Time Travel Paradoxes.
I recently read an interesting article from a book of Robert Heinlein (1907-1988) called "By His Bootstraps". I think it is pretty worthy to share the main story here and debate it:
The narrator does indeed set himself up "by his bootstraps" -- his present and future selves all interact with each other to produce the events. The paradoxical nature of this comes down to the case of a notebook that was provided to the narrator by the older man in the future. It contained a vocabulary of the language that was spoken by people in the future. The narrator learns the language and, as the book wears out over the years, copies it over into a notebook he had fetched from the present. This notebook, as it happens, is the very one he, as the older man, then provides to his other self. He is therefore the same person who both learns the knowledge from the notebook and put the knowledge into the notebook in the first place. The vocabulary as a certain list of items arranged in a certain way was thus complied by no one whatsoever. The knowledge exists in a closed temporal loop and is in an important sense uncaused or uncreated. The narrator himself notes that there is something peculiar about this.
Robert Heinlein's 1941 story writes a philosophy thesis that time travel is impossible because time, in Immanuel Kant's terms, is only empirically real and does not exist independently among things in themselves. The narrator is then suddenly surprised to find two different versions of himself arriving from the future, with conflicting warnings and promises about what he can do. Traveling to the future, he meets an older man who repeats the promises, but whom he ends up distrusting. After some confusion, back in the present, he obtains some supplies and returns to the future to a period significantly earlier than when he would met the older man, intending to contest the future with him. Eventually, however, it turns out that he himself is the older man and his future is in fact, pace Immanuel Kant, secured.
According to Kelley L. Ross in his main page (The Proceedings of the Friesian School, Fourth Series): Every instance of time travel generating an infinite number of alternative universes might be thought to violate Ockham's Razor, especially since the idea that an alternative universe could be generated in the first place has disturbing consequences for the metaphysics of identity. Simplicity and common sense rebel against such principles -- although serious versions of such metaphysics have been produced to deal with quantum mechanics, and multiple real universes were proposed by the philosopher David Lewis to explain possibility and necessity. But without them, time travel, that would allow for the sort of temporal loop in which the paradoxical and impossible watch of Somewhere in Time becomes possible, is itself impossible.
Thoughts? Is it interesting right?
The narrator does indeed set himself up "by his bootstraps" -- his present and future selves all interact with each other to produce the events. The paradoxical nature of this comes down to the case of a notebook that was provided to the narrator by the older man in the future. It contained a vocabulary of the language that was spoken by people in the future. The narrator learns the language and, as the book wears out over the years, copies it over into a notebook he had fetched from the present. This notebook, as it happens, is the very one he, as the older man, then provides to his other self. He is therefore the same person who both learns the knowledge from the notebook and put the knowledge into the notebook in the first place. The vocabulary as a certain list of items arranged in a certain way was thus complied by no one whatsoever. The knowledge exists in a closed temporal loop and is in an important sense uncaused or uncreated. The narrator himself notes that there is something peculiar about this.
Robert Heinlein's 1941 story writes a philosophy thesis that time travel is impossible because time, in Immanuel Kant's terms, is only empirically real and does not exist independently among things in themselves. The narrator is then suddenly surprised to find two different versions of himself arriving from the future, with conflicting warnings and promises about what he can do. Traveling to the future, he meets an older man who repeats the promises, but whom he ends up distrusting. After some confusion, back in the present, he obtains some supplies and returns to the future to a period significantly earlier than when he would met the older man, intending to contest the future with him. Eventually, however, it turns out that he himself is the older man and his future is in fact, pace Immanuel Kant, secured.
According to Kelley L. Ross in his main page (The Proceedings of the Friesian School, Fourth Series): Every instance of time travel generating an infinite number of alternative universes might be thought to violate Ockham's Razor, especially since the idea that an alternative universe could be generated in the first place has disturbing consequences for the metaphysics of identity. Simplicity and common sense rebel against such principles -- although serious versions of such metaphysics have been produced to deal with quantum mechanics, and multiple real universes were proposed by the philosopher David Lewis to explain possibility and necessity. But without them, time travel, that would allow for the sort of temporal loop in which the paradoxical and impossible watch of Somewhere in Time becomes possible, is itself impossible.
Thoughts? Is it interesting right?
Comments (63)
It would be still a paradox because according to Einstein there is not present neither future. Time is just relative or cyclical
Evidence there is no time travel I find very convincing - Where is everybody? Why haven't we seen any people from the future? To me, that's more convincing than any scientific speculation. In response, I've heard arguments that there can be time travel, but only to a receiver in the past, so you can never travel further back than the earliest time machine. In that regard - I recommend what I think is the best time travel film, certainly my favorite - "Primer." Cost $7,000 to make. Feels very realistic. Watching, I said to myself - Yes, if time travel is ever invented, that's how it would happen.
