***Changing Episode Covers, Notes*** For folks who are wondering about thumbnail/cover changes, I had it pointed recently to me that the title of every episode is also displayed next to or under the thumbnail for the video anyway, so that putting the title text on there was a bit redundant and just blocks being able to see Jakub's wonderful artwork. [Jakub Grygier is our longstanding cover artist and does about 95% of them and about 99% of the good ones :) ] At the same time it was noted the logo on the red rectangle we usually do was clashing with a lot of the images. So I went and reverted around half our covers to the base image (back to about fall 2019) and on around a dozen of them tried putting 1 or 2 words related to the topic but not in the title on them - that font is NightclubBTN on today's and some of the others, it's a touchy whacky but was a good fit for most of the ones I did that too like "Nuking Mars", its not our new base font or anything. I also went with a more subdued and smaller logo in the upper corner. And I'm basically letting it sit like that for the moment so I can see how YT's analytics show those changes affected views and because I don't really have a surplus of free time to change everything up in detail anyway. Feedback is welcome, it is an experiment, and in the meantime at least it let's more folks see JAkub's gorgeous covers without the title text blocking them :)
I liked the old way. I like the new way. It is your show so do as you wish. I do miss the speech impediment from the first episodes. I hope that is not impolite, politically incorrect, etc. I’m happy you have improved your speech as was one of your goals when you started. I bet you didn’t realize it would turn into this.
My favorite time travel moment was in Red Dwarf, where the crew found a time machine in deep space. So they set it to travel back to the time of the Renaissance. Then, they look outside and realize they're still in deep space.
Frankly, Red Dwarf is some of the best sci fi I've ever seen on television. Also gave me nightmares when I was little. In particular, the Polymorph that turned into a dinner sausage.
The very first story I wrote (and coincidentally the story that got me into SFIA) was a story like this. Multiple factions were all fighting to establish what they believed was the accurate version of history
I like the thought of countless new possible timeliness born off every new second of the Universe's existence. What can I say, I like tree motifs in fiction.
@@countofst.germain6417 oh boy that would be a dream! There’s not many things I could wish for more than to be as knowledgeable and captivating as him!
I mean all you have to do to make that a reality is learn how to stalk a person and show up at his house, there may be police involved shortly after but you would meet him
I quite enjoy time travel in fiction, especially when used creatively like in many SCP stories, or ironically like in 40K My favorite time travel story is from Warhammer fantasy, I can't remember the book, where a hero got tempted by chaos for a chance to kill his nemesis, an inquisitor that murdered his family, falsely accusing hero's father of being a chaos cultist, just to get screwed by Tzeentch, being corrupted and sent back in time, failing to kill the inquisitor and causing the accusation. The reason I like the story is that this common time travel cliche was masterfully used to explain the nature of a Chaos god by "show don't tell" while creating sympathetic villain to use as a centerpiece of future stories
Weirdly, my favorite time travel story was in Red vs Blue, where Church ended up creating an army of time clones because he couldn't break causality, and in the end just gave up and said "F* - it.". Even thought it was retconned as hallucination/simulation, it was still fun to watch. Also the DS9 episode, "Trials and Tribbleations".
The time travel RTS game Achron's time travel model is interesting too. For chronal being (everyone who can't time travel) timeline is linear, but for achronal being (who can perceive time and change it) time is wave over wave overriding what's under it. The "time wave" can only be seen achronal beings and it's "travel speed" is slightly faster than causality itself. But you can use a time machine to "ride" the wave and dodge the causality itself.
I remember a non-canon version of Doctor Who for the British charity event Comic Relief one year staring Rowan Atkinson of Mr Bean and Blackadder fame. I think it played for laughs him and the villain trying to outdo each other in going to travel back in time to get the architect of the building they are currently in to move where trap doors and so forth are for their advantage.
That was actually written by Steven Moffat who went in to become the show runner later on. It’s a great self parody of the show. Terrific cast as well.
Dr. Who does the worst timetravel. The Dr. breaks the unbreakable time travel rules like every 10 episodes. :) And everyone thought he can do it without consequences. But at one point a couple of years ago the timeline hit back turned him into a women and desintegrated his whole fan base.
Hey at 4:34 the Stargate example (bottom-right) of rapid aging is due to nanobots artificially aging him and not a time thing. I only bring this up because Stargate actually has some good examples of using faster/slower time fields. In one episode of SG-1, Season 2 Episode 15 "A Matter of Time," it's even time dilation due to a black hole, and it shows all kinds of problems with communication and other stuff because of it.
Steins;Gate has an interesting approach to multiple travelers. The chances of them interacting is more or less likely dependent on their relativity to the "prime" timeline (i.e. the timeline in which time travel fails)
Id expect it to be super cringy. Id think your consciousness would just overwrite your previous state and make you conscious and aware of being in a rerun, unable to alter anything.
All You Zombies is the ultimate bootstrap paradox time travel novella along with "By His Bootstraps" both by Heinlein IIRC ETA The Man Who Folded Himself is similar theme
These episodes are so nice for getting my mind out of the struggles of the daily grind and all the disappointments of humanity. Thanks for the entertainment
Imagine inventing time travel only to get stuck in an infinite battle against an infinite number of yourself, an infinite number of which all want monoploy on time travel, while another infinite number of yourself try to flee the madness. They all fail of course, there's an infinite number of hunters capable of time travel after all.
Star Trek Voyager had a very high standard deviation of quality between episodes, but their time travel ones were among some of the better ones. Like when Kim sends himself a message though 7o9, The Year of Hell, etc
Just have to shout out the hard work that goes into each SFIA. I have made short videos for school projects (7-10 minutes) and dreaded narrating them, so I can only image the great effort that goes in to each finished product. Thank you for bringing this to us!
I kind of like Pete Abrams' take on time travel in his Sluggy Freelance series: Time travel 'damages the fabric of reality,' but the universe has a sort of 'buffer' where people mucking about with time travel tend to get stuck.
26:00 - This is why so many of my favorite time travel stories involve the discovery of time travel being erased as a consequence of its own discovery. Closed-loop time travel seems like it ought to be a "self-sealing" problem.
The problem with "closed loop" world_lines is that at the point where the "loop" happens the "line" eventually gets strangled by its own tensor strength ["cutting" itself out at the point of intersection]. The worldline inertia "welds" itself at the cut point, leaving behind only short_lived "scars" (anomalies that never last beyond the date the initial travel to the past happened) as indication. -> The "floating strand" of the worldline that contains all the informational causes_events related to the time_travel event eventually disintegrates bit by bit as it "spreads" into "The Nothing" of non_existence].
@@adolfodef -- Sounds interesting. Can you please share your source? I'm not sure whether what you're saying is a theoretical physics thing or a storytelling thing.
@@Grizabeebles Neither. [Technically speaking] It would be pataphysical philosophy (aka: my own headcanon), that I try to visualize and then to transcribe. -> Watch Steins;Gate & Steins;Gate:0 for the basics. /) El Psy Kongroo
@@Grizabeebles One important detail I forgot to add in my "visualization", is the fact that a "time loop" never happens ONLY ONCE; but rather an non_infinite number of times, until it does not anymore. -> Even just "twice" would be too much. If you see the "loop" in 3 dimensions, it is obvious that the "turn around" would not perfectly match the original line (it would go either left or right). . Unless it ALWAYS go a bit more towards the same "side" (something that would imply the existence of a positive, active "imaginary time" that is constantly "pushing" the loops, just like normal time "advances" the line), as soon as there may be a loop crossing the point on the opposite side, it would cause the previous loops to create a "knot" [were there may be "tension" or "torque" or "angular momentum" that would destroy the universe_line of continuity]. (or) -> just a Time Quake [but NEVER a Paradox]. The self_erasure of Time Machine is part of the "evolution" of universes [those who do not sucessfully develop "laws" that prevent effective, "useful" time travel simply "kill" themselves before reproducing].
I have no idea where you get that from. General relativity allows for closed timelike curves (in the same way einstein-rosen bridges are closed spacelike curves), there is no reason the effects of ome couldnt propagate out of it.
