Time travel a fiction or a reality? This has been the question asked by many… is it the solution to eternal youth? well Hollywood most certainly thinks so… we have heard we have visualised we have dreamt and we have fantasized and yet we have not realised it! some blockbuster movies also came along making us wonder whether someday we will be able to do it… After all if Jule Vernes did imagine a submarine in his time, almost exactly as it is today, without actually seeing one then nothing can really surprise us… from the wormhole in Stargate to the wonder car in Return Towards The Future. But lets get to the reality of it and stop dreaming about science fiction!
Albert Einstein… a name and a fame… re wrote the whole concept of time being an “invariable constant”. According to the millennium’s Genius time is in fact a “variable constant” that is taking a simple example of the formula v=d/t (velocity=distance divided by time) for an object moving with constant velocity applying our logic we would say distance covered per unit time is constant also… and in fact it is! but then lets take a little fictive example… a car moving at 500 km/h and inside the car a child throwing a seed at a speed of 3km/h in the same direction as the car is moving… a person standing on the road will actually see the seed moving at 500+3=503 km/h but the child will see it moving only at 3km/h… now lets assume that human eyes could follow the speed of light (299792458 m/s)… now lets assume the child moving in the car at 500 km/h (138.9 m/s) switching on a flashlight… if we follow the same logic the observer outside the car should have seen the light moving at (299792458+138.9)m/s and the child only at the speed of light… but according to James Clerk Maxwell’s experiments the speed of light is constant and cannot be added up to the speed of any object moving… not coming back to the formula v=d/t, velocity being constant at the speed of light, to compensate for the changes in variables either distance or time should be variable (as a matter of fact both are!)… After years of research Einstein came to a solution… the relativity theory which states that time actually changes “relative” to the experimenter’s or observer’s point of view and the faster the experimenter moves the greater the time distortion… that is the experimenter moving at a speed nearing that of light will actually see time moving faster and the observer who is static will see time moving slower… basically the experimenter will take 10 minutes to drink a cup of coffee while actually for the static observer almost 9 months passed by. (u can use this site to calculate relative ages http://www.pbs.org/wgbh/nova/einstein/hotsciencetwin/ …its fun :p)
Well then that’s great but what stops us from time travelling? If only life was that simple! Einstein also predicted that a body moving faster will actually gain mass (using a varient of F=ma) so basically an object moving at speed of light or near speed of light would require an increasing acceleration to the point of infinity so as to be able to propel the infinite mass of the object moving at a high velocity and for that we will need a source of infinite power which is until now impossible to get!
We also have to face another problem… moving at a high speed would definitely get you stagnating on your timeline while the timeline of stagnating people would keep moving… basically u may age by 2 years while a century passed by… but there is no way to reverse this as TIME TRAVEL IS UNIDIRECTIONAL and is not really what science fiction time travel is that’s what most hollywood film makers tend to ignore… (well personally i think if we decrease the speed of rotation of the Earth we can actually move at a slower rate in our timeline relative to someone moving near speed of light who actually is going on a faster timeline relative to ours but that will only save use like a decade or so and the one travelling at speed of light will still be 90 years ahead! and decreasing earth rotation in theory is possible! maybe someday i’ll postulate a new theory who knows!! :p).
Coming back to our topic… if time travel is unidirectional and u can only move forward that means that u cannot alter anything of your past but u can alter the future… thus eliminating the “grandfather’s paradox” which states that if u kill your grandma before your mum is born u will not eventually be born. but still you will be definitely challenging the law of energy conservation
if you go to the future you will be an increased mass in your present and an excess mass in the future also… that is given that mass and energy is related the energy at your present time will increase the total mass by your velocity (as stated above the faster u move the more mass u gain) and in the future u will be an excess energy which was not supposed to be present… thus energy will not be constant and conserved!
time travel realised through baryonic particles and exotic matter are still under investigation and could reveal to be useful but they do still have many drawbacks (if u r interested to read more go to http://www.daviddarling.info/encyclopedia/W/wormhole.html)
progress never ends and we must always keep up with it… for the betterment of our race and for the future!
Cheers,
Viru5
(souce: http://nussaibah.wordpress.com/2008/04/11/the-relativity-theory-and-time-travel/)
