A JOURNEY THROUGH TIME MACHINE
The concept of time was already mentioned in our Vedas. A lot of science fiction has been written over machine but this may turn into reality after few years. A common question exists in general people like “can we go back in past?” or “can we see our future?” etc. Lets see what are the opinions of our great scientists regarding this. In 1887 Michelson and Morley showed an interesting fact about speed of light. They showed no matter what is your speed you will always see the speed of light 3,00,000 km/sec. How can it be possible? But it didn’t shock one of the greatest scientific mind ever Albert Einstein.
Einstein said, “Time is not universal quantity. Every observer has its 
own time.” This was the evolution of great theory now called “special theory of relativity” and came in 1905. The theory tells that if you increase your speed you slow your rate of spending time and hence you see speed of light same no matter what your speed is. If you go in rocket with very high speed your time will slow and your younger brother living on earth will spend usual time. And when you return you would see that your younger has become elder one. This difference in time rate is called as time dilation.
Consequently it describes that we don’t have only 3- dimension rather than our event occurs in 4-dimension. Popularly 4-d event is known as spacetime. So we must attain speed of light to go in past. But again Einstein said “nothing could go faster than light” and thus he restricted our dream to go in past. Nevertheless he came up with a new theory in 1915 in which gravity was brought into picture since Newton.
The new theory described gravity not as force but it is like curvature of spacetime. But how can space be curved? Yes, although amazing but it is true. Our spaceitme is curved. This is our new clue for time machine. Space near massive object tends to curve itself rather being flat and hence spacetime. It states that a long straight line near sun is not straight in real, in fact curve. One can see all these effects one large scale.
Now think that a straight line is made like circular arc type, one can easily travel from end to other end by moving straight and can save time. This is the present topic of research of scientists. One would be amazed to know that our Euclidean geometry fails in curve spacetime. Parallel lines don’t meet in our geometry and sum of angles of triangle are 180 deg. But these don’t happen in curve spacetime. Parallel lines do meet and sum of angles of triangle are not 180 deg in curved spacetime. It is quite amazing, however true.
Yes there are black holes in our universe where the curvature of spacetime is so high that even light has to bend such that it gets trapped. Nothing can escape from black hole. Thus black holes can’t be seen. Black holes are so much dense that a spoon of it will weigh heavier than our earth. The infinite density of black hole is called as singularity. If one goes inside black hole he will never come out and his speed will be so much high that his time will be very slow. So there is probability of making time machine if we artificially create a black hole. Black holes are very mysterious. Laws of physics break down here. What is then inside black hole?
It is predicted that spacetime so much curved that there might be places in black hole as single point which have more than one time. This place is called as “worm hole” or “time tunnel”. These are such holes that if we go inside it at 10:30 AM today we may come out this hole at 10:30 today AM but that may be the period of King Ashoka. Even we might come out thousands of miles far away from that place. So wormholes are another face of time machine.
But there are logical questions regarding invention of time machine. What happens if one goes to past and kill his grandfather before his father was conceived? Can anyone be able to see his body sitting on chair just an hour before? These logical questions is solved when we think that if one goes to past and kills his grandfather then the two pasts don’t matches exactly .The past in which no one killed his grandfather already been occurred and the past in which one goes and kills his grandfather are different from each other.
It gives another amazing fact that if you desire to go to past you won’t follow same path of reversing time. The path will be different and the past will be different. Hence there exists different world in past called as parallel universe. So if one wants to spend thousand of years with his girlfriend he should sit with her in a rocket having very high speed and fall into a wormhole, but he must beware that he wont able to return.
