When you ask people what would they do if they could time travel, the most common responses you will get will probably be either going back in time and killing Hitler or going 100 years or so in the future to look at how much we have evolved as a society. Those are two very good answers but which of these answers is better?
Personally, I would choose to look into the future. I think that it would help the future of humanity immensely. If humanity is doing perfectly fine, I would not change anything. If humanity was on the verge of collapse, I would find out why that is and do what I can in the present to change it.
But, would it not also benefit humanity if we change the past? You could stop Hitler from killing all those people, you could prevent the burning of The Great Library of Alexandria and you could do so many other things that can benefit you personally. Although, these may sound great, even better than seeing the future, but there can be devastating consequences.
If you have heard about the “butterfly effect”, you know what I mean. A minor change in the past can result in major changes in the future. The most common example is a metaphorical example of a tornado being influenced by a butterfly flapping its wings prior to it. So, a small thing you change in the past can alter the future drastically. For example, penicillin was not discovered intentionally. It was discovered when Sir Alexander Fleming left a petri dish out in the open when he went on a holiday. When he came back, he noticed that there was some mold growing in a Petri dish. He noticed that the mold was preventing bacteria from forming. He soon observed that it was producing a chemical that can kill bacteria. If you went back in time and destroyed that petri dish, there would be no penicillin and millions of people would be dead. Another great example is in a comic named “Thanos Annual #1”. In that comic Thanos, one of Marvel’s villains, helps an old lady cross the street. While that may not sound like a villain would do, It dramatically affected the future of society. When helping an old lady cross the street, he causes a bus to be delayed. On that bus, there was our main character Stephanie. If Thanos had not delayed the bus, Stephanie would bump into another woman named Suzanne. This encounter would inspire Stephanie to change the world. She would have prevented multiple diseases, ended world hunger, and done much more. But by delaying the bus, the two women never bumped into each other. So, Stephanie did not do any of that. She had an unremarkable life. On her deathbed, Thanos visited her. She showed her what would have happened if he had not delayed the bus. Those were her last moments.
Another problem is that travelling back in time and altering it is simply not possible. First, there are paradoxes. And a lot of them, too. One example is the grandfather paradox. What would happen if I invent a time machine and I go back in time to kill my grandfather? My father would have never been born, so I would not have been born. Thus time travel would have never been invented. So, my grandfather would have never been killed. So, I would have invented time travel. So I would have killed my grandfather… Another great example is the predestination paradox. A man goes back in time and meets a woman who will be his mother in the future. He gets married to the woman and has a baby. The baby grows up and becomes the man that marries his mother. The man is his own biological father. What is the origin of his DNA? The second problem is that it contradicts the second law of thermodynamics. It states that the entropy or randomness of something will always increase. When time travelling to the past, we are moving from a high entropy state to a low entropy state, which is not possible. This argument is incomplete at best, though because this does not say anything about time travelling into the future. In practice, travelling to tomorrow is as hard as travelling to yesterday.
If you could see the future, you could get so much information. You could learn new things and teach what you learnt to speed up humanity’s progress. You could see wrong things that humans will do and try to prevent them. You could single-handedly save humanity. You would be considered a god among people in the present.
All things considered, I would always prefer seeing the future to changing the past.