Time traveling is one of the most fascinating branches of physics. The very idea of taking a peek into our future - in the literal sense - and watching our past actions kindles the heart. Scientifically time travel has never been proved. On the other hand, there is no actual proof or theory to deny such a possibility. Let's take a look at some of the interesting theories proposed for this.
The idea closest to time traveling that has strong scientific foundations is time dilation. Time dilation is the idea wherein the clock of a moving person appears to be 'running' slowly when compared to the clock of a stationary person. There is too way of explaining this - special relativity and general relativity. Time dilation and time traveling can be combined in this way. Say me and my friend are at rest with our watches showing 9 am each. If he remains stationary and I start running really fast, then technically my watch would run faster than his. For eg my watch would perhaps show 9 10 am and his would show 9 8 am. Thus I would be in the future when compared to him.
There is also another theory that suggests that objects moving faster than the speed of light would time travel. Let us analyze this logically. If I run faster than the speed of light ( theoretically ofcourse ;) ) and say I turn back. The light particles behind me would fail to reach me and hence I would see only black - the absence of light. I cannot fathom what we would see if he straight ahead. I leave it to your imagination.
Another interesting possiblity arises when time - as every measurable constant possibly - is seen as a relative variable. Consider a man living one light year from us. Now we can see what he does only after one year. Hence he knows stuff happening there before we do - that is he is, technically in the future when compared to our time frame. The reverse is also true i.e. we are living in the past when compared to him.
When considering the possibility of time traveling, we must also consider what will happen if we do manage to travel in time. The only possible idea seems to be the thoery of multiple universes. Like Michael Crichton said in 'Timeline' perhaps the universe is constantly dividing into different universities where the different possiblities of an event happens. For eg an universe where I win the Kriya blog contest, one where my blog gets deleted, one where I am heavily criticed for my works here etc. Now arises one interesting question. If we do time travel, which of these possible universities will we land up in? Can we choose any one? Your guess is as good as mine.
As Stephen Hawking suggested, the absence of people visiting us from the future suggests the absence of time travelin. But then this is not enough evidence to decide the idea as an impossibilty.
While considering all these fascinating theories, one question reamins unconsidered. Where is the Hand Of God come into play when we talk of time traveling? Or is it God that stops us from jumping from one time frame to another?
