"Travel In Time" is the biggest fantasy in modern human science. There are enormous articles around the web predicting how travel to future could be possible but here I will share my views that how travel to past could be possible. Maybe I am 100% incorrect as I am not a geek or expert! It boiled around my head, so I shared it here.
Can We Really Travel Back in Time?
You may know about the revolutionary theories of Einstein regarding the general and specific relativity. There is one phenomenon of Time Dilation.
According to this phenomenon if there are two bodies. One at rest while the other at a supposed speed of 10,000 m/s. And each body has a clock fixed inside it. The clock in the body which is at rest will move faster than the clock in the body which is moving at speed of 10,000 m/s. In short this means that the faster a body moves, the slower is time for that! And vice versa.
You can also understand this phenomenon with another example. Suppose you and I are participating in this experiment at space and we both are 20 years old at the time of beginning of experiment. Consider Ferrari has introduced a brand new space vehicle which moves at the top speed of 149896229 m/s which is half of speed of light. Again consider, you bought the car(paying a huge sum of dollars -:))! You started the engine and sat in the driver seat and started driving. Your car gained the velocity of 149896229 m/s! You continued your motion at this velocity. Time went on. After many years, you stepped out of the car. The time you started the journey you and I were 20 years old and when you stopped the car after many years, suppose I had turned 60 years old then you will be only 40 years old!
That's simple. I was at rest and you were at half speed of light. Thus:
Time for me = original time
Time for you = original time/2
After you stopped the car, the time in space had been 40 years then:
Time for me = 40 years
Time for you = 40/2 = 20 years!
This is it!
I think you understood the phenomenon of time dilation. Now let's apply it in our case. These theories show that as speed of a body starts approaching speed of light, the time for it keeps on slowing down. At half speed of light, the time halves for it. As its speed equals the speed of light, time stops for it!
Then what ahead? If the speed of the body crosses the speed of light and moves faster than light, will time remain zero for that?
.........+3 -> +2 -> +1 -> 0 -> -1 -> -2 -> -3........
No, it won't! It will proceed in negatives! And negatives in time means past! The faster the body moves beyond the speed of light, the faster it will start travelling back in time! So here we are in the past!
One can't approach speed of light. Light has always been dominating us but who knows which inventions are awaiting us in our future?
Maybe at speed beyond light, there would be no physical structures. Everything may change into energy!
Even if someone proceeds beyond speed of light, maybe the time will reverse just for him/her and not for his surroundings. He may age down to 15 to 10 to non-existence! He is moving at that speed not the whole surroundings! But once again who knows the time may reverse for the surroundings? We haven't tried yet!
Maybe I am just fooling around! I am not a scientist, I just have some basic one two three knowledge of science and what I mentioned above aren't facts or theories, just suppositions! Maybe I am 1000% incorrect! But It boiled in my head so I shared it here!