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How Time Travel Works (Live at SD Comic-Con) · Stuff You Should Know

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Speaker 1: Brought to you by the reinvented two thousand twelve Camray.
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Speaker 1: It's ready. Are you welcome to stuff you should know
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Speaker 1: from house Stuff Works dot com. Hey, and welcome to
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Speaker 1: the podcast pre rap. I guess it's what you call that,
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Speaker 1: a right, Chuck? Yeah, sure, prolog Forward is a good one. Um.
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Speaker 1: I'm Josh and that's Chuck, and we are introducing a
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Speaker 1: live podcast that we recorded in San Diego just a
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Speaker 1: little while ago. Wait, July twelve, I think I don't remember.
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Speaker 1: I believe it was the twelfth of July. It was
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Speaker 1: great fun though. At common Con. Yeah, it was a
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Speaker 1: big deal. Um, there were people who waited in line
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Speaker 1: to get in. Some of those very people didn't get
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Speaker 1: in got turned away to see us. That was weird.
0:55
Speaker 1: All those people were sorry for the people that came
0:58
Speaker 1: that weren't fans of the show, and if you happen
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Speaker 1: to be listening now, then welcome and thank you for
1:03
Speaker 1: coming just out of interest. That was pretty weird, you know,
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Speaker 1: to see people They're like, I don't know who these
1:09
Speaker 1: guys are, but it sounds interesting. Those were the three
1:12
Speaker 1: people who had their arms crossed in front of their chests. Yeah,
1:17
Speaker 1: expectantly and then disappointed. Um, so we're gonna just kind
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Speaker 1: of get into this. If if anything seems out of
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Speaker 1: place or you're freaked out by people laughing, just remember
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Speaker 1: it's the recording of a live podcast. Jerry did a
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Speaker 1: great job recording it, and um, so here's us doing
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Speaker 1: time travel at Comic Con two thousand twelve. But those,
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Speaker 1: if you don't know, we have a podcast called stuff.
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Speaker 1: You know, it's on a website called how stuff dot com,
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Speaker 1: our beloved website, and pretty soon we are going to
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Speaker 1: be on the Science Channel too in January. Right, Um,
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Speaker 1: time travel, Yeah, let's do Time Traveler. Everybody ready to
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Speaker 1: learn a little bit about time travel. We're just gonna
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Speaker 1: do our thing. We're recording this live. Everybody, say hi
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Speaker 1: to everybody who's not here. For fans of the show,
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Speaker 1: we have our producer, Jerry is actually here. I want
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Speaker 1: to say hi Jerry. Alright, brass tacks, Jerry, did you
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Speaker 1: press record yet? Okay? So we are recording kid alright,
2:24
Speaker 1: so um chuck, gosh, have you ever heard of a
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Speaker 1: guy named Andrew Basaguel? I never know what to say
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Speaker 1: here because I do, But should I say now? Just
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Speaker 1: say maybe? Maybe? Okay? So let me tell you a
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Speaker 1: little bit about this guy. All right. He's a Seattle attorney.
2:42
Speaker 1: Oh I know this guy, Okay, And ever since two
2:46
Speaker 1: thousand four has been talking publicly about how he was
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Speaker 1: part of something that he says it was called Project Pegasus,
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Speaker 1: which was supposedly a DARPA initiative for time travel. Yeah,
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Speaker 1: the U. S. Government was using children because apparently children
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Speaker 1: were specifically suited for time travel, which I didn't know
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Speaker 1: more so than adults. We should say that this guy
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Speaker 1: is the only source for this information. That's kind of
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Speaker 1: a big qualifier, very much. Um. But so he does
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Speaker 1: have a pretty good story, like Um. Throughout the seventies,
3:17
Speaker 1: from age seven to twelve, he uh did a lot
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Speaker 1: of Lincoln assignments. I guess he traveled to Gettysburg at
3:24
Speaker 1: one point, um, where he was captured in a famous
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Speaker 1: Josephine Cobb photograph. And I went and looked, and I
3:30
Speaker 1: mean it could be him. It's really blurry photographs. There
3:34
Speaker 1: were several guys, but it was from eighteen sixty three,
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Speaker 1: so they didn't know what they were doing back then. Um.
