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 Joe
Speaker 1: McCormick and Robert. I know that many times you must
Speaker 1: have imagined what life is like in a zero gravity environment, right, Oh? Yeah,
Speaker 1: I mean you can't help you. You You can't help thinking
Speaker 1: about it as you read about space exploration and engage
Speaker 1: with with various science fiction scenarios. What what would it
Speaker 1: be like to to float free, uh, inside of a capsule? Yeah?
Speaker 1: And people obviously imagine the very simple stuff, right, you know,
Speaker 1: floating from one end of the room to the other,
Speaker 1: not being able to walk normally, maybe fear that you
Speaker 1: would experience some motion sickness. You know, many, many people
Speaker 1: who go to space I think at least half I
Speaker 1: think is the number, experience some kind of space adaptation
Speaker 1: problems space sickness once they arrive. That might go way
Speaker 1: after some time. Yeah, Or you tend to focus on
Speaker 1: the amazing and the horrible ideas, like you know, for instance,
Speaker 1: how fun it would be to drink orange juice and
Speaker 1: space by chasing the globs around the capsule, or the
Speaker 1: more you know, they're definitely horrible or or almost horrible
Speaker 1: scenarios such as, of course, uh you know, the bone
Speaker 1: mass density loss, as well as the problem of trying
Speaker 1: to poop in a toilet. Right, I thought you were
Speaker 1: going to immediately go to using the bathroom. I was
Speaker 1: immediately going to go to the bathroom, And then I
Speaker 1: thought I should I should reference like the really pivotal
Speaker 1: problem here as opposed to just the one that is difficult. No,
Speaker 1: I mean, going to the bathroom isn't necessarily a big problem.
Speaker 1: You know, you it might not sound all that appealing
Speaker 1: to essentially poop into a vacuum cleaner but or bag.
Speaker 1: You know a lot of people maybe that's something they've
Speaker 1: always wanted to try out. It's not necessarily a horrible idea,
Speaker 1: but it will definitely be horrible. I don't know if
Speaker 1: you make a mistake in this process. Right, That's where
Speaker 1: the horror stories kick in, is when the the the
Speaker 1: super expensive space toilet malfunctions. The same thing, of course
Speaker 1: is true, well not exactly the same thing. A similar
Speaker 1: thing is true of you mentioned chasing orange juice globules
Speaker 1: with your mouth to hunt them down, but eating in space,
Speaker 1: I mean, we depend on gravity so much for a
Speaker 1: lot of our eating activity. Keeping food in a container.
Speaker 1: I mean, you just can't compose dishes in space. You've
Speaker 1: gotta again kind of like you poop into a bag.
Speaker 1: You've got to eat out of a bag um, or
Speaker 1: have something that's relatively solid and doesn't have crumbs that
Speaker 1: are going to get everywhere. I mean, can you think
Speaker 1: about trying to salt your food in space? You sort
Speaker 1: of need to like salt into a bag and shake
Speaker 1: it up or something. Yeah, or just have like a
Speaker 1: hot sauce packet that you you add into your own
Speaker 1: mouth afterwards. I feel like I could get buying a
Speaker 1: number of like bagged curries and whatnot. Yeah. Now, of course,
Speaker 1: another thing astronaut's report about zero gravity environments is that
Speaker 1: your sense of taste is all jam up, Like you
Speaker 1: can't taste things the way you normally would. And part
Speaker 1: of this probably has to do with the fluid redistribution
Speaker 1: in your body that leads your head and upper body
Speaker 1: to swell because you don't have the normal gravity pulling
Speaker 1: all the fluids in your body towards your feet, which
Speaker 1: your body is naturally trying to overcompensate for another gravity
Speaker 1: tidbit that that I always find fascinating is that I
Speaker 1: believe Mary Roach pointed this out in their book Packing
Speaker 1: from Mars. If you're in a microgravity zero gravity environment,
Speaker 1: your bladder doesn't fill up from the bottom up. It
Speaker 1: feels like in the center, right, It fills like all
Speaker 1: around towards the very center. So you don't realize that
Speaker 1: you need a urinate, uh, typically until you're absolutely about
Speaker 1: to burst, because because we have evolved to sense the
Speaker 1: to detect that the need for our own urination on
Speaker 1: a gravity invite, in a gravity environment, on a on
Speaker 1: a world with gravity, we are creatures of gravity. It
Speaker 1: reminds me of a piece of terminology I haven't really
Speaker 1: thought of since elementary school, but back and there would
Speaker 1: be a thing that would be like a p quote emergency.
Speaker 1: Remember the emergency. Yeah, well, I mean I guess if
Speaker 1: you have kids, there's such a thing as an emergency. Yeah.
Speaker 1: I have a five year old son, and so he
Speaker 1: has these where it's like suddenly it's super dire, like
Speaker 1: you have he has to run outside of the front
Speaker 1: doors closer to him, uh, you know, grabbing himself the
Speaker 1: whole time and going I gotta go pee and the
Speaker 1: immediately paying Um, this is the kind of thing adults
Speaker 1: tend not to experience unless perhaps you go into space. Right,
Speaker 1: So those are the the less dire things now you
Speaker 1: already alluded to. Of course, the deterioration of body tissues,
Speaker 1: loss of bone density, loss of muscle mass, and and
Speaker 1: and all the different negative consequences that happened to the
Speaker 1: body under zero gravity or microgravity conditions. These things can
Speaker 1: really stack up. And it's not a trivial effect. Astronauts
Speaker 1: have to exercise constantly when they're in microgravity environments. They've
Speaker 1: got a spend hours a day working out in these
Speaker 1: weird machines just to try to offset some of the
Speaker 1: damage that's being done to their bodies by the lack
Speaker 1: of gravity in their environment. And it's still not enough,
Speaker 1: all right, I mean, they still come back to back
Speaker 1: to Earth messed up, and they need time to really reacclimate.
Speaker 1: Hopefully they will eventually come back to something like full health.
Speaker 1: But but it's not good for you. Yeah, And and
Speaker 1: of course one of the problems is that uh, astronauts
Speaker 1: want to go back to space, so they're not necessarily
Speaker 1: going to be as forthcoming about the about how they're
Speaker 1: exactly feeling. Yeah, I guess that is a thing to
Speaker 1: worry about. You'd hope that they'd be accurately reporting how
Speaker 1: bad it is, but maybe they just they want to
Speaker 1: get back up there. Yeah, I mean that, that's that's
Speaker 1: what what I've I've heard is that generally speaking, and
Speaker 1: you don't go to space then and you're like, oh,
Speaker 1: that's enough of that. I'm good an astronaut. A person's
Speaker 1: worth their whole life to do this for not even
Speaker 1: just to do this, but for the chance of doing this.
Speaker 1: Of course they're gonna want to go back. So my
Speaker 1: question is, why don't the people who run the I
Speaker 1: S S. I don't know whoever they are, NASA, I
Speaker 1: guess maybe not NASA space agencies around the world. Why
Speaker 1: don't the people who run our space stations just take
Speaker 1: advantage of the Holtzman effect and put some gravity plating
Speaker 1: in there so that you can walk around like a
Speaker 1: normal Earth humans. A. Yeah, so yeah, you're so you're
Speaker 1: drawing in both Star Trek and Dune here, but they're
Speaker 1: they're both prime examples because they're straight into the blender.
Speaker 1: Because this is uh, this is one of the key
Speaker 1: aspects of our science fiction when it comes to gravity
Speaker 1: or lack of gravity and space, they're basically three models.
Speaker 1: Either you're gonna you're gonna try and go hard science
Speaker 1: and have some sort of an artificial gravity scenario like
Speaker 1: some of the realistic scenarios we're going to discuss in
Speaker 1: this podcast. You're gonna just go you know, micro gravity
Speaker 1: zero G and have people floating around, which of course
Speaker 1: can be difficult from a special effects standpoint. Or you're
Speaker 1: gonna go space wizards. Yeah, you're just gonna go magic
Speaker 1: artificial gravity and just say hey, we let's star trek.
Speaker 1: We have gravity plates in the floor. Of course there's gravity. Uh,
Speaker 1: it's the and in in in Dune you have the
Speaker 1: the Holtzman effect generated by the Holtzmann field generator, and
Speaker 1: Herbert never explain exactly what it was or how it worked,
Speaker 1: but it allowed for the generation of anti gravity faster
Speaker 1: than light travel, personal shields, artificial gravity on ships, you know,
Speaker 1: all the things you need to sort of go ahead
Speaker 1: and establish your interstellar uh empire, and then tell the
Speaker 1: stories you want to tell. You know, I'm okay with
Speaker 1: that because in lots of science fiction stories, essentially they're
Speaker 1: trying to tell a character drama or it's a fantasy
Speaker 1: story set in space. I don't need all science fiction
Speaker 1: to be hard science fiction, but I really do appreciate
Speaker 1: hard science fiction that tries to take the physics that
Speaker 1: we know seriously. This does not. But that's okay, you know,
Speaker 1: that's doing its own thing. Yeah. I mean, Herbert had
Speaker 1: areas that he was definitely going to focus in on,
Speaker 1: such as ecological issues, philosophical, religious, cultural issues, and of
Speaker 1: course this the drama that is especially seen in the
Speaker 1: first book. So I kind of some slack. I'm fine
Speaker 1: with some magic anti gravity. Now, in terms of sci
Speaker 1: fi properties that do take it really seriously. What are
Speaker 1: What are a few films that come to mind? Well,
Speaker 1: of course you you immediately think of two thousands, one
Speaker 1: of Space Odyssey. Now that's got multiple spacecraft. There's a
Speaker 1: space station and there's a spacecraft that both use something
Speaker 1: we're going to talk about later in the episode rotational
Speaker 1: UH structures for centripetal force driven or centrifical, centrifugal or
Speaker 1: centripetal force driven artificial gravity scenarios. Also, there is a
Speaker 1: good artificial gravity ship in the Martian UH, and I
Speaker 1: remember I think there's one in a space station and
Speaker 1: Interstellar isn't there. Yes, I do believe I remember the
Speaker 1: spinning situation. And I also want to point out James S. A.
Speaker 1: Corey's Expanse series, both the books and the sci fi
Speaker 1: TV show, which which does I think a really good
Speaker 1: job of going after from near future interplanetary culture and technology.
Speaker 1: And it's also the only sci fi property that I
Speaker 1: can think of that that actually explores one of the
Speaker 1: anti gravity schemes we're gonna we're gonna be discussing today
Speaker 1: linear acceleration. Well, linear acceleration. I can see why that's
Speaker 1: limited because it has sort of limited applicability if you're
Speaker 1: going to try to be real about like it only
Speaker 1: works in certain types of ships doing certain types of
Speaker 1: things to a certain extent. We can we can chat
Speaker 1: about this, this this later. Okay, we'll correct me. Well,
Speaker 1: I don't know, but it's not really correction. But I
Speaker 1: think one of the problems is that linear acceleration model
Speaker 1: calls for a spaceship that is not a seagoing vessel
Speaker 1: transported into space, because, as I said before the program,
Speaker 1: I think a lot of our science fiction and our
Speaker 1: sci fi ships are essentially seagoing vessels and tales of
Speaker 1: seagoing vessels and sea and Captain's uh taken from Earth
Speaker 1: and transposed into space. I mean that was basically Gene
Speaker 1: Roddenberry's a whole deal with Star Trek. That was m
Speaker 1: was the Master and Commander books that he wasn't No,
Speaker 1: it was a different one. Um. I can't remember that
Speaker 1: the series offhand. But anyway, he was inspired by by
Speaker 1: literary tales of of of adventurous humans at sea. Uh No, well,
Speaker 1: maybe I don't know. Well, I guess the Wrath of
Speaker 1: con is yeah, from Hell's Haired I staff at the right.