I’ve been toying w/ a sci-fi concept of taking a copy of one’s consciousness at 50 years-old and sending only the consciousness back 40 years to a one’s 10 year-old brain. This video spurred a lot of thoughts for picking a “somewhat plausible” mechanism to do that. I’m sure whatever I come up with will be ridiculous but that’s the fun thing about sci-fi...
Is it bad that my thoughts immediately went to "think of all the girls and money you could get as a ten year old with the knowledge of a fifty year old!
@@StarboyXL9 - No it isn’t bad and it’s a story concept that’s been done before in a number of variations... You can certainly dream up a lot of mischief with such an idea... money and girls being woven into such a plot line could be done as wholesome and charming just as easy as making it appear sleazy and insidious... Depends on your imagination and how you sell it to your audience..
This reminds me of the idea of when you die, you are just reborn into your own self at the beginning of your life, to repeat your life over and over again, but with all the memories of your past lives. If a species had this capacity natively, then they would have a perfect timeline, because your great great great great grand children will know what happened in your time and be able to tell their parents, who would tell their parents, who would tell their parents, who would tell their parents, all the way back to you when you children are born and tell you your future, and you would continue the trend all the way back to correct any event in history.
15:32 I notice you didn't mention Tenet (2020). That's a great example of depicting backwards time travel as just reversing time and having to go through the intermediate time, though the physics doesn't really make sense on close examination, even if you try to "iron-man" it by ignoring a few minor mistakes they made (like comments about antimatter).
Sliders as I remember it was not about alternate timelines. His (he/his/him being the main character) device enabled him to travel to parallel Earths. If I remember right he went to a parallel earth early in the series, possibly in the first episode, and then when he returned to his home earth he soon realized it wasn't the Earth he originally came from. He then spent his time for the duration of the rest of the series trying to make it back to the version of Earth that he originated from, and making enemies along the way most notable with the Cromags. Very underrated series IMO.
As I remember it but I could be wrong, the Cromags discovered they only existed in one reality. This explains their hatred toward the other, human, realities.
@@Emdee5632 That was in some of the earlier episodes featuring the Cromags. In later episodes he encountered Cromags that were essentially more intelligent than humans, had mastered the sliding technology, and would go from Earth to Earth conquering and cannibalizing humans. I should look up if it streaming anywhere. I kind of want to go binge watch the series now.
That would to be relative to something since their is no absolute frame of reference due to relativity. So it could just be relative to Earth and avoid those problems.
The answer to loop paradoxes is including instructions that you need to go back in time and then give yourself the instructions to go back in time, thus you loop around once and your doing it because you told yourself to and not because of the original reason that would get stuck in a causality loop. . FTL also isn't time travel if you separate the concept of perceived time from sequential time, since the rate at which perceived time is flowing is irrelevant to sequential time, moving beyond the speed of causality would only actually affect perceived time, thus you couldn't actually arrive somewhere before you left, you just wouldn't be able to detect the object moving at FTL until after it reached its destination. This understanding of time however does sadly means true backwards time travel isn't possible, unless you reverse time for the entire universe though.
Interesting topic and fun trope for many stories, but Isaac Arthur in his typically through and logical way completely destroyed it! I quit about 17:00 when time travel, multiple timelines, multiple worlds, etc. were already thoroughly beaten to a red spot on the pavement. Why i love this guy.
By now, it´s existence is probably an Atractor Field of Convergence for our local group of worldline iterations. The way how theischannel (& the life of Isaac Arthur too) improved overtime is as suspicious as the many ways Hitler survived accidents & assasination attempts (I am talking of the current historically canonical ones, not the billons retconned). El Psy Kongroo /)
Achron was a game that had a fascinating portrayal of time travel as a propagating wave had a brief period between cause and effect (future to past) that I always thought handled the concept elegantly in a way that still allowed for drama
Thank you to the entire team once again. A wonderful idea to listen to while drawing tattoos before work. I hope yall have a great day. I'll be pondering "Temporal Tattoo Fluctuations of the Quantum Tattooed Man!" Haha good stuff.
23:00 i guess the movie "Freejack" got a working solution for that exact problem. Pretty good writing in more than that regard tho, I definitely recommend it, mick jagger is pretty dope in it ✌🎉
It really is, but I would argue the thing we call the self, is actually an emergent property of an evolving and everchanging and unbroken pattern of information and interactions in the nervous system, that results in thoughts, actions, reactions, sensations, experiences, memories, reason, cognition, and so on... We are also far more than any of these individual components, which can individually degrade, evolve, change, or be altered while the self is retained.
One of the great things about the way Everything Everywhere All At Once is how it handles the multiverse; while there is a common identity, the lives of your alternates can be wildly dissimilar based on choices and happenstance. And in an infinite universe, those changes can be radical.
Stories about invading the past always remind me of the TV show Terra Nova, in which future humans set up a colony in the Cretaceous. I don’t remember anything about the plot, but early in the show they established it was an alternate timeline, only to twist in the final episode of the season that it was the same timeline, and potentially have ripple effects 85 million years in the future. I think it was a setup for the second season they never got.
*Very interesting post.* I'll listen to this one more than once. Thanks. I love your references to Sci-Fi books. I have listened to more than one of them).
What is implied by a lot of time travel stories is that they are traveling to a copy of the past. If in multiverse theory EVERY event causes the universe to copy itself so would the act of time travel itself. This prevents any paradox but has the weird implication that even if you change the past you are not actually changing your home timeline. Often in fiction we see the hero travel back the past, change things, then go back to the future and get confused by how his actions changed history, the ending of "Back to the Future" being one example. Their memories are from one timeline, but they are living in another. Though this implies that they are absent from the original timeline, having hopped into the time machine and disappeared completely and permanently, or maybe replaced by another version of themself with memories from yet another timeline going ad infinitum.
32:40 You have to be very careful with this analysis. This is very similar to the question of the entropy of the universe, which is supposedly very low at the time of the Big Bang, since, as per the Second Law of Thermodynamics, it can only have gone down since then, yet it seems intuitively like the Big Bang should have very high entropy. (Note, this whole discussion and comparison only makes sense if you understand Boltzmann Entropy, where a high entropy apparent macrostate means corresponds to more possible microstates that look the same, and a low entropy apparent macrostate corresponds to fewer possible microstates that look the same.)
My biggest issue with how most thing treat time, is the tendency to treat it as though it's made up of discreet immutable units. For instance if you view time less as a state and more a property, like say momentum, it could limit the possibility of paradoxes without requiring linearity/unidirectionalality as much like how strictly speaking it's possible for a planets orbit to reverse the energy and circumstances required mean this RARELY if ever happens, likewise if thing had a sort of causal momentum then even if retrograde time travel is possible the effort needed for any action that would shift causal sequences would increase in relation to the degree of said shift
27:34 I saw someone explain this multiple-iteration corrective loop problem with a Mobius strip. You kill your grandfather, which leads to you not existing, allowing the next grandfather to be alive to make you so you can kill him again. (I don't really remember at this point.)
I feel Babylon 5 did time travel really well, with not skipping the consequences and effects on the body also the future transmission Ivanova receives is a cool idea
I think when something goes back in time it just creates a new timeline so from the original timeline's perspective it didn't work, but every time they try they creates new timelines in which it did work. I think this also prevents most if not all paradoxes. If you accidentally stop yourself from being born, that doesn't matter because you come from a timeline in which you were born but now exist in one that you don't, simple as that. Also weird timeloops like in the movie "Predestination" wouldn't be possible, which is good because they don't make sense.
I agree that the multiple-worlds thing does resolve pretty much any possible problem. But it kinda does ot at the cost of non-falsifiability. ...this is more a comment on my feelings about Sean Carroll / Everett's whole schpial than your ideas. I don't dissagree with you at all.