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Speaker 1: And then he also traveled a Ford Steater several times,
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Speaker 1: where at one point he ran into another version of
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Speaker 1: himself from another time that had traveled back there for
3:48
Speaker 1: that same night the Lincoln assassination, by the way, so um,
3:52
Speaker 1: and all of this, by the way, was based on
3:53
Speaker 1: technology that was made from schematics found among the personal
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Speaker 1: effects um of Nikola Tesla, that's who died in New York.
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Speaker 1: So supposedly the US government ransacked the department, came up
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Speaker 1: with us bill these time portals. Now, far be it
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Speaker 1: from me to cast this persions on another person's story,
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Speaker 1: Chuck in. My motto is to each his own always. Yes,
4:14
Speaker 1: we should like clink swords when we say um. But
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Speaker 1: I would buy this guy's story a little more if
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Speaker 1: he said that he was traveling to the future. Because
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Speaker 1: after researching for this presentation it's doing a little bit
4:27
Speaker 1: of time travel research, I found that there are a
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Speaker 1: lot of bona fide, legitimate physicist cosmologists who say that, yes,
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Speaker 1: it is entirely possible to travel to the future, and
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Speaker 1: we kind of do it every day. It's pretty exciting.
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Speaker 1: It's just yeah, it's it's true. Do you want to
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Speaker 1: talk about it now? Yeah? You know, Josh, there's an
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Speaker 1: old joke in the scientific community, in the time travel community,
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Speaker 1: about a Let me see if I get this right
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Speaker 1: about an immigrant who comes to the United States las
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Speaker 1: I would, I imagine, and he lost he lost his watch.
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Speaker 1: It's really sad. And he goes up to a science
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Speaker 1: tis and he says, please, what's this time? I don't
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Speaker 1: know what country that is. That's that's a general maybe
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Speaker 1: European act. Okay, he's European. And the scientist replies, I'm sorry,
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Speaker 1: you'll have to ask a philosopher. I'm just a physicist.
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Speaker 1: Kind of a silly joke, a good time travel scientists.
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Speaker 1: This kills it in lab rooms, but it is a
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Speaker 1: silly joke, but it really gets to the heart of
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Speaker 1: the matter. When you're talking time travel, it is very
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Speaker 1: much a philosophical question, and it is Uh, if time
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Speaker 1: flows like a river, like some people think, in one direction, Uh,
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Speaker 1: the question is can you stop that flow, can you
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Speaker 1: reverse that flow? Can you go back in time? Or
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Speaker 1: can you speed up the flow and go forward in time?
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Speaker 1: That's kind of the question. Yeah. I find it hardening
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Speaker 1: to see like physicists and philosophers getting along having a
5:48
Speaker 1: beer talking about time traveler having their brains melt together. Um,
5:54
Speaker 1: and you were talking about time flowing like a river.
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Speaker 1: Can I talk about my boy Stephen Hawking? Yeah? Sure,
6:00
Speaker 1: Do we have any Hawking fans in here? Same here?
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Speaker 1: I love that guy. Yeah, he's my Hawking is my homeboy. Um.