Speaker 1: But it's it's more difficult with linear acceleration because you
Speaker 1: have to you have to take that concept of an
Speaker 1: Earth vessel and you really have to literally turn it
Speaker 1: on its side. You have to think instead of a
Speaker 1: ship going from port to port and stopping, you have
Speaker 1: to think about long, continuous journeys. But we'll get into
Speaker 1: all that in a bit. Okay, Well, I guess we
Speaker 1: should first just take a real quick look at what
Speaker 1: is the problem with artificial gravity, with generating gravity and space.
Speaker 1: Why can't you just do it? Well, I mean, so
Speaker 1: gravity is something that is a field generated by generally
Speaker 1: we think of it as mass. It's generated by the
Speaker 1: stuff in the universe, energy and mass, you know, much
Speaker 1: more by matter that has mass. So we all know
Speaker 1: that objects that have mass have a mutual attractive force.
Speaker 1: They tend to attract one another. And you know, we've
Speaker 1: known this for a long time. It was the laws
Speaker 1: of gravitation were to a certain extent well explained by
Speaker 1: Newton in the seventeenth century, and he basically described the
Speaker 1: laws of gravitation in a way that that makes sense
Speaker 1: for most of the stuff we're going to be looking at,
Speaker 1: for planets, for spaceships, for things like that. Now. Of course,
Speaker 1: later Albert Einstein revolutionized our understanding of what gravity is
Speaker 1: by telling us that gravity is the curvature of space time,
Speaker 1: and that sort of matter tells spacetime how to curve,
Speaker 1: and that the curvature of spacetime tells matter how to move.
Speaker 1: So let's start with masks, and I think that's the
Speaker 1: that's that's the essential part. That's that's a pretty easy
Speaker 1: to understand here. So everything with mass, from a dust
Speaker 1: mote to a star, exerts a gravitational pull. The strength
Speaker 1: of the poll, however, increases with mass. And proximity to
Speaker 1: the object. So a smaller object can only attract another
Speaker 1: small object of it's nearby, but a large object can
Speaker 1: pull in objects from across the vast distance. And this
Speaker 1: is kind of this is key to the structure much
Speaker 1: of the structure of our of our universe. I mean,
Speaker 1: this is how accretion occurs, with little specks of space
Speaker 1: dust and gas forming together and snowballing into larger cosmic bodies. Yeah,
Speaker 1: I mean, this is how our solar system was created.
Speaker 1: Was the coalescing of objects by the force of gravity.
Speaker 1: Things are attracted to each other, eventually becoming stars, planets,
Speaker 1: all that. Yeah. And then Albert Einstein's general theory of
Speaker 1: relativity comes along and propose that the gravity is a
Speaker 1: curve in the fourth dimension of space time. And there's
Speaker 1: proof to back him up. Given sufficient mass, an object
Speaker 1: can cause an otherwise straight beam of light to curve.
Speaker 1: Astronomers called this effect gravitational lensing. Yeah, this was shown experimentally.
Speaker 1: It was one of the fir speak experimental proofs of
Speaker 1: Einstein's theory of relativity is that you could see light
Speaker 1: from stars passing behind the Sun bending as it came
Speaker 1: right around the Sun. So you know, if you could
Speaker 1: have a solar eclipse and shield out the light from
Speaker 1: the Sun, you could see stars in the background being
Speaker 1: warped by the Sun's gravity as the beams of light
Speaker 1: passed close to our Sun. Yeah, and similarly, the less
Speaker 1: gravity there is, the slower time passes. And this is
Speaker 1: a phenomenon is gravitational time dilation, and this is this
Speaker 1: is the less key to what we're talking about. But
Speaker 1: it just drives home like the place of gravity, uh
Speaker 1: in our universe. Yeah, it sounds this is one of
Speaker 1: those things that sounds like fantasy, but it's absolutely true.
Speaker 1: And you saw that We mentioned the movie Interstellar earlier.
Speaker 1: There's actually, Uh, there are a couple of great scenes
Speaker 1: and the demonstrate this where they go down to a
Speaker 1: planet with an incredibly high gravitational pull and uh, while
Speaker 1: they're down there on the planet, much less time passes
Speaker 1: for the people on the planet than passes for people
Speaker 1: in orbit farther away. Yeah. As a physicist Paul Davies
Speaker 1: points out, time runs a little bit faster in space
Speaker 1: than it does down on Earth. It runs a little
Speaker 1: faster on the roof than it does in the basement,
Speaker 1: and that's a measurable effect. Then's the basics on gravity.
Speaker 1: But then there's also this additional area of quantum gravitation
Speaker 1: and the idea that that there is a there's a
Speaker 1: hypothetical particle, the graviton, which in theory could cause optics
Speaker 1: to be attracted to one another. Yeah, and this would
Speaker 1: be the mediating particle of the force of gravity, in
Speaker 1: the same way you've got like the electromagnetic force, the
Speaker 1: mediating particle there is the photon. Hypothetically you'd have some
Speaker 1: mediating particle delivering the force of gravity. But we've never
Speaker 1: seen gravitons in the universe. Right. This is the this
Speaker 1: whole hypothesis comes together because quantum theory, to refresh, addresses
Speaker 1: how the universe works at the smallest subotonic levels, and
Speaker 1: the resulting model here does not explain gravity. So gravitons
Speaker 1: and the theory of quantum gravity isn't a attempt to
Speaker 1: reconcile general relativity with quantum theory. It's a basically an
Speaker 1: attempt to patch up a hole in the standard model
Speaker 1: of particle physics, which cannot explain gravity. Now, the last
Speaker 1: time I read seriously about gravitons was a few years ago.
Speaker 1: I wonder if any recent experiments in our particle colliders
Speaker 1: have have shed any light on that. I mean, our
Speaker 1: physicists now thinking gravitons are more likely or less likely.
Speaker 1: So well, we certainly don't have any definitive proof on
Speaker 1: the matter yet. But I guess for the purposes of
Speaker 1: our discussion here, since we don't have proof of gravitons,
Speaker 1: we can't really come up with a scheme to employ
Speaker 1: them or manipulate them in some way that would give
Speaker 1: us artificial gravity. Yeah, so, I guess are the point
Speaker 1: of our bringing up gravitons is that you can't just
Speaker 1: wave a magic wand and say, ah ha, gravitons will
Speaker 1: be the thing we use to create artificial gravity in space.
Speaker 1: I mean, we don't know if they exist. If they
Speaker 1: do exist, I'm not sure anybody has a coherent idea
Speaker 1: of how they could be harnessed to provide artificial gravity
Speaker 1: in space. It just seems like I don't know what
Speaker 1: is So if they're generated by mass, would you not
Speaker 1: need mass to generate them? Yeah, I could. I looked
Speaker 1: around in my research and I couldn't find any, like,
Speaker 1: any real theories about how gravitons. If the exists might
Speaker 1: be utilized in this fashion, and I'm not I'm not
Speaker 1: aware of any science fiction that explores the possibility, but
Speaker 1: I would love to know about it. I think when
Speaker 1: it does, it's more just the kind of it's the
Speaker 1: hand waving magic. Right. So we come back to mass,
Speaker 1: then yeah, you could I guess, have a spaceship that's
Speaker 1: as massive as the Earth, and then that would have
Speaker 1: that would give you the gravitational pool you'd need. That's
Speaker 1: not exactly a terrible idea, and it's not unexplored. I
Speaker 1: mean there have been these ideas, for example, in you know,
Speaker 1: stellar engineering projects that say, hey, so let's say we
Speaker 1: want to travel to another solar system, wouldn't it be
Speaker 1: easier instead of trying to build an arc ship to
Speaker 1: take us there, to see if we can build a
Speaker 1: structure around the Sun that will reflect some of its
Speaker 1: radiation in and allow us to steer the movement of
Speaker 1: the entire Solar system. Oh yeah, yeah, I just move
Speaker 1: the Solar system. Yeah, so like the Solar system becomes
Speaker 1: our spaceship. You can build these things called a hypothetical
Speaker 1: structure called a scatterw thruster. Essentially, it would just drive
Speaker 1: the Sun Yeah. That actually features into No Surprise and
Speaker 1: Eda in Banks book, but I'm not going to say
Speaker 1: which one because it's kind of it's kind of a spoiler, Okay,
Speaker 1: but it's one of them. Leave it, leave it there. Yeah,
Speaker 1: So that is one idea though, if you wanted to
Speaker 1: travel through space on an object that has Earth gravity,
Speaker 1: you could just take Earth with you. Of course, it
Speaker 1: wouldn't really make sense to say, well, I want to
Speaker 1: build a spaceship that generates Earth gravity through natural mass
Speaker 1: generating effects, because then you would just be building a
Speaker 1: spaceship the massive Earth. Right. And if you can do that,
Speaker 1: then I mean you're already You're already a pretty powerful civilization.
Speaker 1: I'm not sure where you would rank on the Kardashian scale,
Speaker 1: but you'd be you'd be potent. Definitely a cardas chief one,
Speaker 1: maybe a cardas chief two. Alright, So we've talked about
Speaker 1: these scenarios involving natural gravity and and the idea of
Speaker 1: manipulating natural gravitational forces. Luckily we're not, we're not forced
Speaker 1: to contend only with those. We can also deal with
Speaker 1: artificial gravity, not in a magic sense, but in a
Speaker 1: but in a real sense. Yeah, and in this way,
Speaker 1: there are ways to generate artificial gravity that are not
Speaker 1: hypothetical or speculative at all. I mean, this is totally easy,
Speaker 1: standard settled physics, because one of the insights of modern
Speaker 1: physics is that gravity is in fact indistinguishable from acceleration.
Speaker 1: When you're being pulled toward a planet's center and the
Speaker 1: planet has a mass such that it generates a surface
Speaker 1: gravity of nine point eight meters per second per second,
Speaker 1: which is what Earth's surface gravity is, right, or whether
Speaker 1: you're accelerating through space at an acceleration rate of nine
Speaker 1: point eight meters per second per second, the effect you
Speaker 1: experience is exactly the same. You can't tell the difference
Speaker 1: between these two situations. And so knowing this, we couldn't
Speaker 1: turn the idea of acceleration to our advantage. And that's
Speaker 1: where our first model comes into play. But first we're
Speaker 1: gonna take a quick break. All right, we're back. So
Speaker 1: the first model of artificial gravity we're going to discuss
Speaker 1: here is the one that I alluded to earlier and
Speaker 1: discussing the expanse, and one that I think, by and large,
Speaker 1: I cannot think of another single science fiction property that
Speaker 1: employs this as their artificial gravity. On a spaceship. But yeah,
Speaker 1: linear acceleration, I can't really think of many that do.
