You all have heard of the paradox whereas when you travel to the past and kill your grandfather you should not have existed in the presence whatsoever because you have killed your origins. So far so good...but I thought of another case, which I believe is more interesting since so far the Einstein's equations of time dilation seriously question time travel to the past....but with the paradox I just thought about - even time travel to the future might be seriously under question(not really...I will explain below), but before that - here is the paradox itself: Imagine that one day time travel to the future is possible. Given such temptation everyone will like to see the distant future...but at the same time we know that travel to the past is not possible - due to the "grandfather paradox" and because if it was possible, the speed PERHAPS will exceed speed of light, since this is what is shown according to the time dilation simple equations. Now...that means that when you teleportate yourself to the distant future - this is it...there is no way back - you can either stay there or if you don't like it....go even further :). Such as if you don't like 2025...then teleport once again - this time to 2125 hoping that this year will be better(women will be more beautiful). Now...what happens when all people from the present time chose to go to the future? Well...what happens is that if all people go to 2025 - then there will be NO people that have lived in the period 2009-2025, hence the year 2025 will NOT be possible. This is the paradox ;). Now...a few corrections actually - if all people decide to go to the distant future - then this is actually possible, but since all people have done this - they will see no advance in future. Here is what happens: If you were the only one to go from 2009 to 2025 - then from the point of view of the people living in 2025 - you would have dissapeared somewhat in the past and the just came out otta the f*** nowhere. If on the other hand you and another 1000 people do the same - then the effect will be the same - only on larger scale. Finally...what happens if today everyone on earth decides to go the year 2025? Well...when we "arrive" in 2025 - we will discover that the only thing which has changed from 2009 to 2025 is actually the trees and the animals :) - since there are no living humans from 2009 t0 2025. In other words - it will be better if just you and a few friends can travel to the future - since this way you will see immediately what has changed thorough the years that have passed in the meanwhile - otherwise if all people on earth make the jump - then only trees and animals would have been changed :). This is the interesting "paradox" - it's not a paradox in the sense that this doesn't reject the possibility to time travel to the future - but it's interesting to be noted that this is the same like a gold formula - the more people the gold formula - the less valuable it is - if only you knew how to time travel - you can go to the year 2500 and see better computers and hotter girls. The good news is that neither the "grandfather killing paradox" nor this paradox that I just presented actually question time travel. How come??? Well...the human mind fails to understand that when you change time you change another dimension and there are actually not just 10 or 11 :)...but literally infinite amount of dimensions - so each time you travel you literally create a new reality. Need proof? Well...when the astronauts go to space and come back, they comeback younger. Here is another proof - when object is moving faster and faster it's mass is changed due to...speed. Since mass(ok "energy"...what a word...) can be changed - then as it follows time can be too...it's just a matter of time :).