This would be the worst way to find out you were adopted.

They always say "What if you killed your Grandfather" But they never say "Why would you kill your Grandfather"

I think that, the most "practical" solution would be that the moment "you" leave your current timeline and so become a "time traveler" then you become immune to this kind of paradox. As soon as you leave your own timeline for the first time, you do not belong anymore to that timeline and not to any other timeline either. You basically become a timeless entity. So, you going back in time to kill your grandfather, would just result in killing your entire family except of you. If you then would get back on your original timeline, your family won't be there anymore, and never have been, but you would still be there. Another solution would be that "the universe always finds a way". So, if you go back in time and kill your grandfather, then you won't be born and so, "someone else" would be born, and that someone is the one that actually goes back in time to kill you grandfather. If you do not kill your grandfather, then this other "someone else" wouldn't be born.

You could argue that if you did have access to a time machine, it is impossible to kill your grandfather because you already failed. Many people forget that if something happened or didn't happen in the past, then it must stay that way because that moment was solidified into history. You can't "go back and change" the past. For example, if you went back and talked to your past self, then you would have already experienced that at a younger age.

The easy answer: Two timelines The hard answer: this video The complicated lore answer: You ARE your grandfather

I was explaining this to my friend and his grandfather walked in🤦🏻‍♂️

Another solution: each time you travel to the past, your grandfather is moved to the future.

Both of the solutions you used involved a different form of time than the paradox uses. The first one, you used was the one where you travel back in time, and that creates a new reality, the second one, was the one where there are two interconnected reality’s, where your actions in the past, only effect one reality. The grandfather paradox, uses the form of time travel, where there are no others reality’s in existence, or that can be made. If you use a different form of time, it’s not actually the grandfather paradox, it’s not even a paradox.

Someone complained about something about this comment, now no one shall know what it originally was

After watching tenet, youtube recommends grandfather paradox.

You know you’re old when a small kid shoots you saying you’re his grandad.

Another Paradox: If Pinnochio said "My nose will grow now", What happens?

GrandFather is dead and alive at the same time, Schrödinger's CAT : Ah Shit, Here we go again!

I had a found a few errors in your understanding; however over all you are somewhat correct I'm totally kidding, I have no idea what is happening in this video

I believe what would happen is that your grandfather would die and then you would continue existing. So if you were to go back to the present then you would spontaneously appear out of nothing. The way I look at this is to look at the timeline as some sort of word document. The original text said that your grandfather survives, but then you went back in time and made an edit. I don’t really know how to express this theory, it’s hard to put it in words. Another way to look at it is the following scenario. There is a division of soldiers and their major general orders them to attack a nearby enemy base. Then the major general decides to at the enemy base is too well defended and orders the soldiers to retreat. Which order will the soldiers listen to. The most recent one.

I like to imagine that a time machine would only be able to place you back in time on a path that does not create a paradox. After all, it must be able to “see” into the past. You could do anything you want except things that result in you or the time machine not existing. This creates interesting story possibilities, like you fail to kill a villain & later learn he was your own great-great-grandfather, so of COURSE you failed.

_brain.exe has stopped working_

I love how the mathematicians try to solve a problem that isn't even possible

I had 3 solutions to this paradox. 1. When you travel back in time you create another timeline 2. When you travel back in time, you travel as a ghost so that you can't interfere with the past. 3. Anything you did in the past couldn't interfere with critical situations that happened already in the present because it was already destined to happen, meaning you would always fail trying to kill your father by whatever you tried to do because that would change the destiny... Of course the other solution was that the future could be change like you told in the beginning

I like the terminator idea of this paradox.. Basically, it's impossible for you to kill your grandpa.. Whatever you do to the past inevitably cause the future where you came from..

solution: you are now a murderer

today I woke up and said to myself, " I will not learn any physics today" and what do you know... I still didnt learn any physics

So, it's like schreningers cat, except it's your grandfather

If it wasn’t for back to the future we wouldn’t know if we actually made an alternate timeline at all

Solution: *Why the fuck would you kill your grandfather?*

Just call it, Schrodinger's Grandfather.

Heck man, you explained this so much better than I could!

I remember reading a collection of short stories I'd checked out from the local library when I was a kid. I'm pretty sure it was a collection of unfinished tales by C.S. Lewis, but I don't remember the title and a quick google search didn't turn up anything. Anyway, the book included a story about time travel where the main character suggests that you can't send something back in time because the atoms that make that thing up in the present already exist in the past being something else. For example the atoms that make up a chair now were part of a tree in the past, so sending that chair back in time would add a chair's worth of extra mass to the total mass of the universe which is a big no no.

