I was engaging in a discussion in the r/DoctorWhumour subreddit and, I realised that there are so many inaccuracies when it comes to things like Paradoxes in the Whoniverse.
I have pasted the two comments I wrote that relate to Paradoxes and theories stemming from said paradoxes below.
>!It saddens me to say this but, the entire show itself violates the Grandfather Paradox, with The Magician's Apprentice being one of the prime examples of this violation.!< If you aren't familiar with the Grandfather Paradox, it basically states that time travel becomes invalid if you go back in time in an attempt to change the past. The example given in the paradox is that you can't go back in time to kill your grandfather before your father was born because then you would cease to exist. However, if you ceased to exist, your Grandfather would still be alive, meaning you would exist again. The episode operates on the same basis. >!The Doctor went back in time to save Davros and, he did but, the writers overlook the fact that since Davros would now exist in a reality where he didn't need to be saved, the Doctor wouldn't have had to go back in time, meaning he would still need to be saved etc.!< Basically, doing this kind of thing for millennia would put a massive strain on the Space-Time Continuum. >!In fact, three Doctors being together in person in the episode Day of the Doctor would have probably damaged it, resulting in the destruction or mass-production of parallel universes.!<
In a real-world sense, I believe that the Doctor has a problem with time travel itself. There is far too much to worry about when travelling. In fact, if you think about it, the Doctor will never really be able to travel in peace since he/she/they (I don't know which gender to use for the Doctor) must always have a positive impact on people so that the negative impact time travel has doesn't cause too much damage. >!For example, in the Eleventh Hour (I believe that is the correct episode), the only reason the Atraxi go to Earth is because they are looking for the alien dude that is looking for the Doctor, which could be why the Doctor never really gets a break.!< Trouble doesn't just follow him/her/them, he/she/they is/are the cause of it.
In summary, those are my two main observations on Paradoxes and how they affect the Doctor and, I was wondering if anybody has anything else to add to the matter? Have a lovely evening everyone :)
Edit: Thank you all for takin
... keep reading on reddit ➡Hope my question is clear
They're not from our planet, but from another reality with a planet 99% just the same as ours. So, technically these are "aliens" from another Universe. Not from the future!
I guess you could fit this into the Extra-dimensional area.
That version of Earth would have a slightly different timeline of Evolution. A tiny percentage of their genetic material would be different than ours. Thus not humans.
And even if there was no difference, they are not terrestrial to our planet. Thus aliens!
I wanted to share this technicality.
Title
I killed my grandfather and I'm still alive!
An interesting potential solution to the common "grandfather paradox" problem occurred to me a while back and I've been planning to use it in a planned story I'm writing. Thought I would share it here and get thoughts:
The Grandfather Paradox (henceforth, GP) says that if you were to kill your own grandfather -- assuming that we exist in a single universe with a single linear timeline -- that you would cease to exist. However, by ceasing to exist, you no longer exist to kill your grandfather and therefore your grandfather lives and you are born...ad infinitum.
Let's enumerate the steps of causal reasoning that follow from each other in the grandfather paradox:
(1) You kill your own grandfather --->
(2) You cease to exist --->
(3) You didn't exist to kill your grandfather --->
(4) Grandfather lives --->
(5) You exist --->
(6) Back to step (1) --->
Now, the common logic says either that you physically CANNOT kill your grandfather ("Whatever happened, happened"), the past is fixed and by going back in time you are simply becoming part of the past that always was. You aren't changing anything.
Alternatively, so goes the common logic, if you manage to kill your grandfather, he is necessarily not *your* grandfather and you are not in *your own* past. By killing your grandfather in the past -- so this interpretation says -- you are making an alternative timeline completely distinct from the one you were born in and are not changing anything in your own past.
While these interpretations work, they are not actually solutions to the paradox itself. They are cop-outs based on the assumption that the paradox simpliciter is insoluble. I propose a solution based on the axiom that if time travel were possible, one could travel into *one's own* past *and change it*. With this axiom, the GP will indeed play out by the steps I've enumerated above. No alternative timelines, no trickery, just the simple paradox that follows from the axiom I've proposed and simple causal reasoning.
