May 21, 2014 • 34 mins
We tend to take Earth's gravity for granted. But without it, our bodies go on a long, sad journey of decline. Is there any way to create fake gravity so we can survive, thrive and even reproduce in space?
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Episode Transcript
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Speaker 1 (00:00):
Brought to you by Toyota. Let's go places. Welcome to
Forward Thinking. I'll be there, and welcome to Forward Thinking,
the podcast that looks at the future and says I'm
free falling. I'm Joe McCormick and I'm Lauren voc Obama,
(00:20):
and our host Jonathan Strickland is not with us this week.
He is across the ocean in a strange land, Ireland
in fact, so not totally strange. What's he doing there?
I guess not drinking Guinness. No vacationing, taking in the site,
catching some rays in Ireland? Yes, probably Okay, Well, best
(00:41):
of luck to him with whatever he's doing over there.
But today Lauren and I thought we would talk to
you about artificial gravity. Yeah, we are traveling into space,
where you can also get a pretty wicked tan um.
So what happens when you go into space. Let's say
you're a stowaway in a supply capsule that's flying up
(01:01):
to the International Space Station and you get out of
your hiding place, much to the annoyance of the astronauts
around you. Yeah, they're going to be really mad at you,
I think, is the immediate effect of being in space
in that case. I guess, especially if they didn't calculate
your weight into the fuel costs, and you probably cost
like a million dollars unless you're very, very thin. And
(01:23):
then you you go over, you float over to the window.
Wait a second, why are you floating, because that's what
you do in space? You float? Oh, right, because there's
no gravity in space. Uh no, No, that is incorrect entirely.
A common myth is that there's no gravity in space.
But the fact is there's plenty of gravity in space.
(01:44):
At two fifty miles above Earth, which is a sort
of average flight altitude for the International Space Station, less
than two percent of the distance to the Moon, we
still feel about eighty eight point eight percent of the
Earth's gravity. So if that's true, why are the astronauts
floating around in the capsule? Okay, they're technically not floating.
(02:05):
They are falling. That's right. Well, I guess they are floating,
But it's not because there's no gravity, You're exactly right.
It's because they're falling. So it's pretty much the same
phenomenon as if you were to take the I S.
S and and tow it with an airplane up to
jet cruising altitude and then just drop everyone straight down
(02:25):
toward Earth and on its way towards the ground, everybody
and everything inside the capsule would float around because the
vehicle and everything in it is falling at the same speed.
There's no force to hold you to the floor. You're
you're in what's called free fall, right, and so everything
feels like zero gravity because you're in free fall. And
we call this situation micro gravity. So why doesn't the
(02:47):
I S S just hit the ground when it's flying
around the Earth. Well, that's because it's not falling in
a straight line towards the Earth's center of mass the
way you would if you fell out of an airplane. Right.
Orbit is actually falling with style. It's it's falling in
a circle around a big thing. Freestyle falling. Yeah, so cool.
It's like you get to fall forever and never hit
(03:08):
the ground. It's the best of both worlds. It's floating
the superman power of flight. Uh no, no injury from impact.
Let's just have a vadeva due time, right. Uh no, no,
what's wrong with floating everything? It's not good at all
for your body. Yeah, it'sn't that a bummer? So floating
it looks really cool. When you see Chris Hadfield making
(03:29):
the videos from space and everybody's floating around it. I mean,
number one, it's kind of hilarious for some reasons we'll
point out in a minute. But it looks awesome, oh sure,
and well, and it's fascinating, and it's something that we
never get to do here on Earth. So there's there's
a novelty to it, right, unless you ride in the
vomit commet, which a parabolic flight in an airplane can
simulate microgravity for a moment. But if you're just taking
(03:53):
a parabolic flight like in the vomit comment, it only
lasts a few seconds and that's pretty much uch. Okay,
But it turns out, yeah, if you stay in microgravity
conditions for a long period of time, it's really bad
for your body. Just one of the things, and one
of the main things is you have bone density loss. Right,
(04:14):
And okay, both both the bone and muscle components of
what's bad about microgravity have to do with the fact
that even even just walking around on the surface of
our planet, you know, continually having to counteract the force
of Earth's gravity on your body does a lot to
keep your bones and muscles healthy. By by strengthening them
(04:35):
by making them work. Yeah. Well, so you might think
of your bones as something just kind of like rocks,
but they're actually not like rocks. They're not static right there,
living growing things. Yeah, so that they have metabolic interaction
with your body, and if you don't put stress on them,
they can weaken over time. So even if you don't
get a whole lot of vigorous exercise and you're not
an athlete, you're still doing a whole lot of work
(04:57):
just walking around your house because you've got this amazing
force pushing down on you all the time, and you
have to push back against the surface of the Earth. Now,
in space, you don't have the stress of constant force
pushing you down against the floor or surface whatever it is.
So in other words, it's too easy. In microgravity, Astronauts
(05:18):
tend to lose about one to two percent of their
bone mass every month, and according to the e s A,
the European Space Agency, there are records of up to
twenty bone mass loss after a six month mission, and
that's scary. This is especially hard on the weight bearing
bones the lower body, as you can imagine, because they're
(05:39):
doing a lot of the work that normally happens when
you're on the surface of the Earth. Of course, there's
muscle loss too. Astronauts spend a lot of time on
the space station exercising just to stave off the effects
of bone and muscle loss, but that's not enough. There
was a Journal of Physiology report in two thousand ten
called Prolonged space flight induced Alteration in the structure and
(06:01):
function of Human skeletal muscle fibers, and they found basically
that prolonged weightlessness would contribute to substantial muscle loss in
the body, and that even the exercise regimens that were
in place at the time, we're not doing enough to
hold off the muscle loss. So muscle atrophy was still happening,
(06:22):
even though you've got people spending tons of time with
resistance training and on the treadmill. Sure, which means that
when they get back to Earth they have to really
work up to being healthy again, healthy enough to to
not damage their bones from a fall or or you know,
to be able to do the same amount of work
that they previously were. Yeah. One of a quote from
(06:43):
their abstract is our results highlight the need to study
new exercise programs on the I S S that employ
high resistance and contractions over a wide range of motion
to mimic the range occurring in Earth's one G environment.
One G will use that term again, that's just one
amount of Earth's gravity, right, and that's that's not all, folks,
(07:03):
not even the creepiest. What what would you say is
the creepiest? I would say probably fluid redistribution. That doesn't
sound good at all. No, So when you enter a
microgravity environment, pretty quickly your body undergoes fluid redistribution, where
body fluids are concentrated in the upper body, so you
can see a big inflated chest and neck and a
(07:25):
puffy face. Some astronauts apparently report sinus problems and feeling
like they have a cold or sinus infection. Eventually, the
microgravity causes the body to think that there's too much
blood in it, so then it triggers you to pee
a lot, which leads to a fluid deficit. And so
it's just it's it's not good for you. Um, there's
(07:47):
there's also space sickness, am I right? Right? This is
a less uh I guess probably less detrimental to your
permanent health, but unpleasant at the time, and it has
to do with the inner ear, Am I correct. Yeah,
it's kind of like airsickness or any other thing. I mean,
it's caused by an imbalance of fluids in the inner ear,
and you can have nausea, dizziness. It's referred to as
(08:10):
space adaptation syndrome. There are actually lots of funny stories
about how different people have experienced it while adapting to space.