This guy messed with my brain for 2 minutes and 48 seconds straight.

A more interesting paradox is one where you time travel back a second time to stop yourself from doing something that you did the first time you time travelled

I fully understood the solution you gave to the paradox, it is hard to explain to any person in words but I understood it

I feel like if you could go back in time, you are fated in some way to never kill your grandfather or do anything in the past that would contradict your own existences So for example, if you were to be visited by future you and be warned about something, you later on in the future will inevitably go back in time to warn your past self. So if no one has come back in time to warn anyone, then how is time travel (atleast backwards) possible?

I went back in time to kill my neighbor but I started dissapearing from the timeline.

This is what Avengers Endgame was trying to do

That's such a good explanation bro. Loved it truly. Everything's clear by now. ❤️❤️❤️

There's also something, if we're talking about possibilities of abstract concepts, about predestination. That fate destined you to be born to perform the task in order to preserve the flow of time, stating that you were meant to be born, whether into one family or another. Not to suggest that time and space are sentient entities or anything but rather that time flows like a river and moves in the same direction and with the same purpose regardless of the obstacles put in its path. However, predestination is a wholly different topic and really spits in the face of a lot of known sciences so it doesn't really gain any traction... but it would be a simple resolution to a paradox like this.

anvengers endgame writers: “write that down, write that down!”

He says alternate timelines are boring as a solution and he won't do it, then he goes on to explain an alternate timeline.

Wait I’m no scientist and this might be really dumb question but since everyone had two grandfather at some point, wouldn’t that be a second variable to the grandfather paradox?

You can't go back in time, you can only go forward.

People assume that time is a strict progression of cause to effect, but actually, from a non-linear, non- non-subjective viewpoint, it's more like big ball of wibbly wobbly, timey wimey...stuff.

There's also the Novikov Self-Consistency Principle, which basically states that no paradox can happen. If you go back in time, everything you do will be consistent with history. Any attempt to influence events merely causes them to play out exactly as they did in the past. So you would be unable to kill your grandfather no matter how hard you tried. That event never happened, so it can't happen.

I love how I just used this exact theory in an argument in the comments of a short trying to explain why this exact scenario plays out in a science based TV show I watch.

TENET people what’s up

Forget the video, He js sponsored by Google HOLY SHIT

Most meaningful few minutes of my day today

I love how mathematician try to solve a problem that will be never be a problem.

My brain is melting

So u mean, *_YES BUT ACTUALLY NO._*

I've already solved this theory, it took me 2 weeks to solve actually, and now i am planning write an article about it, great video btw👍

#minutephysics: grandfather paradox in under 3 minutes Also Neil DeGrass Tyson: grandfather paradox in 13 minutes kzfaq.info/get/bejne/mMeFhsR33Z6xYaM.html Also find the nervous look over his shoulder in the woods at the end of the video! 😂

Him: But that's just avoiding the paradox Also him: By the way there is no paradox MOVING ON

Did you really put a subliminal of one direction in your video?

So how would you trace the two timelines forwards from the loop? It sounds like the time-traveler from the timeline where they are alive would return to their own timeline where the murder never happened, while the other would continue on without grandfather or time traveler. I ask because I've heard of a similar story, but where the time-traveler went back to kill someone who killed their daughter; thus the time traveler exists in both timelines. Would the version of the time traveler who went back return to their own timeline where their daughter was still killed, while their counterpart from the timeline where the daughter was saved continues in their own timeline because they never went back?

Your right. The correct ways to solve paradoxes is redefining the possibilities of reality. Kind of like how the alternative timeline solution does. That you said is just avoiding it.

At the end of the video, did that guy look backwards to see if his future grandson was chasing him with a knife?

okay i can understand this video 1:11 Nevermind

I believe if it were possible to go back in time then we could be just an observer. We cannot change situations at all.

It’s not a paradox but the closed time loop would still be a problem because it would mean the whole universe is stuck in looping that timespan for eternity and that would effectively end the universe. But what would happen if you kill you grandfather to create a loop and then travel to the future again to a point after you started the time loop? Is there even a future to travel to if the universe is stuck in a time loop?

Btw why would anyone want to kill their grandfather anyways?

