Speaker 1: Welcome to Stuff to Blow your Mind from how Stuff
Speaker 1: Works dot com. Hey you welcome to Stuff to Blow
Speaker 1: your Mind. My name is Robert Lamb and I'm Julie Douglas.
Speaker 1: And today we're talking about tidle lock which is we're
Speaker 1: discussing earlier sounds like it would have been like an
Speaker 1: awesome lady surfers in prison movie from like mid nineties
Speaker 1: cinematic tidal Lockdown. Yeah, title Lockdown. They were rebels on
Speaker 1: the board and they paid dearly beneath the sea something
Speaker 1: like that. Yeah, yeah, yeah, that's I like the ided
Speaker 1: to mention that's an underwater prison. Yeah yeah, yeah, yeah,
Speaker 1: it's wind so difficult to break out off. But now
Speaker 1: we are not talking about that wonderful film idea. What
Speaker 1: we are instead of talking about title locking in terms
Speaker 1: of the way our planets and the ware Moon's gravitate
Speaker 1: around other objects. Yeah, and how it actually affects the
Speaker 1: planets um and the stars and the moon's And if
Speaker 1: you think about the Moon and the Earth, for instance,
Speaker 1: the moon is tidally locked to the Earth. We look
Speaker 1: into the night sky and we always see the same
Speaker 1: side of the moon, the same face, the same face
Speaker 1: of the moon and the Moon's backside is always facing
Speaker 1: away from us. Uh the dark side of the moon,
Speaker 1: if you will, even though it's not technically dark all
Speaker 1: the time because it gets sunlight as well, it's just
Speaker 1: we never see it. It's it's tidally locked to us,
Speaker 1: not to the Sun. If we were tidally locked to
Speaker 1: the sun. Uh I, if an objects were titally locked
Speaker 1: to the Sun, it would be a different scenario where
Speaker 1: only one side of the planet would receive sunlight and
Speaker 1: the other side would be cast in perpetual darkness. Yeah,
Speaker 1: but for us, this is a very stable arrangement right
Speaker 1: right as having the moon tidally locked to us and
Speaker 1: the man the moon just bean that that same face
Speaker 1: that we see every night, and presumably his his hind
Speaker 1: quarters on the other side. Yeah. The Moon, of course
Speaker 1: is rotating like it's It's important to note it's not
Speaker 1: that the moon is motionless up there, but it completes
Speaker 1: one rotation about its axis in the same time it
Speaker 1: takes to complete one orbit around the Earth. So it's
Speaker 1: it's just lined up perfectly. It's there's a synchronicity and
Speaker 1: in the way these these worlds are moving and meanwhile
Speaker 1: we're just you know, turning to run our access going
Speaker 1: hey son and getting day and night right right, And
Speaker 1: the title inners it because the synchronization is caused by
Speaker 1: strong tidal forces from the Earth that effectively lock the
Speaker 1: moon's orientation. And it's really interesting to know that it
Speaker 1: wasn't always like this. The rotation has sort of set
Speaker 1: in over time, which I think is pretty fascinating. That's right.
Speaker 1: The gravitational poll has has changed the rate of the speed,
Speaker 1: I should say, of our rotation. But this has happened
Speaker 1: over millions and millions and millions. Yea. And there of
Speaker 1: course other moons that have a similar situation going, and
Speaker 1: you see a lot with moons. If we look all
Speaker 1: the way to the edge of our solar system to
Speaker 1: the Planetoi Pluto, you'll find that it has a little
Speaker 1: moon called sharone Um or Sharon, however you want to
Speaker 1: say it. My Dante teacher always such Sharon. Yeah, Salva Maria.