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Speaker 1: Stephen Hawking was talking about how he wrote this this
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Speaker 1: really great article or essay or whatever you want to
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Speaker 1: call it for the Daily Mail of all people, UM
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Speaker 1: about time travel, and then he talks about time as
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Speaker 1: a river. He says, it's very poetically. It's like a
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Speaker 1: river because it flows in one direction, you know, and
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Speaker 1: we're all just kind of going along with it. But
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Speaker 1: it's also a bit like a river in that UM
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Speaker 1: in different spots, it travels at different speeds, and if
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Speaker 1: we can figure out how to exploit those different spots,
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Speaker 1: then we can get to like the brass texts of
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Speaker 1: time travel. Yeah, Hawking basically thinks you can travel into
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Speaker 1: the future. All you have to go is really really,
6:46
Speaker 1: really really fast. And we're talking, uh, I think the
6:50
Speaker 1: stat is the fastest thing ever was Apollo ten yea
6:56
Speaker 1: thousand miles an hour. That's very very fast. If you
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Speaker 1: want a time travel wall, Hawking says, you need to
7:01
Speaker 1: go two thousand times faster than that. That's really fast
7:05
Speaker 1: man interject something. Sure, I actually did the math, and
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Speaker 1: Hawking got his math wrong way tim from what he
7:13
Speaker 1: goes on to say that you need to get very
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Speaker 1: close to the speed of light. You have to go
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Speaker 1: like twenty thousand times more, not two thousands. So I
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Speaker 1: just corrected. Homeboy been hawking and it's math. And I
7:27
Speaker 1: hope he doesn't hear this because there will be a
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Speaker 1: SmackDown afterward. I'm sure be like, oh, you know math,
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Speaker 1: huh well. And one of the big problems with going
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Speaker 1: that fast is fuel. In order to go that fast,
7:37
Speaker 1: you need a humongous ship that can carry fuel enough
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Speaker 1: to travel. I think he said six years, like ramping
7:44
Speaker 1: it up speed wise, right, And that's not very likely
7:47
Speaker 1: at least any time. You would need the seed ship
7:50
Speaker 1: to go towards the speed of light, accelerating constantly for
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Speaker 1: six years. And then like the fourth year you'd started
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Speaker 1: time travel, could you hit speed of light which is
8:00
Speaker 1: like six d million miles an hour pretty fast? Um?
8:03
Speaker 1: And then I think at that point time goes um
8:06
Speaker 1: an hour on the ship equals two hours back on Earth,
8:10
Speaker 1: so you're starting to travel into the future relative to
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Speaker 1: the Earth. Right. Then after another two years, you get
8:15
Speaker 1: to like the speed of light, which is like six
8:18
Speaker 1: hundred and sixty. That's when like a day, is it
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Speaker 1: a day? A day on the ship equals like a
8:26
Speaker 1: year on Earth, which okay, then that's that's time travel.
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Speaker 1: It's that's very very fast. And if you turned around
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Speaker 1: and went back to Earth, you could be like, check
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Speaker 1: me out, I'm from the past. Because really, this is
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Speaker 1: another thing I figured out from from researching. This is
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Speaker 1: time travel is really it doesn't matter if you don't
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Speaker 1: have anyone to show it off to, Like you can
8:46
Speaker 1: go travel out and outer space as long as you
8:48
Speaker 1: want and live forever. But if no one's there to
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Speaker 1: see it, who cares? You know? Exactly the philosopher's exactly. Yeah,
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Speaker 1: So you go ahead. Are we at Carl Sagan or yeah, okay,
9:03
Speaker 1: that's always a great question to ask, are we at
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Speaker 1: Carl Sagan? So Carl Sagan, who's my homeboy, has a
9:09
Speaker 1: viewpoint that sort of body slams the skeptics of the world.
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Speaker 1: And I know there are skeptics, and skeptics like to
9:16
Speaker 1: unite and tell people things a lot with great vigor,
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Speaker 1: but I am not one. I've always been more of
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Speaker 1: a molder than a scully you know what I'm saying,
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Speaker 1: And uh yeah, thank you for that. And here's what
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Speaker 1: Carl Sagan has to say, because basically what skepticals say is, well,
9:33
Speaker 1: if you can dime travel, then why aren't we always
9:35
Speaker 1: visited by time travels all the time? That's skeptics. That's
9:39
Speaker 1: what skeptics sound like. I think we just said a
9:42
Speaker 1: skeptical form there than and Dunning, he's gone. Uh So
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Speaker 1: Carl Sagan has this to say about gonna read it
9:48
Speaker 1: because I cannot summarize it any better than he says it.
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Speaker 1: He says, first of all, it might be that you
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Speaker 1: can build a time machine to go into the future
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Speaker 1: but not into the past, and we don't know about it,
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Speaker 1: but couzy, because we haven't yet invented that time machine.
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Speaker 1: Little brain melting, but it makes sense. Secondly, it might
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Speaker 1: be that time travel into the past is possible, but
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Speaker 1: they haven't gotten to our time yet. They're just really
10:13
Speaker 1: far into the future. And the further back in time
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Speaker 1: you go, the more expensive it is. That when I'm
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Speaker 1: a little bit like a little economics into it. Uh.