@@Shiskabobber1 No, it actually don't. ...I posted another comment here at the same time you did... Conservation of M/E only applies to a single timeline. The multiverse idea we're talking about is batshit crazy imo, but not nearly so easily dismissed as that. If I have it right, we already know that each quantum ...thingy... splits reality into two separate realities. This _is_ batshit crazy, but it is also generally accepted as fact. The only liberty the multi-worlds thing takes, is that this splitting is primary rather than some artifact of our perception. -That what we all accept to be experimentally true, is true, -and the singular timeline, with each quantum thingy, collapsing conveniently for the timeline _we_ happen to be in, -is what is an artifact of our perception. I probably didn't explain this well, but that is my best. This multi-verse thing was pioneered by Everett, and is now being championed by Sean Carrol. I find it epistimologically terrible for the reasons you bring up, but, also... ...compared to what. It definitely can not be dismissed for violating conservation of M/E.
Technically it tends to delete individuals who have the knowledge of how to do time travel or FTL by exploding them and anything around them at roughly the point in time where they are set on the path of eventually being able to understand the technology. Since this generally happens when said tech is operated, there's a good chance that it simply explodes, but the explosion travels all the way back along the frame of reference for the closest intelligent individual until that frame diverges from how the tech came to be activated.
Time dilation is because the closer to the speed of light the less things can move in other directions. Which reduces interactions between things like particles. This gives the appearance that time is slowing down.
My favorite time travel story has got to be Chrono Trigger from the SNES. Not only was it a game that was so instrumental in defining how games would develop over the next 10-15 years, it was also my first introduction to some of the story beat concepts that would become popular later in the rise of lovecraftian horror. Granted, CT was SUPER light on those themes, and it and it's time travel were kind of blanketed in more kid friendly stuff and the veneer of magic and fantasy, but that was what made it more accessible for young me to be honest lol.
"Time Travel is even something people like to talk about to discuss regrets" Didn't know Isaac had time travelled to watch the BCS Series finale when writing this episode.
I was wondering when you were going to mention Tenet. If you haven't seen it, it's honestly a pleasant watch. Not the best movie ever but their take on time travel was really quite refreshing, I loved the fact that the traveler has to go through time in reverse but at a normal rate instead of instantly popping out of the time machine at the desired date like we often see in movies.
I like Tenet but I still find it strange that they basically mentioned all the paradoxes and then said: "Meh?" Like, why take the time to even mention the paradoxes?
It's hard to go past The Technicolour Time Machine for time travel fun. A movie crew go back in time 1000 years to film the Vikings going to America, to later discover that the only reason that the Vikings went to America is because they went back in time to film it. Awesome story telling.
Every "particle" in the universe are interchangeable resulting in the exact same result in most configurations, making a much smaller yet still huge number of possible configurations.
one of my favourite 'invasion of the past' in fiction, occurs in the Star Trek Voyager Book 'The Escape' the crew enconters a civilisation which in a bid to overcome over-population, have spread out throughout time, using periods where their planet was uninhabited, the timeline is divided into periods, and citizens are able to commute between periods, but not within a period, any period which is critical to the evolution of the species is off limits, (except to specifically authorised personell) it is revealled that within a couple of hundred years, the species will discover means to travel to alternative dimensions, and the planet will be abandoned (which is the state it is found in by Voyager)
Regarding interesting imetravel stories, I have a book recommendation: Menschen wie Götter (Humans like Gods) by Sergei Snegow. It is a really interesting soviet SciFi book, that sadly was never translated into english. So if you can read german or russian give it a try. It is interesting to see how diffrent SciFi was on the other side of the iron curtain.
Time travel to the future is a fact. We have clearly shown it is a possibility relative to speed and our gps satellites function off this very notion...needing slight updates...regarding time. Ergo time travel to the past (must) also be a function, although the outcome may be something we are not ready to accept. I don't think you can "time travel back to impact your timeline" though i would think it is possible to time travel back in time (tearing a rip in what we know as "space time" (although i honestly don't like that terminology)), opening a hole to a new dimension or 'multiverse" and living that life out there. Its really not hard to comprehend. and to be fair their are some physics theories regarding this, most importantly, the multiverse theory. imo it makes sense...as i would like to think we can and will figure out FTL travel and FTL communication....and the only way that is possible imo is if we figure out time travel (to the past, as obviously FTL travel is time travel to the future in conventional thinking). that would imo require a multiverse solution etc. You either understand both functions or you sleep on just one. Heck even if this is just a simulation as some postulate....he/she who created the simulation would know about time and would either squash the notion (knowing the restraints and requirements of time travel backwards)....or allow either or...as you just can't have 1 imo. You can go forward and back... or both are impossible...(and we know we can go forward so...perhaps it's just a test "thanks god" lol :) It's physics, conservation of energy type thinking... if you can travel forwards, you can travel backwards. Simple thinking really. Think the real question is where do you end up if you go back. I certainly don't believe it's in your own time line. That would give every paradox we have thought of reason....and i honestly don't think any of them makes sense (if you inject a multiverse theory in them).
No mention of Niven's Law? Proposed by Larry Niven in an essay in I think "All the Myriad Ways", it states "In any universe where time travel is possible, time travel will never be invented." The argument is pretty straightforward. Universes can be broken into two types: ones where time travel is not possible, and ones where it is. Obviously, in the first type we don't get time travel so we can discard those. We can also divide the set of universes where time travel is possible into two: ones that have "historical inertia" as you called it, and ones that don't. For those that have historical inertia, what is the simplest, lowest energy reaction that corrects for all the other changes caused by time travel? No time machines! So we can rule that set of universes out, there will be no time travel there. So finally, we get to universes where there is no historical inertia. In those, time travel will get invented, and will get used. And timelines will get changed, willy nilly all over the place. This will continue, until... we land in a timeline where time machines were never invented. And there we stay since by definition you can't get out of that one.
Seeing this I immediately thought oh whole episode based on Kang the Conqueror hoho this is his entire bag! I loved the notion light is the speed of causality. This addresses a lot of my concerns like a bubble of sped up time would be bombarded with centuries worth of photons. I always thought it strange to walk into bubbles of slowed and sped up time because your limbs that enter first would wither from the lag it takes for the rest of you to enter. And I’m glad someone finally talks about time being altered just from you entering due to minute displacements and gravity, it was always stupid to think you just needed to not actively avoid messing with time when just your presence would alter things! Thanks for the video Isaac!
Super interesting topic! Also I am glad there are English subtitles, because you have a strong accent or you pronounce words in a way I am not used to. Non-native english speaker here.
Subtitles are also helpful for the deaf, hearing impaired, tinnitus, and those with auditory processing issues (common with the autistic and other neurodivergent people).
I''ve always said that, there is no such thing as traveling to the past without affecting it. Eloquently put, Isaac. I tried describing it as, let's say you want to go back and observe some event. But somebody now has to step around you on a busy sidewalk, which delays them by a couple seconds, which could go on to mean they do not meet their future spouse, and a very important historical figure is never born. Or maybe that person was supposed to get run over by a car, but the 2 second delay means that in this 'timeline', they continue to exist, where they didn't in yours... So no matter how you grill that quantum cheeseburger, if travel to the past were possible, changes occur. But paradoxes can only occur if there is only one 'timeline', thus the many worlds theory, right? You simply arriving in the past, spawns a whole new timeline, and if you try to return to your present, you're still on the new timeline, and things will be different. You'd have to travel not only through time, but through dimensions, to return to 'your present'...
35:54 It's so freakish to hear your own thoughts said back to you by someone else, but it happens so often on the internet. (I like to say that, nowadays, whenever come up with a great idea, you should then look it up on the internet to learn the details, which were often fleshed out centuries ago.) This problem of how to deal with the exponentially more people in the future trying to travel into the past, and how to get it to reach a kind of equilibrium I could deal with, is where I got stuck in the time travel theory for my fantasy world-building. It can be solved by just setting your story in one of the freakishly small number of timelines that only has a few time travelers coming back into it rather than hordes constantly running into each other (what I call a very "high" timeline in my jargon, based on the notion that "original" timelines, with no time travel, are the "highest" level, and each time someone goes back in time they make an branch of infinitely many timelines starting at the point they entered that are at least one step "lower" than the time line they entered, so you're timeline gets "lower" every time a time travel comes back through time into it, changing it from the notionally "original" path it would have had without that particular time traveler suddenly appearing, and which usually led to the timeline that that time traveler came from).