Speaker 1: If anyone anyone at Tense University of tennessee Knox Fall
Speaker 1: and wants a good Italian Dante teacher, h check up
Speaker 1: old Steal anyway, So Sharon's or a bit around Pluto
Speaker 1: takes six point for earth days and one Pluto rotation
Speaker 1: takes six point four earth days. What's interesting here is
Speaker 1: that sharone neither rises nor sets, but basically hovers over
Speaker 1: the same spot on Pluto's surface all the time. So
Speaker 1: it's like a really extreme example of tidal locking. Yeah,
Speaker 1: and this again happens with moons, but it also is
Speaker 1: very common that it happens with stars as well, red
Speaker 1: dwarf stars most commonly. So a planet gets locked into
Speaker 1: or rather I should say, yes, the planet gets locked
Speaker 1: into the star's orientation, and that changes everything for the planet, right,
Speaker 1: because if you are just facing one side of the sun,
Speaker 1: you would never experience day and night like we do.
Speaker 1: One side would constantly be in darkness while the other
Speaker 1: side would constantly be in light. There are various old
Speaker 1: folk tales where like they'll be like a maiden whose
Speaker 1: task with a job like she has to before the
Speaker 1: sun comes up, she has to finish knitting a scar
Speaker 1: for ori. Generally it's something a little more complex, like
Speaker 1: draining an entire pond with a straw or a spoon
Speaker 1: or something that sounds just like those old folk tales are. Yeah,
Speaker 1: it's always some ridiculous task. And then like a good
Speaker 1: fairiy or something will come along and turn back the clock.
Speaker 1: In real life, there would be just catastrophic consequences because
Speaker 1: the cycle of night and day is vital to the
Speaker 1: way our weather works, but the way that the Earth
Speaker 1: as we experience it works. I mean you have one side,
Speaker 1: you have daylight regions heating up, you have night regions
Speaker 1: cooling down, you have airflow moving back and forth. I mean,
Speaker 1: it's all part of the system. There's an article on
Speaker 1: house the work's called How Weather Works that I happen
Speaker 1: to write. But it is a good job of taking
Speaker 1: some of the very simple elements of night and day
Speaker 1: and using that as a starting point for understanding how
Speaker 1: global weather operates well and also how it affects every
Speaker 1: living organism. Right, And we take that for granted sometimes
Speaker 1: because of course the sun rises in the sunsets um
Speaker 1: and we we live and die by this configuration. But
Speaker 1: you know, they're they're of at the other configurations going
Speaker 1: on in the universe. And the question is what does
Speaker 1: this look like? And if you did have this sort
Speaker 1: of configuration where it was only day only night on
Speaker 1: one half of the planet, would there be opportunities for life?
Speaker 1: Would organisms have a habitable area, and so that's what
Speaker 1: we're going to talk about a little bit more in depth. Um,
Speaker 1: you know, what, what does the weather look like? You know?
Speaker 1: My mind immediately turned to science fiction, so I I
Speaker 1: was looking up to see what other examples I could
Speaker 1: think of that were sci fi related. If anyone out
Speaker 1: there knows of a good example of a tidally locked
Speaker 1: world in science fiction where they actually explore weather and
Speaker 1: some of the more realistic effects, I would love to
Speaker 1: hear about them, because the main examples would come to
Speaker 1: my mind, or things like there's the nineteen twelve novel
Speaker 1: The Night Land by William Hope Hodgson, which I'm pretty
Speaker 1: sure I've mentioned here before. This is the early post
Speaker 1: apocalyptic book that is so filled with this fantastic, wonderful
Speaker 1: ark ideas, but it's written so tiresomely, so badly, that
Speaker 1: it's you're just constantly sifting for these nuggets of gold
Speaker 1: amid just utter crap. It has its lovers, and I
Speaker 1: have kind of I have a very much of love
Speaker 1: hate relationship with this book. But it takes place in
Speaker 1: a world where the sun is burned out and the
Speaker 1: remnants of humanity retreat into these massive geothermal powered pyramids,
Speaker 1: and they grow crop crops and subterranean chambers, and they're
Speaker 1: telepaths and they're spinning disc weapons all you know, monsters
Speaker 1: out in the dark and all. But what's really cool
Speaker 1: about it is that Hodgson's fiction was based on Lord
Speaker 1: Kelvin's theories of the way gravity works. So the night
Speaker 1: land in the scenario this whole plant is the world
Speaker 1: again where the sun has going going dark and title
Speaker 1: Dragon slow the earth rotation to a crawl. He depicts
Speaker 1: this world is one where you have an entire just
Speaker 1: frozen night side of the world and then this dying
Speaker 1: side of the world that's facing a sun that's fading out.