Speaker 1: But so, what's the basic idea here, Robert? All Right, So,
Speaker 1: if you've ever written on a roller coaster and felt
Speaker 1: yourself plastered to the back of the seat, then you've
Speaker 1: experienced some of the power here. If you were in
Speaker 1: a fighter jet and you were, you know, traveling at
Speaker 1: a sufficient speed to pull you multiple g's, you're you're
Speaker 1: also experiencing this as you're pushed back into the chair. Right, So,
Speaker 1: if you can imagine being in that fighter jet and
Speaker 1: you're being pulled back into your chair, except instead of
Speaker 1: going back into your chair, you put your feet on
Speaker 1: the chair, put your head in the direction that the
Speaker 1: fighter jet is going, and the acceleration rate of that
Speaker 1: fighter jet is nine point eight meters per second per second,
Speaker 1: it would suddenly feel a lot like it feels to
Speaker 1: stand on the ground. Right. Imagine a skyscraper as a
Speaker 1: rocket ship. Imagine it blasting through space at such a
Speaker 1: speed that the G force uh equaled the pull of
Speaker 1: Earth's gravity on the internal environment. I'm actually gonna read
Speaker 1: a couple of quick quotes from James S. A. Corey's
Speaker 1: UH first Expanse novel, because I believe that these really
Speaker 1: capture what we're talking about. So he's describing the Donager
Speaker 1: space ship here quote. Like all long flight spacecraft, it
Speaker 1: was built in the office tower configuration. Each deck one
Speaker 1: floor of the building. Ladders are elevators running down the axis.
Speaker 1: Constant thrust took the place of gravity. Now, there's also
Speaker 1: a Mormon generation ship in the book that uses both
Speaker 1: linear thrust and a rotating wheel, which we'll get into,
Speaker 1: and this is the description for it. Each compartment within
Speaker 1: the massive rings was built on a swivel system that
Speaker 1: allowed the chambers to reorient to thrust gravity when the
Speaker 1: ring stopped spinning and the station flew to its next
Speaker 1: work location. Okay, so by describing these ships with floors
Speaker 1: like an office building, what you what you should really
Speaker 1: picture is like you've got a skyscraper and it's flying
Speaker 1: through space with the top of the skyscraper as the
Speaker 1: front the nose of the ship, and all of the
Speaker 1: floors are where your feet would be towards the back
Speaker 1: of the ship and your head would be facing the
Speaker 1: front of the ship. It's taking the holes like starship
Speaker 1: enterprise situation and turning it sideways. If you imagine the
Speaker 1: starship Enterprise flying in such a way that the top
Speaker 1: of the ship is the front of the ship. I
Speaker 1: realized this gets complicated when you're talking about outer space.
Speaker 1: But you're you're taking and in this part of the problem.
Speaker 1: Like we we understand the movement of things in our
Speaker 1: situational uh positioning in a gravity rich world, and when
Speaker 1: we try and take it out of that, it's it's
Speaker 1: kind of hard to picture some of these, uh, these situations, right.
Speaker 1: But yeah, so if this is taking place in space,
Speaker 1: you would be able to generate a force towards the
Speaker 1: floor that simulates Earth gravity. Now, this would this would
Speaker 1: have some complications I'm imagining because in order to perfectly
Speaker 1: simulate Earth gravity, maybe you don't care how perfect it is,
Speaker 1: but if the goal was to perfectly simulate Earth gravity,
Speaker 1: you would need to be constantly accelerating at nine point
Speaker 1: eight meters per second per second, that's a lot of
Speaker 1: constant acceleration. You're always going that much faster. Yeah, yeah,
Speaker 1: I mean, we we see the required propulsion at work
Speaker 1: when a chemical rocket creates enough thrust to counter this
Speaker 1: gravitational pull and achieve escape pul loss. But they're only
Speaker 1: achieving it from a matter of seconds or minutes. For
Speaker 1: our spaceship here are theoretical spaceship, our office building on
Speaker 1: its side, you'd need something more constant. So just to
Speaker 1: refresh on the gs here, standing on the Earth, you'd
Speaker 1: experience one G in free fall, saying an elevator or
Speaker 1: the vomit comet, you'd experience zero G. At two G
Speaker 1: feel twice as heavy. So you'd need a spaceship capable
Speaker 1: of propelling you fast enough, like you said, to exert
Speaker 1: a constant one G. So one of uh, the sources
Speaker 1: we turned to for this was a wonderful two thousand
Speaker 1: seven book Artificial Gravity, edited by Giles Clement and Angelie Buckley,
Speaker 1: And there's an article in there by Buckley, Clement, and
Speaker 1: William Pulaski of NASA's Johnson Space Center, and uh they
Speaker 1: point out that a spaceship could, in theory accelerate for
Speaker 1: the first half of a Mars journey, then decelerate on
Speaker 1: the second half, and in doing so maintain one G
Speaker 1: and reach Mars in two to five tays depending on
Speaker 1: the distance I mean that would be. You'd have to
Speaker 1: have incredible power, yes, incredible thrust like a powerful fuel
Speaker 1: to accelerate that much. Also, I'm how did so that
Speaker 1: they explain how you do the flip over. You'd have
Speaker 1: to be accelerating one g the like half the way there,
Speaker 1: and then you have to be decelerating at one g
Speaker 1: the other half of the way there, which means I
Speaker 1: guess you'd have to flip the spaceship around so that
Speaker 1: the floors stays the floor. Yeah, or you'd have to
Speaker 1: have some sort of like an internal habitat that's like
Speaker 1: a capsule on it rotates that or yeah, I guess
Speaker 1: you could have a spaceship where the floors and ceilings
Speaker 1: are both can both work as floors, right, And of
Speaker 1: course the distance here involved not to go into the
Speaker 1: Mars opposition details here too much, but the maximum distance
Speaker 1: between these two planets is two and fifty million miles
Speaker 1: with the sun between the two. So I guess that's
Speaker 1: not doable in two to five days. The I would
Speaker 1: assume you would not try and make the journey there
Speaker 1: unless I mean, but but if you're achieving speeds like that,
Speaker 1: then you know, maybe you'd go you'd go for it,
Speaker 1: but that the average distance is more like one forty
Speaker 1: million miles and the closest possible distance is a tantalizing
Speaker 1: thirty three point nine million miles. But anyway, that's this
Speaker 1: is the basic Yeah. But yeah, you would need to
Speaker 1: have uh, some pretty awesome power at your disposal, so
Speaker 1: awesome that I believe in the Expanse books like they
Speaker 1: basically can't be the authors who publishes as as James S. A. Corey, Uh,
Speaker 1: they had to sort of create their own fictionalized propulsion
Speaker 1: breakthrough to make that possible. Here's where you need the
Speaker 1: magic in this version. Yeah, instead of having magic gravity plating,
Speaker 1: you have magic propulsion. And I guess this is the
Speaker 1: case with a lot of sci fi Like you, there's
Speaker 1: a certain place you you want human civilization and or
Speaker 1: alien civilizations to be at, you know, to be able
Speaker 1: to discuss them and look at the ramifications. But yeah,
Speaker 1: we don't have all the steps worked out about how
Speaker 1: we'd get there. There's there are certain breakthroughs that we
Speaker 1: need to take place, and you could explore them and
Speaker 1: try and come up with some sort of uh, you know,
Speaker 1: complex of physics space theory, or you could just you know,
Speaker 1: put a post it note there and and maybe write
Speaker 1: magic on it. Yeah, even in a lot of so
Speaker 1: called hard sci fi or mostly hard sci fi. You know,
Speaker 1: you've got like a list of steps in how something
Speaker 1: is achieved, and most of the steps are something that's
Speaker 1: scientifically rigorous, but one of the steps in the middle
Speaker 1: is like, here's a magical element. I mean, it's kind
Speaker 1: of like with a lot of speculative properties that I enjoy.
Speaker 1: Sometimes they'll be something completely ridiculous, uh, something completely magical,
Speaker 1: But then you discuss all the real world ways it
Speaker 1: might play out. Like one example that comes to mind
Speaker 1: is a World War z you know, the Zombie book.
Speaker 1: Not so much of the movie, but the book looked
Speaker 1: at it's some possible ideas for how this would play out,
Speaker 1: like culturally and politically, uh, without really getting bogged down
Speaker 1: in the fact that zombies are are kind of a
Speaker 1: dumb idea and can't actually exist. But it's like, roll
Speaker 1: with me. Zombies are real, Let's discuss how this might work.
Speaker 1: I want to defend zombies just a little bit. There
Speaker 1: are different types of zombie scenarios, and some some are
Speaker 1: much more plausible than others. Reanimated corpses, no, but you know,
Speaker 1: rage zombies, some kind of weird virus, okay, maybe, okay,
Speaker 1: all right, yeah, I mean we have raybies. I mean,
Speaker 1: we don't have rabies, but there is ray you never know, alright,
Speaker 1: So you're probably wondering. Okay, we've established how this would work,
Speaker 1: we've talked a little about the sci fi, but what
Speaker 1: kind of work has actually gone into testing it. Well,
Speaker 1: they've been at least a couple of experiments. The European
Speaker 1: Space Agency e s A experimented with this in nineteen
Speaker 1: eighty five on the Space Lab D one. Now I
Speaker 1: couldn't find an image of it, but I'm assuming it's
Speaker 1: it's the same sled or one similar uh that was
Speaker 1: used in the nine eight one experiment where they were,
Speaker 1: you know, messing with the nineteen eight one. It's basically this,
Speaker 1: this chair on a if you okay, imagine a short
Speaker 1: train track that you could fit in a room and
Speaker 1: then you have a chair on it. I'm glad, I'm
Speaker 1: glad you've provided this picture. But this is crazy. It
Speaker 1: is It looks crazy. There's so there's a imagine a
Speaker 1: little train on a little train car, and there's a
Speaker 1: chair on it, and a chair swivels and you have
Speaker 1: somebody strapped into the chair with a bunch of you know,
Speaker 1: electronic dud dads connected to them, and then they would, uh,
Speaker 1: they would essentially like fly back and forth on this
Speaker 1: little train track with the with the seat swiveling along
Speaker 1: the way. It's a very Terry Gilliam contraption, isn't it. Yes,
Speaker 1: it it does. It looks very Terry Gilliam. Now, they
Speaker 1: tried this out and it peaked speeds, it only provided
Speaker 1: point to G and according to a Clementon company, the
Speaker 1: threshold for the perception of linear acceleration in humans is
Speaker 1: on the order of point zero zero seven G, and
Speaker 1: the threshold for humans in space seems to be more
Speaker 1: like between somewhere between point twenty two and point five G. Yeah.
Speaker 1: I've got some notes about that later on, about what
Speaker 1: exactly would be tolerable as artificial gravity, But I don't know,
Speaker 1: maybe maybe maybe you're getting to it right now. So
Speaker 1: you the the idea here is that you wouldn't necessarily
Speaker 1: have to have one full G in order to counteract
Speaker 1: some of the worst effects of microgravity. Yeah, it kind
Speaker 1: of comes down to what are you looking to do?
Speaker 1: Are you looking to to to counteract the effects of
Speaker 1: microgravity to a certain extent to like just get you
Speaker 1: there a little bit, or have like a perfect Earth simulation. Right,
Speaker 1: do you want to, um, you know, awaken a comma
Speaker 1: patient a board your spaceship and trick them into thinking
Speaker 1: that there's still on Earth, right, Like that's a tricker scenario.
