Time travel in itself proposes an infinite paradox which likely leads to irrepairable damage. Lets say you were to travel back in time and warn yourself of something coming in the future. Past you, would know this information already and once the time came that the future you traveled back from to warn you, you would likely think that because you've already been warned, you don't need to travel back and warn yourself. Then, who would go back in tell you what you needed to know? The only way that this could even come close to happening is for time to happen exactly all at once. Everything, past, present, and future are all simultaneous. And, like many religions state (that god is omnipresent and sees all of time), this also creates impossibilities. By stating the power of their god, they disprove it completely. For any force of the universe to see all of time all at once, they must meet several requirements. Firstly, they must be completely free of the time stream. With the exception of time crystals, there is no knowledge of any way to free yourself of time. Secondly, the force would have to be so astronomically slow that everything around them is proceeding at an infinitely increasing rate. Thirdly, they must also be able to comprehend all things transpiring within the time stream that they are not a part of. Nothing discovered by science has ever reached these requirements, and nothing in the near future will. Man was not made to be omnipresent because of our innate human-ness. Say you were given this gift, and you could see past, present, and future all at once. Say you were even given the power to change the time stream by pulling little strings of the universe. First of all, you are moving way too slow to be able to do anything on time, unless you could also halt the flow of time, which creates even more paradoxes and impossibilities. Second, even if you did change anything, even for the better, you likely create a paradox in which you never change it. Let's rewrite history for our sake for a moment. Say all of history, man has simply worked together in peace. No pollution, world peace and happiness for all. With one small exception. One person was killed because it was discovered that in the future all his children would become killers and rapists and lead to the inevitable downfall of humanity. Some would agree with the killing of one to save countless lives, others wouldn't. Now let's return to the notion that you have the ability to change history as it has happened and how it will happen. (and keep in mind this is all happening in mere second to you in your "godhood") You decide that you will keep this man alive, because humans can only focus on the short term. You prevent the only murder in Millenia of human existence. The second after, you see this saved man's children spread his foul genes across the Earth, leading to life as it is today. You would of course move to change your original course of action, but because you come from the future, post this act, where time travel is invented and you escape the time stream, you have erased all knowledge of the man's time, place, and name from your mind. There is no way to undo the evil you've done. So you realize, you must simply create a preventative measure. This last act has caused you to see in the long run. You release famine and death and evil things to hopefully weed out the genes that lead to humanity's great mistake, but it is not an exact science. Because you're still human, you create a patsy. A scapegoat for these ill things you've released on the world. But once again, it plays out even worse than after your first change. So this time you decide to go to just after the spread of evil. You find the only good souls that you hope will carry out the repopulation of the earth, as well as all animals that you can gather. Because you cannot recreate the evolution of animals over the course of more time than you are capable of, you simply take what you have and destroy everything else. Then you set your repopulation in order, and promise to never do so again. You remember in your head a similar story from a book you read once. Before you had all this power. It was a book about life and how there was a "god" above us. And how he did this about this time. That would also, no doubt, have played a part in your idea to reset the earth, and thus, kill your self. Because you exist outside of the temporal norm, you don't immediately erase from the universe and it is likely that you, in your last "moments" realize what you've done. You've restarted a cycle that has been going on for eons. Man was not made to time travel. With powers like this, we think to be gods. But gods all along have simply been us tampering with power we can't hope to handle.