Speaker 1: Another example that comes to mind is Jack of Shadows
Speaker 1: by Roger zelaz Name. This is a pretty fabulous little
Speaker 1: novel that has a that has a lot of magic
Speaker 1: in it. So it's not really you know, like I say,
Speaker 1: he's not really concerned with weather patterns. But there's a
Speaker 1: side of that. It's a tidally locked world. There's a
Speaker 1: night world and then there's a day world. The day
Speaker 1: world is ruled by science and technology, in the night
Speaker 1: world is ruled by magic. And you have a character
Speaker 1: who's from the night world and every time he dies
Speaker 1: in the daylight world, he's he's reborn on the far
Speaker 1: side and dreams. Yeah. Uh. And then and of course
Speaker 1: that we have to look at Star Trek. There are
Speaker 1: a few different planets that pop up there, but the
Speaker 1: most notable seems to be the planet Remus, which is
Speaker 1: the third of four planets in the Romulan system. And
Speaker 1: you have a situation here where it's basically a mining world,
Speaker 1: and you have a race of individuals called the Riemans.
Speaker 1: It's playing on the whole Remus and Romulus. You know,
Speaker 1: the Riemans are either a separate species that evolve on
Speaker 1: the dark side of the planet, or they're sort of
Speaker 1: like the early Romulan setters who have devolved or evolved
Speaker 1: into nighttime species, so they look like kind of big
Speaker 1: bat creatures. They've evolved to live in this dark portion
Speaker 1: of this tidally locked world. Well see, and that's what
Speaker 1: that's why our imagination can't help but go wild with this,
Speaker 1: because when you start to think about tidally locked world,
Speaker 1: you start to think about, you know, some sort of
Speaker 1: organism that may I'm not saying that they're there are
Speaker 1: bad people um. But but obviously there are adaptations that
Speaker 1: nature makes, and so you start to wonder what that
Speaker 1: would look like. But before you can even start to
Speaker 1: look at that, you have to really start to think
Speaker 1: about what this planet would feel like, um, what sort
Speaker 1: of weather systems. Obviously, there would be no seasons, right.
Speaker 1: The only change in the amount of sunlight would come
Speaker 1: from the slight variation and distance from the Sun because
Speaker 1: of the like for instance, if if Earth were to
Speaker 1: become locked to the Sun UM because the Earth's orbit
Speaker 1: being slightly out of round. So if that were to
Speaker 1: happen with the Earth, then you'd have slight variations. There
Speaker 1: might be different climate depending on how far away you
Speaker 1: are from the center of the side that always faces
Speaker 1: the sun UM. On the equator of the sun facing side,
Speaker 1: you'd have like these incredibly high temperatures, and in the
Speaker 1: center of land masses that are facing the sun, you'd
Speaker 1: have hot as haitise deserts. Right. And then by the coast, okay,
Speaker 1: there would be an incredible amount of thunderstorms because of
Speaker 1: the rapid evaporation of water. So yes, their water could
Speaker 1: exist in some of these scenarios, and there have been
Speaker 1: tons of computer models that have told us there's an
Speaker 1: opportunity for atmosphere to die off, to completely evaporate, right,
Speaker 1: or it could sustain itself in this continuous cycle where
Speaker 1: if you have thunderstorms depositing weather systems of rain over
Speaker 1: to the dark side. I love to think of this
Speaker 1: dark side is sort of a snow globe effect. You
Speaker 1: know that it's constantly you know, snowing over there or
Speaker 1: raining over there, and uh, and then again the cycle
Speaker 1: just continues on. Yeah, and then like you said, there
Speaker 1: are other models of it that should there being very
Speaker 1: little person to station on the night side, because you
Speaker 1: end up with the substantial precipitation at the what it's
Speaker 1: called the subsolar point, the point where the sun is
Speaker 1: baking the earth the most though, like the dead on
Speaker 1: sun zone, and then you have net evaporation, and so
Speaker 1: you have all the the atmospheric water is transported from
Speaker 1: the night side of the day side. You eventually have
Speaker 1: oceans just freezing on the other side of the world. Right.