But I'm sure it's not funny at the time, especially
when you're or whatever. It's not not good. No, no, no,
it's very unpleasant. And you can imagine how it's a
much bigger deal when you're talking about somebody in space.
(08:32):
I mean, this is somebody who needs to be using
their time very efficiently because of how expensive and dangerous
what they're doing is. Uh So it's not just like
being s sick on a on a cruise, which is
a bummer, but you're not essentially detrimental to you and
your country exactly. But even if you overlook all of
these major health concerns, because they might come up with, say,
(08:55):
better ways of exercise on the space station that can
really really do a good job holding off the muscle
and bone loss, or some kind of super dramamine too,
to calm down your inner ear receptors. Exactly. Yeah, they're
they're drugs. Maybe that might help with fluid redistribution, or
just maybe some kind of physical exercise you could do
(09:15):
that could help with that. Uh, there are lots of
things we can learn. Even if we imagine that we
eliminate all of those medical problems, there's still just major
problems with lifestyle in zero gravity. Oh right, Because I
mean the way that we eat food here on Earth
is dependent upon that food being exposed to gravity. Exactly. Um,
(09:35):
why why can't we have crumb cake in space? Because
you don't You don't want the crumbs getting into the
instruments or your face, I mean, or the rest of
your face. I mean you want them in your face, clearly,
but you want the muscle in your mouth, not in
your eyes. But on the space station, it's going to
be harder to keep them from getting in your eyes. Actually,
do you know do you know what would happen if
you tried to put salt and pepper on your food
(09:57):
in microgravity? Oh? I had never thought about the before,
but that's terribly like, I don't want salt pepper in
my ears. You you'd fail. So you get clouds of
salt and pepper everywhere, and they get in your eyes,
and they get in the instruments, and then the insectoid
invaders would see that the I S s Alien Sentinel
post is not being manned and they'd mount their invasion.
There you go, all because of pepper. So instead, this
(10:20):
is actually true. I've seen pictures of it. Astronauts on
the I S have literally had droppers for salt and pepper.
So I guess saltwater and pepper water water to to
deposit a droplet that will cling to your food and
not float away. Well, I mean, that's that's a that's
a genius idea. And I'm glad that they can seeds
in things properly in space and even from a dropper. Well,
(10:43):
I mean, and the foods that they have to deal
with to begin with, they're sort of designed to be
in bite sized pieces and to have such a consistency
that they don't easily crumble or have little parts that
come off right. Sure, sure, like if you were going
to eat an apple and space you and just crunch
down on an apple, it would have been prepared in
little apple cubes for you. So that you can just
(11:04):
pop one in your mouth and not have to bite
stuff off. Um, so they're sleeping. That's a funny one.
You have to sleep in these hilarious bags kind of
kind of like a like a space hammock, except much
more embarrassing. Yeah, actually they're kind of cute. I think
it's funny. I saw a video from the I S
S of one guy showing off his bag and it's
(11:26):
just stuck to the wall and it's like, this is
where I sleep. And I don't know, it felt like
somebody showing me like like pulling out a drawer from
their dresser, like this is where I sleep. Yeah, yeah,
um okay. And the big issue that I'm sure that
everyone is thinking about right now in terms of life functions,
how how do you use the bathroom in space? Yeah,
going to the bathroom in microgravity. Just pause for a
(11:49):
moment and consider it. I actually don't want to consider
it all that all that hard. Um. I mean, I
mean classically, this was basically just a diaper situation, right,
you could have a diaper or uh So. There's actually
a great guest blog post on Gizmoto by the astronaut
Leroy Chow about space toilet behavior um, and he talks
(12:11):
about how bathroom activities. Yeah, I used to mean you
you'd wear a diaper or you'd go into a sealable bag,
and so it was a clear bag and you really
didn't have any privacy while you were using it. And
that sounds fun a really good way to get really
close to your coworkers, right. Yeah, Apparently with the advent
of the Shuttle program, we finally got some bathroom accommodations.
(12:33):
And so the International Space Station has a toilet, but
in a very loose definition of the word toilet. So
in the absence of gravity, how are you going to
get everything where it needs to be. So the toilet
uses quote airflow two direct waste to its intended destination.
And to me, that sounds like a somewhat euphemistic way
(12:56):
of saying that you poop into a vacuum cleaner. Uh Man,
space is so sexy, you guys. Fortunately, according to Leroy Chow,
there is a funnel at the end, so apparently they
worked pretty well. But sometimes sometimes accidents happen and people
(13:17):
make a mess and then they have to clean it up.
You can already see why the idea of artificial gravity
is very appealing, right right, Okay, But but there's there's
also some more perhaps I mean, not that using the
bathroom in space it's not a serious problem. That's a
that's a daily thing that everyone has to do, and
it's definitely a major concern. But but what about something
even even more concerning, like like what if you needed
(13:39):
surgery in space? What if something happened? Oh yeah, Actually,
just earlier this year, there were reports that a Nebraska
based company called Virtual Incision was coming up with a
single incision surgical robot that was specifically designed for emergency
surgeries during space flight. So it would be remote operated
by another member of the crew, and it would enter
the body through us single hole. And one of the
(14:01):
purposes of this model is to require as little opening
of the skin as possible, because, as you can imagine,
it really wouldn't be a good idea to have fluids
from insides you soaring out into the cabin through a
large open incision. Uh, certainly not. Also, as we all
learned from Event Horizon, it gets really messy when globules
(14:22):
of blood are just flying everywhere. Yep. And we have
learned a lot from Event Horizon. We truly have. If
you haven't heard it, please go listen to the tech
Stuff episode about the technology of Event Horizon. Uh. One
more thing, a little more future focused, or hopefully future focused.
And this is not applying to anything. Now. Let's say
that we want to colonize space, so just which we
(14:44):
kind of do. Yeah, yeah, spread out from Earth, go
into space and live there indefinitely. All the things we've
mentioned already will matter a lot, but it will really
start to matter when we want to introduce the next generation. Yeah,
how how do we reproduce in space? And that's not
merely just like a mechanical problem. I mean it's like
(15:06):
a biological issue. There are serious questions about what happens
when mammals try to conceive and ingested to grow a baby. Yeah,
in a microgravity environment. I mean little little on all
of the other radiation and other issues that there are
with being in space. But yeah, we it's such a
huge issue that we did a whole two podcasts about it.
(15:27):
They published on February twelve, and and we're called Babies
in Space Inconceivable, Get it. It's kind of a pun
about conception. Um. I think that one was more about
radiation and then The second one was about microgravity, right right. Yeah,
the second one is called babies in space. That's heavy
because my microgravity. Well, it is heavy because there are
(15:51):
some studies to suggest that it really might be a
bad idea trying to conceive in space. Right. So there's
something about inter cellular protein transfer. Right, there's a few
issues that we that we know are at play. Um.
There there's evidence in both plant cells and fruit flies
the microgravity could disrupt intracellular protein transfer um. In in
(16:12):
fruit flies that were developed in space, this led to
a much weakened immune system, which is actually really significant
to human beings because we, along with lots of other mammals,
share a similar immune system to fruit flies, especially when
it comes to fungal resistance. So what this means is that, um,
that there's a possibility that if you have a baby
in space, it will die of a terrible fungal infection.