Speaker 1: I mean maybe you could do it by telling them
Speaker 1: that they're they're they're nauseous or something. I don't know, Um,
Speaker 1: they have they have some sort of illness, but you've
Speaker 1: got an inner ear problem. Gravity is normal. Yeah, as
Speaker 1: a Clinton company point out in the article, quote, perhaps
Speaker 1: it is not necessary to perceive artificial gravity at the
Speaker 1: cognitive level for it to be effective as a countermeasure. However,
Speaker 1: for purposes of defining the comfort zone of astronauts and
Speaker 1: artificial gravity environments, whether it's a rotating spacecraft or an
Speaker 1: onboard centrifuge, it would be extremely useful to determine the
Speaker 1: threshold value of perceived artificial gravity. Unfortunately, there are no
Speaker 1: plans to put a human centrifuge on board the I
Speaker 1: s S, at least in the near term. So when
Speaker 1: it comes to g's um, you know, Mars is point
Speaker 1: three seven six gs, Neptune is one point fourteen G
Speaker 1: Saturn is one point of seven ges. Guess they're not
Speaker 1: gonna be standing on the surfaces of Neptune or but
Speaker 1: we have stood on the surface of the Moon, which
Speaker 1: is point one six gs. And Clement and Company point
Speaker 1: out that when astronauts visited the Moon, they had trouble
Speaker 1: figuring out which weight was up and down. They didn't
Speaker 1: they didn't perceive a four point five degree floor tilt
Speaker 1: in their landing unit during Apollo eleven. Can you imagine that,
Speaker 1: Like you're you're on a slope, but the gravity is
Speaker 1: so weak you can't you don't get that you're on
Speaker 1: a slope, like you can't feel it. And then when
Speaker 1: they're bouncing around out there on the lunar surface, Uh,
Speaker 1: there were a lot of dumbles, and a number of
Speaker 1: these stemmed up from the inability to evaluate ter rain slope. Yeah. Again,
Speaker 1: like you can't tell the difference between uphill and downhill.
Speaker 1: It's hard to imagine. Yeah, and yet, I mean the
Speaker 1: moon gravity is perfectly enough to keep you tethered to
Speaker 1: the surface of the Moon. You're not gonna fly away
Speaker 1: or anything, right, Yeah, You're not gonna leap up and
Speaker 1: achieve you know, escape velocity. Now there is another study
Speaker 1: and this is actually a proposed study currently and this
Speaker 1: is the NASA funded turbo lift the turbolator. Yeah, and this, Uh.
Speaker 1: The idea here is to combat the effects of microgravity
Speaker 1: by accelerating an astronaut literally had one G for what
Speaker 1: a round of one second, and then it's rotated uh
Speaker 1: degrees to prepare for one G deceleration. It's kind of
Speaker 1: like being shaken up in a cocktail shaker, uh, and
Speaker 1: only your legs always point in the direction of the
Speaker 1: shake it. It would, theoretically, according to the the proposers here, uh,
Speaker 1: feel like bouncing on a trampoline. So this would be
Speaker 1: a suggestion, not for a habitable environment or from a
Speaker 1: for a spaceship, but maybe for essentially some kind of
Speaker 1: exercise machine. Is that what we're thinking? Yeah, that that's
Speaker 1: what That's what I'm getting from this is that said quote.
Speaker 1: The intermittent loading is intended to reduce or eliminate the
Speaker 1: physiological deconditioning in a comprehensive multisystem manner. It would be
Speaker 1: it would be a situation where like, hey, Joe, I
Speaker 1: know you've got stuff to do on the spaceship, but
Speaker 1: it's time for your your one G treatment. You need
Speaker 1: to climb in the capsool here and we're gonna shoot
Speaker 1: you back and forth for however long your treatment last.
Speaker 1: The flipping bullet. Yeah, Now, this does indicate that there
Speaker 1: are these two very different schools of thought about what
Speaker 1: to do when generating artificial gravity. I guess we sort
Speaker 1: of alluded to this a minute ago, but you still
Speaker 1: should keep in mind this question of what is the goal.
Speaker 1: Is the goal just to have an environment you can
Speaker 1: go into often enough to offset some of the negative
Speaker 1: health effects of being in space. Is it just sort
Speaker 1: of like tiny jim for your body to stay healthy,
Speaker 1: or are you actually trying to create an environment where
Speaker 1: some of the effects of Earth gravity are simulated for
Speaker 1: normal living purposes, so you can salt your food, so
Speaker 1: you can go to the bathroom without pooping into a
Speaker 1: vacuum cleaner. Now I do have to say that, um,
Speaker 1: I can't help but think that this the jumper scenario,
Speaker 1: this turbo lift scenario, I could see it working if
Speaker 1: you had somebody in a hibernation state or some sort
Speaker 1: of suspended animation, like maybe you load their their corpsicle
Speaker 1: into one of these and shoot them back and forth.
Speaker 1: To to keep their to avoid any debilitating effects involved
Speaker 1: with their space travel. But of course for that to work,
Speaker 1: you have to have some sort of hibernation um, a
Speaker 1: technique worked out, and that's a whole. That's a whole
Speaker 1: another podcast topic. Now. In terms of complications with this
Speaker 1: linear model here of artificial gravity, you of course you
Speaker 1: have to be in motion, you right, to be able
Speaker 1: to produce that effect. Uh, you have to always be
Speaker 1: on your way somewhere or taking a roundabout way to
Speaker 1: continue the effect. But I'm not sure if that's such
Speaker 1: a detriment because, after all, space is big. The distance
Speaker 1: between planets, but certainly between stars is vast, and there's
Speaker 1: plenty of room to to run around out there. Well yeah,
Speaker 1: I mean if you actually want to travel to say,
Speaker 1: another star system, and not just say to Mars, but
Speaker 1: if you want to go to Alpha Centauri or wherever.
Speaker 1: I mean, as much acceleration as possible is good. Uh,
Speaker 1: it's still I guess I have the question about what
Speaker 1: the propulsion idea is, Like, how do you constantly generate
Speaker 1: that much acceleration exactly? Yeah, I guess with some models
Speaker 1: you have these ideas of like you know, kind of
Speaker 1: like beamed propulsion back from Earth where you line you know,
Speaker 1: you like you line up this payload delivery of energy. Um,
Speaker 1: that's right. That's what we have in Blindside, the novel
Speaker 1: that you just finished reading and I'm currently reading. Yeah.
Speaker 1: I mean the whole thing about this is this seems
Speaker 1: like a method that would work and would be very interesting. Um,
Speaker 1: but I guess it's just waiting on some kind of
Speaker 1: abundance of energy and propulsion technology and the than the
Speaker 1: means to use it or the opportunity to use it.
Speaker 1: All right, Well, that's linear acceleration for you. That's one model.
Speaker 1: We're gonna take another break, and when we come back,
Speaker 1: we're going to dive into the much more popular artificial
Speaker 1: gravity scheme, the one that you see in the movies.
Speaker 1: And then of course is the spinning habitats, the Taurus,
Speaker 1: the standard towards the double Taurus. All these different models
Speaker 1: were of course talking about, uh, the manipulation of centripetal force.
Speaker 1: All right, we're back. So, Robert, you've seen two thousand
Speaker 1: one of Space Odyssey. Oh yeah, one of my favorites.
Speaker 1: And so if you've seen that movie, you've seen at
Speaker 1: least a couple of different versions of the design for
Speaker 1: artificial gravity that exploits centripetal force or centrifugal force. I'll
Speaker 1: talk about the difference between them in a minute now.
Speaker 1: One example in the movie is this giant space station
Speaker 1: called space Station five V for five, and it's shaped
Speaker 1: like a wagon wheel. And the other is this round module.
Speaker 1: It's a spherical module within this spaceship that how controls
Speaker 1: in the movie, the spaceship the Discovery one, which is
Speaker 1: the one that's on the way to I think it's
Speaker 1: Jupiter in the movie and Saturn in the book. Is
Speaker 1: that right, I believe. So, yeah, this is the one
Speaker 1: that's like really round in the front and long in
Speaker 1: the back, right, And so in this crew module in
Speaker 1: the Discovery one in the movie, you see a gravity
Speaker 1: like effect pulling passengers to the floor along the equator
Speaker 1: of this compartment. So we can see the effect in
Speaker 1: this one scene where Frank Pool, the astronaut, is jogging
Speaker 1: in full circles around the inside wall of the sphere.
Speaker 1: So he's jogging laps, but he's not jogging horizontal laps.
Speaker 1: He's jogging full circular orbital laps. Yeah, say it's one
Speaker 1: of it's it's one of you, not like the greatest
Speaker 1: sequence in a science fiction film. It's just so beautiful
Speaker 1: and and and and and thought provoking. So there are
Speaker 1: multiple ways that you could set something like this up,
Speaker 1: and I'll explore a few of those models in a minute,
Speaker 1: But the basic idea is that you create a spinning
Speaker 1: structure within your spacecraft, and the outside edge of the
Speaker 1: spinning environment becomes a floor that pushes up against your
Speaker 1: feet the same way the ground pushes up against your
Speaker 1: feet as you are attracted steadily towards the center of
Speaker 1: the earth. So, in other words, it simulates the effect
Speaker 1: of gravity. Now, like linear acceleration that we just talked about,
Speaker 1: rotation based gravity also relies on the pseudo forced sensation
Speaker 1: generated by inertia to simulate gravity. It's your body's inertia
Speaker 1: feeling like the gravitational force that pulls you towards the
Speaker 1: center of the Earth. Now, in the case of the
Speaker 1: spinning model, this is known as trifical force or the
Speaker 1: centrifugal pseudo force. Now, there are two terms that are
Speaker 1: easy to get confused here, centripetal force and centrifugal force. Uh.
Speaker 1: Centripetal forces is the real force in physics, and this
Speaker 1: is really there two sides of the same coin. So
Speaker 1: centripetal force is something that you will notice if you've
Speaker 1: ever done the old experiment, you know, the thing you
Speaker 1: do when you're a kid, is you get a bucket
Speaker 1: of water and you spin it around in a vertical
Speaker 1: circle so that the top of the circle your buckets
Speaker 1: upside down, but the water stays in the bucket doesn't
Speaker 1: fall out like it would if you just held the
Speaker 1: bucket upside down, and you you realize intuitively something's going
Speaker 1: on there about the force of your swinging motion with
Speaker 1: your arm. For some reason, it being at the top
Speaker 1: of a circular motion keeps the water in the bucket
Speaker 1: in a way that just turning the bucket upside down
Speaker 1: in the same place wouldn't. And so what that is
Speaker 1: is the centripetal force of the bucket pushing down on
Speaker 1: the water to hold it in, while the inertia of
Speaker 1: the water flying in this circular motion wants it to
Speaker 1: fly off in a tangential pattern, uh, and a tangent
Speaker 1: going straight out from the path it's flying along. So
Speaker 1: you can think about it's sort of like anytime something
Speaker 1: is is flying around in a circular motion. Say a
Speaker 1: space station is orbiting the Earth, what it really wants
Speaker 1: to do is keep traveling in a straight line forever. Right,
Speaker 1: So if you've got the I s s it's orbiting
Speaker 1: the Earth, what what it wants to do if there
Speaker 1: were suddenly no Earth is just travel straight ahead, So
Speaker 1: it just keep going off into space. But what the
Speaker 1: Earth does is it exerts a certain amount of force,
Speaker 1: pulling that the space station down towards its center of
Speaker 1: gravity and curving its path. And the same thing happens
Speaker 1: when you've got an object swinging in a circular path,
Speaker 1: but contained by some kind of physical structure or force,
Speaker 1: like your arm and the bucket holding the water in place. Now, so,
Speaker 1: so the centripetal force is the inward force that pulls
Speaker 1: everything toward the center of motion in a circular pattern.
Speaker 1: The centrifugal force sometimes referred to as a pseudo force
Speaker 1: because it's really just inertia in a moving reference frame.
Speaker 1: That's the apparent force that acts on an object moving
Speaker 1: in a circular path to push it outward from the
Speaker 1: center around which it rotates. And this would be taking
Speaker 1: the place of the gravity that actually pulls your feet
Speaker 1: towards the ground on Earth. Now you can also feel
Speaker 1: the intuitive physics of this on your body, just in
Speaker 1: your imagination. If you've ever done the carnival ride Robert,
Speaker 1: where you get on the what is it the cyclotron,
Speaker 1: the circulator gravitron, it's the thing where they put you
Speaker 1: in a cage and your back is against the wall,
Speaker 1: and it's this big disc where everybody's back is against
Speaker 1: the inside wall of the disk, and then it starts
Speaker 1: spinning you around very fast, and suddenly you're just pinned
Speaker 1: to the back while you can't lift your arms up. Uh.