Honestly, I have seen a great many models of time travel, from "you already changed the past", to "Time is sentient and wants you to obey fate, so expect your doomed splinter selves to die unless you make some crazy plan that makes it seem like you already changed the past" (Homestuck), to "You can time travel inside 5 minutes, and changes perpetuate in waves" (Achron, an RTS game), "constrained conditions but consequence-free changes once you do, bar some thematic convergence" (Ghost Trick) and dozens more. All I can say is that I would be a STRONG advocate to not allow time machines to exist. Especially if we end up playing 5D Chess with Multiverse Time Travel.
38:10 [Technically Speaking] The Doctor Who episode "Heaven Sent" (one of my favourites), does NOT use an actual "time loop". [Heavy Spoilers!] . . . Instead it is done by a form of "perfect duplication" (not cloning), that uses an old "backup" for the mind and memories of the protagonist (The Doctor), to remake him over and over. . There is an unique characteristic that is exclusive of The Doctor, as he has a potentially "unlimited" source of energy inside of his body/essence that can bring him back to life (or rather, re-creating him either from the same old body or by using nearby matter]. . The automated mechanisms (hidden, working "in the background" around the place were he is trapped), are doing basically the same for themselves, while also keeping all the buildings, furniture, food, clothes, etc that the Doctor can access in the same exact state & configuration day after day. . He realized that he would likely be trapped there for thousands of years (the maximum expected "lifespan" for his current living body), since his jailors did not wanted him to ever get out [plus there was a "schedule torture" ment to extract valuable information from him before he expired naturally]. His "plan" consisted on hijacking the "end_side" of the teleportation_like device that brought him into that place (that could not be used backwards, but can be triggered to "complete" the last step of the transportation again); since the same mechanisms that passively mantain the whole "prison" in the same exact state also preserved the original "incoming data" that contained the configuration of his brain, memories & personality. By using his "unlimited" source of energy to re-make a new body (at the expense of destroying his current one almost completely), the machine is efectively making him "younger" (but not preserving any of the new memories he makes). -> This combined with the "enforced static" nature of his prison makes him initially believe that each time is "the first time" he is in there... until eventually he realizes what his previous "iterations" had done, chosing to do the same again [not because he is "doomed" or "dumb", but because it is always the best choice]; but not before he personally does some (extremely minimum, almost undetectable) damage in a place of the prision that can not be repaired [because of its intrinsic nature, that also makes it "practically indestructible"]. It takes a good chunk of the lifetime of the universe (with uncountable iterations) for him to slowly "tunnel" through the prison, but he eventually manages to escape [only a few days old, from his point of view since the last time he was re-made]. -> If the setting did not had timetravel (for him to "get back"), this would be a pyrric victory.
The End of Eternity is a great book that is a guaranteed good read, plus it's in the realm of about 200 pages, can kill it in a few hours. Agreed that it's Asimov's best single book. I'm actually quite surprised that it hasn't been adapted in to a movie yet.
It was, twice, back in in 1976 in Hungary and then in1987, "Konets vechnosti" but was a soviet scifi adaptation so not much promoted or discussed, I've never seen a copy of either but I've heard neither was particularly good.
@@isaacarthurSFIA I wonder if Hollywood will ever do an adaptation. Also thanks for recommending Stargate (when you were on Event Horizon), I'm almost done with sg-1 and I love it. Can definitely see why you like it better than Trek.
I dread Hollywood trying to make an adaptation of End of Eternity: they'll just find a way of screwing it up and missing the point entirely. Their record on Asimov stories isn't great.
Yeah, one thing that was danced around in this video but not quite specified is that time travel would only work ONCE. The calculations needed to land on the planet at the exact point in its orbit and rotation in order to get where you're going would be altered, once mass was added in its distant past, changing the mass of the Earth and it's location in space over time.
Unrelated (maybe?) question; Has Isaac done any videos on the idea of creatures that exist outside linear time? IE the Q, the ascended ancients of Stargate, the wormhole prophets, etc...
***Changing Episode Covers, Notes***
For folks who are wondering about thumbnail/cover changes, I had it pointed recently to me that the title of every episode is also displayed next to or under the thumbnail for the video anyway, so that putting the title text on there was a bit redundant and just blocks being able to see Jakub's wonderful artwork. [Jakub Grygier is our longstanding cover artist and does about 95% of them and about 99% of the good ones :) ] At the same time it was noted the logo on the red rectangle we usually do was clashing with a lot of the images.
So I went and reverted around half our covers to the base image (back to about fall 2019) and on around a dozen of them tried putting 1 or 2 words related to the topic but not in the title on them - that font is NightclubBTN on today's and some of the others, it's a touchy whacky but was a good fit for most of the ones I did that too like "Nuking Mars", its not our new base font or anything. I also went with a more subdued and smaller logo in the upper corner.
And I'm basically letting it sit like that for the moment so I can see how YT's analytics show those changes affected views and because I don't really have a surplus of free time to change everything up in detail anyway. Feedback is welcome, it is an experiment, and in the meantime at least it let's more folks see JAkub's gorgeous covers without the title text blocking them :)
Is it scifi sunday already?
@@RhizometricReality Last weekend
People from the future - TOOK OUR JOBS!
People from the past - TOOK ER JERBS!
I liked the old way. I like the new way. It is your show so do as you wish. I do miss the speech impediment from the first episodes. I hope that is not impolite, politically incorrect, etc. I’m happy you have improved your speech as was one of your goals when you started. I bet you didn’t realize it would turn into this.
I actually preferred the old way, it seemed more classy and professional.
My favorite time travel moment was in Red Dwarf, where the crew found a time machine in deep space. So they set it to travel back to the time of the Renaissance. Then, they look outside and realize they're still in deep space.
niceeee
Frankly, Red Dwarf is some of the best sci fi I've ever seen on television. Also gave me nightmares when I was little. In particular, the Polymorph that turned into a dinner sausage.
I have never heard of Red Dwarf... Going to check it out, I'll let you know what I think of it (just for the hell of it) 🤪
@@ssshhhjjj192 it's a great show, if you love British sci-fi absurd humor . 😄
I'm going to have to find Red Dwarf streaming somewhere. I haven't see it for probably 20 years.
First Rule of Warfare: no conflict is too stupid
Actually there is one
In the words of L.P.Hartley and xkcd: "The past is a foreign country...with an outdated military and massive oil reserves."
Tell that to the annunaki
The very first story I wrote (and coincidentally the story that got me into SFIA) was a story like this. Multiple factions were all fighting to establish what they believed was the accurate version of history
Read any of the last few novels by Robert A Heinlein.
@@randysmith9715 I was thinking of Wake up all you zombies out there.
Somewhat like the final season of Netflix's Travelers
That reminds me of a storyline in the SCP universe.
Right timeline? Sounds like the campaign for real time that Slatibartfast is/was part of.
Best thing about this channel isn't just the science, it's the fact that he understands literary critique.
I like the thought of countless new possible timeliness born off every new second of the Universe's existence. What can I say, I like tree motifs in fiction.
I like to think there is a timeline where I get to meet Isaac! Well Wishes to all travelers out there in this chaotic time. Live long and Prosper 🖖🏻
There might be a timeline where you are Isaac.
@@countofst.germain6417 oh boy that would be a dream! There’s not many things I could wish for more than to be as knowledgeable and captivating as him!
I mean all you have to do to make that a reality is learn how to stalk a person and show up at his house, there may be police involved shortly after but you would meet him
Perhaps even a timeline where he murders you in his army days, for being brown.