(16:34):
That's that's that's not good. We need to work on
that kind of thing. Um. There was also in simulations
of micro gravity on Earth with mice. The babies produced
were normal, So that's cool, but um, but fewer embryos
made it to birth than usual. Oh yeah, there were
also studies with jellyfish. Remember, oh right, Yeah, So they
took some jellyfish up in a Space Shuttle flight Aurelia,
(16:57):
Rita moon least, and these jellyfish underwent stroblation during the procedures.
So stroblation reminds me of what that. What that was
where the polyps separates into the f array, which is
like a larva. And they did that before and after launch.
And so there was a study published on this in
(17:20):
and they studied what happened to the jellyfish after they
spent nine days aboard the Space Shuttle during the larval
and polyp stages, and then they returned to Earth. So
jellyfish have graviceptors, which are these little hairy pockets that
contain calcium sulfate crystals that help them orient their bodies
with respect to Earth's gravity. So again sort of like
(17:40):
the inner ear thing that we've got where we've got
you know, tiny receptors and fluid and everything working together. Well,
except this is a crystal mechanism, not a fluid mechanism,
but right, And the study found that the jellyfish they
developed pretty much normally, like their bodies looked normal. They
were quote morphologically very similar. I think that just means
it looked a jellyfish. They looked pretty much normal, but
(18:02):
they had pulsing abnormalities, which difficulty moving right because the
jellyfish pulses right share in order to swim swimming quotation marks.
And then there was a follow up study the same
year that basically confirmed that something wasn't working right with
their movement. So so even though they looked fine, just
(18:23):
something was off. Yeah, and we should take that very
seriously because as as sad as it is to make
jellyfish that have pulsing abnormalities, we really wouldn't want to
subject to human baby to that. I mean, assuming that
that something didn't go wrong even before that point. If
a baby was born after being conceived in space, we
(18:43):
just don't know what would happen to it, And and
that is a really scary, deep level trial to to undertake.
We don't want to just willy nilly dive into that
sort of thing, right, So I hope we've made the
case now that there is a really really pressing need
for artificial gravity, Like it's a big deal if we
actually want to do things in space. It's not just
(19:04):
kind of a convenience. It matters a lot. Sure, Sure,
it's it's not just for strutting through the hallways like
like Ryker looking all looking all cool. Right, it's really
it's important to well different different levels of importance. But unfortunately,
unlike in the movies, wherein it's just kind of assumed.
I think that that, oh, in the future will have
(19:25):
worked out this artificial gravity thing and we don't even
really need to talk about it that much. Yeah, Usually
what you see in the movies is it's modeled on
something that would normally work within Earth's atmosphere, so like
an airplane or something where there's just a floor hallway
and seats or a deck, you know, even like a
like a sailing ship. Yeah, and people just walk around
on them there. Uh. It seems to be an assumption
(19:48):
that there maybe there's something underneath the floorboards that's creating
the gravitational field that holds you there. So that's an
interesting question. Do we have a way to create real
gravity without having something with mass? And the answer is no, Yeah,
that's that's not how gravity works. To create gravity, as
(20:11):
far as we know, you need something with mass. Everything
with mass creates gravity. But to have an appreciable amount
of gravity that you could walk around, and you need
a lot of mass, an appreciable amount of mass, right,
I say something about the size of the Earth if
you're going to have people walking around as though it
is the Earth's gravity. Yeah, okay, So what if you said, like, well,
(20:33):
what if we just got some kind of really really
dense material and put that underneath the floorboards your spaceship
so it would pull you down towards the floor. Yeah,
a nice idea, But first of all, what kind of
dense material would that be? So if the spaceship is
going to be of any manageable size, it sounds like
you're proposing exotic, as yet unknown material that somehow don't
(20:56):
decay as very dense material tends to do pretty quickly. Yeah,
so that's basically just playing pretend. That's not a lot
of help. So second, what what if you create Earth
gravity with real mass? How would you move your ship?
As the mass of your ship increases, you're essentially eliminating
the difference between the ship and the planet you came from.
(21:18):
So what's the point? You might as well just move
the Earth wherever you want to go. Yeah, it's it's
not like it needs to be aerodynamics. So, you know, uh,
plowing a little bit deeper into people on the internet
and lazy science fiction writers. What about gravitons. Can't we
just use gravitons to create gravity? Well, we might if
they weren't entirely hypothetical, right maybe, I mean, we don't
(21:40):
even know the thing is, so gravitons are hypothetical particles.
They are a hypothesis, and they're predicted to mediate the
force of gravity in what's called quantum field theory. So
the same way that photons are the particle of electromagnetism,
gravitons would be the equivalent massless particle delivers the force
(22:00):
of gravity. Right there. They're really nice because they make
math work out just fine in terms of what we
have already theorized about the universe. However, we've never detected them, right, Well,
we don't even have a viable theory of quantum gravity yet.
Please keep in mind that gravitons have never been observed
in reality. Thus they're currently still considered hypothetical. Like we said,
(22:23):
they're consistent with some popular theories like superstring theory, but
there's no direct evidence that these things exist in the
words of the American particle physicist Don Lincoln quote at
the moment, gravitons are entirely theoretical constructs that delicately walk
the knife edge precipice between the domains of scientific respectability
(22:45):
and the shady world of handwaving. I think the handwaving
he's invoking there is, you know, the thing you stick
in to make your equation work. Right. So, furthermore, from
what I can tell, the people who talk on the
internet at about using gravitons to create artificial gravity are
not physicists. And even if we were to discover the
(23:06):
existence of gravitons, I don't really see how they would
help us generate gravity without mass. Well, you just have
a graviton drive. Yeah, yeah, Okay, now I'm not buying
that one. The bottom line is, if you want real gravity,
you need mass. You need a lot of mass. But
can we simulate gravity? There's the ticket. So we can't
(23:28):
have real gravity without mass, but we can simulate gravity
because we feel the effects of gravity is a pushing
interaction between ourselves and the ground. So the force of
gravity can be represented as your tendency to accelerate towards
the ground at nine point eight meters per second per second,
and we can accelerate stuff like woe. Oh sure, yeah,
(23:51):
of course. The other part of it is that the
ground is pushing back against you. Otherwise you're just in
free fall again. So there's more than one way to
create a pushing interaction like this. How about linear acceleration,
So that's that's like if you're in a if you're
in a car and an airplane running down the runway. Yeah, okay,
So Lauren, you've been in an airplane taking off. You know,
(24:12):
when they ramp up the speed going down the runway
and they're about to take off the ground, how do
you feel in relationship to your chair? You get kind
of pressed back into it, right, So, because there's massive
forward acceleration, you feel the force pulling you backward, and
there's something there to stop you. Your chair, your pin
to the back of your seat. So if you were
(24:33):
to get up during takeoff, you'd feel yourself pulled towards
the back of the plane. So what if we built
a spacecraft where the floor was the interior aft of
the spacecraft, So the place back in the plane where
they keep all the goodies and the toilets and and
a flight attendant sitting there chatting with their buddies about
how annoying the passengers are. That could work. Right, So
(24:58):
there's a spacecraft veling in a straight line. Now imagine
the interior of the spacecraft is a single room. The
floor of that room is the aft of the of
the spacecraft, the stern in the face in the back,
and the ceiling is the bow the nose. You would
feel the forces of motion pushing you down towards the ground,
(25:19):
and if you accelerated it just the right rate, you
could produce the sensation of one G one Earth gravity.