Now, can this paradox be solved? I propose that it can:
Notice in the steps enumerated above that it is true by causal reasoning that (1) causes (2), (2) causes (3), (3) causes (4) and so on. What I've never seen anyone else point out, though, is that the interesting thing about this causal chain is that any pair of these steps can be causally linked, in any order.
Here's what I mean: going purely linearly, we just reason from (1) to (2) to (3) and so
... keep reading on reddit ➡I just came across the Grandfather paradox (you go back in time to kill your grandfather but if you kill your grandfather you don’t exist so you can’t kill him etc.) and I thought it would be the COOLEST book idea. I was thinking something along the lines of having a main character who goes back to kille his grandpa throughout the book, and then we find out what happens. I’m not looking for something specific though but if it has something to do with the grandfather paradox (or any paradox) that would be awesome.
Edit: thanks everyone for the suggestions, I will check them out 😁
Part 2 of my theory that expands on my beliefs after episode 3:
As I stated in my previous topic about the time-keepers, I have a theory that Wanda, Dr. Strange and Loki are actually the 3 time-keepers shown.
After episode 3, the time-keeper theory expands with the idea that all 3 know magic.
Dr. Strange is or will become The Sorcerer Supreme.
Wanda is Literally the Scarlet Witch.
And Loki (atleast this version) was taught magic by his mother.
The time-keepers look like them, all have time related events, and all know some form of magic.
Why do these 3 have so much in common? Is it just a coincidence??...
Hey there,
Just looking for some guidance. Currently studying the Grandfather Paradox, and I’m looking for some objections to Lewis’ assertions that there are multiple definitions of ‘can’ depending on context.
In this case, Tim’s ability to go back and kill his Grandfather is both true and untrue, depending on which set of facts you read.
Does anyone have an idea of some stellar objections to this that set out to prove that it is impossible for Tim to hold both the ability to kill his Grandfather and an inability to kill his Grandfather?
I personally query that there are multiple definitions of ‘can’ but I haven’t been successful in finding anyone who agrees, haha. It would be great to get an idea of the kind of objections that exist to Lewis’ response.
Grandfather paradox is not really true.
Here is how.
The first time it is done... There is no paradox... So it is no problem... Going off the way time travel works for proponents of Gradnfather paradox... aka... Those that think time works like that...
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If you go back in time,,, and kill your grandfather... And one asks "but how did you do it if you no longer exist"... The answer is... You did not longer exist YET.
Until your grandfather is dead, or the timeline is changed so your traveling back did not happen... There is no reason for Grandfather paradox to have any barring.
So you go back in time to kill your Grandfather... IF so successful... You would not have been born.
Ok.. Fine... But you did not kill him YET... So... No issue.
Once he is dead... Ok... You don't get born... But that did not stop you from killing him.
It won't happen a second time in some time loop... But... Grandfather paradox did not stop you from killing your grandfather.
How it would really work... Assuming changing the past would effect you personally at all, if you would be on a mission to kill your Grandfather... is that.
It would only work once...
You go back... You kill your Grandfather... and... Your both GONE.
It wont happen again... Not by you.. You don't exist... Your Grandfather is dead... In fact you don't exist so he is not even your Grandfather... He is just a dead guy.. And your someone who never existed. (even though you DID... Or how else would your "Grandfather" have got killed when he did?... And yet you "didn't" exist.)
So if your Grandfather was killed by you... You DID exist, but do not exist any longer. And as far as anyone naïve to the circumstances would know,,, you "never" existed.
And this would not happen again.. .Not by you.. You already wiped yourself out.
Now what if someone went back in time... And killed YOU, before you killed your Grandfather?
Then that is the end of your life... And you end up existing again... Killed at the point where you got intercepted when you went back in time.
Of course... If you never existed.. How could they have intercepted you during your mission to kill your Grandfather?
Well... It DID happen... It just won't happen again... As soon as you succeed... That's it... You are gone.
But if they go back to right at the moment before you killed him... And killed you... And the time line was not disturbed... Then the same thing happens as the first time... Nothing changed... You exist
... keep reading on reddit ➡
And then somehow justify that as a proper response
How does inheritance work?
