Transcription
[Music] so chuck it seems like we've done this before but you can't do it too many times and it's it's the number one lesson against traveling back in time. what you don't realize neil is that we've actually done this a hundred times before. i see what you did there. yeah, did you see that? yeah, okay, i see what you, i see what you did there.
so if there were a rule book of time travel, the number one item would be: you cannot go back in time and prevent your parents from meeting each other because then you would have never been born to have gone back in time to have prevented your parents from meeting each other. this is the fundamental paradox of time travel. and so that if there were a rule book, that'd be number one rule.
right, here's what movie people get wrong, or they don't get it wrong, they don't think it all the way through. so what's the most famous of these movies where they can't have somebody get born? what's his face, uh, the boy that with the hoverboard and uh, no, no, no, no, not that one. that has other rules. you're not supposed to break. down the whole thing was you gotta get your parents to smash because if they don't, you're not born. oh, right. but that was gonna happen anyway, he just can't mess it up. oh, right. okay, okay, okay. the point is, don't go back and stop. oh, terminator, because you got to stop, you got to stop.
"okay, i am looking for sarah connor. i was told that she was here." or "your name is sarah connor? i'll kill you anyway, no matter what." and killed every surrogate, killed every serotonin. okay, so here's the thing. so yes, you wouldn't have a terminator movie if the terminator's sole job was to prevent sarah connor from becoming pregnant. okay, that's a different movie from killing systematically every sarah connor in the phone book, right? so, and he didn't have to do that. he could go one generation earlier and prevent the grandparents from eating, or prevent the great-grandparents from eating, or the great-great-great parents. i mean, anywhere in that genetic chain, if you disrupt it, then you are not born. and so introduce the great-great-grandmother to a much better looking guy, and you just have a better looking time traveler. there you go. this is like [Laughter] [Music] that's a different terminator movie, right? exactly.
so, so i'm just saying, these people think they're on some loctite theme when the theme is way broader than that. in fact, uh, forgive me for not remembering which movie this was, it'll come to me in a moment, where they realized that if two people, if if two people had sex 10 minutes later than they otherwise did, then a different sperm fertilizes, likely the same egg, and that's, but it's nonetheless a completely different person. wow. so even if you don't disrupt the sex, just delay it. make the train come a little later, make the, you know, uh, have the the cup of coffee be extra delicious so they get a second cup before they, or or the wine, whatever is the romantic forces operating that evening. make sure they have other kids because that will stop you from ever being able to do it again. i mean, five other kids are running around like, you got to do, you know. this is just like, i mean, that's what i found out during the pandemic, you know, you in the house, you'll be late, man. we've been here for a while. what are we gonna do? every time you try to disappear, they show right up, knocking on the door. what are you guys doing? what's going on in there?
okay, so that's a time travel movie, never, never conceived. see what I did there? very nicely. let's see what you did there. it's you're trying to prevent the parents from having sex. they're not having it anyway. that's it. because they've got five kids running upside down, bouncing off the walls. that's the other kids. just like now, in popular parents, it's called the grandfather paradox, but it's a paradox to any one of your ancestry because disrupting that chain will prevent you from being born. someone else could be born. now, now you can, you can introduce a more interesting idea that maybe the forces of the timeline care about major events, even in spite of you changing minor events. that'd be an interesting fact, right? i, i, i don't really agree with that idea, but it'd be an interesting sci-fi.