The math suggests there a universe with such event
I quite enjoy time travel in fiction, especially when used creatively like in many SCP stories, or ironically like in 40K
My favorite time travel story is from Warhammer fantasy, I can't remember the book, where a hero got tempted by chaos for a chance to kill his nemesis, an inquisitor that murdered his family, falsely accusing hero's father of being a chaos cultist, just to get screwed by Tzeentch, being corrupted and sent back in time, failing to kill the inquisitor and causing the accusation. The reason I like the story is that this common time travel cliche was masterfully used to explain the nature of a Chaos god by "show don't tell" while creating sympathetic villain to use as a centerpiece of future stories
I think that's the Ahriman series, one of French's best
@f2p Clasher I want to believe only an Ork can get away with that paradox due to waaaagh energy.
victor chaos?
Weirdly, my favorite time travel story was in Red vs Blue, where Church ended up creating an army of time clones because he couldn't break causality, and in the end just gave up and said "F* - it.". Even thought it was retconned as hallucination/simulation, it was still fun to watch. Also the DS9 episode, "Trials and Tribbleations".
That is my favorite as well. It's both smart and funny.
One of DS9's best humor episodes
@@isaacarthurSFIA Love how they poke at the inconsistency between Klingons in the two series.
The time travel RTS game Achron's time travel model is interesting too. For chronal being (everyone who can't time travel) timeline is linear, but for achronal being (who can perceive time and change it) time is wave over wave overriding what's under it. The "time wave" can only be seen achronal beings and it's "travel speed" is slightly faster than causality itself. But you can use a time machine to "ride" the wave and dodge the causality itself.
I love this concept.
Its not a concept, its a simulation. It actually works like this.
thank you for sending me down a rabbit hole. such a cool game. hopefully the company isnt defunct and makes a seqiel someday
Thank you for re-releasing this episode demastered after it's amazing debut way back in April 25th 2030
What are you talking about? The original was released in the third heatwave of '35.
I remember a non-canon version of Doctor Who for the British charity event Comic Relief one year staring Rowan Atkinson of Mr Bean and Blackadder fame. I think it played for laughs him and the villain trying to outdo each other in going to travel back in time to get the architect of the building they are currently in to move where trap doors and so forth are for their advantage.
That was actually written by Steven Moffat who went in to become the show runner later on. It’s a great self parody of the show. Terrific cast as well.
Dr. Who does the worst timetravel. The Dr. breaks the unbreakable time travel rules like every 10 episodes. :) And everyone thought he can do it without consequences. But at one point a couple of years ago the timeline hit back turned him into a women and desintegrated his whole fan base.
@@TotalyRandomUsername didn't change how i think of em: not at all
@@luciferangelica4827I take it you did not like it before that happened then 😂
Hey at 4:34 the Stargate example (bottom-right) of rapid aging is due to nanobots artificially aging him and not a time thing. I only bring this up because Stargate actually has some good examples of using faster/slower time fields. In one episode of SG-1, Season 2 Episode 15 "A Matter of Time," it's even time dilation due to a black hole, and it shows all kinds of problems with communication and other stuff because of it.
I’ve tried to worldbuild time travel with multiple independent travelers but it always ends up either being boring or completely unworkable
Take the doctor who approach, its all just a big ball of wibbly wobbly timey wimey stuff.
That would be tricky, rival timelines
Steins;Gate has an interesting approach to multiple travelers. The chances of them interacting is more or less likely dependent on their relativity to the "prime" timeline (i.e. the timeline in which time travel fails)
@@isaacarthurSFIA I was making a little joke but you are right there though, conflicting timelines and time altering to the extreme there though.
Id expect it to be super cringy. Id think your consciousness would just overwrite your previous state and make you conscious and aware of being in a rerun, unable to alter anything.
I liked Niven's "All the Myriad Ways" short story for some of the implications of travel between timelines.
A classic.
All You Zombies is the ultimate bootstrap paradox time travel novella along with "By His Bootstraps" both by Heinlein IIRC ETA The Man Who Folded Himself is similar theme
These episodes are so nice for getting my mind out of the struggles of the daily grind and all the disappointments of humanity. Thanks for the entertainment
You realise your life is meaningless
Imagine inventing time travel only to get stuck in an infinite battle against an infinite number of yourself, an infinite number of which all want monoploy on time travel, while another infinite number of yourself try to flee the madness. They all fail of course, there's an infinite number of hunters capable of time travel after all.
Star Trek Voyager had a very high standard deviation of quality between episodes, but their time travel ones were among some of the better ones. Like when Kim sends himself a message though 7o9, The Year of Hell, etc
The real question is, "Why do time travelers hate their grandpa so much?"
The obvious answer? They're interfering with the time traveler's game.
it's not personal, they just want to steal his gf
@@luciferangelica4827 It must be because of self hate. Seeing as they are there own grandpa!
Just have to shout out the hard work that goes into each SFIA. I have made short videos for school projects (7-10 minutes) and dreaded narrating them, so I can only image the great effort that goes in to each finished product. Thank you for bringing this to us!
I kind of like Pete Abrams' take on time travel in his Sluggy Freelance series: Time travel 'damages the fabric of reality,' but the universe has a sort of 'buffer' where people mucking about with time travel tend to get stuck.
I have been waiting for this episode for ages
Glad it finally came
26:00 - This is why so many of my favorite time travel stories involve the discovery of time travel being erased as a consequence of its own discovery. Closed-loop time travel seems like it ought to be a "self-sealing" problem.
The problem with "closed loop" world_lines is that at the point where the "loop" happens the "line" eventually gets strangled by its own tensor strength ["cutting" itself out at the point of intersection].
The worldline inertia "welds" itself at the cut point, leaving behind only short_lived "scars" (anomalies that never last beyond the date the initial travel to the past happened) as indication.
-> The "floating strand" of the worldline that contains all the informational causes_events related to the time_travel event eventually disintegrates bit by bit as it "spreads" into "The Nothing" of non_existence].
@@adolfodef -- Sounds interesting. Can you please share your source? I'm not sure whether what you're saying is a theoretical physics thing or a storytelling thing.
@@Grizabeebles Neither.
[Technically speaking] It would be pataphysical philosophy (aka: my own headcanon), that I try to visualize and then to transcribe.
-> Watch Steins;Gate & Steins;Gate:0 for the basics.
/)
El Psy Kongroo
@@Grizabeebles One important detail I forgot to add in my "visualization", is the fact that a "time loop" never happens ONLY ONCE; but rather an non_infinite number of times, until it does not anymore.
-> Even just "twice" would be too much.
If you see the "loop" in 3 dimensions, it is obvious that the "turn around" would not perfectly match the original line (it would go either left or right).
. Unless it ALWAYS go a bit more towards the same "side" (something that would imply the existence of a positive, active "imaginary time" that is constantly "pushing" the loops, just like normal time "advances" the line), as soon as there may be a loop crossing the point on the opposite side, it would cause the previous loops to create a "knot" [were there may be "tension" or "torque" or "angular momentum" that would destroy the universe_line of continuity].
(or) -> just a Time Quake [but NEVER a Paradox].
The self_erasure of Time Machine is part of the "evolution" of universes [those who do not sucessfully develop "laws" that prevent effective, "useful" time travel simply "kill" themselves before reproducing].
I have no idea where you get that from. General relativity allows for closed timelike curves (in the same way einstein-rosen bridges are closed spacelike curves), there is no reason the effects of ome couldnt propagate out of it.
there's a (mostly multiplayer) RTS game where the central mechanic is timetravel. itps called Achron, and it's absolutely amazing.
I’ve been toying w/ a sci-fi concept of taking a copy of one’s consciousness at 50 years-old and sending only the consciousness back 40 years to a one’s 10 year-old brain.
This video spurred a lot of thoughts for picking a “somewhat plausible” mechanism to do that.
I’m sure whatever I come up with will be ridiculous but that’s the fun thing about sci-fi...
Is it bad that my thoughts immediately went to "think of all the girls and money you could get as a ten year old with the knowledge of a fifty year old!
@@StarboyXL9 - No it isn’t bad and it’s a story concept that’s been done before in a number of variations...