This is actually doable, and the only problem would be
designing the spacecraft and how you're going to continue to
accelerate the proper rate continuously. Right, And I guess kind
of without stopping or with having everything nailed down appropriately
(25:41):
or et cetera. Right, is it might well be a
strain on fuel or energy reserves, because remember we're talking
about an acceleration, not just movement. Sure, or you might
you know, want to stop eventually and then yeah, well,
I mean one thing that's proposed is if you're going
to your destination, you accelerate at a constant rate that
(26:02):
produces this force halfway there, and then you turn around
and decelerate at the same rate after the halfway point.
That could work, but I've got a better one. If
you're trying to design, say something like a space station
on me, how about rotational force? So you have a
rotating object, Okay, yeah, sure. Have you ever gotten in
(26:25):
one of those carnival rides where there's a big wheel
and everybody goes into a cage along the inner surface
of the wheel, and then it starts whirling around really
fast in the air, And if you try to lift
your arms up off the outside edge of the cage,
it's really hard. You can't do it without a lot
of effort. I I have been on one. I try
not to after that first experience. I did not enjoy
(26:47):
it because if someone uh you know, becomes a little
motion sick and and empties the contents of their stomach
onto the ride, it gets whirled around on everyone and
sticks to the wall like you yeah. Uh. So this
is essentially the type of force we're talking about. It's
when you have a rotating object, there's a force that
(27:07):
pulls outward from the axis of rotation. It's the same
reason that if you hold a bucket of water in
your hand and you whirl it around really fast. Even
at the point in the windmill you're making with your
arm where the bucket is upside down, the water doesn't
fall out of the bucket, and that's because of the
force you've created by spinning it around the axis of rotation,
which in this case would be your shoulder. So that's
(27:31):
essentially the concept behind a rotating space station for artificial gravity.
So let's try to picture this. Imagine a space station
in the shape of a torus, which is a yeah,
a hollow donut. Uh So from inside the cabin would
be kind of like a tunnel. It's a tunnel that
goes all the way around and loops back on itself
(27:52):
and you're floating along. And what happens in this tunnel
once the space station starts to spin like a wheel
around the don't that hole? Well, all of the contents
of the tunnel, including the air and your body, feel
force pulling them out away from the axis of rotation
like we're just talking about. But once you hit the
floor of the tunnel, which is the outside surface of
the tourists, there's the structure pushing back against you, just
(28:15):
like the ground on Earth pushes back against you to
react to the force of gravity, pulling you towards the
center of the earth. So so your floor is is
that outer wall and your ceiling is the inner wall.
That's exactly right. Or here's another cool idea for a
spinning artificial gravity station. What about a capsule tethered to
a counterweight. So, for example, like if if you've got
(28:38):
to two hollow containers on either side of a string,
you know, sort of like one of those things that
people throw at each other in movies. I don't know
what they're called. Yeah, yeah, bullus kind of thing. Um,
they're in video games too, sure, sure, but but if
you if if you had one of those critters and
except giant enough to stand in, and then your your
floor in either capsule would be the point furthest away
(29:02):
from that from that center of rotation, right to be
the outside of the containers, the opposite of the side
where the string is attached. So then you could just
have like rooms that rotate with relationship to each other.
So why don't we have anything like this, Well, there's
really no reason we couldn't start building one of these today.
(29:23):
As far as I know, I can't see that there's
any missing puzzle piece, right, there's no mathematical reason. Um.
I think it's all about the money and the resources involved.
That's exactly right. It would require a massive, massive investment
of money and human resources. And why is that. Well,
so imagine you're in one of these spinning stations. How
(29:46):
do you generate enough force to simulate Earth's gravity. The
force you generate is going to be a product of
the radius of the station, so how far it is
from the center of rotation to the floor, and how
fast it's spinning. You've got to multiply those things together.
So you could have a small station that's spinning really
(30:08):
really fast. And that is horrible. That's that's really something
you don't want. Yeah, you're you're also running back into
those those motion sickness I imagine kind of areas at
a certain point. Yeah. Well, one thing I've read is
that physicists talk about how this would entail that because
your head is a much more significant fraction closer to
(30:31):
the center of rotation than your feet are. If it's
not a very big radius, you would feel a lot
more gravity at your feet than you went at your head. Oh,
I don't want that at all. Yeah, no, thank you.
So you can only imagine the kind of weird Actually,
I can't even imagine what that would feel like. It
just seems like it would be very unpleasant, kind of
a nightmare. Yeah. Um. So, so small is hard, um,
(30:54):
and big is also hard for money purposes, right, big
is the way to go. If you're going to build
one of these things. You can spin it much slower
if you have a longer angle, if you have a
longer radius. Uh. But how big does it have to be? Well,
it needs to be really big, like bigger than a
football field. Uh. How are you going to get that
(31:15):
much material into space? Very expensively? Right? Because we couldn't
just build it on the surface of the Earth and
launch it of I mean, that would be expensive enough
to begin with. But the things we build in space
generally can't withstand the stress of a rocket launch, especially
if they are not built for being launched, if they're built,
for example, for spitting around themselves really effectively. Right, So
(31:38):
we we built like we built the I, S. S
piece by piece in space, and that works fine because
there's no air resistance in space. I mean, that works,
but you need to have strong materials to have something
like this, because there'd be a lot of stress on
it if it's spinning continually, right right, Uh, it's just
a really hard job. It would mean lots and lots
(32:00):
of space launches, taking lots and lots of really heavy
materials into space, building the thing in space, which is
dangerous and expensive. It's basically just a really huge project.
And that's the reason we don't have it right And
and granted that project might become very worthwhile in the
next fifty years or whenever it is um when when
(32:23):
we decide that that space travel, long term space travel
is for serious. Oh, I already think this is a
very worthwhile project. It's just you know, where are you
going to get the money? I don't have it. No, old,
do you have the money? He's shaking his head. Yeah, now, well,
so I guess that's it for artificial gravity for now.
(32:45):
We love the idea. It's really important for our future,
but it's a massive investment. So if you want to
go listen to some of those Neil deGrasse Tyson talks
about how we need to invest more in space exploration
and in NASA and in the kinds of tech knowlogies
that we need to sustain our future beyond the planet Earth.
I recommend it. Yeah, that about wraps it up for today. Yes,
(33:09):
so um. If you would like to hear more from us,
or perhaps watch some videos or read some excellent blog posts,
you can find all of that at our website, which
is FW thinking dot com. If you would like to
get in touch with us, if perhaps you have a
question about anything that we've said today, or a topic
suggestion for something that you would like to hear from
us in the future, then please do let us know.
(33:30):
We would absolutely love to hear from you. You can
email us at FW thinking at discovery dot com, or
you can find us on Twitter, Facebook, or Google Plus
or all three if you really want to span us,
we would enjoy it. Where a handle is FW thinking.