Speaker 1: So it takes a little time because you also they're
Speaker 1: also those oceans are growing saltier due to the evaporation,
Speaker 1: and there you know, it's still a system of water
Speaker 1: that's very much and flows, so it takes longer for
Speaker 1: it to to freeze up. Yeah, and so you would
Speaker 1: have all these different circles of climates. Basically, it wouldn't
Speaker 1: just be like, oh, this one half of of you
Speaker 1: know on Earth that had become locked to the Sun
Speaker 1: was completely hot boiling and the other half was frozen zero.
Speaker 1: I mean, there would be variations in between. And that's
Speaker 1: the really exciting thing about whether or not um there
Speaker 1: would be habitable zones that could support life, right, And
Speaker 1: this is very much a question when we're looking at
Speaker 1: these exoplanets, because we're catching the planets in the habitable zone,
Speaker 1: but there's a little there's a certain amount of crossover
Speaker 1: between habitable zone planets and potentially tidally locked planets, especially
Speaker 1: when it comes to in the stars, which are stars
Speaker 1: that are slightly bigger than the one that we call Sun.
Speaker 1: It would be one of those situations where you'd be like,
Speaker 1: all right, the planets in the right spot. It's in
Speaker 1: that Goldilocks zone where it's just the right size where
Speaker 1: it could conceivably have life. Oh, but it's not rotating.
Speaker 1: So it's kind of like the house looks great, but
Speaker 1: there's no power you know, it's uh, there's something drastically
Speaker 1: wrong here. Alright, we're gonna take a quick break and
Speaker 1: then we're gonna get back to all this. So hanging
Speaker 1: there for one sec. All right, we're back now. Astrobiologists
Speaker 1: think there might be some situations to where you would
Speaker 1: have a certain amount of what's called substellar weathering instability
Speaker 1: occur where basically you have higher temperatures that resulting in
Speaker 1: stronger rainfall, and those the rainfall is weathering away the soil,
Speaker 1: exposing more and more minerals, which then react with the
Speaker 1: chemicals in the air into a certain extent that could
Speaker 1: be counteracted by volcanic activity on the planet. So there
Speaker 1: might be a situation where tidily locked world would be
Speaker 1: balanced out a bit and you would have this habitable
Speaker 1: zone on the world. Generally, it would be that that
Speaker 1: ring that sort of exists as a borderland between the
Speaker 1: night land and then in the dayland, right, Which is
Speaker 1: that That's the part that I just get so excited
Speaker 1: about because I think where there's there's the opportunity for
Speaker 1: for life existing. And it kind of made me think
Speaker 1: about when we were talking about star dust though, about
Speaker 1: how difficult it is to build up life on a planet,
Speaker 1: and you just have you have to have the absolute
Speaker 1: right conditions and the right building blocks. So I mean,
Speaker 1: you know, remember that life evolved on Earth for two
Speaker 1: billion years before it began to produce and use oxygen,
Speaker 1: for instance, and organisms used photosynthesis, which use carbon dioxide,
Speaker 1: and all those little guys produce little puffs of oxygen
Speaker 1: and over millions and millions of years, created more and
Speaker 1: more oxygen and what is now our atmosp fhere, right,
Speaker 1: So you know, we talked about this and we say
Speaker 1: there could be habitable zones, but again, all these elements
Speaker 1: have to be just right, yeah, and the only model
Speaker 1: for life that we have is very much a rotating planet.