Barry fucking stop now

I think Back to the Future 2 handles it best in a most understandable way. When Biff gives himself the sports almanac, it does create an alternate timeline, yet still affects the lives of Doc and Marty when they go back to the present day. The time machine naturally takes them to the present along the skewed alternate timeline. So to the time machine, affecting the past changes the present because the time machine didn't have to choose which timeline's 1985 to bring them to. It naturally brought them to the present that was affected by the change in the past, and likewise, if they traveled to the future like Doc said, it would've been the future of the alternate timeline. Yet it is also an alternate timeline for our characters because they are from the other timeline with the memories and experiences from the other timeline

It took me a few times going over the paradox to actually get it and it's mind boggling 🤯

Barry don't fuck up the timeline

The solution is that you become the grandfather

Time doesn't exist, we just made it up to connect our memories with the fact that we get older and die

That millisecond 1 Direction edit was GOLD

"Time only moves in one direction." *Flashes picture of the band called One Direction*

I've always thought of it that way: What you did in the past happened in the past so it must have already affected the future you are currently in. By time-traveling you are causing the future that you came from. So no matter what you do in the past it makes the future that you come from happen in the first place, a future where your grandfather is alive. Therefore, you can try as hard as you like, but you cannot kill your grandfather because something will always happen to prevent it. Otherwise you wouldn't be there to kill your grandfather in the first place. Hope this explanation made sense.

If one ventures into the past and disrupts the chain of events leading to their own birth, it creates a divergence, a splintering of timelines. The act of eliminating the grandfather results not in self-annihilation but rather in the emergence of an alternate reality where the individual still exists. This aligns with a metaphysical interpretation that suggests the unfolding of multiple possibilities coexisting in a complex temporal tapestry.

My favorite theory is that if you go back in time, you can't change the past events. Because what already happened has happened already. So if you would go back in time, you wouldn't be able to kill your grandfather, because the birth of your mother or father and you had already happened in the future. And actually, the future that the other people haven't seen yet, is your past already.

War machine had an idea to go to the past and kill baby thanos

Me seeing the beginning: hmm ok simple Looks away for 1 second: ***quantum physics***

Second question, if say your in a fixed timeline where you are bound to be born even in the case where your grandfather dies by your hand would you than just end up killing multiple different people or killing your grandfather at earlier and earlier points in their life?

The issue with causal loops in sci-fi is always "it happens because it always happened". But that catalyst or motivation or object always has to be introduced to the loop. If I give my future self my cell phone because my past self gave me _their_ cell phone, the phone had to originate somewhere. Same goes for the motivation of why you're acting out of character, or taking a drastic action.

"Time only moves in 1 direction" *shows 1 direction*

Most people think of time as a strictly linear progression of cause and effect, but actually, from a nonlinear, non subjective viewpoint, it's more of a...oh, never mind.

0:25 this man predicted the plot of Endgame.

If you were to quantum superposition time travel to the past and kill your grandfather, the speed at which you travel would far exceed the flow of time, meaning that while your grandfather's death would take place instantaneously, the events following his death would occur at a normal rate. As a result, the changes resulting from his death would most likely never catch up to you once you return to the present instantaneously

The real answer is that you didn't actually kill your grandpa because you were adopted.

Is it just me, or do these videos never actually answer the question?

The history of time travel movie on Amazon is pretty interesting. It was presented as a documentary, but it’s a fun fiction. If you watch it, keep an eye on the maps in the background, the territory’s keep changing because someone is constantly going back in time and altering the present

This has already been solved. For a perfect example, watch the Red Dwarf episode "Tikka to Ride." basically, it's built on the idea that you don't actually have the level of free will that we like to think we do, and that going back in time changes nothing, because you going back in time has already happened. You don't know it yet, because you haven't experienced it yet, but everyone else HAS, they just didn't know it was you. Everything you attempt to do while in the past has already happened, but you don't know it has. Therefore you may believe at the time that you have free will to do things in the past, but you actually don't. Therefore the Grandfather Paradox is better understood by reframing it as the "free will paradox."

Polt Twist: your grandmother had an affair that's how your father Born. Knowing this after killing you Grandpa: "WASTED"

It all depends on what logic of time travel you follow. There are 3 main theories. The first, as mentioned in the video, is that there are alternate timelines in which certain major events in your life happened differently, so going back in time and changing something wouldn’t affect your timeline, but instead it would make a new timeline in which such an event had occurred. An example of this logic being used would be avengers endgame. This means if you go back in time and kill your grandfather, you’ll just be opening up an alternate timeline in which you were never born. However, this timeline would not affect yours at all. The second theory is that it’s a closed loop. This means that while the events do happen in your own timeline, they don’t affect them, since they’re predestined to happen the same way and nothing will change that. This event has occurred many times before and will continue to happen many times over since it’s a loop. An example of this logic being used would be the movie tenet. This would mean that if you went back in time, you might’ve tried to kill your grandfather, but somebody would’ve stopped you, this is because you’re obviously alive up to the point where you’ve went back in time, which means your grandfather hasn’t been killed. This means you’re destined to fail at killing your grandfather, and this event has probably occurred a million times before and will continue to occur a million times more. The final theory is the one most people follow, which is what makes it a paradox. This is the one in which changes to the past will directly have an affect on your timeline. This means that by killing your grandfather you would in fact cease to exist, but in doing so, your grandfather would still be alive. This remains unanswered within the context of this theory.

