Time Travel Theory
Are we aware that we don’t live in a three dimensional world but just perceive it that way? The way we see our universe isn’t the way it is. The genius of Albert Einstein unleashed a strange view of our universe, the view of space and time as a united entity, the theory of time travel arrived!
However the concept of an individual traveling through time isn’t new in our culture. Various ancient texts have also described people traveling back or forth through time but in spite of being very popular in human imagination, Time Travel is very tricky to understand. The whole theory proposes a new dimension to our world, Time, a physical dimension which forms the fabric of space- time.
According to Einstein, space and time are not two different entities but are one and always remain connected. The special name given to the unison is space-time continuum. For example, if you need to meet your friend you will have to specify him space and time. If you say lets meet at Nariman Point, the immediate question your friend will ask will be “When?” And if suppose you would have asked your friend “Lets meet tomorrow” the immediate response in this case would have been “But Where?”
You cannot locate a person without knowing the exact four coordinates, 3 of space and 1 of time. These coordinates makes the whole of universe and everything, living or dead, are moving through these four dimensions.
We are three dimensional beings, we can move through the three dimensions of space with ease and for us time remains the one barrier we cannot breach. We are the slaves of time. Time travel is actually a concept of movement (of especially a human body) from one point in the time to another. This concept has a very less support in the theoretical physics but is possible in quantum mechanics or Einstein-Rosen Bridges (popularly known as wormholes).
Time travel can be categorized into two broad concepts:
Backward Time Traveling:
Traveling back in time is one of the greatest human fantasies. Who doesn’t want to go back in time and watch the Pyramids being built or the Romans ruling their territory? Everyone wants to go back and undo the one life changing mistake of their lives or to see their lost loved ones once again. We are so much emotionally connected to Backward Time Traveling that it is a very important part of our imagination. The best part of this form of time travel is that we have evidence and it smiles at us every night. The night sky is the best example of looking into past. All the stars that shine at night are millions and billions of light year away so even if they cease to exist, their light will still continue to reach us for the next millions and billions of years making us see something which was a part of past. Night sky is a canopy of forgotten past.
Theoretically backward time travel is possible by two spectacular means:
Traveling Faster Than Light:
If you are traveling faster than light then according the Time Dilation, time will slow down for you with respect to the outside world. So this means you can actually reach your destination before you have even started. This gives a perception of travelling back in time. Unfortunately the cosmological limit of the speed of light is very tough to break. According to the special theory of relativity an infinite amount of energy will be required to break the speed of light limit.
Diving into a wormhole:
According to Eintein’s theory of general relativity, wormholes are theoretical warps in the fabric of reality that connects two points of space-time by a shorter distance even if they are separated far apart in the larger continuum. It is theoretically possible that wormholes can connect distant galaxies, separated universe and possibly different times. Certain types of wormholes, it's theorized, could allow for time travel in either direction, if we could accelerate one mouth of the wormhole to near-light speed and then reverse it back to its original position. Meanwhile, the other mouth would remain stationary. The result would be that the moving mouth would age less slowly than the stationary mouth thanks to the effect of time dilation—more on this in a second.
But there are several major caveats of traveling back in time with this method. Chief among them is the simple fact that we'd need a method for creating wormholes, and once created the wormhole would only allow us to travel as far back as the point in time when it was created. So we'll definitely never be spectators to Great Pyramids' construction.
Forward Time Traveling:
Traveling forward in time is proved to be more theoretically possible than traveling back in time. For traveling ahead in time there are two theoretical ways:
Time dilation:
Time dilation is a phenomenon by which time passes quickly for an object with respect to an observer due to the object’s very high speed or it being in a very high gravitational field. According to relativity the time will theoretically stop when the object’s speed approaches the speed of light. Since that is not possible and if the speed of the object is very close to the speed of light, like say 90% of the speed of light (0.9c, where c is the speed of light), the time will slow down for the object. If there are two clocks, one with the high speed object and one with a stationary observer, the time in the object’s clock will slow down with respect to the observers as it reaches 0.9c. This will make all the activities in the object’s ship to slow down, even the aging process of the body will slow down and when the object will return back to meet the observer he will notice that the observer has aged more than he had or even dead and if object took just an hour to return, the time passed at the observer’s end can be more than a 100 years. So the object has actually traveled forward in time, into the future. The same happens with high gravity zones. At high gravity areas, time passes slowly with respect to the less gravity areas. The scene in the movie “Interstellar” where the space crew took a round in a very high gravity zone and came back, the time difference between them and the other crew member in the mothership was 22 years. This is the example of time travel in the presence of gravity.
Hibernation/Suspended animation:
If any person is sent into induced coma which makes its growth slow hence prevent aging while the person being in hibernation, he will wake up in distant future being the same aged person and everything around him has passed forward in time. He has thus in some sense travelled forward in time.