It’s a nonfiction book, it has a lot of information to back up its claims, as well as it cites its sources. The book didn’t have a particular plot, it was mainly a book that discussed the theories in the title. I did notice that the author seemed to have a voice in this book. Every chapter or so was a different topic. It’s a science/conspiracy theory/space theory book. It was a pretty decent sized book, probably about 1-1.5 inches thick. I’m not sure weather it was paper or hardback but I faintly remember paperback. The cover had a bunch of symbols and theories on the front I believe (sort of like a mixture/collage of them) and they were mostly likely this blue/baby blue color. I think the background was black or something along the lines. It’s a nonfiction book, however I would say it was more recent because of the theories it talked about. The book was in English.
I read this book my freshmen year (2017) after I borrowed it from a conspiracy theorist friend of mine. I think he got it from the library. It was in okay condition. I was 14 at the time, I would say it was age appropriate. Wasn’t vulgar or anything like that. It was not new when I read it. I have no way of knowing what the age range was, but there were some concepts I couldn’t fully grasp, but the author made it easy for a beginner to understand. It was jam packed with information.
I’ve been trying to find this book for YEARS, which no luck. I’ve typed in keywords into google and nothing ever comes up. I hope to be able to be reunited with this book! It was truly a great book! Feel free to ask any questions and i’ll try my best to remember.
So I am rewatching Farscape and I was wondering if John was supposed to end up back in 1985. With the exception of John starting to fade from existence when his younger self was practically dead, it seemed like nothing that already happened for John would have if he and the crew of Moya weren't supposed to be there in the first place.
So I think I figured something out, but I need someone with a quantum or physics background to input. Assume we have the energy resources and capable knowledge. My thought is that the Grandfather Paradox will never happen for the following reason. If you go back in time, and alter history, that history is no longer apart of this timeline. It would create, or rather divert into, a parallel universe where said timetravel did happen and will always happen at that point in time. This paradox states that if you kill your grandfather in the past you would never have been born in the future to kill him. But I posit this could never happen because the grandfather you kill in the past is not yours', but your parallel universe doppelganger. Therefore after you kill him, you may live long enough to be an old man in the universe where you killed your grandfather, but your previous life in the parallel universe would be drastically changed. That's only if you couldn't go back. If you could however, nothing but the future after you left in the first place would change. Any thoughts?
From what I could understand about how time and world lines work in the S;G universe, all of the world lines that we get to see are all "built up" from the experiences in the previous world lines, due to Okabe's Reading Steiner ability. A lot of events happening are only possible due to Okabe's knowledge of a previous world line.
Before anything in this series to even occur, there must be an "original" world line where time travel was only first used in 2025, and none of the world line altering events we see have occured.
However, we learn that John Titor, the original author of the time travel theory that later let Okabe and Makise develop the phone microwave and time machines, was actually Suzuha coming from the future. If that's the case, then who developed the original time travel theory?
They make a pretty big deal out of making sure that Daru never gets to examine the time machine, because he needs to invent it himself. Which is why it wouldn't make sense for Okabe to have learned the theory from Suzuha's John Titor. Was there is a real John Titor who lived in the "original" worldline who laid the groundwork for time travel theory?
The idea of the "original" worldline also bothers me. In the first scene of Steins;Gate, we already see Suzuha on the rooftop with the time machine. Which means that the worldline has already diverged from the original. Which makes my entire theory unprovable, because we have no way of knowing what the other worldlines are like before Okabe learned about Reading Steiner.
Anyways, sorry for the incoherent ramble. Let me know what everyone thinks about these ideas.
Tl;dr: Doesn't Suzuha being John Titor in 2000 break the Grandfather Paradox because she brought the time travel theory from the future for Okabe to study? Do we know anything about the "original" worldline, where nobody tries to alter time until the time machine was invented in 2025?
What if every form of life coexisting in this universe at this very point in time is just another version of the same entity living simultaneously to an infinite number of different universe versions of itself. What I mean by this is can be better explained in the following example:
Supposedly, something happens that could result in your death, time diverges into multiple outcomes that create multiple world-lines with these different outcomes. The version(s) of you that survive move forward in time, continuing to live with the memories of their past self still in tact.