So thank you for tuning in and we will talk
to you again really soon. For more on this topic
(33:56):
and the future of technology, visit Forward Thinking dot Com Problems,
brought to you by Toyota. Let's Go Places,
Brought to you by Toyota. Let's go places. Welcome to
Forward Thinking. I'll be there, and welcome to Forward Thinking,
the podcast that looks at the future and says I'm
free falling. I'm Joe McCormick and I'm Lauren voc Obama,
(00:20):
and our host Jonathan Strickland is not with us this week.
He is across the ocean in a strange land, Ireland
in fact, so not totally strange. What's he doing there?
I guess not drinking Guinness. No vacationing, taking in the site,
catching some rays in Ireland? Yes, probably Okay, Well, best
(00:41):
of luck to him with whatever he's doing over there.
But today Lauren and I thought we would talk to
you about artificial gravity. Yeah, we are traveling into space,
where you can also get a pretty wicked tan um.
So what happens when you go into space. Let's say
you're a stowaway in a supply capsule that's flying up
(01:01):
to the International Space Station and you get out of
your hiding place, much to the annoyance of the astronauts
around you. Yeah, they're going to be really mad at you,
I think, is the immediate effect of being in space
in that case. I guess, especially if they didn't calculate
your weight into the fuel costs, and you probably cost
like a million dollars unless you're very, very thin. And
(01:23):
then you you go over, you float over to the window.
Wait a second, why are you floating, because that's what
you do in space? You float? Oh, right, because there's
no gravity in space. Uh no, No, that is incorrect entirely.
A common myth is that there's no gravity in space.
But the fact is there's plenty of gravity in space.
(01:44):
At two fifty miles above Earth, which is a sort
of average flight altitude for the International Space Station, less
than two percent of the distance to the Moon, we
still feel about eighty eight point eight percent of the
Earth's gravity. So if that's true, why are the astronauts
floating around in the capsule? Okay, they're technically not floating.
(02:05):
They are falling. That's right. Well, I guess they are floating,
But it's not because there's no gravity, You're exactly right.
It's because they're falling. So it's pretty much the same
phenomenon as if you were to take the I S.
S and and tow it with an airplane up to
jet cruising altitude and then just drop everyone straight down
(02:25):
toward Earth and on its way towards the ground, everybody
and everything inside the capsule would float around because the
vehicle and everything in it is falling at the same speed.
There's no force to hold you to the floor. You're
you're in what's called free fall, right, and so everything
feels like zero gravity because you're in free fall. And
we call this situation micro gravity. So why doesn't the
(02:47):
I S S just hit the ground when it's flying
around the Earth. Well, that's because it's not falling in
a straight line towards the Earth's center of mass the
way you would if you fell out of an airplane. Right.
Orbit is actually falling with style. It's it's falling in
a circle around a big thing. Freestyle falling. Yeah, so cool.
It's like you get to fall forever and never hit
(03:08):
the ground. It's the best of both worlds. It's floating
the superman power of flight. Uh no, no injury from impact.
Let's just have a vadeva due time, right. Uh no, no,
what's wrong with floating everything? It's not good at all
for your body. Yeah, it'sn't that a bummer? So floating
it looks really cool. When you see Chris Hadfield making
(03:29):
the videos from space and everybody's floating around it. I mean,
number one, it's kind of hilarious for some reasons we'll
point out in a minute. But it looks awesome, oh sure,
and well, and it's fascinating, and it's something that we
never get to do here on Earth. So there's there's
a novelty to it, right, unless you ride in the
vomit commet, which a parabolic flight in an airplane can
simulate microgravity for a moment. But if you're just taking
(03:53):
a parabolic flight like in the vomit comment, it only
lasts a few seconds and that's pretty much uch. Okay,
But it turns out, yeah, if you stay in microgravity
conditions for a long period of time, it's really bad
for your body. Just one of the things, and one
of the main things is you have bone density loss. Right,
(04:14):
And okay, both both the bone and muscle components of
what's bad about microgravity have to do with the fact
that even even just walking around on the surface of
our planet, you know, continually having to counteract the force
of Earth's gravity on your body does a lot to
keep your bones and muscles healthy. By by strengthening them
(04:35):
by making them work. Yeah. Well, so you might think
of your bones as something just kind of like rocks,
but they're actually not like rocks. They're not static right there,
living growing things. Yeah, so that they have metabolic interaction
with your body, and if you don't put stress on them,
they can weaken over time. So even if you don't
get a whole lot of vigorous exercise and you're not
an athlete, you're still doing a whole lot of work
(04:57):
just walking around your house because you've got this amazing
force pushing down on you all the time, and you
have to push back against the surface of the Earth. Now,
in space, you don't have the stress of constant force
pushing you down against the floor or surface whatever it is.
So in other words, it's too easy. In microgravity, Astronauts
(05:18):
tend to lose about one to two percent of their
bone mass every month, and according to the e s A,
the European Space Agency, there are records of up to
twenty bone mass loss after a six month mission, and
that's scary. This is especially hard on the weight bearing
bones the lower body, as you can imagine, because they're
(05:39):
doing a lot of the work that normally happens when
you're on the surface of the Earth. Of course, there's
muscle loss too. Astronauts spend a lot of time on
the space station exercising just to stave off the effects
of bone and muscle loss, but that's not enough. There
was a Journal of Physiology report in two thousand ten
called Prolonged space flight induced Alteration in the structure and
(06:01):
function of Human skeletal muscle fibers, and they found basically
that prolonged weightlessness would contribute to substantial muscle loss in
the body, and that even the exercise regimens that were
in place at the time, we're not doing enough to
hold off the muscle loss. So muscle atrophy was still happening,
(06:22):
even though you've got people spending tons of time with
resistance training and on the treadmill. Sure, which means that
when they get back to Earth they have to really
work up to being healthy again, healthy enough to to
not damage their bones from a fall or or you know,
to be able to do the same amount of work
that they previously were. Yeah. One of a quote from
(06:43):
their abstract is our results highlight the need to study
new exercise programs on the I S S that employ
high resistance and contractions over a wide range of motion
to mimic the range occurring in Earth's one G environment.
One G will use that term again, that's just one
amount of Earth's gravity, right, and that's that's not all, folks,
(07:03):
not even the creepiest. What what would you say is
the creepiest? I would say probably fluid redistribution. That doesn't
sound good at all. No, So when you enter a
microgravity environment, pretty quickly your body undergoes fluid redistribution, where
body fluids are concentrated in the upper body, so you
can see a big inflated chest and neck and a
(07:25):
puffy face. Some astronauts apparently report sinus problems and feeling
like they have a cold or sinus infection. Eventually, the
microgravity causes the body to think that there's too much
blood in it, so then it triggers you to pee
a lot, which leads to a fluid deficit. And so
it's just it's it's not good for you. Um, there's
(07:47):
there's also space sickness, am I right? Right? This is
a less uh I guess probably less detrimental to your
permanent health, but unpleasant at the time, and it has
to do with the inner ear, Am I correct. Yeah,
it's kind of like airsickness or any other thing. I mean,
it's caused by an imbalance of fluids in the inner ear,
and you can have nausea, dizziness. It's referred to as
(08:10):
space adaptation syndrome. There are actually lots of funny stories
about how different people have experienced it while adapting to space.