Speaker 1: And it's it's all this force that's that wants to
Speaker 1: throw you off into space, but in fact there's a
Speaker 1: wall they're stopping you, so instead of being thrown off
Speaker 1: into space, you're just pinned to the wall. Yeah, that's
Speaker 1: a carnival death machine that I've probably only written once,
Speaker 1: but but I have written the similar device, and that
Speaker 1: is of course the like the pirate swinging ship. You know, Okay,
Speaker 1: it has a similar similar effect as the bucket scenario
Speaker 1: if the pirates swinging ship or to go all the
Speaker 1: way around, not the ones I ride, but so interesting.
Speaker 1: Uh well, it's also yeah, this the centripetal centrifical force.
Speaker 1: It's the same thing also that allows you in a
Speaker 1: roller coaster to go around a loop. Roller coasters that
Speaker 1: have loops because the force that's keeping you, you know,
Speaker 1: you want your body wants to continue on a straight
Speaker 1: line as it gets to the top of the loop
Speaker 1: and just be flung off up into the sky. But
Speaker 1: instead you've got that roller coaster they're holding you, so
Speaker 1: instead you're pressed down into your seat, which is actually
Speaker 1: straight up from the ground. Um. And so the same
Speaker 1: thing you can imagine could happen in space. If you've
Speaker 1: got a space environment and you're on a thing that's spinning,
Speaker 1: you know that you will experience some kind of force
Speaker 1: pinning you to the outside wall of that spinning structure
Speaker 1: in the same way as as the bucket of water
Speaker 1: and the loop de loop on the roller coaster. So
Speaker 1: then the question is how do you generate the right
Speaker 1: amount of force there. Obviously, you don't want your the
Speaker 1: inside of your space station to be like the Gravitron
Speaker 1: ride where you can't even lift your arm and you're
Speaker 1: just pinned to the floor. Uh, you want to simulate
Speaker 1: something within the realm of one G or one of
Speaker 1: these fractions of one g that seemed like they might
Speaker 1: be a tolerable living environment or at least help offset
Speaker 1: some of the effects of micro gravity. And so you
Speaker 1: calculate how much force you generate towards the floor of
Speaker 1: a spinning structure by multiplying the radius of the structure
Speaker 1: by the speed of the rotation squared. So your two
Speaker 1: main variables are going to be how fast is the
Speaker 1: thing spinning around and how big is it? And since
Speaker 1: you're multiplying these together, the bigger the structure is and
Speaker 1: the faster it rotates, the more force there is towards
Speaker 1: the floor. And unlike the problem I just mentioned about
Speaker 1: being pinned to the floor, actually mostly the problem that
Speaker 1: we're going to experience is how to generate enough force,
Speaker 1: not how not to generate too much. Alright, so we
Speaker 1: have the basic principle here. We've already mentioned some of
Speaker 1: the sci fi scenarios. But what are some specific proposals. Well,
Speaker 1: you've got some basic shapes that you could think about,
Speaker 1: and then I'll talk about how those shapes have been
Speaker 1: proposed in the history. Now, one thing you could obviously
Speaker 1: look at is something like the two thousand one space station,
Speaker 1: which is like a wheel. So you'd have a donut,
Speaker 1: and inside the donut it's hollow, and people are walking
Speaker 1: around on the outer wall of the inside of the
Speaker 1: hollow donut. This would be the torus shape or the
Speaker 1: wheel shape. And we tend to gravitate towards this because
Speaker 1: everyone loves the wheel, like the wheel is such a
Speaker 1: such an excellent human symbol. There, of course we want
Speaker 1: to see it in space, uh, magnifying our glory as
Speaker 1: a species. Yeah, well, there's that. There's there's the flying saucer.
Speaker 1: You know, we love to see a wheel that way.
Speaker 1: There's the passage in Ezekiel about seeing wheels, wheels and wheels. Now,
Speaker 1: there's also sort of the cylinder model right where you
Speaker 1: you'd have the same effect where you'd be moving on
Speaker 1: the outs or the inner wall or sorry, now here
Speaker 1: you'd have a similar effect where you'd be walking along
Speaker 1: on the inside of the outer wall of a spinning cylinder,
Speaker 1: and that would be a lot like the effects caused
Speaker 1: by the wheel. Another thing that's kind of interesting is
Speaker 1: the idea of something like a bolus or a or
Speaker 1: a tethered counterweight, where instead just imagine putting yourself in
Speaker 1: a box and then tying that box via a rope
Speaker 1: to an equally weighted counterweight out in space, and then
Speaker 1: you just the two of you rotating against one another.
Speaker 1: This would also generate a force toward the outer floor
Speaker 1: of the box. The you know, the wall facing away
Speaker 1: from the rope would become the floor. Okay, it's less elegant.
Speaker 1: And the other thing about it is that it is
Speaker 1: called a bolus, which brings to mind various things, uh,
Speaker 1: flying out of either orifice. Right, so you're saying, like,
Speaker 1: if you had to perform the Heimlich maneuver on a fellow,
Speaker 1: ask or not, they might cough up a bolus of
Speaker 1: food they've been choking on. Or you're reading, well, you're
Speaker 1: in the bullus. Yeah, And then of course I've also read, uh,
Speaker 1: I think I've read in like space manuals about uh
Speaker 1: using the toilet in space, they refer to the fecal bolus.
Speaker 1: So the less you have to think about the fecal
Speaker 1: bolus or the traditional you know, bolus of food that
Speaker 1: you're your your your tongue helps form before you swallow. Yeah,
Speaker 1: you don't want to think about that when you're spinning
Speaker 1: around in a capsule in space. No, you don't, Robert, No,
Speaker 1: you don't at all. Okay, So let's look at some
Speaker 1: specific examples of proposals for for spinning artificial gravity stations
Speaker 1: in spacecraft throughout the years. And here I'm gonna cite
Speaker 1: a lot from a specific chapter from that same book
Speaker 1: you mentioned earlier about artificial gravity. This would be the
Speaker 1: chapter on the history of artificial gravity, and that's again
Speaker 1: in that book by uh by Clement, Bookley, and Pulaski.
Speaker 1: So one of the earliest known designs for a space
Speaker 1: station with artificial gravity created by rotation comes from the
Speaker 1: Russian physicist Konstantin L. Tilkowsky, who lived from eighteen fifty
Speaker 1: seven and nineteen thirty five. And Tilkowsky was an interesting dude.
Speaker 1: He was one of the pioneers of rocketry theory, but
Speaker 1: he also was one of those futurists, right. He was
Speaker 1: one of these people who became obsessed with the idea
Speaker 1: of colonizing space. He wanted humans to colonize space. He
Speaker 1: wanted earth domination of the galactic neighborhood. And one interesting
Speaker 1: story I found is that he at one point built
Speaker 1: a big centrifuge to who test out the effects of
Speaker 1: acceleration or artificial gravity on the human body. But he
Speaker 1: didn't use human test subjects. He tested it on chickens
Speaker 1: and made the gravity chickens rest in peace anyway. In
Speaker 1: his manuscript the title, which translates to free space in
Speaker 1: eighteen eighty three, Tiolkowski sketched a hypothetical spacecraft and designed
Speaker 1: how you could spin a spaceship to give it artificial
Speaker 1: gravity on the outward facing walls. Another pioneer who would
Speaker 1: be Sergey kral V, one of the great minds behind
Speaker 1: the Soviet space program. He was a really ambitious guy,
Speaker 1: and in nineteen fifty nine he was designing a trip
Speaker 1: to Mars in nineteen fifty nine via a spacecraft called
Speaker 1: the Heavy Interplanetary Manned Vehicle. And no, this was nineteen
Speaker 1: fifty nine. This was before Urikagarin's first space flight in
Speaker 1: nineteen sixty one. No human had been to space at
Speaker 1: this point. And this guy's like, all right, we gotta
Speaker 1: get this Mars trip on the road. Um, And anyway,
Speaker 1: this the spaceship that he was designing, the h I
Speaker 1: m V. It would have a mass of seventy five tons,
Speaker 1: a length of twelve meters, and it would have this
Speaker 1: cabin that was six meters in diameter. That's not a
Speaker 1: whole lot, but he he did imagine that he would
Speaker 1: be able to use this ship as a rotating artificial
Speaker 1: gravity environment. Um we can talk later about exactly how
Speaker 1: feasible very small rotating artificial gravity environments are. The short
Speaker 1: answer is not very um. So, coral Lev's dreams were
Speaker 1: severely limited by material and political constraints, and during the
Speaker 1: nineteen sixties he was forced to focus more on attempting
Speaker 1: to sort of match Apollo scale space projects UH and
Speaker 1: to work on weapons programs, of course, and so he
Speaker 1: also ended up proposing a tethered capsule based artificial gravity experiment,
Speaker 1: but it was never carried out, and coral Lev died
Speaker 1: in nineteen sixty six and the project was shut down.
Speaker 1: What I mentioned this this tether system, the bolus, Right,
Speaker 1: You have two things attached by a tether and you
Speaker 1: rotate them against one another to see if you can
Speaker 1: generate a force. That kind of system was actually tried
Speaker 1: in space by the Americans. Now, if you'd asked me
Speaker 1: a few weeks ago, I think I would have thought
Speaker 1: that the nobody had ever carried out large scale artificial
Speaker 1: gravity experiments on or at least on the human scale
Speaker 1: in space. I know they you know, they've centerfuged a
Speaker 1: few small animals and little contraptions, but I did not
Speaker 1: know there had ever been anything on the human scale.
Speaker 1: This experiment may count though it's it's a pretty weak attempt,
Speaker 1: but it wasn't attempt. I don't mean to say weak,
Speaker 1: like these astronauts and scientists didn't know what they were doing,
Speaker 1: but they didn't attempt all that much in terms of
Speaker 1: artificial gravity, right, I mean, it has will become clear
Speaker 1: as you explain it. It's still like anything you do
Speaker 1: in orbit is pretty balls. Yeah. So this this definitely qualifies,
Speaker 1: but to your point in m it's not exactly a
Speaker 1: robust exploration. Yeah. So this this is the Bullus method
Speaker 1: and it was tested to a to a very small
Speaker 1: extent during the Gemini eleven mission in nineteen sixty six,
Speaker 1: or as the people at the time would say, jiminy,
Speaker 1: and it was crewed by Charles Pete Conrad and Richard Gordon,
Speaker 1: and while in orbit around the Earth, the Gemini spacecraft
Speaker 1: was attached to a heavy counterweight object called the Agena
Speaker 1: Target Vehicle by h and that Agena target vehicle had
Speaker 1: on it a thirty meter tether. Now, at the time,
Speaker 1: we didn't have these really good complicated robotic arms or
Speaker 1: auto locking cable jacks. To get these two objects connected
Speaker 1: via the tether, Richard Gordon, the crew member, had to
Speaker 1: leave the cabin in a space suit and attached the
Speaker 1: tether manually, and apparently this job was grueling. Gordon got
Speaker 1: so overexerted doing it that his life support system was
Speaker 1: stressed and he was sweating so much inside his space
Speaker 1: suit that he couldn't see out of his right eye.
Speaker 1: Oh man, because I imagine it's just kind of like
Speaker 1: pulling up puddling up right, exactly like the dripping off
Speaker 1: the frozen in the lake at the bottom of Dante's Inferno,
Speaker 1: you know, Oh oh man, Yeah, wow, I never thought about.
