyway. You just wouldn't be able to kill him. There are no solid explanations as to why this is not possible though.

As always, science fiction has always tinkered with Time-travel. A number of Star Trek episodes talk about the timeline, and how the information from the future can "contaminate the timeline" and so on. There is also the 'Back to the Future' trilogy, directed by Robert Zemeckis which is also an interesting flick. The 'Terminator' series also has some time traveling associated with it, with machines with artificial intelligence sending an agent into the past to kill off their enemy - a human soldier's mother before he is born and later the soldier himself.

Suppose, for the sake of argument, let us suppose that time travel to the past is possible. Then I wonder why we are not seeing visitors from the future visiting us right now? After all, we are past to them, aren't we? :)