I love the mobius strip explanation lol, mobius strip has only one surface but we have two different situations going on simultaneously

The thing about super position is, it is only possible as long as it's not observed. The moment you gain consciousness in this theory you become the observer thus destroying the super position and going back into the paradox. In my opinion there are only 2 possible scenarios. One is as you said you don't go back in your own time but the universe splits up and you influence a timeline that you don't originate from. Or if you want to go actually back in time in this universe you have to literally reverse time/make every molecule in this universe go the exact same way back as it cane for as long as you want and then, only then if you manage to break physic and make every particle in the universe, EXCEPT YOURS go back in space you can move to another point in time thus killing your grandfather. The results will be that you as an adult exist in a world that will be different from the world you used to know by only one factor: your family line. It will not impact you because you have already freed yourself from the laws of the universe and you will continue to exist in this new world as a independent variable. In both scenarios the outcome will basically be the same because you are independent from the rest of the universe but because that is impossible in the first place with the exact same reason as time traveling into the past it doesn't matter anyway

That one direction band picture in the beginning though...

Science teachers: the test won’t be that hard! The test:

me : kills grand father Grand father : dead Me : still alive THIS IS THE WROST WAY TO REALIZE THAT YOU ARE ADOPTED

Read full article about "The Time Paradox: How Understanding Time Perception Can Transform Your Life." : eternalthinkerofficial.blogspot.com/2023/07/The%20Time%20ParadoxHow-Understanding-Time-Perception-Can-Transform-Your-Life.html

Time Travelling Back In Time GuideLines 1. Wear clothes that are clothes from that time period. 2. Stand still in the past and watch history for 1 minute. 3. Hide the time travel machine in an area where no one would see time travel machine. 4. No talking to other people in the past. 5. No changing past event's.

Time Paradox: (exists) Netflix Dark : Let us introduce ourselves

"Then your father and mother won't have been born" this isn't Alabama bro

i remember watching it when i was a child now 7 years later i can undersand

There's an lnteresting theory, called Novicov's self consistensy principle, that resolves this paradox. Basically, it states that there's only one reality that has already experienced all of time travellers' actions. So, for example, if you were born, then any attempt by any time traveler(including yourself) to prevent that is doomed to fail. There's a great videogame called "Quantum break" who's whole plot revolves around Novicov's principle.

Dormammu ,I've come to bargain

Grandpa I've come to bargain. Thanks for 1k😇😇😇😇😎😎😎

Here's my explanation of the paradox + a fun brain teaser: Time travel works in the way you are sending back matter and energy to a different time, so therefore when you travel back in time, there is absolutely no way of preventing yourself from being born; you will be born, because it happens. A more interesting paradox (I haven't thought too much on the solution to this one) is lets say is receiving an book from 10 years in the future, and 10 years later, sending the same book back in time again. After you have just sent this book back in time, where would the book be located? Would there be infinite copies of the book?

The fun part here is that we don't have concrete evidence that the grandchild that IS born wouldn't make the same decisions regardless of who ends up being their alternative grandfather. Yes it changes who his grandfather is, but not the mother and if that side of the genepool is the one that decides you're smart enough to invent a machine to time travel with, then the only change you're doing is a minute one. You might look different, sound different, have different beliefs, but you'd be still; you. Now, we ASSUME that because of the different grandfather, the decisions they make affects who the children become. Maybe the father is more religious and you end up becoming a priest. But that is only speculation and assumption, because we do not have an actual evidence that that would actually happen. The future you after your old self killed your grand-dad would possibly end up making the same decisions in life. And because we can't prove it, because we don't know for absolute certainty... We also can't prove that we all live in a simulation where every child, parent and mother end up making the same decisions regardless of who their mother or father is. And is free will just an illusion set by the matrix the elude us from the truth. The truth that you are you, not because of who raised you, where you were born or where you went to school, but because the program made you so. Think about that.