so is that kind of like inevitability? so it's like, even though you change these minor things, the inevitable will still happen, correct? so it could be that, you know, you killed the some ancestor of yours, so you don't exist, but somebody else arises in the life of the other partner because you just have to kill one of the partners, right? that creates some other person who basically does exactly what you were gonna do in your life, right? so it's not you, but the larger scale events still unfold. and my favorite example of this, which involves no killing at all, is if you could communicate backwards through time. we have a hypothetical particle that does that. you know what it's called? you never hear, no. it's called the tachyon. oh, tachyon. okay. tachyon. and it's, uh, i think it's from the greek tacticos, meaning fast. yeah, the tachometer. it's the same route. the tachometer, which gives you the the the speed of your engine, uh, if you're still having an rpm car. yeah, yeah, the rpms, that's a tachometer. so we have this hypothetical part, it's never been observed, but we sort of introduce it. it's called a tachyon. it exists moving faster than the speed of light. and as you may remember, chuck, as you go faster and faster and faster, your time slows down relative to everybody else, right? at the speed of light, time stops. but what happens if you cross the speed of light? then time goes backwards, according to the equations. so we are imagining if you could ever accomplish this, time would go backwards for you. so we introduced this particle, it's called tachyons. so now you have a tachyon texting smartphone. okay? and your buddy's walking down the corridor, and you see your buddy slip on a banana peel and fall. and you say, i don't want my buddy to slip on a banana peel and fall. so you pull out your tachyon text message service and you say, watch out for the banana peel. you send it to them after this event has already happened, but they receive the text before it happens, right? you got this because it moved backwards in time, right? okay. so then what happens is they're walking down the corridor, and then the text alert happens. okay? so they pull out their smartphone and start reading the smartphone, and it says, watch out for the banana peel. but the very fact of having pulled out the smartphone and looked at it meant they weren't looking down in that moment, and they slip on the banana, they slip on the peel. so you caused the very event that you thought that you were avoid, uh, preventing. correct. correct. and that's another inevitability scenario that where it would declare that there's nothing you can do about it.
in fact, in h.g. wells's time machine, uh, half the movie is weirdly in a future that he had no clue that he thinks would happen. but the first part of the movie, the protagonist goes back in time, and he has a love interest. he meets in the park, but then she gets mugged and get and killed. and he's very upset about this. he said, well, i got a time machine. let me go back and make sure that doesn't happen. it goes back and says, don't walk this way, walk that way. so she walks the other way, crosses the street, gets hit by a bus. okay, right. and then she, so three or four ways he's trying to save her life, and then she dies every single time. and he concludes it was her. it was it was her time. that is amazing. i, you know what, i didn't remember that part of that. yeah, i never read the book. i actually saw the movie. um, that was only the two movies. there's original, you know, from the 50s or 60s, and then one more recently in the 90s. yeah. so, but, um, what you just described is a marvel multiverse, um, doctor strange, not the movie. this was an animated where dr. strange is in love with a woman who dies, and he finds ways to keep going back in time and manipulating the timeline, and she dies in every single timeline. and so he loses his mind. he he goes insane because he can't figure out how to save her.
well, okay, so there's another one of these inevitability things. so we don't, we don't know. we don't know. for me, the fact that you existed in a past time, displacing air molecules, you might have stepped on a worm or an ant in the street. to me, that's changing the timeline, right? so you'd be cherry-picking all the possible, all the things that you caused and saying, well, this, this one is more important than the rest. but what's the molecule say, dude? you pushed me out of my way. i was like there, and now i'm not there. that's a different universe as far as the molecule is concerned. it's like, so you go back in time, right? and you land at a cookout, and you slap a mosquito on your neck. but that mosquito was actually on its way to bite someone else. that would have done the same thing. and by slapping their neck while they were driving a car, they ran into a tree and they died. and that person ended up being a dictator who eventually took over the entire world. chuck, i don't know where it is. i don't know where this story is going. neil. [Laughter] help me out, neil. what happens? i'll help you out. i'll, i'll help you out. there is a story where someone goes back in time, warned not to affect, not to touch anything, right? don't touch it. and then he comes back and says, i didn't touch anything. and the scene ends as his foot is up on his knee, and there's a dead butterfly in the bottom of his foot. oh, man. and everyone, and we're all nazis because of that butterfly. so if there was some air-currented cause that created a monsoon and a tsunami and a hurricane and whatever. so that's, it's called the butterfly effect in reference to that scene. oh, cool.
but anyway, this all started talking about the grandfather paradox, which could easily be a grandmother paradox. there's no reason you have to specify gender in this. it's an ancestry paradox. is oh, man, you just gave it a new, um, term. another accessory. yeah, let's do it. that's that's so much better. the ancestry paradox, because it works anywhere in your entire timeline. that's right. yeah, you got it. all right, chuck, it's all the time we have. this explainer. absolutely. that's by the paradise. now all we have is time. long as we don't touch nothing. as long as we don't touch nothing. all we got is, i'm teaching you too much. see, if you, you think you know, and then you only know some, but you think you know all. that's dangerous too. all right, this has been another star talk explainer. the other guy section. always good to have chuck. always a pleasure. [Music]