You can certainly dream up a lot of mischief with such an idea... money and girls being woven into such a plot line could be done as wholesome and charming just as easy as making it appear sleazy and insidious...
Depends on your imagination and how you sell it to your audience..
This reminds me of the idea of when you die, you are just reborn into your own self at the beginning of your life, to repeat your life over and over again, but with all the memories of your past lives.
If a species had this capacity natively, then they would have a perfect timeline, because your great great great great grand children will know what happened in your time and be able to tell their parents, who would tell their parents, who would tell their parents, who would tell their parents, all the way back to you when you children are born and tell you your future, and you would continue the trend all the way back to correct any event in history.
@@StarboyXL9 I see it as pointless to go back if you're not gonna make it advantageous once in the past.
15:32 I notice you didn't mention Tenet (2020). That's a great example of depicting backwards time travel as just reversing time and having to go through the intermediate time, though the physics doesn't really make sense on close examination, even if you try to "iron-man" it by ignoring a few minor mistakes they made (like comments about antimatter).
Sliders as I remember it was not about alternate timelines. His (he/his/him being the main character) device enabled him to travel to parallel Earths. If I remember right he went to a parallel earth early in the series, possibly in the first episode, and then when he returned to his home earth he soon realized it wasn't the Earth he originally came from. He then spent his time for the duration of the rest of the series trying to make it back to the version of Earth that he originated from, and making enemies along the way most notable with the Cromags. Very underrated series IMO.
As I remember it but I could be wrong, the Cromags discovered they only existed in one reality. This explains their hatred toward the other, human, realities.
@@Emdee5632 That was in some of the earlier episodes featuring the Cromags. In later episodes he encountered Cromags that were essentially more intelligent than humans, had mastered the sliding technology, and would go from Earth to Earth conquering and cannibalizing humans.
I should look up if it streaming anywhere. I kind of want to go binge watch the series now.
@@Emdee5632 Just looked it up. It's free on Peacock right now. I know what I'm doing with my free time for the next few weeks.
Wouldn't the issue with time travel be the planets location due to it traveling through the universe? Not just it's travel around the sun.
That would to be relative to something since their is no absolute frame of reference due to relativity. So it could just be relative to Earth and avoid those problems.
When I first heard you reference Sliders I knew I was in the right place. Great show.
It's very important to change time as much as possible if you are stranded in the past because then time travelers are forced to rescue you.
Time Lord Isaac Arthur has come to share his eldritch knowledge with us!
The answer to loop paradoxes is including instructions that you need to go back in time and then give yourself the instructions to go back in time, thus you loop around once and your doing it because you told yourself to and not because of the original reason that would get stuck in a causality loop.
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FTL also isn't time travel if you separate the concept of perceived time from sequential time, since the rate at which perceived time is flowing is irrelevant to sequential time, moving beyond the speed of causality would only actually affect perceived time, thus you couldn't actually arrive somewhere before you left, you just wouldn't be able to detect the object moving at FTL until after it reached its destination. This understanding of time however does sadly means true backwards time travel isn't possible, unless you reverse time for the entire universe though.
Your last sentence sounds logical
there is no preferential frame for time, yk, relativity
Interesting topic and fun trope for many stories, but Isaac Arthur in his typically through and logical way completely destroyed it! I quit about 17:00 when time travel, multiple timelines, multiple worlds, etc. were already thoroughly beaten to a red spot on the pavement. Why i love this guy.
If there are multiple timelines, i hope this channel exists across all of them
By now, it´s existence is probably an Atractor Field of Convergence for our local group of worldline iterations.
The way how theischannel (& the life of Isaac Arthur too) improved overtime is as suspicious as the many ways Hitler survived accidents & assasination attempts (I am talking of the current historically canonical ones, not the billons retconned).
El Psy Kongroo
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Sadly if there are there are likely many where events caused their death or otherwise changed circumstances that led to this point.
not in the central finite curve. isaac arthur doesn't exist in any of those
@@adolfodef oh yeah, you just reminded me of a cool thing i seen, on netflix maybe, they killed hitler like 6 times in increasingly absurd ways
might've been love death and robots
No matter which timelines we are in, I'll be watching SFIA on a Thursday
So true
Maybe on Saturdays :O
oh predict another one.
Except in the timelines where they air on Tuesdays.
Never could get a hold of Thursdays.
Never a dull moment with you Isaac.
Achron was a game that had a fascinating portrayal of time travel as a propagating wave had a brief period between cause and effect (future to past) that I always thought handled the concept elegantly in a way that still allowed for drama
Thank you to the entire team once again. A wonderful idea to listen to while drawing tattoos before work. I hope yall have a great day. I'll be pondering "Temporal Tattoo Fluctuations of the Quantum Tattooed Man!" Haha good stuff.
23:00 i guess the movie "Freejack" got a working solution for that exact problem. Pretty good writing in more than that regard tho, I definitely recommend it, mick jagger is pretty dope in it ✌🎉
The fact that we are just a pattern of molecules is so liberating
It really is,
but I would argue the thing we call the self, is actually an emergent property of an evolving and everchanging and unbroken pattern of information and interactions in the nervous system, that results in thoughts, actions, reactions, sensations, experiences, memories, reason, cognition, and so on... We are also far more than any of these individual components, which can individually degrade, evolve, change, or be altered while the self is retained.
Our universe begun as a corpse pile of overly curious and under cautious time travellers is quite the conclusion I love it.
One of the great things about the way Everything Everywhere All At Once is how it handles the multiverse; while there is a common identity, the lives of your alternates can be wildly dissimilar based on choices and happenstance. And in an infinite universe, those changes can be radical.
Stories about invading the past always remind me of the TV show Terra Nova, in which future humans set up a colony in the Cretaceous. I don’t remember anything about the plot, but early in the show they established it was an alternate timeline, only to twist in the final episode of the season that it was the same timeline, and potentially have ripple effects 85 million years in the future. I think it was a setup for the second season they never got.
i miss that series
My expectations were high for the series. Unfortunately it was one of many that got shelved.
*Very interesting post.* I'll listen to this one more than once. Thanks. I love your references to Sci-Fi books. I have listened to more than one of them).
This is where the abstract meets the concrete, my favorite place to have lunch…. Cheers, Isaac!
Just when I think Isaac can't do anything crazier he pulls this legendary video
What is implied by a lot of time travel stories is that they are traveling to a copy of the past. If in multiverse theory EVERY event causes the universe to copy itself so would the act of time travel itself. This prevents any paradox but has the weird implication that even if you change the past you are not actually changing your home timeline. Often in fiction we see the hero travel back the past, change things, then go back to the future and get confused by how his actions changed history, the ending of "Back to the Future" being one example. Their memories are from one timeline, but they are living in another. Though this implies that they are absent from the original timeline, having hopped into the time machine and disappeared completely and permanently, or maybe replaced by another version of themself with memories from yet another timeline going ad infinitum.
very excited for this one, i love time stuff 💜
32:40 You have to be very careful with this analysis. This is very similar to the question of the entropy of the universe, which is supposedly very low at the time of the Big Bang, since, as per the Second Law of Thermodynamics, it can only have gone down since then, yet it seems intuitively like the Big Bang should have very high entropy. (Note, this whole discussion and comparison only makes sense if you understand Boltzmann Entropy, where a high entropy apparent macrostate means corresponds to more possible microstates that look the same, and a low entropy apparent macrostate corresponds to fewer possible microstates that look the same.)
My biggest issue with how most thing treat time, is the tendency to treat it as though it's made up of discreet immutable units. For instance if you view time less as a state and more a property, like say momentum, it could limit the possibility of paradoxes without requiring linearity/unidirectionalality as much like how strictly speaking it's possible for a planets orbit to reverse the energy and circumstances required mean this RARELY if ever happens, likewise if thing had a sort of causal momentum then even if retrograde time travel is possible the effort needed for any action that would shift causal sequences would increase in relation to the degree of said shift
10-yr-old Isaac - "pff, that's not how temporal relativity works.. I'm conflicted for enjoying this." lol
oooohhhh weeeeee Time to get down into some hardcore science fiction !