Speaker 1: I had really not thought about, like the sweating in
Speaker 1: space and blinding yourself with your own tears horrible. But anyway, yes,
Speaker 1: sweating so much he blinded himself in his right eye. Anyway,
Speaker 1: he did manage to get the two spacecraft attached by
Speaker 1: the tether. He got back inside the Gemini cabin and
Speaker 1: they were able to close the hatch and repressurize. Later
Speaker 1: after they were connected via the tether, the two spacecraft
Speaker 1: undocked from one another, so they disconnected except for the tether,
Speaker 1: and then they stretched out and pulled the tether taut
Speaker 1: and they began a rotation movement. And apparently it was
Speaker 1: hard to get this stable because they were what they
Speaker 1: called oscillations. I imagine that's like the tether being taught
Speaker 1: but then loosening maybe or moving side to side. Um,
Speaker 1: there were ascilly sins in the rotation and for the
Speaker 1: first twenty minutes or so, and then after that the
Speaker 1: rotation rate was was increased, and the crew successfully managed
Speaker 1: to generate a tiny artificial gravity effect inside the Gemini
Speaker 1: eleven capsule. Uh. Supposedly, one way they measured this is
Speaker 1: somebody dropped a camera and it went in a straight
Speaker 1: line toward the floor, toward the outside wall of the
Speaker 1: capsule that was away from where the tether was. So
Speaker 1: they measured it and figured that they had generated about
Speaker 1: zero point zero zero zero five G. And but that
Speaker 1: was with zero point fifteen revolutions per minute, So this
Speaker 1: is a very slow rotation. It's not a huge construct. Um. So,
Speaker 1: I mean, that's a reasonable thing to generate if they
Speaker 1: had been rotating faster, or if the tether had been longer,
Speaker 1: they might have been able to to create a more
Speaker 1: powerful effect. But anyway, this did prove the principle and
Speaker 1: afterwards the tether was released and the edge in a
Speaker 1: vehicle was dropped to its orbital fate after about three hours.
Speaker 1: Now moving on, the author's also talk about how in
Speaker 1: nineteen eight there was this Slovene engineer named Herman Potasnik,
Speaker 1: writing under the pseudonym Herman Nerdung, who proposed a wheel
Speaker 1: shaped space station with habitation around the rim of the wheel.
Speaker 1: And his idea was that you'd have this wheel that
Speaker 1: people would live in, and then the hub of the
Speaker 1: wheel you'd have a power generating station. And this would
Speaker 1: have been thirty meters in diameter. It was called the
Speaker 1: one rod or living wheel. And then in nineteen fifty
Speaker 1: three in Collier's Weekly, the German American rocket scientists Werner
Speaker 1: von Braun took this wheel shaped model and updated it
Speaker 1: to be larger with a seventy six meter diameter. And
Speaker 1: von Braun calculated that if you had a wheel seventy
Speaker 1: six ms wide and it rotated at three revolutions per minute,
Speaker 1: you could simulate a gravity of zero point three G,
Speaker 1: which is sort of close to the gravity of Mars,
Speaker 1: which is zero point three a G. And this would
Speaker 1: make it suppose is a good training facility from ours expeditions,
Speaker 1: but also, as we were talking about earlier, might be
Speaker 1: within livable tolerances for human life. You know, if if
Speaker 1: that's the best you could do in space, that might
Speaker 1: still be better than micro gravity, better than nothing at all, right,
Speaker 1: I mean, without without like actually doing any math on this,
Speaker 1: if you could make it to wear a really rigorous
Speaker 1: exercise regime for your space faring human if it allowed
Speaker 1: them to like could cleanly break even against you know,
Speaker 1: loss to to bone and muscle, then it would be
Speaker 1: worth it, right, right. I mean, I'd imagine three hours
Speaker 1: of exercise a day and zero point three G does
Speaker 1: a lot more work than three hours of exercise a
Speaker 1: day and zero G. Yeah. And on top of that,
Speaker 1: you're getting acclimatized to the gravity that you're headed towards totally. Yeah.
Speaker 1: And so there have also been some really interesting proposed
Speaker 1: odd models, like in nineteen sixty four, Dandridge Cole and
Speaker 1: Donald Cox proposed this interesting idea. So Cole was really
Speaker 1: interested in the mining and colonization of asteroids. And one
Speaker 1: of his proposed ideas was that you'd capture a large
Speaker 1: asteroid to be about thirty kilometers in length, that ideally
Speaker 1: to be an elliptical asteroid, kind of egg shaped, and
Speaker 1: you'd hollow out the inside of it, and then you
Speaker 1: would use propulsion to get the asteroid rotating along its
Speaker 1: major axis, and this would generate artificial gravity inside the
Speaker 1: hollowed out asteroid, and you could sort of build a
Speaker 1: bubble city on the inside walls of the hollow space rocks,
Speaker 1: sustained by shining sunlight into the core with mirrors. This
Speaker 1: was also explored on the Expanse. By the way they
Speaker 1: talk about colon cox Um. I don't remember if they
Speaker 1: if they actually referenced them in any way, but there's
Speaker 1: they discussed, like the the early efforts to reach these
Speaker 1: various asteroids and to create a spin mine amount get
Speaker 1: them spinning and then you can build habitats inside them.
Speaker 1: Did it work or not work? I mean in the
Speaker 1: knovel work. Okay, the only thing that didn't work in
Speaker 1: the novels was the colonization of Venus, like that ended
Speaker 1: up failing. They're trying to create like floating cities. Yeah,
Speaker 1: but anyway, Elsman, that could go really bad. Well anyway,
Speaker 1: so yeah, another weird idea this, Well it's actually maybe
Speaker 1: not that weird because here you get something like it.
Speaker 1: In two thousand one of Space Odyssey would be a sphere.
Speaker 1: So the American physicist Gerard K. O'Neill proposed a rotating
Speaker 1: sphere that he called Island one and this would be
Speaker 1: five in diameter, would rotate once every thirty seconds, which
Speaker 1: he said would generate about one earth G at the equator.
Speaker 1: Now that's an important thing to consider a rotating sphere.
Speaker 1: It would be different than a rotating wheel, and that
Speaker 1: there'd be areas you could access that would not have
Speaker 1: the same gravity. Right Like, if if you go to
Speaker 1: the equator, you'd get your maximum gravity, but then if
Speaker 1: you walk up to the poles of the rotating sphere,
Speaker 1: you'd basically be waitless because it wouldn't be a like
Speaker 1: a Hall Earth scenario where you would ideally have like
Speaker 1: the mass of the crust. Like the mass it's not
Speaker 1: going to play a part in this, So yeah, you
Speaker 1: would you would only experience the the maximum g's at
Speaker 1: that equator. Because again it's not actually due to gravity.
Speaker 1: It's due to acceleration. R. It's due to your inertia
Speaker 1: against the constant angular acceleration of the rotating reference frame.
Speaker 1: Later that same guy, Gerard O'Neill, he proposed a larger
Speaker 1: model he called Island two and eventually this gigantic aluminum
Speaker 1: structure that came to be known as the O'Neill cylinder.
Speaker 1: And this would end up measuring more than thirty kilometers
Speaker 1: long and three point two kilometers in radius. And you
Speaker 1: do this by rotating a little over once every two minutes,
Speaker 1: which could create earth gravity around the inside edges of
Speaker 1: the cylinder. And he envisioned this model would actually it
Speaker 1: would be like an Earth in space. It would contain
Speaker 1: natural landscapes that have forests and rivers and individual illages within. Yeah,
Speaker 1: you'd have sunlight directed inside from external mirrors. I mean
Speaker 1: crazy stuff that there's a he had a book book,
Speaker 1: The High Frontier Human Colonies in Space, and the illustrations
Speaker 1: from this are just magnificent. I know you included one
Speaker 1: in in our notes for this this episode. Not trying
Speaker 1: to include some on the landing page for this episode
Speaker 1: of Stuff to Blow your Mind dot Com. Because these
Speaker 1: are just gorgeous, gorgeous sci fi illustrations that really capture
Speaker 1: that sort of retro optimism for humanity's future beyond Earth.
Speaker 1: Why they kind of make me think of like Broigel
Speaker 1: or something. Yeah, yeah, I mean it's it's it's these
Speaker 1: just landscapes, you know, turned on their side and looped
Speaker 1: together to create this uh this this this internal rotating world. Yeah.
Speaker 1: I'm not quite sure why, but this one illustration we've
Speaker 1: got included here, it reminds me of U. Broigel's landscape
Speaker 1: at the Fall of Icarus. Though I don't think you're
Speaker 1: to invoke chorus when contemplating such titanic feats of human achievement,
Speaker 1: and with so many lives at stake, it is a
Speaker 1: temptation of the gods to call down uh misfortune on
Speaker 1: our hubris. And I mentioned the lives involved, because, for instance,
Speaker 1: in in O'Neill's Island one here he's talking about tens
Speaker 1: of thousands of people living inside there and uh, you know,
Speaker 1: a living there out their planet free lives and a
Speaker 1: technological uh simulacrum of their home world environment. Anyway, you'll
Speaker 1: have to you have to look at the images that
Speaker 1: truly beautiful stuff totally and you can see in the
Speaker 1: images that, like the idea for the hollow asteroid, this
Speaker 1: would use huge windows and mirrors to shine sunlight inside
Speaker 1: for night and day cycles, which would be another thing
Speaker 1: that would be absolutely crucial if you're trying to fully
Speaker 1: simulate an Earth environment. Now, I guess it's finally time
Speaker 1: to talk about probably the favorite model, the thing that
Speaker 1: everybody usually goes to, which is the Taurus. Yes it's
Speaker 1: the standard. Yes, it is the standard, and it is
Speaker 1: the standard from Stanford, the Stanford Taurus. So this is
Speaker 1: really the answer to what's most feasible, or at least
Speaker 1: what scientists have concluded in the past. So in nine five,
Speaker 1: NASA and the American Society for Engineering Education put together
Speaker 1: a study comparing submitted designs for spacecraft habitats, and this
Speaker 1: was published by Johnson and Holbrow in nineteen and it
Speaker 1: looked at wheel shaped design, cylinder design, spherical designs, and
Speaker 1: NASA ultimately decided that a design submitted by Stanford students
Speaker 1: was the most feasible, and this was the design that
Speaker 1: came to be known as the Stanford Taurus. So it
Speaker 1: Taurus is like we've been saying a ring, it's a
Speaker 1: hollow doughnut, and the Stanford Taurus would be a ring
Speaker 1: shaped tube. So it's a tube like a cylinder, except
Speaker 1: it's a tube that goes around in a circle and
Speaker 1: connects on itself a hollow donut. And so inside that
Speaker 1: tube it would be a hundred and thirty meters across.