10:23
Speaker 1: And then thirdly, maybe backward time travel is possible, but
10:27
Speaker 1: only up to the moment that time travel is invented,
10:30
Speaker 1: so we haven't invented it yet, so it can't come
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Speaker 1: to us. We are s o l So that is like, yeah,
10:37
Speaker 1: you need to be drinking something to understand that. Uh
10:41
Speaker 1: so No, not really, not really. He's just saying like
10:43
Speaker 1: maybe there's like a like you just can't go back
10:46
Speaker 1: beyond the point where time travel is invented. He's just
10:49
Speaker 1: being a rabble rouser. And the final thing he says
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Speaker 1: is there's a possibility that time travel is really perfectly possible,
10:55
Speaker 1: but it requires such a great advance on our technology
10:58
Speaker 1: that the human civil is Asian will destroy itself before
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Speaker 1: they can invent it. That's the gloom and Doom one exactly.
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Speaker 1: But and segands raising all these points to say, like,
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Speaker 1: you know, if somebody's saying, if time travel is possible,
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Speaker 1: where are all the time travelers? And he's saying, hey,
11:12
Speaker 1: hey man, keep an open mind. That's what he used
11:15
Speaker 1: to say. And put on this turtleneck, right, let's all
11:18
Speaker 1: just wear turtlenecks. Everyone will mellow out. And I like
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Speaker 1: Carl Sagan. And there was one other thing about um
11:23
Speaker 1: hawkings view. He made a good point where if you
11:27
Speaker 1: aren't a show off, and you don't need to time
11:29
Speaker 1: travel just to impress your friends in the future. Um,
11:33
Speaker 1: you could use the same ship that's going super super
11:37
Speaker 1: fast towards the speed of light to just go to
11:39
Speaker 1: other parts of the Milky Way. It would come in
11:41
Speaker 1: handy very much for these long distance trips. Right. So, UM,
11:45
Speaker 1: say you wanted to make it to the iryan Nebula,
11:47
Speaker 1: you could do this several foul goption Chucks come in, Man,
11:53
Speaker 1: you hear something, Joshing Chuck, come in this time pilot
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Speaker 1: John Hodgman speaking to you from the future. Hey, Hogy,
12:07
Speaker 1: she probably shouldn't be talking to me because I can't
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Speaker 1: hear you. This is a time message. It only goes
12:12
Speaker 1: in one direction backwards, and I'm not even sure that
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Speaker 1: I reached you. It all depends on if I got
12:16
Speaker 1: the time coordinates correct time coordinates by the way, just
12:20
Speaker 1: latitude and longitude and altitude and time. But listen, Josh
12:25
Speaker 1: and Chuck, if you're getting this message, I need you
12:27
Speaker 1: to do something. Things have gone horribly wrong and this
12:30
Speaker 1: time stream and it's all because of something that happens
12:33
Speaker 1: at comic conve that you are intimately involved with. Basically,
12:38
Speaker 1: you piss off John Sweden because you's already pressn't so
12:42
Speaker 1: I urge you look at a picture of John Sweden
12:46
Speaker 1: and don't piss him off, because if you do, he
12:48
Speaker 1: gets so angry and he hates podcasts and then he
12:51
Speaker 1: becomes a dictator and and stops making movies. But if
12:56
Speaker 1: you recognize him, I guarantee you he will make um
13:02
Speaker 1: another season of Firefly completely. Also, Josh and checked that
13:07
Speaker 1: person in the Wookie costume is not a Wookie. H Okay, Well,
13:11
Speaker 1: I hope that fixes everything. It's really not good here
13:15
Speaker 1: in the future, so I hope you can fix it.
13:18
Speaker 1: I also hope that this message went to my time
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Speaker 1: stream in the past and didn't get booted off to
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Speaker 1: another multiverse, in which case is this is reaching you
13:27
Speaker 1: in a different multiverse. Watch out for the flood and
13:30
Speaker 1: ghostly piranha um. They will eat your face off. All right,
13:34
Speaker 1: I've got to go. It's all the time I have
13:39
Speaker 1: so to speak. Time pilot John Hodgman from Unnamed Future
13:43
Speaker 1: signing off goodbye and wow, I was a guy. He
13:50
Speaker 1: is always looking out or you never know when the
13:53
Speaker 1: future John Hodgman is going to pop in. Does anyone
13:56
Speaker 1: know what Joss Wheden looks like, Okay, we need to
13:59
Speaker 1: pick later. He's not here. Is anyone going to the
14:02
Speaker 1: firefly panel? Yeah, you better go get in lined right
14:06
Speaker 1: after this? Yeah, which we should we talk about methods
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Speaker 1: of time travel? Maybe? Oh yeah, go ahead. Okay, So
14:17
Speaker 1: if you're talking time travel, which we are, Uh, there
14:20
Speaker 1: are two directions. You can go go into the future
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Speaker 1: or you can go into the past. I'm a past guy.