If time has no beginning and end, the version of that one entity who lives indefinitely even past the point of when world-line ends and starts over. That would mean that the version of this entity that prevails would coexist with the version of that entity from the previous timeline. This cycle would happen infinitely and indefinitely creating an infinite amount of versions of this world-line with each version of this entity not capable of ever truly dying. Each version of this entity would be living in its own world-line coexisting with previous versions of their self that are from world-lines where they didn’t survive/prevail forward in time.
Let me know what you guys think about this and if it is similar to/agrees with any other previously mentioned time theories.
This article talks about the time traveler being unable to shape the sequence of events to the extreme that would allow them to change or eliminate their motivation for traveling back in time. The events would still happen, just in a different way, that would result in the traveler traveling back in time. Space time healing itself around the traveler to prevent too much alterating with the timeline as to cause a paradox. Now say people have been attempting to change the past but the universe has been changing to accommodate for their efforts, this would explain the small changes we remember called the Mandela effect. https://www.independent.co.uk/life-style/gadgets-and-tech/time-travel-possible-grandfather-paradox-free-will-b713939.html
Edit: link to the scientific paper not just the article: https://iopscience.iop.org/article/10.1088/1361-6382/aba4bc
This is a ridiculous subject, but it's fun to talk about, so whatever I suppose :P
Personally, from what I know of physics, I don't think it's possible to travel into the past. However, I've always been a fan of time travel movies though and I never quite understood how people logically justified bootstrap and grandfather paradoxes.
From my understanding, in keeping with simple cause and effect, it's entirely possible to kill your grandfather if you somehow managed to travel into the past, simply because while yes, if you killed your grandfather then you wouldn't be born, but in your causal line (the chain of cause and effects events in your life), you were born before you traveled into the past and you'd still be alive (in the past) afterwards. The chain of events that lead to your birth would no longer take place, but you'd still exist. You would just more or less be considered a free agent, as far as determinism goes. Don't get me wrong, you'd still be guided by your causal history, but the history of it all wouldn't exist anymore is all. I don't see how this is paradoxical.
Regarding the bootstrap paradox, as seen in such films as Tenet, etc. - They're self-referencing temporal causality loops and according to cause and effect, these models can't exist. They need to have a beginning somewhere, something to cause them to come into existence in the first place and even then, temporal loops such as these could never be perfectly consistent and would unravel eventually.
Fun fact though, non-temporal causality loops can theoretically exist. If they did though, they could never have been "created", but rather would simply have always existed. They'd have to be perfectly causally isolated from every aspect of the universe though, never coming into contact with anything from ours and so essentially would be their own self-contained universe. Because of their perfect isolation though, we'd never be able to detect one if they exist and if we live inside of one, we'd never be able to prove it because causality loops are self-referencing systems that can't validate their own consistency.
It seems like the only two solutions that I've ever heard are that either you can't kill your grandfather no matter how hard you try or the universe splits into alternate timelines. Are there any other possible solutions?
He got the sack.
It's the best explanation for why Spock never mentioned her, among other inconsistencies.
ok so i understand the grandfather paradox but wouldn’t you be able to go to a point in the past where your grandfather already had your parent and then kill him at that point. that wouldn’t mess anything up would it? because your grandfather already had your parent.
Let's talk about the Grandfather Paradox. People think if you go back in time and kill your grandfather you'll no longer exist because you would have never been born. When in fact that's not the case.
Everything that happened, happened. Meaning you exist and will always have existed. It's just once you travel to the past your past then becomes your present. Once you kill your grandfather in your time you would just no longer exist from the moment you pulled the trigger. To the people who knew you, you would just have vanished. Missing persons style. But for you, you've now created an alternate timeline where you're alive but you were never born, hence making yourself into a paradox.
Let's talk about the Grandfather Paradox. People think if you go back in time and kill your grandfather you'll no longer exist because you would have never been born. When in fact that's not the case.
Everything that happened, happened. Meaning you exist and will always have existed. It's just once you travel to the past your past then becomes your present. Once you kill your grandfather in your time you would just no longer exist from the moment you pulled the trigger. To the people who knew you, you would just have vanished. Missing persons style. But for you, you've now created an alternate timeline where you're alive but you were never born, hence making yourself into a paradox.
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