Speaker 1: Now keep in mind that's not the diameter of whole
Speaker 1: ring that's inside the tube that makes the ring, but
Speaker 1: the diameter of the whole thing would be about one
Speaker 1: point eight kilometers across, and then it would be the
Speaker 1: two would be about five point six kilometers long. So
Speaker 1: that would be the circumference and spinning the ring at
Speaker 1: one revolution per minute at these dimensions, it would generate
Speaker 1: about one G along the outer edge of the tube
Speaker 1: or earth gravity, and so feasibly you could build whole
Speaker 1: earth environments inside, like the O'Neill cylinder. If this were built,
Speaker 1: you could supposedly have running water, farms, woods, all that
Speaker 1: kind of stuff to make a space habitat as lovely
Speaker 1: and wonderful as our natural earth habitat. And in the
Speaker 1: nineteen sixties and seventies, NASA did investigate ideas for creating
Speaker 1: artificial gravity environments for upcoming space missions. There's one illustration
Speaker 1: I found that I thought was pretty cool. I I
Speaker 1: don't know what the name of this is. I don't
Speaker 1: know if it had a name. I'm calling it the
Speaker 1: Rod because it's also a rotating a station. But it's
Speaker 1: just a big rod. Now it's not rotating. It's not rotating,
Speaker 1: you know, like rolling as a rod. It's spinning, spinning baton,
Speaker 1: which I thought was interesting. So in nineteen sixty nine,
Speaker 1: the U. S Space Agency concept drawing for for this
Speaker 1: space station was produced. And I think it's an interesting concept,
Speaker 1: but obviously has you know, so it's got less material
Speaker 1: investment than the construction of a huge wheel. But I
Speaker 1: would imagine it also has drawbacks. Like the farther you
Speaker 1: farther along you are towards the ends of the rod,
Speaker 1: the more gravity you experience, right, because gravity is a
Speaker 1: product of the speed of the rotation and the radius,
Speaker 1: And so as you go toward the center of the rod,
Speaker 1: you're shortening your radius, and as you go toward the
Speaker 1: outside of the rod, you're lengthening your radius, and so
Speaker 1: at the center you'd be waitless. So I can imagine
Speaker 1: maybe something like this would be a system where the
Speaker 1: end compartments are again the places you go for your
Speaker 1: daily workouts in Earth gravity, the habitable zones really, yeah,
Speaker 1: to keep your your muscles and bones strong. And then
Speaker 1: the lower gravity environments would be I guess where you
Speaker 1: do other things. Maybe you sleep there, you know, I
Speaker 1: don't know, store stuff there or something like that. Or
Speaker 1: it's just where the captain gets to live, you know.
Speaker 1: Everyone else has to float and deal with it. Yeah,
Speaker 1: And and this does draw on conceptually something that we
Speaker 1: see in science fiction a lot of the time, which
Speaker 1: is that maybe not the entire habitable portion of the
Speaker 1: of a spacecraft has artificial gravity. Maybe much of it
Speaker 1: is going to be a micro gravity environment where you're
Speaker 1: floating around, but there's like one room that's a rotating
Speaker 1: drum or taurists or something that you can go into
Speaker 1: and there's artificial gravity and that one contained environment. Yeah. Now,
Speaker 1: in in Peter Watt's blind Side, if I remember correctly, here,
Speaker 1: there are portions of the ship that have artificial gravity
Speaker 1: via spin, but they're also working in even sweeping in
Speaker 1: the zero gravity area. I think so, yeah, I think so.
Speaker 1: I think most of the ship, uh, if I recall,
Speaker 1: is going to be a zero gy environment where you're
Speaker 1: floating around, you have to propel yourself, and then there's
Speaker 1: one portion of the ship known as the drum that's
Speaker 1: the gravity environment. So there have been a lot of
Speaker 1: these propositions over the years. You know, NASA's looked at
Speaker 1: how to create space stations like this, but ultimately these
Speaker 1: designs would be extremely expensive to produce and difficult to
Speaker 1: execute a little bit more on that later. But another
Speaker 1: factor is that you know, NASA's scientists are looking at
Speaker 1: this and they're saying, well, a lot of the experiments
Speaker 1: we want to carry out or microgravity experiments anyway. Right,
Speaker 1: So I don't know, do do we really need to
Speaker 1: spend all this money making the International Space Station UH
Speaker 1: an artificial gravity environment when people aren't going to be
Speaker 1: spending their whole lives there. They're just gonna be there
Speaker 1: for a short period of time and then they're gonna
Speaker 1: come back and they'll be able to recover some of
Speaker 1: the negative health effects. Yeah, I mean noticed to two
Speaker 1: of the main points wrapped up in that we don't
Speaker 1: really need need um artificial gravity right now, not based
Speaker 1: on what we're currently doing. Yeah, and we're still there's
Speaker 1: still so much to learn about the effects of micro
Speaker 1: gravity on organisms right now, there's also still a lot
Speaker 1: to learn about the effects of artificial gravity on organisms. Now,
Speaker 1: if that's with the qualification, it's taught. What you're talking
Speaker 1: about there is the specific effects of centrifugal artificial gravity,
Speaker 1: because those are going to be somewhat different than just
Speaker 1: a pure, say, linear acceleration type artificial gravity that's going
Speaker 1: to be mostly indistinguishable from earth um in centrifugal environments,
Speaker 1: if you're in a spinning environment, depending on how small
Speaker 1: the radius is and how fast you're spinning, it could
Speaker 1: have weird effects. And I'll talk about those complications in
Speaker 1: a minute. But so to study those weird effects, scientists
Speaker 1: have conducted uh experiments on animals like fish, rats, turtles,
Speaker 1: and generally animals seem to survive centerfuging in space just fine,
Speaker 1: though in systems with a very high rotation rate, rats
Speaker 1: seem to have a problem with orientation, movement, and vestibular
Speaker 1: and motor coordination. So it's not a big surprise. But
Speaker 1: if you put them in a rotating centerfuge with a
Speaker 1: small radius and very fast rotation, you get some very
Speaker 1: dizzy and confused and uncomfortable rats. But on the plus side,
Speaker 1: the centerfuging process does appear to stave off the wasting
Speaker 1: effects of zero G. So if you put animals in
Speaker 1: a centerfuge like this, their bones and muscles do appear
Speaker 1: to stay strong. Now, just to turn to one more
Speaker 1: recent proposition of an artificial gravity spacecraft, h I thought
Speaker 1: we should look at real quick at the Nautilus X.
Speaker 1: Apparently this is also the name of some vaping product,
Speaker 1: which is most of what the Google results are about,
Speaker 1: So God help us there. But uh, the Nautilus X
Speaker 1: was a proposed NASA spacecraft that would contain a rotating centerfuge.
Speaker 1: It would have a torus ring that was built to
Speaker 1: simulate partial Earth G for the habitable quarters. And the
Speaker 1: spacecraft was designed but never built, and you can look
Speaker 1: up images of the design on the internet. It's kind
Speaker 1: of interesting to see. I think the idea is that
Speaker 1: part of it here would have this hollow doughnut that
Speaker 1: would be rotating and you could you could transfer its
Speaker 1: momentum to a flywheel and uh, and so it'd be
Speaker 1: rotating around the ship and you could get in there
Speaker 1: to have some gravity time. And there have also been
Speaker 1: plenty of proposals over the years to add a centerfugure
Speaker 1: to the I S S in order to test artificial gravity.
Speaker 1: As far as I can tell, I don't think anything
Speaker 1: like that is still on the runway right now. I
Speaker 1: think these plans have pretty much stalled out. I don't
Speaker 1: know if you were able to across anything, but yeah,
Speaker 1: that was it seemed actually active right now. Yeah, but
Speaker 1: there may be hope. So I don't know if you're
Speaker 1: out there working on a center fugure for the I
Speaker 1: S S and you think it might one day get
Speaker 1: up there, let us know. Well, you know, the turbo
Speaker 1: lift that I mentioned, like that news of it being funded,
Speaker 1: that's just this year. So it's possible that there's some
Speaker 1: additional initiatives that have been funded in the past couple
Speaker 1: of months. I hope they're not in competition. Would it
Speaker 1: be turbo latter versus centerfuge. It sounds like a great battle,
Speaker 1: that's for sure. Now. I've mentioned several times the possible
Speaker 1: complications of a spinning artificial gravity environment, right you can
Speaker 1: sort of imagine that there might be some that's spinning
Speaker 1: around in a circle towards the floor. Is not going
Speaker 1: to be exactly the same as having a gravitational force
Speaker 1: pulling you toward the ground. It It might in most cases,
Speaker 1: or depending on the radius and the rotation rate, be
Speaker 1: mostly indistinguishable, but especially at smaller scales, there are going
Speaker 1: to be some weird complications. This is gonna be the
Speaker 1: frozen from concentrate orange juice version of fresh orange juice. Yep,
Speaker 1: I think we should talk about the Coriolis force. So, Robert,
Speaker 1: imagine you're on a ferris wheel. You at home as well.
Speaker 1: Imagine you're up there. You're in the car on the
Speaker 1: ferris wheel, and you're just coming up over the top
Speaker 1: of the ferris wheel, and you notice that a friend
Speaker 1: of yours is directly below you, and you want to
Speaker 1: pour some mountain dew on their head, so you pour away.
Speaker 1: You pour the mountain dew to hit your friend, but
Speaker 1: you miss, and the dew instead hits the people in
Speaker 1: the car directly behind your friend. And this really shouldn't
Speaker 1: surprise anybody, right, this is just duh. I mean, you're
Speaker 1: on a ferris wheel. Even though your friend was directly
Speaker 1: below you. When you began pouring the liquid straight straight down,
Speaker 1: the wheel was in motion, and by the time the
Speaker 1: liquid fell and reached the bottom. Your friend had moved
Speaker 1: out of the way, and somebody else had moved in. Now,
Speaker 1: this is totally normal, totally intuitive physics on a ferris
Speaker 1: wheel because we're generally looking at a ferris wheel from
Speaker 1: the outside. But if you try to imagine riding a
Speaker 1: rotating machine like a ferris wheel around in a circle
Speaker 1: in zero G in a closed environment, the rotation becomes
Speaker 1: your new stationary reference frame you the The whole idea
Speaker 1: is that you're supposed to be able to forget that
Speaker 1: you're rotating, and instead of feeling rotation, just feel a
Speaker 1: pull toward the floor. Like. Notice how even though your
Speaker 1: section of the Earth is orbiting the Sun and rotating
Speaker 1: around the Earth's axis, everything seems perfectly still. Right, this
Speaker 1: is your inertial reference frame, And since everything around you
Speaker 1: is moving it roughly the same speed in the same direction,
Speaker 1: everything feels like it's holding still. And the same thing
Speaker 1: could happen inside a closed environment rotating into constant speed
Speaker 1: in direction in space, and so then the exact same
Speaker 1: trajectory we saw with pouring the liquid down from the
Speaker 1: top to the bottom of the ferris wheel still applies.
Speaker 1: But because we're not looking in from the outside, it
Speaker 1: starts to look super odd, Like you could throw a
Speaker 1: packet of dehydrated space lasagna straight at somebody's face across
Speaker 1: the torus from or across the cylinder or whatever it
Speaker 1: is in this spaceship, and it would appear that even
Speaker 1: though you threw it straight, this thing you threw would
Speaker 1: suddenly arc over to the side, and so from your perspective,
Speaker 1: things would have this bizarre motion that wouldn't appear to
Speaker 1: make any sense at all unless you were looking at
Speaker 1: the ship from the outside. Yeah. And there's actually a
Speaker 1: point in blind Side where they reference this where one
Speaker 1: individual throws it's either it's a ball or fruit or
Speaker 1: an apples. I think it's an apple, yeah yeah, and
Speaker 1: uh and it kind of goes wide. Yeah yeah, yeah,
Speaker 1: And this would be a problem. Now that might not
Speaker 1: be a big deal because you're like, well, how often
Speaker 1: do you need to throw something to somebody? Well, actually,
Speaker 1: if you watch people in the International Space Station, they're
Speaker 1: sort of tossing stuff to each other a lot. Yeah,
Speaker 1: they're taking advantage of the microgravity. But it gets a
Speaker 1: lot worse than just tossing stuff to each other, because
Speaker 1: this also is going to affect just general movement. If
Speaker 1: you're at a small enough scale, like if your radius
Speaker 1: is small enough and your rotations are fast enough, this
Speaker 1: is going to be affecting how your body itself moves.