14:26
Speaker 1: I'd always like to see the Old West. You were
14:28
Speaker 1: going to see Old West? Well, I just want to
14:30
Speaker 1: be a gun slinger. Yeah, and we're less right. But
14:36
Speaker 1: if you want to advance into the future, here's what
14:38
Speaker 1: you're gonna have to do. You're gonna have to exploit uh, spacetime,
14:42
Speaker 1: which isn't the easiest thing in the world, but it's possible.
14:44
Speaker 1: It actually happens every day up in the sky with
14:48
Speaker 1: GPS satellites. I don't know that guy's nodding, he knows, uh,
14:52
Speaker 1: But many of you may not know that these satellites
14:55
Speaker 1: actually a crew an extra third of a billionth of
14:58
Speaker 1: a second every day. It doesn't sound like much, but
15:01
Speaker 1: it's time trouble and it's kind of cool. And the
15:04
Speaker 1: reason this happens is time passes faster in orbit. Uh.
15:08
Speaker 1: Down here on Earth. Basically, Earth is like a big
15:11
Speaker 1: dope st Bernard like dragging on time, and all the
15:15
Speaker 1: mass on Earth is just slowing down time in little
15:18
Speaker 1: tiny increments. Out there in deep space, you don't have
15:20
Speaker 1: to worry about that kind of thing. And that's called
15:22
Speaker 1: gravi gravitational time dilation, and it's a real thing. Uh,
15:27
Speaker 1: and we observe this all the time scientists. Two astronomers
15:29
Speaker 1: do UH. When they see light in deep space. They'll
15:33
Speaker 1: see light moving in uh in a straight line, and
15:37
Speaker 1: if it gets close enough to a sufficiently large object
15:41
Speaker 1: like say Sagittarius A, which have which has the mass
15:46
Speaker 1: of four million sons, time will actually bend and they
15:52
Speaker 1: see this, and it's called the gravitational lensing effect. So uh,
15:55
Speaker 1: if you were to, let's say, travel to Sagittarius A
15:58
Speaker 1: and circle it is black hole and if you don't
16:01
Speaker 1: fall in, which would be bad, Actually it might be
16:03
Speaker 1: pretty cool. It would be really what would be bad.
16:05
Speaker 1: There's a word for it, like what happens to you
16:08
Speaker 1: kind of It's called spaghettification, like the the infinite density
16:14
Speaker 1: of the center of a black hole. Just finge you
16:16
Speaker 1: out into a spaghetti version of yourself that is not
16:19
Speaker 1: alive anymore. Could use that actually would be a good look. So, um,
16:24
Speaker 1: if you were to be able to circle sagittaries a
16:26
Speaker 1: for a little while, uh without falling in, you would
16:30
Speaker 1: experience time at half the rate on Earth, which is
16:33
Speaker 1: time trouble again, and you come back to Earth and
16:35
Speaker 1: you show off for everybody. Yeah, and that's basically the
16:38
Speaker 1: center of this sagittary, say, is a really super dense point.
16:41
Speaker 1: It's called a singularity. But don't confuse that with the singularity,
16:45
Speaker 1: two very different things. That's a that's another big future problem. Yeah,
16:49
Speaker 1: I'll be in big trouble at the singularity. Yet, Can
16:51
Speaker 1: I throw out some of my favorite, um, please, universal
16:55
Speaker 1: cosmic anomalies? So Chuck was talking about a black hole. Um,
17:00
Speaker 1: one of my favorites is called the carring or curring.
17:03
Speaker 1: We can't figure out how you say it. Honestly, we looked,
17:06
Speaker 1: We really looked, so probably for the rest of the
17:09
Speaker 1: time when I say it, I'm gonna say curring or carring, Okay, okay, um.