But I'm sure it's not funny at the time, especially
when you're or whatever. It's not not good. No, no, no,
it's very unpleasant. And you can imagine how it's a
much bigger deal when you're talking about somebody in space.
(08:32):
I mean, this is somebody who needs to be using
their time very efficiently because of how expensive and dangerous
what they're doing is. Uh So it's not just like
being s sick on a on a cruise, which is
a bummer, but you're not essentially detrimental to you and
your country exactly. But even if you overlook all of
these major health concerns, because they might come up with, say,
(08:55):
better ways of exercise on the space station that can
really really do a good job holding off the muscle
and bone loss, or some kind of super dramamine too,
to calm down your inner ear receptors. Exactly. Yeah, they're
they're drugs. Maybe that might help with fluid redistribution, or
just maybe some kind of physical exercise you could do
(09:15):
that could help with that. Uh, there are lots of
things we can learn. Even if we imagine that we
eliminate all of those medical problems, there's still just major
problems with lifestyle in zero gravity. Oh right, Because I
mean the way that we eat food here on Earth
is dependent upon that food being exposed to gravity. Exactly. Um,
(09:35):
why why can't we have crumb cake in space? Because
you don't You don't want the crumbs getting into the
instruments or your face, I mean, or the rest of
your face. I mean you want them in your face, clearly,
but you want the muscle in your mouth, not in
your eyes. But on the space station, it's going to
be harder to keep them from getting in your eyes. Actually,
do you know do you know what would happen if
you tried to put salt and pepper on your food
(09:57):
in microgravity? Oh? I had never thought about the before,
but that's terribly like, I don't want salt pepper in
my ears. You you'd fail. So you get clouds of
salt and pepper everywhere, and they get in your eyes,
and they get in the instruments, and then the insectoid
invaders would see that the I S s Alien Sentinel
post is not being manned and they'd mount their invasion.
There you go, all because of pepper. So instead, this
(10:20):
is actually true. I've seen pictures of it. Astronauts on
the I S have literally had droppers for salt and pepper.
So I guess saltwater and pepper water water to to
deposit a droplet that will cling to your food and
not float away. Well, I mean, that's that's a that's
a genius idea. And I'm glad that they can seeds
in things properly in space and even from a dropper. Well,
(10:43):
I mean, and the foods that they have to deal
with to begin with, they're sort of designed to be
in bite sized pieces and to have such a consistency
that they don't easily crumble or have little parts that
come off right. Sure, sure, like if you were going
to eat an apple and space you and just crunch
down on an apple, it would have been prepared in
little apple cubes for you. So that you can just
(11:04):
pop one in your mouth and not have to bite
stuff off. Um, so they're sleeping. That's a funny one.
You have to sleep in these hilarious bags kind of
kind of like a like a space hammock, except much
more embarrassing. Yeah, actually they're kind of cute. I think
it's funny. I saw a video from the I S
S of one guy showing off his bag and it's
(11:26):
just stuck to the wall and it's like, this is
where I sleep. And I don't know, it felt like
somebody showing me like like pulling out a drawer from
their dresser, like this is where I sleep. Yeah, yeah,
um okay. And the big issue that I'm sure that
everyone is thinking about right now in terms of life functions,
how how do you use the bathroom in space? Yeah,
going to the bathroom in microgravity. Just pause for a
(11:49):
moment and consider it. I actually don't want to consider
it all that all that hard. Um. I mean, I
mean classically, this was basically just a diaper situation, right,
you could have a diaper or uh So. There's actually
a great guest blog post on Gizmoto by the astronaut
Leroy Chow about space toilet behavior um, and he talks
(12:11):
about how bathroom activities. Yeah, I used to mean you
you'd wear a diaper or you'd go into a sealable bag,
and so it was a clear bag and you really
didn't have any privacy while you were using it. And
that sounds fun a really good way to get really
close to your coworkers, right. Yeah, Apparently with the advent
of the Shuttle program, we finally got some bathroom accommodations.
(12:33):
And so the International Space Station has a toilet, but
in a very loose definition of the word toilet. So
in the absence of gravity, how are you going to
get everything where it needs to be. So the toilet
uses quote airflow two direct waste to its intended destination.
And to me, that sounds like a somewhat euphemistic way
(12:56):
of saying that you poop into a vacuum cleaner. Uh Man,
space is so sexy, you guys. Fortunately, according to Leroy Chow,
there is a funnel at the end, so apparently they
worked pretty well. But sometimes sometimes accidents happen and people
(13:17):
make a mess and then they have to clean it up.
You can already see why the idea of artificial gravity
is very appealing, right right, Okay, But but there's there's
also some more perhaps I mean, not that using the
bathroom in space it's not a serious problem. That's a
that's a daily thing that everyone has to do, and
it's definitely a major concern. But but what about something
even even more concerning, like like what if you needed
(13:39):
surgery in space? What if something happened? Oh yeah, Actually,
just earlier this year, there were reports that a Nebraska
based company called Virtual Incision was coming up with a
single incision surgical robot that was specifically designed for emergency
surgeries during space flight. So it would be remote operated
by another member of the crew, and it would enter
the body through us single hole. And one of the
(14:01):
purposes of this model is to require as little opening
of the skin as possible, because, as you can imagine,
it really wouldn't be a good idea to have fluids
from insides you soaring out into the cabin through a
large open incision. Uh, certainly not. Also, as we all
learned from Event Horizon, it gets really messy when globules
(14:22):
of blood are just flying everywhere. Yep. And we have
learned a lot from Event Horizon. We truly have. If
you haven't heard it, please go listen to the tech
Stuff episode about the technology of Event Horizon. Uh. One
more thing, a little more future focused, or hopefully future focused.
And this is not applying to anything. Now. Let's say
that we want to colonize space, so just which we
(14:44):
kind of do. Yeah, yeah, spread out from Earth, go
into space and live there indefinitely. All the things we've
mentioned already will matter a lot, but it will really
start to matter when we want to introduce the next generation. Yeah,
how how do we reproduce in space? And that's not
merely just like a mechanical problem. I mean it's like
(15:06):
a biological issue. There are serious questions about what happens
when mammals try to conceive and ingested to grow a baby. Yeah,
in a microgravity environment. I mean little little on all
of the other radiation and other issues that there are
with being in space. But yeah, we it's such a
huge issue that we did a whole two podcasts about it.
(15:27):
They published on February twelve, and and we're called Babies
in Space Inconceivable, Get it. It's kind of a pun
about conception. Um. I think that one was more about
radiation and then The second one was about microgravity, right right. Yeah,
the second one is called babies in space. That's heavy
because my microgravity. Well, it is heavy because there are
(15:51):
some studies to suggest that it really might be a
bad idea trying to conceive in space. Right. So there's
something about inter cellular protein transfer. Right, there's a few
issues that we that we know are at play. Um.
There there's evidence in both plant cells and fruit flies
the microgravity could disrupt intracellular protein transfer um. In in
(16:12):
fruit flies that were developed in space, this led to
a much weakened immune system, which is actually really significant
to human beings because we, along with lots of other mammals,
share a similar immune system to fruit flies, especially when
it comes to fungal resistance. So what this means is that, um,
that there's a possibility that if you have a baby
in space, it will die of a terrible fungal infection.