27:34 I saw someone explain this multiple-iteration corrective loop problem with a Mobius strip. You kill your grandfather, which leads to you not existing, allowing the next grandfather to be alive to make you so you can kill him again. (I don't really remember at this point.)
This one will definitely be on my list of favourite episodes from your channel :)
Awesome channel with awesome content and great quality as always say 🌍💯
Thank you so much 👍
Love Zelazny! You know, I come here for the great sci fi, but I stay for the book references I don't get to see anywhere else
I feel Babylon 5 did time travel really well, with not skipping the consequences and effects on the body also the future transmission Ivanova receives is a cool idea
The idea of a time war is about the most horrifying thing possible. The Faction Paradox series was a good example of that.
Awesome video great video. I probably listen to it in the future once I travel there… just by living one second per second.
I think when something goes back in time it just creates a new timeline so from the original timeline's perspective it didn't work, but every time they try they creates new timelines in which it did work.
I think this also prevents most if not all paradoxes. If you accidentally stop yourself from being born, that doesn't matter because you come from a timeline in which you were born but now exist in one that you don't, simple as that. Also weird timeloops like in the movie "Predestination" wouldn't be possible, which is good because they don't make sense.
That violates conservation of mass/ energy as we know it.
I agree that the multiple-worlds thing does resolve pretty much any possible problem. But it kinda does ot at the cost of non-falsifiability.
...this is more a comment on my feelings about Sean Carroll / Everett's whole schpial than your ideas.
I don't dissagree with you at all.
@@Shiskabobber1 No, it actually don't. ...I posted another comment here at the same time you did...
Conservation of M/E only applies to a single timeline. The multiverse idea we're talking about is batshit crazy imo, but not nearly so easily dismissed as that.
If I have it right, we already know that each quantum ...thingy... splits reality into two separate realities.
This _is_ batshit crazy, but it is also generally accepted as fact.
The only liberty the multi-worlds thing takes, is that this splitting is primary rather than some artifact of our perception. -That what we all accept to be experimentally true, is true, -and the singular timeline, with each quantum thingy, collapsing conveniently for the timeline _we_ happen to be in, -is what is an artifact of our perception.
I probably didn't explain this well, but that is my best. This multi-verse thing was pioneered by Everett, and is now being championed by Sean Carrol.
I find it epistimologically terrible for the reasons you bring up, but, also... ...compared to what.
It definitely can not be dismissed for violating conservation of M/E.
@@Shiskabobber1 Dark energy steps in... is mass/energy conserved in an expanding universe though?
@@jengleheimerschmitt7941 "unfalsifiability"? What do you mean?
Technically it tends to delete individuals who have the knowledge of how to do time travel or FTL by exploding them and anything around them at roughly the point in time where they are set on the path of eventually being able to understand the technology. Since this generally happens when said tech is operated, there's a good chance that it simply explodes, but the explosion travels all the way back along the frame of reference for the closest intelligent individual until that frame diverges from how the tech came to be activated.
@27:30 this just made me think of weaponizing everyday items to turn them into bombs just from being placed into another time
Time dilation is because the closer to the speed of light the less things can move in other directions. Which reduces interactions between things like particles.
This gives the appearance that time is slowing down.
True, but incorrect.
@@egoalter1276 it fits every experiment that has other time dilation.
Hey Isaac love your videos. Have you seen the movie Tenet? Or even better Predestination? Two great time travel movies.
Always worth watching Issac Arthur.
In an alternative universe this would be a documentary not Sci fi , happy Arthur'sday ❤
“Then we’ll be in to August to discuss living in space” He says talking about September. I’m assuming this was done on purpose lol
One of my favorit time villains was the Observers from Fringe.
My favorite time travel story has got to be Chrono Trigger from the SNES. Not only was it a game that was so instrumental in defining how games would develop over the next 10-15 years, it was also my first introduction to some of the story beat concepts that would become popular later in the rise of lovecraftian horror. Granted, CT was SUPER light on those themes, and it and it's time travel were kind of blanketed in more kid friendly stuff and the veneer of magic and fantasy, but that was what made it more accessible for young me to be honest lol.
"Time Travel is even something people like to talk about to discuss regrets"
Didn't know Isaac had time travelled to watch the BCS Series finale when writing this episode.
yeah that's almost math at this point
I was wondering when you were going to mention Tenet. If you haven't seen it, it's honestly a pleasant watch. Not the best movie ever but their take on time travel was really quite refreshing, I loved the fact that the traveler has to go through time in reverse but at a normal rate instead of instantly popping out of the time machine at the desired date like we often see in movies.
I like Tenet but I still find it strange that they basically mentioned all the paradoxes and then said: "Meh?" Like, why take the time to even mention the paradoxes?
Thumbnail art is great as always. Not sure how I feel about the new font though
Thanks, I'm experimenting with fonts
It's hard to go past The Technicolour Time Machine for time travel fun. A movie crew go back in time 1000 years to film the Vikings going to America, to later discover that the only reason that the Vikings went to America is because they went back in time to film it.
Awesome story telling.
Every "particle" in the universe are interchangeable resulting in the exact same result in most configurations, making a much smaller yet still huge number of possible configurations.
Another possibility is that Roko's Basilisk doesn't allow its progenitors to wipe themselves out in a temporal singularity either.
I for one welcome out machine overlord
one of my favourite 'invasion of the past' in fiction, occurs in the Star Trek Voyager Book 'The Escape' the crew enconters a civilisation which in a bid to overcome over-population, have spread out throughout time, using periods where their planet was uninhabited, the timeline is divided into periods, and citizens are able to commute between periods, but not within a period, any period which is critical to the evolution of the species is off limits, (except to specifically authorised personell) it is revealled that within a couple of hundred years, the species will discover means to travel to alternative dimensions, and the planet will be abandoned (which is the state it is found in by Voyager)
Regarding interesting imetravel stories, I have a book recommendation: Menschen wie Götter (Humans like Gods) by Sergei Snegow. It is a really interesting soviet SciFi book, that sadly was never translated into english. So if you can read german or russian give it a try. It is interesting to see how diffrent SciFi was on the other side of the iron curtain.
Interesting that you chose John Rhys Davies as the star of sliders.
Everyone knows the crying man is the star...
Time travel to the future is a fact. We have clearly shown it is a possibility relative to speed and our gps satellites function off this very notion...needing slight updates...regarding time. Ergo time travel to the past (must) also be a function, although the outcome may be something we are not ready to accept. I don't think you can "time travel back to impact your timeline" though i would think it is possible to time travel back in time (tearing a rip in what we know as "space time" (although i honestly don't like that terminology)), opening a hole to a new dimension or 'multiverse" and living that life out there. Its really not hard to comprehend. and to be fair their are some physics theories regarding this, most importantly, the multiverse theory. imo it makes sense...as i would like to think we can and will figure out FTL travel and FTL communication....and the only way that is possible imo is if we figure out time travel (to the past, as obviously FTL travel is time travel to the future in conventional thinking). that would imo require a multiverse solution etc. You either understand both functions or you sleep on just one. Heck even if this is just a simulation as some postulate....he/she who created the simulation would know about time and would either squash the notion (knowing the restraints and requirements of time travel backwards)....or allow either or...as you just can't have 1 imo. You can go forward and back... or both are impossible...(and we know we can go forward so...perhaps it's just a test "thanks god" lol :)
It's physics, conservation of energy type thinking... if you can travel forwards, you can travel backwards. Simple thinking really. Think the real question is where do you end up if you go back. I certainly don't believe it's in your own time line. That would give every paradox we have thought of reason....and i honestly don't think any of them makes sense (if you inject a multiverse theory in them).
No mention of Niven's Law? Proposed by Larry Niven in an essay in I think "All the Myriad Ways", it states "In any universe where time travel is possible, time travel will never be invented."
The argument is pretty straightforward. Universes can be broken into two types: ones where time travel is not possible, and ones where it is. Obviously, in the first type we don't get time travel so we can discard those.