17:14
Speaker 1: And basically, this is like a black hole that forms
17:16
Speaker 1: from a lot of neutron stars that have collapsed, and
17:19
Speaker 1: neutron stars are about the size of Manhattan, but they
17:23
Speaker 1: have like the mass of our sun, so they're super dense,
17:26
Speaker 1: and a bunch of will form into this ring that
17:28
Speaker 1: kind of turns into this whirlpool um and because of
17:31
Speaker 1: the centrifugal force of these things, they're a singularity doesn't form.
17:35
Speaker 1: Hence spaghettification doesn't befall you when you go through the
17:39
Speaker 1: center of these things. But it's still a black hole, right.
17:43
Speaker 1: They think that if you go through, though, it's a
17:45
Speaker 1: one way ticket because probably on the other side is
17:47
Speaker 1: what's called a white hole, which is the opposite of
17:50
Speaker 1: a black hole, and it pushes light and matter out
17:53
Speaker 1: away from it, so there's no way of getting back.
17:55
Speaker 1: But it's still possible that you can travel through time
17:58
Speaker 1: at the very least to another part of space. Yeah. Right,
18:02
Speaker 1: So you want me to tell you about another one, Well,
18:04
Speaker 1: this next one is my favorite. Oh, the the Einstein
18:07
Speaker 1: rosen Bridge, which wow, that got applause. Yeah, and here
18:12
Speaker 1: comes the rest also known as a wormhole. Yeah, but
18:16
Speaker 1: everyone calls it a wormhole because like you couldn't have
18:19
Speaker 1: a TV show called Through the Einstein rosen Bridge with
18:22
Speaker 1: Morgan Freeman. I guess you could. But through the wormhole
18:26
Speaker 1: with Morgan Freeman is like catchy, right, it's sexy. It
18:28
Speaker 1: is very sexy, super sexy. Um. And so an Einstein
18:33
Speaker 1: rosen bridge or a wormhole. Uh, it's it's kind of
18:35
Speaker 1: actually easy to grasp if if you consider time or
18:39
Speaker 1: space spacetime, it's like a flat sheet that you fold
18:43
Speaker 1: it in half and you left some space in between, right,
18:46
Speaker 1: and then you have a sheet if you want to demonstrate,
18:48
Speaker 1: do you I like this? Uh? And then gravity is
18:51
Speaker 1: pushing towards the center, towards this empty space in the middle.
18:54
Speaker 1: So if you have the sheet like that and you
18:55
Speaker 1: put like a baseball on either side, these depressions are
18:59
Speaker 1: going to form that are kind of akin to um,
19:01
Speaker 1: the bending of time time delation, gravitational time delations thing.
19:06
Speaker 1: And if the depressions that they form connect, you've got
19:09
Speaker 1: a wormhole. Boom. Yeah, and you may be able to
19:12
Speaker 1: travel through this. No one knows for certain, but it's
19:15
Speaker 1: this kind of like the physicist or at the point
19:17
Speaker 1: now where they're like, oh, and there's also this other
19:19
Speaker 1: weird thing and maybe you can travel through time and
19:21
Speaker 1: that is that what they say, that's kind of what
19:24
Speaker 1: they say. But so, Chuck is an Old West kind
19:27
Speaker 1: of time travel guy. I like time travel of the
19:29
Speaker 1: past two UM. I tend to think the time travel
19:32
Speaker 1: of the future is the one we're gonna accomplish first.
19:36
Speaker 1: But the reason most physicists pooh poo the idea of
19:38
Speaker 1: traveling back in time is because paradoxes our eyes. And
19:43
Speaker 1: when a paradox arises, usually that means like the point
19:46
Speaker 1: is moot, Like you can't argue it any further with
19:48
Speaker 1: a learned person. Yeah, we uh. This is a point
19:51
Speaker 1: where we talk about something called causality. And everything we
19:54
Speaker 1: know here on planet Earth, as I say, is based
19:58
Speaker 1: on and in a time sense, it's based on cause
20:00
Speaker 1: and effect, and it's a one way street. Something happens
20:03
Speaker 1: first and that leads to something that happens after. You
20:05
Speaker 1: can't have something. You can't have an effect without the cause, right,
20:09
Speaker 1: And it's a one way street going then in that direction,
20:12
Speaker 1: cause effect, cause effat, cause effects cause out and you
20:15
Speaker 1: have um. One of the big, great famous paradoxes is
20:19
Speaker 1: the grandfather paradox. Right, the status of all paradoxes, which
20:22
Speaker 1: is it kind of demonstrates Yeah, this bums Chuck out
20:25
Speaker 1: because the grandfather is like, it's like, what the grandfather
20:28
Speaker 1: do you know? Um? But let's say that you went
20:31
Speaker 1: back to kill your grandfather, right, you're an assassin. Maybe
20:34
Speaker 1: you'll do anything for money, a looper if you will.