Speaker 1: And it's even worse when you think about how it
Speaker 1: could affect, like affect your internal body systems. Yeah, I
Speaker 1: mean you could. You could find yourself in your chamber
Speaker 1: and no matter how how else the rest of you
Speaker 1: feels about your your your artificial gravity scenario, you might
Speaker 1: feel a bit nauseous. The coreolis effects on inner ear,
Speaker 1: indo limp flow and on moving limbs creates a disorientation, nausea, vomiting,
Speaker 1: and even can cause loss of coordination. Yeah, and this
Speaker 1: actually isn't all that hard to understand because you've probably
Speaker 1: experienced something like this in your life, if you've ever
Speaker 1: been car sick while trying to read inside a moving car.
Speaker 1: In both cases, what's going on is that the fluids
Speaker 1: inside your body are slashing around in directions that don't
Speaker 1: make sense to your eyes based on your environmental reference frame.
Speaker 1: So in a car, you're sitting in the car, you
Speaker 1: don't really feel like you're moving. You just kind of
Speaker 1: feel like, Okay, I'm sitting here stationary in a car,
Speaker 1: especially if you're reading or doing something with your eyes down,
Speaker 1: you're not getting the information in about movement around in
Speaker 1: your environment. Meanwhile, the inside of your body, especially your
Speaker 1: inner ears, saying like whoa, we're all over the place,
Speaker 1: what's going on? And that discuss This discontinuity or disagreement
Speaker 1: between the movement information supplied by your senses and felt
Speaker 1: by your inner ear causes this destabilizing sensation. It makes
Speaker 1: you sick. Now. One of the issues here that we
Speaker 1: keep coming back to is that the smaller you're rotating environment,
Speaker 1: the more it is actually a carnival ride, and that
Speaker 1: the larger it is, uh, the better chance you have
Speaker 1: it's smoothing some of the more undesirable effects out exactly right.
Speaker 1: So if you, I mean, one thing you'll notice is that, like,
Speaker 1: there are Coreolis effects in the rotation of the earth, right,
Speaker 1: but normally comes up in aviation. Yeah, if you throw
Speaker 1: a baseball, if you are just standing around, like, the
Speaker 1: Coreolis effect of the rotation of the Earth is not
Speaker 1: messing with you too bad because the Earth is huge. Um,
Speaker 1: if you if you're in a much smaller rotating reference frame,
Speaker 1: it would be messing with you a lot more. I mean,
Speaker 1: mainly on Earth, you only see the rotation of the
Speaker 1: Earth causing Coreola's forces to affect a large scale movement
Speaker 1: such as like tides and weather patterns, you know, huge
Speaker 1: movements over long distances and long time. Yeah, and so
Speaker 1: the same would be generally true in an artificial gravity
Speaker 1: environment that was rotating, if it was a very very
Speaker 1: big radius and a slow rotation. In this environment, the
Speaker 1: Coriolis forces would be much less likely to have a
Speaker 1: noticeable effect on your body and on the stuff you're doing.
Speaker 1: Another side effect, especially of a small radius fast rotation system,
Speaker 1: would be in a rotating environment, you could have unequal
Speaker 1: gravity loading. That's about as weird as it sounds. So
Speaker 1: the centrifugal force you feel, like we were saying, is
Speaker 1: partially determined by your distance from the hub. So in
Speaker 1: a big wheel, this isn't it's not gonna matter very much.
Speaker 1: You know, the percent distance from the hub between your
Speaker 1: head and your feet, if the hub is hundreds and
Speaker 1: hundreds of meters away, is just you know, it's just
Speaker 1: not that much. If it it's ten meters away, then
Speaker 1: suddenly you might start to feel a significant difference between
Speaker 1: the gravity affecting your feet and the gravity affecting your head,
Speaker 1: and this could affect it could lead to problems with
Speaker 1: things like circulation. But it would also just be disorienting
Speaker 1: and make movement difficult, partially negating the benefits of artificial gravity.
Speaker 1: Another reason that if we were going to make one
Speaker 1: of these things and it was to be effective, it
Speaker 1: would need to be very big. And that is the
Speaker 1: answer to one of our final questions. Here at the end,
Speaker 1: you're saying, Okay, so we know basically that we could
Speaker 1: make some form of artificial gravity sort of work. I mean,
Speaker 1: it might not be perfect, but this is you know,
Speaker 1: basic physics. This is not something that's totally hypothetical. It
Speaker 1: could work, So why haven't we done it? The main
Speaker 1: issue is size and cost. For a spinning artificial gravity
Speaker 1: environment to be tolerable to human occupants, it would need
Speaker 1: to be pretty big. And to be that big, you
Speaker 1: would need lots of construction materials. And to get lots
Speaker 1: of construction materials into space, you need a lot of
Speaker 1: rocket launches, and rocket launches are very expensive. They're getting cheaper,
Speaker 1: but they're still very expensive For the tons of materials
Speaker 1: you need to get up there to build this stuff.
Speaker 1: So it really at this point is mainly a matter
Speaker 1: of cost, right, And I mean you can basically any uh,
Speaker 1: any space mission, any space initiative. I mean, they're going
Speaker 1: to be priorities, and you can even if if something
Speaker 1: like this is on the list, it's going to get
Speaker 1: pushed down by other initiatives. Yeah, yeah, totally. And I mean,
Speaker 1: so building a one of these big, functioning artificial gravity
Speaker 1: environments that would be something habitable, generating something close to
Speaker 1: Earth g could fit a lot of people on it,
Speaker 1: You're you're probably talking about just a multi trillion dollar
Speaker 1: project here. It would just be so huge it's kind
Speaker 1: of not feasible for Earth space programs at the investment
Speaker 1: levels they're encountering. Now here's another problem. We've got some
Speaker 1: limits on research. Right. Ideally, if you're gonna launch one
Speaker 1: of these things in space, you'd want to do a
Speaker 1: lot of preparation research up front to make sure you're
Speaker 1: not making a big mistake about what what's the best
Speaker 1: thing to do in space? But on Earth, there's really
Speaker 1: no feasible way to perfectly test out artificial gravity concepts
Speaker 1: because on the surface of the Earth you have to
Speaker 1: deal with the constant complications of Earth gravity. So you
Speaker 1: can kind of try to simulate weightlessness. And so you
Speaker 1: could do like neutral buoyancy experiments, you know, where you're
Speaker 1: in water with a sort of balanced out buoyancy weight ratio,
Speaker 1: or you could do you could get in an airplane
Speaker 1: and do parabolic flights to have you know, twenty five
Speaker 1: seconds at a time or so of weightlessness. But these
Speaker 1: things aren't all that helpful when you're talking about trying
Speaker 1: to test out an artificial gravity environment at a like
Speaker 1: ship or space station size scale. Yeah, you really need
Speaker 1: a nothing eg. Zero G micro g environment and to
Speaker 1: get that you have to go into space. You have
Speaker 1: to go to orbit, right, So to really test one
Speaker 1: of these things, you essentially have to do it. You
Speaker 1: can't really test it without just making this thing and
Speaker 1: putting it in space. Now, I guess the good news
Speaker 1: is that it's kind of tom to to sort of
Speaker 1: reference the old Mitch Hedberg a bit about about an escalator.
Speaker 1: What do you call it? Broken escalator? It's stairs, right, Um,
Speaker 1: is like if the thing didn't work, you just turn
Speaker 1: it off and you float. I guess right, Like it's
Speaker 1: still going to be serviceable. On some level, and you
Speaker 1: can imagine that. I can imagine a scenario. Maybe they've
Speaker 1: even done this in a sci fi where you have
Speaker 1: like a non functional tourists space station where people arriving like, hey,
Speaker 1: what's with the walls? How come? How come this thing
Speaker 1: didn't work? Well, it's it's it. We're working on it.
Speaker 1: We gotta work out the kinks, so it's not fully
Speaker 1: functional yet, right yeah, yeah, And the people could complain.
Speaker 1: They'd be like, oh, but I'm I'm experiencing space sickness.
Speaker 1: And you'd have to be like, hey, look, it's not
Speaker 1: as bad as the coreolas sickness. Or it's a or
Speaker 1: it's a hotel where you have various rotating modules are
Speaker 1: rotating wings the hotel, and like, I'm sorry, all the
Speaker 1: all the rotating rooms are taken, all our gravity books. Sorry,
Speaker 1: we've only got smoking rooms or smoking and micro gravity.
Speaker 1: That's it. Sorry. Uh. But so hey, we're saying why
Speaker 1: it's going to be a problem, uh to to build
Speaker 1: these environments. But we don't want to end on a downer,
Speaker 1: because I've got something optimistic to say. To revisit a
Speaker 1: comment we made earlier. If you're willing to limit your ambitions,
Speaker 1: artificial gravity starts looking a lot more achievable. If only
Speaker 1: a small part of your spacecraft needs gravity, or if
Speaker 1: you're willing to settle for significantly less than Earth gravity,
Speaker 1: you've got a lot more options, right. For example, the
Speaker 1: rotating sphere compartment in two thousand one of Space Odyssey,
Speaker 1: they say it produces only about the gravity of the
Speaker 1: surface of the Moon. That's not a lot, but it
Speaker 1: might be enough that you can sort of jog like
Speaker 1: the character does. Basically, it's better than nothing. Things still
Speaker 1: fall towards the floor, even if it's not quite like
Speaker 1: being on Earth. And we mentioned some of those tests earlier,
Speaker 1: tests on human subjects in the night teen sixties in
Speaker 1: these parabolic flights to basically determine what was tolerable or
Speaker 1: acceptable to people, you know, and they found out that
Speaker 1: zero point two G is actually a lot better than
Speaker 1: zero point one G. So there's like a pretty steep
Speaker 1: drop off point about what's acceptable somewhere in that range
Speaker 1: that normal human activities were mostly doable starting it about
Speaker 1: zero point two G. At about zero point five G
Speaker 1: once you get to half of Earth gravity, subjects felt
Speaker 1: about as sure of their movements as they did at
Speaker 1: one g. So once you're halfway there, it's basically good
Speaker 1: enough to do your movements and you know, maybe even
Speaker 1: sleep better at night. Yeah, all right, so there you
Speaker 1: have it. Artificial gravity. Uh, not to be confused with
Speaker 1: anti gravity. That's an entirely different podcast there. Now, how
Speaker 1: many times did we accidentally say anti gravity in this
Speaker 1: episode today? None that I know of, but there could be.
Speaker 1: How many are going to catch later? I kept catching
Speaker 1: myself doing it in the note It's I kept I
Speaker 1: kept typing in um anti gravity, and I have to
Speaker 1: go back and it was like, not anti gravity because
Speaker 1: anti gravity is sort of sort of even though it's
Speaker 1: fun and science fiction as well, it's sort of a
Speaker 1: dirty word in scientific research. There are other terms that
Speaker 1: you would use. But but again that's a that's a
Speaker 1: topic for another time. If you guys want to discuss
Speaker 1: anti gravity, we can do that in a later date.
Speaker 1: Anti gravity it's actually fairly simple. It's commonly known as
Speaker 1: jumping and lifting. All right, Well, don't spoil it all,
Speaker 1: don't blow it all, Joe. Alright, So hey, if you
Speaker 1: wanna listen to more episodes of Stuff to Blow your mind,
Speaker 1: you want to explore past episodes and we have a
Speaker 1: bunch of them, many of which deal with space and
Speaker 1: space exploration. Head on over to stuff to Blow your
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