Top Ten Philosophical and Science Fiction Paradoxes

This has nothing to do with nihilism. The sentence just indicates that you cannot prove the sentence itself. The theory of Kurt Gödel has a same logic with the sentence: "This sentence cannot be proven" which means if this is true, then it must be untrue, and if it is not true, it must be true. The latter also means that if we cannot prove the truth of the sentence, then the sentence cannot be intern consistent. In its final system it means that the sentence is true but cannot be proved which also indicates that the human mind (and even a computer) has limits. And limitation doesn't mean nihilism.

Now this paradox does concern a grandfather (and I am not joking). Actually, the grandfather of the time traveler concerned.
Lets take a short story to explain this.
Mr. Adams, a scientist, worked very hard and finally made a time machine to fulfill his one and only dream; to kill his grandfather. His grandfather was a cruel, cold blooded murderer, and he was the cause of the death of his girlfriend's grandfather (she was already born before that). Now out of hurry, he travels back to past and kills his own grandfather aged 21 (so that his grandfather doesn't kill his girlfriend's granddad when they both become 67 years), without realizing that his father was not yet born at that time.
Now a contradiction takes place here
1. If his father is yet to be born, then he shouldn't exist or cease to exist.
2. If he ceases to exist in this timeline, then his grandfather must die, but for this he must kill him, but then he can't because his grandfather died so he doesn't exist anymore to kill him.
So who killed his grandfather? If Adams did this, then how did he exist to do this job.
And yes his grandfather didn't really kill Adams' girlfriend's granddad. He was framed.

An adult goes to a windmill hut and meets an angry man there. The angry windmill man mentions a young boy who played a magical song and messed up his windmill. The adult learns the song from the windmill man and plays it. The adult then goes back in time to when he was a young boy. The young boy goes to windmill. He plays the song for the man who lives in the windmill. The song messes up the windmill causing the man to get angry.

If the adult only knew the song because the angry windmill man taught him, and the angry windmill man only knew it because the young boy played it, and if the young boy only knew because his adult self went back in time after learning it, then who created the song? Where did the information come from? That is the paradox.

(From: The Legend of Zelda: Ocarina of Time: Learning the Song of Storms paradox.)

Water is cheaper and diamonds not that cheap just because diamonds are less in quantity to find and for that matter rare. But in the end when it comes to make profits in money, it's water that will give more money because it's sold more iall over the world than diamonds. The end result is that water has more value. You just need to sell more quantities. It's like saying that Toyota is cheaper than Lamborghini but ithe end result of benefits and profits is that Toyota makes more money because they sell more cars than Lamborghini.

Lets take a story to understand this.
In 1850, Bob's horse was spooked by something, and almost took Bob over a cliff, had it not been for a strange man stopping the horse. This strange man was later honored by having a statue of him erected. Two hundred years later, Bob goes back in time to sight-see, and sees someone's horse about to go over a cliff. He rushes to his aid and saves his life. (this story is taken from a wikipedia article)
So how was Bob able to save himself? If you say that his future self saved him, then how did the FUTURE SELF survive for that long to save himself. But then again it can be said that the FUTURE SELF'S Future Future self saved him. Then how did THIS FUTURE FUTURE self survive that long to save himself!

One story will explain this paradox completely. This is taken from wikipedia.
"Zhuangzi dreamed he was a butterfly"
One night, Zhuangzi (369 because) dreamed that he was a carefree butterfly, flying happily. After he woke up, he wondered how he could determine whether he was Zhuangzi who had just finished dreaming he was a butterfly, or a butterfly who had just started dreaming he was Zhuangzi. This was a metaphor for what he referred to as a "great dream":

Hedonism comes from the Greek word "Pleasure" and not "Happiness". Hedonism is looking for instant pleasure at a certain moment (once done with one pleasure they move to the next pleasure without looking back). Hedonism sometimes waits for a certain pleasure (for instance, eating something you like) so that you can have a greater pleasure of the taste when you finally eat what you've waiting for. All these subtle things of "pleasure" can make you happy. In other words, hedonism is not seeking "the" happiness. It seeks the pleasure in one way or another or grabs the pleasures whenever that comes or whenever you didn't expect it (the "carpe diem"). Hedonism is not a paradox because it's a way of life you freely choose.

What's the paradox in that? If you take for instance a substance like LSD, you will experience strong emotions that seems real and those emotions can even come back many months or years after you took those substances (flashbacks). Why? Because you are altering some chemicals in your body like dopamine, serotonin, adrenaline, nor-adrenaline and some neurotransmitters like glutamate. So, if you experience an emotion without substances, it's still because some chemicals in your body start to react (in a way it doesn't react all the time or like it's supposed to do).

This paradox was laid down by Lewis Carroll in one of his stories. The wikipedia article states this:
Uncle Joe and Uncle Jim are walking to the barber shop. There are three barbers who live and work in the shop - Allen, Brown, and Carr - but not all of them are always in the shop. Carr is a good barber, and Uncle Jim is keen to be shaved by him. He knows that the shop is open, so at least one of them must be in. He also knows that Allen is a very nervous man, so that he never leaves the shop without Brown going with him.
Uncle Joe insists that Carr is certain to be in, and then claims that he can prove it logically. Uncle Jim demands the proof. Uncle Joe reasons as follows.
Suppose that Carr is out. If Carr is out, then if Allen is also out Brown would have to be in "since someone must be in the shop for it to be open. However, we know that whenever Allen goes out he takes Brown with him, and thus we know as a general rule that if Allen is out, Brown is out. So if Carr is out then the statements "if Allen is out then Brown is in" and "if Allen is out then Brown is out" would both be true at the same time.
Uncle Joe notes that this seems paradoxical; the two "hypotheticals" seem "incompatible" with each other. So, by contradiction, Carr must logically be in.

While eating lunch with his friend Enrico Fermi asked his friends,"Where Are They" (they meaning extraterrestrials). His statement asked many questions on E.T's existence and there has been many solutions and oppositions to his questions, but we still don't have answers.

The idea that if one twin went into space and accelerated near light speed while the other stayed behind, the effects of time dilation mean the twin in space comes back younger than the other twin.

The fact is the space twin doesn't become younger, but time passes slower to him. Time passes faster to the twin who stays behind.

They will pas trough eachother, the object can't be moved and the force can't be stopped so that's the only possible result.

What happens when an Unstoppable Force meets an Immovable object?

This paradox is when Pinocchio says my nose will grow now. That means he was lying than because he lied his nose will grow but that would mean was telling the truth.