Speaker 1: It's it is not tidally locked. So it becomes even
Speaker 1: more difficult to try imagine how that process might take
Speaker 1: place on a world where you have just a night world,
Speaker 1: a day world and then this potentially happenable twilight zone
Speaker 1: ringing around them right, right, and you'd have to have
Speaker 1: an atmosphere, right, So that's that's the first thing again though,
Speaker 1: there there's this opportunity to have the atmosphere, as you said,
Speaker 1: if you've got enough going on day and night side
Speaker 1: that they sort of converge to have these habitable zones
Speaker 1: that could support um, you know, an atmosphere and keep
Speaker 1: it in. Yeah, and what's interesting to there's some models
Speaker 1: for tidally locked worlds where it's not it's not like
Speaker 1: a perfect tidal lock, where they'll be the two rotations
Speaker 1: don't completely line up, so they'll be like a little
Speaker 1: bit of wiggle room there. You could potentially have a
Speaker 1: world where there would be regions that would sort of
Speaker 1: have a little night and day going on in that
Speaker 1: habitable ring. Well, and a lot of people have thought
Speaker 1: about this, particularly in terms of Earth, like whatever, Earth
Speaker 1: became totally locked to the Sun because Mercury, it's thought
Speaker 1: was once tinally locked. Um Radar observations of Mercury revealed
Speaker 1: that the planet rotates three times on its access for
Speaker 1: every two orbits yea. Early on, we actually thought it
Speaker 1: was titlely locked like the n Yeah. The thing is,
Speaker 1: because of the planet's tiny size and the proximity to
Speaker 1: the Sun, it makes it a really good candidate for
Speaker 1: being tital a locked. So here's the thing though, They
Speaker 1: think that this this weird sort of rotation system that
Speaker 1: has going on is the result of a giant impact
Speaker 1: from the asteroid that knocked Mercury once it was totally
Speaker 1: locked um into what is now sort of odd rotation configuration. Yeah,
Speaker 1: it's got a massive hole in it called Rambat Crater,
Speaker 1: which is about a seven and fifty kilometers wide. Would
Speaker 1: is pretty substantial for a planet that's under five thousand
Speaker 1: kilometers in size. Yeah, and they said that asteroid would
Speaker 1: have been about forty three miles wide and about fifty
Speaker 1: trillion metric tons in mass. So can you imagine this
Speaker 1: object hurling into Mercury tile a locked world and actually
Speaker 1: changing not just the spin but the but it even
Speaker 1: being locked. Yeah, there's there's a theory that this planet
Speaker 1: size impact may have also had an effect on the
Speaker 1: density of the planet because it is an extremely dense world.
Speaker 1: And there are a number of theories as the wine
Speaker 1: that may be, but one of them is that this
Speaker 1: enormous impact may have knocked it round. Here's here's what
Speaker 1: I want to get to is that the what effs? Right?
Speaker 1: And I immediately start thinking how you've got this perpetual
Speaker 1: night and my mind goes to cave fish. Yes, because
Speaker 1: kfish are a great example of something that has adapted
Speaker 1: to its environment. Cavefish are indigenous to Somalium, and they
Speaker 1: have been cut off from the sun for up to
Speaker 1: two point six million years and they lived in dark
Speaker 1: caves under the Smilean dessert for millions of years um.