20:37
Speaker 1: And uh, And you go back and you you walk
20:41
Speaker 1: up to your grandfather and you shoot him and kill
20:43
Speaker 1: him dead. But this is the vision of your grandfather
20:45
Speaker 1: before he's conceived your father. Therefore you can't possibly exist. Therefore,
20:51
Speaker 1: how could you get back to time travel in the
20:53
Speaker 1: first place to kill yourself? That's so sad, it is,
20:56
Speaker 1: said the grandmother. Paradox, that's where you go back. And
21:02
Speaker 1: they couldn't call it that they did. They tried it
21:03
Speaker 1: and they were like, go back and kill your grandmother?
21:05
Speaker 1: Are you serious? They're like, can you just call a
21:09
Speaker 1: grandfather at least because maybe he hits you once or something.
21:13
Speaker 1: You know, at the very least he made you mow
21:14
Speaker 1: the lawn for a nickel or something. Yeah, grandmother just
21:17
Speaker 1: caddles you and pet you chicken and pie or at
21:20
Speaker 1: least mine. Did you miss you miss Granny Bryant? Don't
21:24
Speaker 1: you do? Um? Although she lived to be a hundred
21:26
Speaker 1: I know that's a right hold age. That's a right
21:28
Speaker 1: poled age. Um, that's called a sidebar. There's also so
21:34
Speaker 1: that's a that's an inconsistent uh, inconsistent cause of loop night.
21:39
Speaker 1: My favorite is the consistent cause a loop. Yeah, this
21:42
Speaker 1: is pretty cool because it's paradox free, which means it
21:45
Speaker 1: could actually happen. And there's a physicist named Paul Davies
21:49
Speaker 1: who describes it like this. Let's say a math professor
21:52
Speaker 1: travels into the future and steals this really valuable math theorem.
21:56
Speaker 1: Then he goes back to the past and he gives
22:00
Speaker 1: theorem to a student, and that student ends up growing
22:02
Speaker 1: up to be the very person he stole it from.
22:05
Speaker 1: Everyone's going pretty awesome. No one dies in paradox free, right.
22:11
Speaker 1: My favorite example of this, though, is, um, well, we
22:14
Speaker 1: have a special guest here named Brian who's gonna help
22:17
Speaker 1: us with this. Come on up here, Brian. Everybody give
22:19
Speaker 1: Brian a round of applause. So this is Brian. He's
22:28
Speaker 1: going to read to us an example, an explanation of
22:32
Speaker 1: probably the coolest example of a consistent causal loop. So Brian,
22:39
Speaker 1: will you take it away? Probably the best demonstration of
22:44
Speaker 1: a consistent causal loop is found in the film Back
22:46
Speaker 1: to the Future. Towards the end of the movie, Marty
22:49
Speaker 1: McFly performs Johnny be Good on his guitar during the
22:52
Speaker 1: enchantment under the Sea Dance. His playing catches the attention
22:56
Speaker 1: of one Marvin Barry, cousin of the famed musician Chuck Berry.
