Yes, that topic. Time travel. Seems fun, advanced, futuristic, and powerful, right? Imagine that thing you did in the past that you’re always embarrassed of, you constantly wish it never happened like being caught picking your nose by your crush, peeing inside your pants, you name it. But is it what it seems? Well, I don’t think so.
The idea of traveling through time must face a challenge before it even become calculated & predictable, let alone becoming a common & practical thing: consistency challenge. What is consistency?
con·sist·en·cy
kənˈsistənsē/
noun
- conformity in the application of something, typically that which is necessary for the sake of logic, accuracy, or fairness.
2. the way in which a substance, typically a liquid, holds together; thickness or viscosity.
The definition being used in this case is definition number 1 which is related to logic. Yes, the logical consistency is needed. What for? To avoid possible emerging paradoxes. What is a paradox?
par·a·dox
ˈperəˌdäks/
noun
- a seemingly absurd or self-contradictory statement or proposition that when investigated or explained may prove to be well founded or true.
2. a statement or proposition that, despite sound (or apparently sound) reasoning from acceptable premises, leads to a conclusion that seems senseless, logically unacceptable, or self-contradictory.
3. a situation, person, or thing that combines contradictory features or qualities.
The definition being used in this case is definition number 1 because this is what we’re going to talk about in this post in the infamous (probably the most well known) time travel paradox: The Grandfather Paradox.
The paradox goes like this: imagine you have a time machine or you’re finally able to build one. You want to kill your grandfather so he wouldn’t have married your grandmother and later gave birth to your father because you hate your father so much that you wish he was never your father. You get inside that time machine, traveled back to the time when your grandfather was getting ready to go on his first date with your grandmother. Then you took the knife from your pocket and stabbed him right in his heart. He’s dead “now”. But suddenly you realized you’re starting to disappear. You lost your consciousness and suddenly you wake up on the same place and time before you took the travel through time. You still have your current father as your father, that time machine is still there standing next to you. Then you decide to kill your grandfather again. Well, unfortunately the loop goes on.
Why? What went wrong? Now stay with me and read carefully: the time you actually killed your grandfather, he died. He never made it to his first date, let alone his marriage with your grandmother. Without the presence of your grandfather, your grandmother wouldn’t be able to…ehm…”craft” your current father (The word “craft” sounds funny to me in this context. Yeah I know, my sense of humor isn’t really that good, sorry) or maybe she decided to move on and date and marry someone else. Without the presence of your current father, your mother would’ve probably date and marry someone else or on the other hand might’ve decided not marrying anyone. Either case, the current you wouldn’t have been born back then in the first place, let alone the event of you building a time machine and using it. Without you and your time machine’s presence in the timeline, you wouldn’t be able to go back in time and kill your grandfather. So your grandfather could make it to his first date with your grandmother. And history goes on from there. They got married, gave birth to your father, your father later got married with your mother and you were born nine months after that..”that”. You grew up, invented the time machine and decided to kill your grandfather…again. This is the grandfather paradox.
Of course scientists and various other thinkers have tried to resolve this problem. One hypothetical solution is found by mathematical calculations using the concept of probability. There is always a 50–50 probability of you actually being able to kill your grandfather and another 50–50 chance of your grandfather escaping you. But well…sick math and I’m not going to get into it (I’m also so bad at statistics, especially at probabilities and combinatorics section). The most famous (and probably the best one we are able to wrap our brains around) solution is the “alternate timeline” hypothesis. You somehow still exist without the presence of your current grandfather-grandmother and father-mother. The reason is that you switched universe, a parallel universe among an infinite number of them to be exact. You’ve managed to escape the current universe, your current space-time you’re trapped in, and move to another space-time where you do exist and your parents and grandparents don’t. An analogy which may help is the “highway” analogy. You never really go back the exact same road you’ve traveled. Instead, you traveled back to your “origin” using a parallel highway.
Now notice that both solutions don’t allow you to travel the exact same space-time & timeline. It will create a paradox, an inconsistency, and probably worse-an infinite loop until you somehow decide to give it up. Also please note that those two (among many) offered solutions are still hypothetical, none of them, not a single one has been proven true, let alone realistic and/or practical. Think about this: maybe the universe itself, our current universe, doesn’t allow time travel. After all these thoughts, I hope we are going to be able to reconcile with the current fact that time goes on, never stops, let alone run backward. One day, maybe one day, time travel will really become possible. But as far as I’m able to deduce, it’s not going to happen any time soon. So until that time, let’s just enjoy our current universe and all of its’ existing laws of physics, all its’ features which some of them we encounter in our everyday life; the day & the hot sun, the dark night & our beautiful moon, the visible stars in the night sky, our friends, our enemies, the ones we love, the ones we hate, etc. And last but not least, in my personal and honest opinion; love yourself along with your history and just enjoy being the current you while keep on learning and later improvise your life.