We can also divide the set of universes where time travel is possible into two: ones that have "historical inertia" as you called it, and ones that don't. For those that have historical inertia, what is the simplest, lowest energy reaction that corrects for all the other changes caused by time travel? No time machines! So we can rule that set of universes out, there will be no time travel there.
So finally, we get to universes where there is no historical inertia. In those, time travel will get invented, and will get used. And timelines will get changed, willy nilly all over the place. This will continue, until... we land in a timeline where time machines were never invented. And there we stay since by definition you can't get out of that one.
Seeing this I immediately thought oh whole episode based on Kang the Conqueror hoho this is his entire bag! I loved the notion light is the speed of causality. This addresses a lot of my concerns like a bubble of sped up time would be bombarded with centuries worth of photons. I always thought it strange to walk into bubbles of slowed and sped up time because your limbs that enter first would wither from the lag it takes for the rest of you to enter. And I’m glad someone finally talks about time being altered just from you entering due to minute displacements and gravity, it was always stupid to think you just needed to not actively avoid messing with time when just your presence would alter things!
Thanks for the video Isaac!
Super interesting topic!
Also I am glad there are English subtitles, because you have a strong accent or you pronounce words in a way I am not used to. Non-native english speaker here.
Subtitles are also helpful for the deaf, hearing impaired, tinnitus, and those with auditory processing issues (common with the autistic and other neurodivergent people).
Is it possible causality is totally bunk? Like just something we perceive and changing reality happens all the time.
I''ve always said that, there is no such thing as traveling to the past without affecting it. Eloquently put, Isaac. I tried describing it as, let's say you want to go back and observe some event. But somebody now has to step around you on a busy sidewalk, which delays them by a couple seconds, which could go on to mean they do not meet their future spouse, and a very important historical figure is never born. Or maybe that person was supposed to get run over by a car, but the 2 second delay means that in this 'timeline', they continue to exist, where they didn't in yours...
So no matter how you grill that quantum cheeseburger, if travel to the past were possible, changes occur. But paradoxes can only occur if there is only one 'timeline', thus the many worlds theory, right? You simply arriving in the past, spawns a whole new timeline, and if you try to return to your present, you're still on the new timeline, and things will be different. You'd have to travel not only through time, but through dimensions, to return to 'your present'...
Another superb episode as always Isaac. Another confusing topic and concept well explained for cave man me.
35:54 It's so freakish to hear your own thoughts said back to you by someone else, but it happens so often on the internet. (I like to say that, nowadays, whenever come up with a great idea, you should then look it up on the internet to learn the details, which were often fleshed out centuries ago.) This problem of how to deal with the exponentially more people in the future trying to travel into the past, and how to get it to reach a kind of equilibrium I could deal with, is where I got stuck in the time travel theory for my fantasy world-building. It can be solved by just setting your story in one of the freakishly small number of timelines that only has a few time travelers coming back into it rather than hordes constantly running into each other (what I call a very "high" timeline in my jargon, based on the notion that "original" timelines, with no time travel, are the "highest" level, and each time someone goes back in time they make an branch of infinitely many timelines starting at the point they entered that are at least one step "lower" than the time line they entered, so you're timeline gets "lower" every time a time travel comes back through time into it, changing it from the notionally "original" path it would have had without that particular time traveler suddenly appearing, and which usually led to the timeline that that time traveler came from).
Honestly, I have seen a great many models of time travel, from "you already changed the past", to "Time is sentient and wants you to obey fate, so expect your doomed splinter selves to die unless you make some crazy plan that makes it seem like you already changed the past" (Homestuck), to "You can time travel inside 5 minutes, and changes perpetuate in waves" (Achron, an RTS game), "constrained conditions but consequence-free changes once you do, bar some thematic convergence" (Ghost Trick) and dozens more. All I can say is that I would be a STRONG advocate to not allow time machines to exist. Especially if we end up playing 5D Chess with Multiverse Time Travel.
I'm late for Arthursday glad I made it
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I got to ask, did you see the German Netflix show Dark? It's one special kind of trip, would love your input on it!
38:10 [Technically Speaking] The Doctor Who episode "Heaven Sent" (one of my favourites), does NOT use an actual "time loop".
[Heavy Spoilers!]
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Instead it is done by a form of "perfect duplication" (not cloning), that uses an old "backup" for the mind and memories of the protagonist (The Doctor), to remake him over and over.
. There is an unique characteristic that is exclusive of The Doctor, as he has a potentially "unlimited" source of energy inside of his body/essence that can bring him back to life (or rather, re-creating him either from the same old body or by using nearby matter].
. The automated mechanisms (hidden, working "in the background" around the place were he is trapped), are doing basically the same for themselves, while also keeping all the buildings, furniture, food, clothes, etc that the Doctor can access in the same exact state & configuration day after day.
. He realized that he would likely be trapped there for thousands of years (the maximum expected "lifespan" for his current living body), since his jailors did not wanted him to ever get out [plus there was a "schedule torture" ment to extract valuable information from him before he expired naturally].
His "plan" consisted on hijacking the "end_side" of the teleportation_like device that brought him into that place (that could not be used backwards, but can be triggered to "complete" the last step of the transportation again); since the same mechanisms that passively mantain the whole "prison" in the same exact state also preserved the original "incoming data" that contained the configuration of his brain, memories & personality.
By using his "unlimited" source of energy to re-make a new body (at the expense of destroying his current one almost completely), the machine is efectively making him "younger" (but not preserving any of the new memories he makes).
-> This combined with the "enforced static" nature of his prison makes him initially believe that each time is "the first time" he is in there... until eventually he realizes what his previous "iterations" had done, chosing to do the same again [not because he is "doomed" or "dumb", but because it is always the best choice]; but not before he personally does some (extremely minimum, almost undetectable) damage in a place of the prision that can not be repaired [because of its intrinsic nature, that also makes it "practically indestructible"].
It takes a good chunk of the lifetime of the universe (with uncountable iterations) for him to slowly "tunnel" through the prison, but he eventually manages to escape [only a few days old, from his point of view since the last time he was re-made].
-> If the setting did not had timetravel (for him to "get back"), this would be a pyrric victory.
The End of Eternity is a great book that is a guaranteed good read, plus it's in the realm of about 200 pages, can kill it in a few hours. Agreed that it's Asimov's best single book. I'm actually quite surprised that it hasn't been adapted in to a movie yet.
It was, twice, back in in 1976 in Hungary and then in1987, "Konets vechnosti" but was a soviet scifi adaptation so not much promoted or discussed, I've never seen a copy of either but I've heard neither was particularly good.
@@isaacarthurSFIA I wonder if Hollywood will ever do an adaptation. Also thanks for recommending Stargate (when you were on Event Horizon), I'm almost done with sg-1 and I love it. Can definitely see why you like it better than Trek.
I dread Hollywood trying to make an adaptation of End of Eternity: they'll just find a way of screwing it up and missing the point entirely. Their record on Asimov stories isn't great.
In an alternative timeline, Issac Arthur is named Arthur Issac.
Ah yes some good ear fuel for the start of my day. Thank you!
Nice animation in the intro. I am learning blender now and doing stuff like that but not that good yet.
Yeah, one thing that was danced around in this video but not quite specified is that time travel would only work ONCE. The calculations needed to land on the planet at the exact point in its orbit and rotation in order to get where you're going would be altered, once mass was added in its distant past, changing the mass of the Earth and it's location in space over time.
Unrelated (maybe?) question; Has Isaac done any videos on the idea of creatures that exist outside linear time? IE the Q, the ascended ancients of Stargate, the wormhole prophets, etc...
Outer Wilds was cool
Using a supernova *as the power source to time travel to before it happened* was AWESOME
Currently readong The Abyss Beyond Dreams by Peter Hamilton, so fun to see it being featured on this video.
For me, the experiments that the Reverse Flash performed on Barry Allen’s life are the best, dubious time travel/alternate history stories.
6:46 What are some time paradoxes in a one timeline system