Is Time Travel possible?
For Ages the term “Time Travel” has excited the Sci-fi film makers. All I want to say is that i am staying away from all that. What I am going to do is put down in writing, what I infer from time and the mystery of time travel
Ok let us hang back and take a look at what is time travel all about. Time travel basically means travelling through time. For starters all of us are time travelers. I am travelling through time as i am writing this post and so are you while reading this. In a sense we all are time travelers
What we actually mean by time travel is the act of us going back and forth in time with freewill like we move forwards, backwards, sidewards, upwards and downwards. The problem is we are 3 dimensional beings and Time forms the 4th dimension in our universe along with 3 space dimensions. Our movement is restricted to 3 dimensions hence our inability travel time back and forth.
According to Einstein if an object can travel at the speed of light it can surpass time. But there is one glitch the object should be in an inertial state or to put it in simple words it should be moving at a constant speed without acceleration.
The time dilation equation would explain this better. Time dilation is the difference experienced by an object travelling close to the speed of light. We too experience time dilation because the Earth is always revolving around the sun. Time is a relative it changes accordingly. Now let us look at this equation.
When the velocity of the travelling object reaches the speed of light, if you solve the equation you would get T’ as 0.
So what does that mean? It simply means it has surpassed the time barrier. But that is impossible because anything that has mass can never reach the speed of light. Light has effective mass that is why it is affected by gravity. But we talking in respect to rest mass. Rest mass is mass of body when it is at rest. Light cant be brought to rest hence its rest mass is 0. Light is made of photons which doesn't have the concept of time and hence light doesn’t. So there is the reason why you cant travel at the speed of light because you or any object has rest mass, light doesn’t and hence time travel may not be possible.
However If we do manage to achieve that; which is higly unlikely; we may not be able to travel to the past. We all know the time travel to future is possible because we are doing that now. What is present, is turning into past and future is becoming present. But we can never go back to the past not even using the so called ‘Time Machine’.
Why cant we travel to the past?
The answer is simple it creates paradoxes. Paradoxes are nothing but errors. One of the famous ones is “Grandfather Paradox”. For example If I invent a so called time machine, go back to the past and kill my grandfather, I wont exist. If I kill my Granps, my Pops wouldn't exist and so I wouldn't too. But how come I travel time and kill granps if i did not exist because my grandfather was killed in the first place. Now do you get what error i am talking about?
This can be possible if only parallel universes exist. Existence of these universes is very debatable. String theory or the M theory claims they exist but it is still under construction and has to be worked upon. You can know more about the String Theory by watching these three videos Part 1, Part 2 and Part 3. It is explained in a simple manner by NOVA.
They may be right; they may be wrong only time will tell, perhaps it wont.
Tell me what you thought about this write up. Leave your comments
And for more about this, you can read the view of Stephen Hawking here in Swathi Pradeep’s Blog