Speaker 1: And then they had lost their eyes and scales and
Speaker 1: their coloring. And now researchers think that they're they're actually
Speaker 1: losing their their internal body clocks. What is fascinating about
Speaker 1: that is that it's taken that long for their internal
Speaker 1: clocks to kind of get off a bit. Wow, So
Speaker 1: that's the pace in which these changes occur. Really, yeah,
Speaker 1: I mean, you know, the obviously their their physical changes occurred,
Speaker 1: you know, much faster than that. So if you can
Speaker 1: imagine humans, if this were to happen to the Earth
Speaker 1: right for some reason, uh, you know, our eyes kind
Speaker 1: of scaling over with skin uh and then you know,
Speaker 1: our pigment changing, but still even two point six million
Speaker 1: years after the event, having some sort of pull towards this,
Speaker 1: you know, dining in old World even though you're in
Speaker 1: perpetual darkness because their entire evolutionary history hinges on it.
Speaker 1: Even if we ended up becoming some sort of more
Speaker 1: lock or or like the creatures in the descent, you know, yeah,
Speaker 1: so I mean if you were sun deprived, can you
Speaker 1: can you imagine the sort of traditions and metaphors that
Speaker 1: would arise in language if you if you are sun
Speaker 1: starved and still dependent on it and yet you had
Speaker 1: adapted in some ways. Yeah, of course, there would be
Speaker 1: a lot of questions as to how you were obtaining food,
Speaker 1: and because as we've explored the the situation on the
Speaker 1: dark side of the world would be pretty grim. I mean,
Speaker 1: there's no there's no light, so photosynthesis is coming to
Speaker 1: a close. Um, you have freezing temperatures, you have moisture
Speaker 1: being drawn to the other side of the world. So
Speaker 1: it's it's hard to imagine what life would consist of
Speaker 1: in that situation unless you you did have a scenario
Speaker 1: where individuals were somehow technologically sustained, or if there was
Speaker 1: some sort of trade situation with the with the daylit world.
Speaker 1: But but things are gonna be pretty severe there too,
Speaker 1: so I guess it would be more like you would
Speaker 1: have to have some sort of trade scenario with the
Speaker 1: twilight world, like that's the that's the area where civilization
Speaker 1: is going to thrive more because you can have the
Speaker 1: baked side and the frozen side and only in the
Speaker 1: middle of things going to be just right right. And
Speaker 1: of course we're talking about you know, if this were
Speaker 1: to occur on the Earth, this is not something that
Speaker 1: would happen like the next dayking about millions of millions. Yeah, yeah, yeah, right,
Speaker 1: but you know, I mean, you'd have life forms that
Speaker 1: could not subsist on the on the sunlit side, and
Speaker 1: by some versa, well you've seen what happens to say,
Speaker 1: like the neighborhoods in Atlanta when when there's a severe
Speaker 1: snowstorm like two weeks and it's full on cannibalism and
Speaker 1: road warriors in the street. Yeah, Atlanta would not farewell, Yeah,
Speaker 1: with this situation at all. But the heat side conscious
Speaker 1: sign we could. We could probably roll with that pretty
Speaker 1: much what we do in the summer anymore. Yeah, you're right, right,
Speaker 1: I mean, actually like eight months of a year. Yeah,
Speaker 1: you hear us Florida, you hear us Alabama. All right,
Speaker 1: So tell us what you think about all that. Do
Speaker 1: you have any thoughts on a tidally locked world? You
Speaker 1: have some other great examples from science fiction you would
Speaker 1: like to do or fantasy you would like to share
Speaker 1: with us. There is I mean, there's a whole wonderful
Speaker 1: sub genre of to see zi fi with the dying
Speaker 1: art scenario where you have the sun dying, and I
Speaker 1: think I did a blog post about that a while back.
Speaker 1: It's the fascinating zone of imagination. But I have not
Speaker 1: encountered much in the way of tidily locked world. So
Speaker 1: send me some examples. I would especially again love to
Speaker 1: hear examples that take weather into account. Yeah, especially if
Speaker 1: if you've ever come across, uh, some sort of idea
Speaker 1: of an extra planet with half of the planet being
Speaker 1: a snow globe. Yeah, that's that's That's all I'm interested in, really,
Speaker 1: the snow globe part of it. Snow global girl. Yeah
Speaker 1: all right. Well, hey, if you want to share it
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