A book sounding similar to the one you referenced is "The Man Who Folded Himself" by David Gerrold. It also has someone interacting with different selves from different times and different timelines.
Another really good book, dealing with paradoxes piled on paradoxes, is "One Day All This Will Be Yours" by Adrian Tchaikovsky. I also find this one very convincing in describing just how far time-travel paradoxes could go.
Time travel either exists or it doesn't. If it does exist, it is a physical phenomenon, not a theory, therefore Occam's razor doesn't apply. The existence of time travel is not a metaphysical question, it's a question of fact, no matter what "disturbing consequences" it may or may not have.
Thanks for the book recommendation! :up:
Quoting T Clark
My guess is that when the article refers to “consequences” is related to multiuniversal scenarios. Because if it could be possible to manipulate how time “works”, then, it would be possible to manipulate our universe too. This would create different worlds with different (or similar…) T Clarks and Javis… well this is just my guess trying to see it as metaphysical but it is true that the opinion of Kant is more rigid:[Time] does not exist independently among things in themselves.
Quoting 180 Proof
I prefer the more plausible, though equally speculative (or absurd), idea of a "viewing" rather than "traveling" to the past, particularly as imagined by Arthur C. Clarke in this co-authored novel ... https://en.m.wikipedia.org/wiki/The_Light_of_Other_Days ... and which is an older idea several other scifi luminaries have written about: https://en.m.wikipedia.org/wiki/Time_viewer
Thanks for sharing it. Another interesting perspective indeed. As I see, time has always been an important topic to both philosophers and scientists to discuss about.
We can see and debate a lot of views over the same topic!
Interesting view. But if we "jump" through the time, what would happen? Do you think we would observe a metaphysical change in our world or just a loop of ourselves jumping infinite times?
Hic sunt dracones!
Sabrá Mandrake! señor/señorita!
"I know that I know nothing"
- Socrates
:death: :flower:
The (sad) clown Pagliacci! Visit Wikipedia for details.
We're left with [s]mere[/s] opinion! Coherence theory of truth!?
I think it doesn't goes wrong. It is just another example of time paradox. You used an interesting one according to Pascal triangle and I liked it. But my guess is that we end up in the same place: time doesn't exist "outside" our existence. It is an empirical term. We cannot put different concepts of time (present, future, past, conditions, etc...) because they are all dependent on us.
Multiple worlds explain potentials. But like potential and kinetic energy, kinetic is what actually happens. This doesn't mean there must be a world in which one person dropped a ball, and in another world another person did not.
What has happened has happened. What has not happened, has not happened. There is no reversing it or going back.
I know theoretically it is possible to "travel" into the future, but not into the past.
Therefore:
Quoting javi2541997
Is not possible because going into the same point in the future is impossible because it requires first going into the past for a new journey into the (previous) future.
Exactly :100: :up:
You are right :up: I guess we should see time as pure forwarded pathway to walk through. Past is just some experiences we have lived and learned about
Kant was wrong. The flowing river is time.
We don't walk through time. The walking itself is time.
It is not the same when you are only 5 years old, or 25 or 65...
Time makes an impact in our life
Yes. The walking can take long or fly by. It depends. It is said older people go to bed already when they wake up.
[Just to clarify what I said previously]
When I typed: we walk through time, I guess it sounded pretty poetic. As Virgil stated: tempus fugit. What I wanted to share is that time is very important, or at least influential, to humans when they do so artistic works. Since a paint to write a poem
You mean the time in which the artist lives influences his works? If I look to ancient Greek art it looks as if they experienced the world rather flat, and consisting of disconnected parts. I wonder if they would recognize realistic paintings.
Or do you mean you don't look at the clock while creating art?
No, I mean the opposite. I say that time could be a good motivation to create art. I am not referring about Ancient Greeks but all the ages. For example: a painting about an autumn afternoon because it makes you feel nostalgic
Ah, paintings, or art about time?
Quoting Hillary
:fire:
The Fermi Paradox redux: Where are they – all the backtravelers (chrononauts) from the future? :chin:
Both.
:up:
This begins to sound like the Liar paradox, where, if a sentence is true, it's false, and, if it is false, it's true
A very similar paradox, allowed by the possibility of the same kind of temporal loop, can become a reductio ad absurdum for time travel
11 April 1954!
I did quick research and I found out what happened that day all over the world. Here is a brief examples:
Was April 11, 1954 the Most Boring Day in History? :chin:
So they all showed up on "The Most Boring Day in History" when nobody would notice arrivals from the future? :ok:
Quoting 180 Proof
To both posters above:
If a day can boring so can a week, a month, a year, a decade, a century, a millennium (or two). Despite what we think/believe, this current epoch in human history may not be the most attractive of tourist destinations for chrononauts!
Furthermore, tampering with the past may not be such a good idea, oui?
:heart:
11 April 1954: The Most Boring Day in History
An AI made that judgment. I'm dying to know what its criteria for interesting/exciting were.