22:59
Speaker 1: His interest, Pete Marvin calls Chuck Berry to alert him
23:02
Speaker 1: to this unusual sound, which prompts we must assume Chuck
23:05
Speaker 1: Berry to write and record Johnny Be Good. But since
23:08
Speaker 1: he is from the future, we must assume that Marty
23:10
Speaker 1: McFly learned to play the song Johnny Be Good in
23:13
Speaker 1: his own time based on the song recorded by Chuck
23:15
Speaker 1: Berry years in the past. This is impossible, however, because
23:19
Speaker 1: it was Marty McFly's performance of Johnny Be Good that
23:21
Speaker 1: prompted its creation. This paradox, where the origination of a
23:25
Speaker 1: thing comes as the result of time travel, violates the
23:28
Speaker 1: law of causality a truly important lie. Indeed, it's true
23:32
Speaker 1: that we could have also cited the Pocket Watch and
23:33
Speaker 1: the Christopher Reave movie Somewhere in Time as an example,
23:36
Speaker 1: but Back to the Future was a way better movie.
23:40
Speaker 1: All right, right, very much time, Nicety Good? Thanks well down,
23:44
Speaker 1: to and then the final possibility, uh is my favorite one,
23:51
Speaker 1: which is many worlds, parallel universes. You can times. I
23:55
Speaker 1: saw some head nods. People love that one because he
23:57
Speaker 1: can time travel all over the place. Man, And you're
23:59
Speaker 1: just create separate timelines and you're in many different sandboxes,
24:03
Speaker 1: and it just doesn't even matter, right because if you
24:05
Speaker 1: go back and kill your grandfather in another version of
24:08
Speaker 1: the universe where you weren't born, who cares? Who cares? Man,
24:12
Speaker 1: because I'll just go in another timeline. Do you know
24:15
Speaker 1: why are you talking like that? Because that's what they
24:17
Speaker 1: hit these like, Man, Yeah, are you do you want
24:21
Speaker 1: to stumma? I guess in summation. You know, we certainly
24:25
Speaker 1: don't know if it's for sure possible, but I think
24:28
Speaker 1: it's important to ask these questions. You know, with people
24:30
Speaker 1: like Stephen Hawking and Carl Sagan and sixth century philosophers
24:35
Speaker 1: are talking about slowing down time and speeding up time,
24:37
Speaker 1: then it's worthwhile to me, agreed, And that's a That
24:42
Speaker 1: is our presentation on time travel. Thanks so um, I
24:56
Speaker 1: think we're about out of time unless we have a
24:59
Speaker 1: few minute for Q and A. Do we one question?
25:04
Speaker 1: Let's do one question? Let's do too quick. Your hand up,
25:08
Speaker 1: there's a microphone right there. Nice rocket. Have either of
25:11
Speaker 1: you ever wanted to be on Celebrity Jeopardy so you
25:14
Speaker 1: could just smoke them? Thank you? I would love to
25:19
Speaker 1: be on Jeopardy. I don't know if we qualified for
25:21
Speaker 1: Celebrity Jeopardy yet, but I used to sit around in
25:25
Speaker 1: college all the time and play with my roommates. Uh
25:28
Speaker 1: and I did pretty well. I thought. I think that
25:31
Speaker 1: the X factor is whether or not you freeze on TV.
25:34
Speaker 1: So one more, one more bam in the hat in
25:39
Speaker 1: the back baseball hat. You just yeah, yeah, yeah, yeah,
25:45
Speaker 1: thank you for John. Hello. H question, do you are
25:50
Speaker 1: you guys gonna like do books like you know, how
25:52
Speaker 1: do you have the little books so and all this stuff?
25:54
Speaker 1: Are you gonna like release those eventually or do you
25:57
Speaker 1: plan on it? We have two audio books which are
26:01
Speaker 1: like books, but they're way easier than um. But yeah,
26:07
Speaker 1: that's stuff. We've definitely talked about that before, like we're
26:10
Speaker 1: still trying to figure out what the idea would be
26:12
Speaker 1: behind it, but um, yes, we're definitely not opposed to that.
26:15
Speaker 1: So look for in like maybe yes, we get all
26:18
Speaker 1: time job there right now exactly so um, let's see.
26:21
Speaker 1: If you want to get in touch with us, you
26:22
Speaker 1: can tweet to us on s Y s K podcast,
26:25
Speaker 1: you can visit us on Facebook dot com, and you
26:28
Speaker 1: can always send us a good old fashioned email by
26:30
Speaker 1: wrapping it up, spanking it on the bottom and sending
26:33
Speaker 1: it off to Stuff Podcast at Discovery dot coms and
26:39
Speaker 1: very much everybody for more on this and thousands of
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