(16:34):
That's that's that's not good. We need to work on
that kind of thing. Um. There was also in simulations
of micro gravity on Earth with mice. The babies produced
were normal, So that's cool, but um, but fewer embryos
made it to birth than usual. Oh yeah, there were
also studies with jellyfish. Remember, oh right, Yeah, So they
took some jellyfish up in a Space Shuttle flight Aurelia,
(16:57):
Rita moon least, and these jellyfish underwent stroblation during the procedures.
So stroblation reminds me of what that. What that was
where the polyps separates into the f array, which is
like a larva. And they did that before and after launch.
And so there was a study published on this in
(17:20):
and they studied what happened to the jellyfish after they
spent nine days aboard the Space Shuttle during the larval
and polyp stages, and then they returned to Earth. So
jellyfish have graviceptors, which are these little hairy pockets that
contain calcium sulfate crystals that help them orient their bodies
with respect to Earth's gravity. So again sort of like
(17:40):
the inner ear thing that we've got where we've got
you know, tiny receptors and fluid and everything working together. Well,
except this is a crystal mechanism, not a fluid mechanism,
but right, And the study found that the jellyfish they
developed pretty much normally, like their bodies looked normal. They
were quote morphologically very similar. I think that just means
it looked a jellyfish. They looked pretty much normal, but
(18:02):
they had pulsing abnormalities, which difficulty moving right because the
jellyfish pulses right share in order to swim swimming quotation marks.
And then there was a follow up study the same
year that basically confirmed that something wasn't working right with
their movement. So so even though they looked fine, just
(18:23):
something was off. Yeah, and we should take that very
seriously because as as sad as it is to make
jellyfish that have pulsing abnormalities, we really wouldn't want to
subject to human baby to that. I mean, assuming that
that something didn't go wrong even before that point. If
a baby was born after being conceived in space, we
(18:43):
just don't know what would happen to it, And and
that is a really scary, deep level trial to to undertake.
We don't want to just willy nilly dive into that
sort of thing, right, So I hope we've made the
case now that there is a really really pressing need
for artificial gravity, Like it's a big deal if we
actually want to do things in space. It's not just
(19:04):
kind of a convenience. It matters a lot. Sure, Sure,
it's it's not just for strutting through the hallways like
like Ryker looking all looking all cool. Right, it's really
it's important to well different different levels of importance. But unfortunately,
unlike in the movies, wherein it's just kind of assumed.
I think that that, oh, in the future will have
(19:25):
worked out this artificial gravity thing and we don't even
really need to talk about it that much. Yeah, Usually
what you see in the movies is it's modeled on
something that would normally work within Earth's atmosphere, so like
an airplane or something where there's just a floor hallway
and seats or a deck, you know, even like a
like a sailing ship. Yeah, and people just walk around
on them there. Uh. It seems to be an assumption
(19:48):
that there maybe there's something underneath the floorboards that's creating
the gravitational field that holds you there. So that's an
interesting question. Do we have a way to create real
gravity without having something with mass? And the answer is no, Yeah,
that's that's not how gravity works. To create gravity, as
(20:11):
far as we know, you need something with mass. Everything
with mass creates gravity. But to have an appreciable amount
of gravity that you could walk around, and you need
a lot of mass, an appreciable amount of mass, right,
I say something about the size of the Earth if
you're going to have people walking around as though it
is the Earth's gravity. Yeah, okay, So what if you said, like, well,
(20:33):
what if we just got some kind of really really
dense material and put that underneath the floorboards your spaceship
so it would pull you down towards the floor. Yeah,
a nice idea, But first of all, what kind of
dense material would that be? So if the spaceship is
going to be of any manageable size, it sounds like
you're proposing exotic, as yet unknown material that somehow don't
(20:56):
decay as very dense material tends to do pretty quickly. Yeah,
so that's basically just playing pretend. That's not a lot
of help. So second, what what if you create Earth
gravity with real mass? How would you move your ship?
As the mass of your ship increases, you're essentially eliminating
the difference between the ship and the planet you came from.
(21:18):
So what's the point? You might as well just move
the Earth wherever you want to go. Yeah, it's it's
not like it needs to be aerodynamics. So, you know, uh,
plowing a little bit deeper into people on the internet
and lazy science fiction writers. What about gravitons. Can't we
just use gravitons to create gravity? Well, we might if
they weren't entirely hypothetical, right maybe, I mean, we don't
(21:40):
even know the thing is, so gravitons are hypothetical particles.
They are a hypothesis, and they're predicted to mediate the
force of gravity in what's called quantum field theory. So
the same way that photons are the particle of electromagnetism,
gravitons would be the equivalent massless particle delivers the force
(22:00):
of gravity. Right there. They're really nice because they make
math work out just fine in terms of what we
have already theorized about the universe. However, we've never detected them, right, Well,
we don't even have a viable theory of quantum gravity yet.
Please keep in mind that gravitons have never been observed
in reality. Thus they're currently still considered hypothetical. Like we said,
(22:23):
they're consistent with some popular theories like superstring theory, but
there's no direct evidence that these things exist in the
words of the American particle physicist Don Lincoln quote at
the moment, gravitons are entirely theoretical constructs that delicately walk
the knife edge precipice between the domains of scientific respectability
(22:45):
and the shady world of handwaving. I think the handwaving
he's invoking there is, you know, the thing you stick
in to make your equation work. Right. So, furthermore, from
what I can tell, the people who talk on the
internet at about using gravitons to create artificial gravity are
not physicists. And even if we were to discover the
(23:06):
existence of gravitons, I don't really see how they would
help us generate gravity without mass. Well, you just have
a graviton drive. Yeah, yeah, Okay, now I'm not buying
that one. The bottom line is, if you want real gravity,
you need mass. You need a lot of mass. But
can we simulate gravity? There's the ticket. So we can't
(23:28):
have real gravity without mass, but we can simulate gravity
because we feel the effects of gravity is a pushing
interaction between ourselves and the ground. So the force of
gravity can be represented as your tendency to accelerate towards
the ground at nine point eight meters per second per second,
and we can accelerate stuff like woe. Oh sure, yeah,
(23:51):
of course. The other part of it is that the
ground is pushing back against you. Otherwise you're just in
free fall again. So there's more than one way to
create a pushing interaction like this. How about linear acceleration,
So that's that's like if you're in a if you're
in a car and an airplane running down the runway. Yeah, okay,
So Lauren, you've been in an airplane taking off. You know,
(24:12):
when they ramp up the speed going down the runway
and they're about to take off the ground, how do
you feel in relationship to your chair? You get kind
of pressed back into it, right, So, because there's massive
forward acceleration, you feel the force pulling you backward, and
there's something there to stop you. Your chair, your pin
to the back of your seat. So if you were
(24:33):
to get up during takeoff, you'd feel yourself pulled towards
the back of the plane. So what if we built
a spacecraft where the floor was the interior aft of
the spacecraft, So the place back in the plane where
they keep all the goodies and the toilets and and
a flight attendant sitting there chatting with their buddies about
how annoying the passengers are. That could work. Right, So
(24:58):
there's a spacecraft veling in a straight line. Now imagine
the interior of the spacecraft is a single room. The
floor of that room is the aft of the of
the spacecraft, the stern in the face in the back,
and the ceiling is the bow the nose. You would
feel the forces of motion pushing you down towards the ground,
(25:19):
and if you accelerated it just the right rate, you
could produce the sensation of one G one Earth gravity.
