well....that was when Quantum Mechanics came into light...and not to mention general theory of relativity....they deviatedcompletely from the Common sense and Logic.....
Well, doesn't the idea that Sun doesn't rotate around the Earth is also deviant from the common sense? =) If you look into what Quantum Mechanics actually does you won't see anything illogical there, it is just a bunch of theories and models that come from them, some proven by experimentation and some aren't. You can also check every result they got, because it is mostly just math. All problems that people have with it actually come from irresponsible interpretations, that postulate things like time travel and other stuff that has nothing to do with the science itself.
Theoretically..........But it is obvious, right? When you say that speed of light is the only invariant, then time is also a relative quantity, then time travel is possible, of course, only when you travel close to the speed of light.............Time slows down and you get years ahead.........
Nope it isn't. When you talk about time travel I assume you mean that you can go into the future or the past or something. But that is a pretty liberal interpretation of the results from the theory. What I remember they managed to show is that a clock which moves with a certain speed relative to another clock would develop a mismatch, which you can interpret as "the speed of time is different for the moving object". But I don't see any logical problems with that. Think about it, even if you take a rocket that moves pretty fast compare to most things you encounter in your everyday life, that effect that doesn't show at all, unless you do a really thorough measurement. What I want to say is, we humans have no way to experience this change in the flow of time, we never move fast enough. But that is a bad reason to deny the effect. It would be the same as denying existence of magnetic field just because you can't see it.
And "you get years ahead" - unless you are an electron or some other extremely small particle I don't think that would be possible for you. I mean, moving with a speed close enough to the speed of light to get that effect. This notion of "getting years ahead of your own time" comes exclusively from science fiction and not from the science itself.
But don't get me wrong, I am not a proponent of some quantum theory or General relativity or anything of that, I don't think I have good enough understanding to have a say there. But I do like methodical and logical way of describing natural phenomena. When a theory is mathematically sound and agrees with the experiments - why not use it, even the results it yields are not what you would expect. Btw, if you wonder, this time dilation thing has experimental proves, you can read a little about it here -
Time dilation, experimental confirmation