Time travel is not possible.

Question

I don't think that time travel is possible.

For time travel to be possible, all the past, and present, and future should exist somewhere in material (physical / tangible) form.

This means that the state of earth 5 seconds ago should be existing somewhere in material form. This also means that the state of earth 15 minutes into the future should also exist somewhere in material form.

If we assume the least count of 1 second, then given the age of earth as 4.543 billion years, there should exist 143 quadrillion (past) earths somewhere in material form.

But there is no evidence that another earth exists somewhere in material form, forget about 143 quadrillion earths existing simultaneously.

Same goes for future, if earth will remain around for another 4.543 billion years, then there should exist 143 quadrillion (future) earths somewhere in material form but there is no proof of this also.

Same theory can be applied to universe and it can be said that quadrillion of past/future universes should be existing somewhere in material form but there is no proof of that.

One theory is that when you start time travel then "that earth" to which you are time traveling to will come into existence but there is no proof of this.

So, I think that time travel is not possible.

Comments

Try to watch a movie in the opposite direction - from the end to the beginning. Each movie frame contains a different "universe" $U_i=U(t_i)$ in a material form  ;-)

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1) I guess a logical error in your argument is that you consider travelling in time and then require that multiple earths (or universes) exist "simultaneously". 

2) Also, your argument mentions a "somewhere" where these copies are to exist. As long as you don't know/specify  anything about this "somewhere", it might well be that this "somewhere" is such that we do not have experimental access to it, except at a specific point in time. Therefore the fact that there is no proof of earth copies existing "somewhere" appears not to be a convincing argument against time travel.

3) There is no reason to assume a minimum time interval of one second. 

4) All of us are travelling in time, more specifically into our respective future.

5) Travelling into the past (at least as it is usually conceived of) leads to paradoxes (you could travel into the past and kill your former self, which implies you would not have lived to travel back in time ...)