This is actually doable, and the only problem would be
designing the spacecraft and how you're going to continue to
accelerate the proper rate continuously. Right, And I guess kind
of without stopping or with having everything nailed down appropriately
(25:41):
or et cetera. Right, is it might well be a
strain on fuel or energy reserves, because remember we're talking
about an acceleration, not just movement. Sure, or you might
you know, want to stop eventually and then yeah, well,
I mean one thing that's proposed is if you're going
to your destination, you accelerate at a constant rate that
(26:02):
produces this force halfway there, and then you turn around
and decelerate at the same rate after the halfway point.
That could work, but I've got a better one. If
you're trying to design, say something like a space station
on me, how about rotational force? So you have a
rotating object, Okay, yeah, sure. Have you ever gotten in
(26:25):
one of those carnival rides where there's a big wheel
and everybody goes into a cage along the inner surface
of the wheel, and then it starts whirling around really
fast in the air, And if you try to lift
your arms up off the outside edge of the cage,
it's really hard. You can't do it without a lot
of effort. I I have been on one. I try
not to after that first experience. I did not enjoy
(26:47):
it because if someone uh you know, becomes a little
motion sick and and empties the contents of their stomach
onto the ride, it gets whirled around on everyone and
sticks to the wall like you yeah. Uh. So this
is essentially the type of force we're talking about. It's
when you have a rotating object, there's a force that
(27:07):
pulls outward from the axis of rotation. It's the same
reason that if you hold a bucket of water in
your hand and you whirl it around really fast. Even
at the point in the windmill you're making with your
arm where the bucket is upside down, the water doesn't
fall out of the bucket, and that's because of the
force you've created by spinning it around the axis of rotation,
which in this case would be your shoulder. So that's
(27:31):
essentially the concept behind a rotating space station for artificial gravity.
So let's try to picture this. Imagine a space station
in the shape of a torus, which is a yeah,
a hollow donut. Uh So from inside the cabin would
be kind of like a tunnel. It's a tunnel that
goes all the way around and loops back on itself
(27:52):
and you're floating along. And what happens in this tunnel
once the space station starts to spin like a wheel
around the don't that hole? Well, all of the contents
of the tunnel, including the air and your body, feel
force pulling them out away from the axis of rotation
like we're just talking about. But once you hit the
floor of the tunnel, which is the outside surface of
the tourists, there's the structure pushing back against you, just
(28:15):
like the ground on Earth pushes back against you to
react to the force of gravity, pulling you towards the
center of the earth. So so your floor is is
that outer wall and your ceiling is the inner wall.
That's exactly right. Or here's another cool idea for a
spinning artificial gravity station. What about a capsule tethered to
a counterweight. So, for example, like if if you've got
(28:38):
to two hollow containers on either side of a string,
you know, sort of like one of those things that
people throw at each other in movies. I don't know
what they're called. Yeah, yeah, bullus kind of thing. Um,
they're in video games too, sure, sure, but but if
you if if you had one of those critters and
except giant enough to stand in, and then your your
floor in either capsule would be the point furthest away
(29:02):
from that from that center of rotation, right to be
the outside of the containers, the opposite of the side
where the string is attached. So then you could just
have like rooms that rotate with relationship to each other.
So why don't we have anything like this, Well, there's
really no reason we couldn't start building one of these today.
(29:23):
As far as I know, I can't see that there's
any missing puzzle piece, right, there's no mathematical reason. Um.
I think it's all about the money and the resources involved.
That's exactly right. It would require a massive, massive investment
of money and human resources. And why is that. Well,
so imagine you're in one of these spinning stations. How
(29:46):
do you generate enough force to simulate Earth's gravity. The
force you generate is going to be a product of
the radius of the station, so how far it is
from the center of rotation to the floor, and how
fast it's spinning. You've got to multiply those things together.
So you could have a small station that's spinning really
(30:08):
really fast. And that is horrible. That's that's really something
you don't want. Yeah, you're you're also running back into
those those motion sickness I imagine kind of areas at
a certain point. Yeah. Well, one thing I've read is
that physicists talk about how this would entail that because
your head is a much more significant fraction closer to
(30:31):
the center of rotation than your feet are. If it's
not a very big radius, you would feel a lot
more gravity at your feet than you went at your head. Oh,
I don't want that at all. Yeah, no, thank you.
So you can only imagine the kind of weird Actually,
I can't even imagine what that would feel like. It
just seems like it would be very unpleasant, kind of
a nightmare. Yeah. Um. So, so small is hard, um,
(30:54):
and big is also hard for money purposes, right, big
is the way to go. If you're going to build
one of these things. You can spin it much slower
if you have a longer angle, if you have a
longer radius. Uh. But how big does it have to be? Well,
it needs to be really big, like bigger than a
football field. Uh. How are you going to get that
(31:15):
much material into space? Very expensively? Right? Because we couldn't
just build it on the surface of the Earth and
launch it of I mean, that would be expensive enough
to begin with. But the things we build in space
generally can't withstand the stress of a rocket launch, especially
if they are not built for being launched, if they're built,
for example, for spitting around themselves really effectively. Right, So
(31:38):
we we built like we built the I, S. S
piece by piece in space, and that works fine because
there's no air resistance in space. I mean, that works,
but you need to have strong materials to have something
like this, because there'd be a lot of stress on
it if it's spinning continually, right right, Uh, it's just
a really hard job. It would mean lots and lots
(32:00):
of space launches, taking lots and lots of really heavy
materials into space, building the thing in space, which is
dangerous and expensive. It's basically just a really huge project.
And that's the reason we don't have it right And
and granted that project might become very worthwhile in the
next fifty years or whenever it is um when when
(32:23):
we decide that that space travel, long term space travel
is for serious. Oh, I already think this is a
very worthwhile project. It's just you know, where are you
going to get the money? I don't have it. No, old,
do you have the money? He's shaking his head. Yeah, now, well,
so I guess that's it for artificial gravity for now.
(32:45):
We love the idea. It's really important for our future,
but it's a massive investment. So if you want to
go listen to some of those Neil deGrasse Tyson talks
about how we need to invest more in space exploration
and in NASA and in the kinds of tech knowlogies
that we need to sustain our future beyond the planet Earth.
I recommend it. Yeah, that about wraps it up for today. Yes,
(33:09):
so um. If you would like to hear more from us,
or perhaps watch some videos or read some excellent blog posts,
you can find all of that at our website, which
is FW thinking dot com. If you would like to
get in touch with us, if perhaps you have a
question about anything that we've said today, or a topic
suggestion for something that you would like to hear from
us in the future, then please do let us know.
(33:30):
We would absolutely love to hear from you. You can
email us at FW thinking at discovery dot com, or
you can find us on Twitter, Facebook, or Google Plus
or all three if you really want to span us,
we would enjoy it. Where a handle is FW thinking.
So thank you for tuning in and we will talk
to you again really soon. For more on this topic
(33:56):
and the future of technology, visit Forward Thinking dot Com Problems,
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