Oh boy the AI again... they are always surprising me. What would be the next? The most philosophical day ever?
So interesting argument indeed. :up:
Related to your question and opinion, the article I have shared previously, says:
Every instance of time travel generating an infinite number of alternative universes might be thought to violate Ockham's Razor, especially since the idea that an alternative universe could be generated in the first place has disturbing consequences for the metaphysics of identity. Simplicity and common sense rebel against such principles -- although serious versions of such metaphysics have been produced to deal with quantum mechanics, and multiple real universes were proposed by the philosopher David Lewis to explain possibility and necessity (after Saul Kripke used Leibniz's idea of "possible universes" to produce a quantified version of modal logic.
I feel it would all depend on the nature of the analysis if we could call it that. If what's involved is going through mountains of data, a computer (AI) is the right person for the job.
Fun fact: Computer punch cards were invented for the US census; you know, to speed things up so that the census bureau could meet government deadlines which was 10 years!!!
What about our dear ol' pal the observer effect?
Indeed. But that data was implemented by us. So we are the guilty fellows here :chin: some programmers put a lot of information in the AI but we are ones who put the subjective portion.
I wish we could know what happened that day and then conclude if it was a real boring day or not!
That's why I'd like to know the criteria for interesting/boring the AI used. Why is 11 April 1954 the most boring day in history? No births/deaths of the movers & shakers of our planet, no disasters, no wars, nada, zilch, nothing!
There's this paradox in mathematics called the Interesting Number Paradox. Have a read, if you like.
So, 11 April 1954 is blah blah blah and that's precisely why it's soooooo interesting! :grin:
Thanks! :up:
Quoting Agent Smith
Well if that is the criteria... I wish we could have more boring days as 11 April 1954 :rofl:
[quote=Ms. Marple]Most interesting. :chin: [/quote]
Quoting Agent Smith
Exactly! Si! I would feel excitement whenever I pass an important exam (or I pursue the ability to travel through the time!) But panic comes with fear and it can be caused by an earthquake or other natural disaster
Oldham Athletic footballer Jack Shufflebotham sr. died that day! A most memorable day! Any time tourist would have revealed themselves!
Quoting Agent Smith
:chin:
The only way to travel back in time would be a temporary reversion of motion. And if that motion were reversed again at my day of birth (24-09-1985), I would have traveled back in time. The past is gone, and only on far away planets they could see me how I acted 10 years ago (at the habitable planet around Proxima Centauri. Can we ourself look at our past? If we could use black hole, maybe. We could direct light and watch the light we emit. But our particles can't go back in time to meet their past versions. Only virtual particles can travel back in time be it over a short span. Suppose I travel back in time a day. I watch myself for a day and see myself travel back. I travel back with myself. We hide together. We watch again, and wait a day. It would get crowded in the past, if my present matter shows up there. Imaginary parallel worlds, from which matter is taken to solve this riddle, won't save the travel.
Good one! :fire: :100:
Another one: Tempus fugit! The life is short and time flies so fast.
The Butterfly, crushed, that Eckels finds (A Sound of Thunder, Ray Bradbury).
I can't seem to parse the rest of your post.
:smile:
It is not even worthy at all. Which happened back in the day remains in the past. We cannot change it neither fix it. We only can learn thanks to the experience
Well, that depends on the past. And because time can only be experienced by looking and remembering the past, it deserves a revisit.
It deserves to be considered for. But not so deeply because you cannot modify what happened previously...
I only read one year old papers. Makes me feel I'm ahead of my time...
I also read public documents from the 1970's to not forget what happened back in the past.
Without a past we can't live the present, in my quite humble opinion. It's very difficult (if not impossible) to experience the present without involving the past.
I am agree with you. Past is one of the main reasons of what is happening in our present.
I love your English (no offense!). :grin:
Thank you. Appreciated it! :heart:
I've found another interesting point of view from Irwin C. Lieb: [i]Past, Present, and Future,
A Philosophical Essay[/i]
The past consists of what was becoming definite in a present; it became fully definite in being past. The past consists of what is fully actual. While individuals are present they are becoming definite and actual, and the completion of that process is their being past. Individuals are transformed when they become past, and the most prominent change in them is that their singularity is lost. In the present, individuals are singular and extended; they resist and oppose one another. They are spatial and outside one another. None of these features becomes past. What becomes past is the definiteness the individuals have achieved from inside themselves, and the definiteness of each individual is joined with the definiteness of all the other individuals that were their contemporaries. Together, they are the achieved definiteness of a moment of the entire world, joined to the past to which they have conformed. There is one whole past. There is no space in it and it has no length; duration and spatiality are only in a present time. [p.126] :100: :sparkle:
I am descended from you, and exist in your future.
Thou shalt not violate causality within my historic light cone. Or else.[/quote]
:nerd: