From the Vault: Creature of the Gear

What is a gear and when did humans invent it? Plus, Rob and Joe discuss the only known creature to have gears in its anatomy. Plus hear about a couple of wheel-based mythical creatures in this classic episode of Stuff to Blow Your Mind. (originally published 9/2/2021)

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Episode Transcript

Speaker 1 (00:05):
Hey, welcome to Stuff to Blow Your Mind. This is
Robert Lamb. Joe is away at the moment, but we're
gonna go ahead and slot in a vault episode for today.
This is just helping us deal with some some some
late summer or at least late summer break um disruptions here,
but we're gonna go ahead and play Creature of the Gear.

(00:28):
This originally published on nine to one. UH. It's an
interesting look at gears and when did humans invent gears?
And also what do we find that are like gears
in nature? And we'll even look at a few wheel
based mythological creatures. Now, don't fret, we're gonna be back
on Thursday. We should be back on Thursday with a

(00:50):
fun interview episode and then we'll be back into the
regular schedule right after that. So, without further ado, let's
dive right in. Welcome to Stuff to Blow Your Mind
production of My Heart Radio. Hey, welcome to Stuff to

(01:13):
Blow your Mind. My name is Robert Lamb and I'm
Joe McCormick. Today we're gonna be in a way we're
continuing on past discussions concerning the wheel Um, also past
discussions concerning UH like rolling creatures. But we're gonna be
getting more specifically into the realm of the gear in

(01:34):
this episode. Now, I have to say, I'm anytime we
get into one of these discussions, I'm always reminded of
a few lines from The Omega Man. Uh. In part
because it's in its own way, it's a weirdly interesting film. Also,
I probably listened to a bit too much Wide Zombie

(01:55):
back in high school. Uh, because there's some or maybe
it's a zombie song that that samples this movie. But
there's this one wonderful line from Anthony zerve Is character says,
the creature of the Wheel, the lord of the infernal engines. Um,
what is he talking about the vampires? Or is he
talking about about Charlton Heston. He's talking about old Chuck Heston. There,

(02:17):
he's the This man represents the wheel and the technology
of the wheel and all the terrible things that we're
done with it. Um, but wait, I recall the vampires
using wheeled vehicles. Do they not? Don't they have like
a sort of zombie mobile. Yeah, I'm not saying it
makes sense. I'm not saying it's a fair criticism. I'm
just saying that Anthony Zerva had a really cool voice,

(02:41):
and uh and when he said these lines, it was like, yeah,
that sounds cool. I don't know what it means exactly,
but it sounds pretty cool. You know, it would be
a really good movie Monster Bug Fight and and both
are Charlton Heston movies. If you pick the vampires from
the Omega Man versus the Adam Bomb Cult from the
second Planet of the Apes movie, you know, they're they're
pretty similar. I think, pretty similar morbid humanoids. But I

(03:05):
would like to see them duke it out and Charlton Heston,
I guess can just watch this time. Yeah, what was
that beneath the Planet of the Apes? I always like that.
As far as any eight movies that came after Planet
of the Apes, that one, that one always appealed to me.
I'm not sure why. Uh. I remember there's a part
where they sing a hymn to the atom bomb. You remember, Yep,

(03:28):
they have just a big old atom bomb in there
that they worship. I think it's like a minor key
version of all things bright and beautiful. But it's interesting
all these things are connected because we're dealing with with
a human technology and the idea of worshiping the technology,
being bound to the technology and and the wheel, and

(03:49):
by virtue of the wheel, gears and machines being this
thing that is particular to human beings, something that that
that we have created. It's a part of our various civilizations.
And I think it's interesting to think about humans as
creatures of the wheel empire, because of course there have
been plenty of cultures and civilizations where the wheel, at
least in terms of of vehicles, has played no practical role.

(04:12):
Perhaps it you know, that you had the wheel as
a toy, perhaps it was used as a spiritual aid
or device that could serve as a metaphor. But then certainly,
by the time we get to the you know, the
age of roads and engines, humanity very visibly becomes a
people of the wheel. But then, as we'll discussed in
this episode a little bit, you also get into this
domain of wheels and gears, of of wheels doing things

(04:34):
that they don't have have anything directly to do with vehicles,
but it's all about using the energy of the wheel
to do other things. And yet at the same time,
and this also makes me think of the field of biomemetics,
bioble metics, of course, as when we we say, okay,
I have an engineering problem. I need to turn to
the realm of nature for a possible solution, because I've

(04:56):
only been working on this engineering problem for you know,
X amount of time. But evolution has been working around
similar engineering problems just for for millions of years. So
perhaps we can we can cheat off of nature in
that regard. But of course, one of the problems is
that the wheel almost never comes up in nature itself.

(05:18):
Gears almost never come up in nature, So biomometically, you're
not going to turn to nature and say, oh, well,
well there's a there's a solution involving the wheel that
I might use. Oh let's look and see how this
particular creature uses rotary blades to fly that sort of thing. Yeah,
you know, I actually really enjoy thinking about this in

(05:40):
terms of comparing animal bodies to different types of machines,
machine components, simple machines, you know, the stuff you learn
about in those first physics lessons when you're a kid.
So you know, you know the lever and the inclined
plane and the and the pulley and the screw and
all that. And I feel like when you do this exercise.
There is one type of simple machine that absolutely dominates

(06:04):
the landscape of biology, and that is the lever. Biology
is full of levers. I think you could make an
argument that almost all of the skeletal muscle in our
bodies is designed by evolution for the operation of levers.
Maybe there are some exceptions that aren't occurring to me,
but I would say, if not all of them, almost
all of them. So, for example, when you use your

(06:26):
bicep to do an arm curl, you're curling a dumbbell.
You know, the muscle primarily the bicep. I think also
somewhat the muscle in your forearm is exerting the effort.
The load is what's in your hand, it's your your fist,
and the full crum is the elbow joint, and of
course the bone is the lever. So I think most
of the body's gross motor activity is based on the

(06:46):
action of levers with joints as the fulcrum. Uh. And
then but then when you start looking for other simple
machines and animal bodies, you can turn up some examples,
but it suddenly gets a lot more difficult to scope
things out. Like you can maybe make the argument that
sharp teeth and fangs, or a type of wedge which
is technically a form of the simple machine known as

(07:08):
the inclined plane. But then there are other types of
of machines and machine parts that are pretty rare or
even non existent in nature, and the wheel is a
good one of these. There there are really only a
few examples that people can point to of things that
might be considered freely rotating wheels and axles. In biology,

(07:29):
sometimes people bring up versions of the bacterial flagella as
something that sort of operates like a wheel, kind of
spinning like a propeller to move the bacterium uh through
through a liquid medium and uh. And then there are
also I think some possible parts of animal digestive systems
that may function kind of like a wheel. But animal

(07:51):
body plans clearly favored the versatility of legs based on
levers instead of wheels. And you can make a few
different arguments about why evolution overwhelmingly goes that route. You
could you could say maybe it has something to do
with just morphological precedence, like that levers are easier to
evolve from the pre existing forms that were available for

(08:14):
animal bodies to work on when in you know, adapting
through small mutations. But you could also argue that there
are natural uh, terrain negotiation advantages to levers. You know,
if you're not in a world of clean paved surfaces,
wheels can actually pretty easily get hung up on things,
and you need the articulation of levers and limbs in

(08:35):
order to say, uh, you know, get over rugged terrain,
or to flip yourself back over if you fall on
your back. I think it's also telling that when we
look to the world of mythological creatures and beings, we
don't see a lot of wheels, or at least we
don't see a lot of wheels that are innately organic.
And then if we do, we tend not to see

(08:57):
a creature or a being that is supposed to be
of this world. Um and uh. And perhaps there's some
exception to this rule that I'm overlooking, but I thought
I might bring up a couple of examples. One and
I know I've mentioned this this critter on the show before.
There is a demon by the name of Bure. I

(09:18):
believe it is b U e R described in Johann
of Viers fifteen sixty three. Grimore Pseudo Monarchia demonium Um.
This covers a number of different of supposed demons, and
this demon Buer is the great President of Hell, kind
of a goblin faced lion with kind of a wheel

(09:42):
of five legs going around it, which I find reminiscent
of the pet rail wheel which I mentioned in a
previous Artifact episode, an experimental tank wheel that had legs
on it. Um. So as the wheel turns, the legs
are are placed down onto the ground. Uh this case,
they are goat legs, and I've I've read that they're

(10:03):
supposed to symbolize the demon's ability to move in any direction.
So I'm not entirely sure that we're even supposed to
imagine this creature turning like a wheel or like a
clock or something. But when I look at him, that's
all I can see. Like he basically moves on the
page or on the screen when I stare at him,
and I can imagine I'm kind of lumping around along.
You know. Well, I tend to think about um when

(10:26):
wheels are imagined in the imagery of mythology and religion,
it's often to say something about the fact that the
vision is boggling the mind. It You know that it's
transcending familiar forms and just completely awing you and humbling
you with confusion. Uh. So I think, for example, about
Ezekiel's vision of the wheels in in in the Hebrew Bible,

(10:50):
and and how the wheels there. Uh, it seems to
me at least, I mean, I'm you know, no professional
legs ag eat on that, but it seems like that
they symbolize something about a concept that sort of like
surpasses human understanding. You're looking at something that your mind
can't even fit around. Yeah, I mean, we can easily
imagine the various connotations that are being drawn in there

(11:12):
when you have a wheel like appearing in the sky,
because you have the idea of technology, something created by
rational beings. You have the idea of sort of cosmic
wheels and circular forms related to the movements of the
stars and the planets and so forth. Uh. And then
the idea too that if if this is mixed with
some sort of biological or faintly biological or hybrid form,

(11:36):
that that is again something that is not reflected in nature.
It is something there is something inherently unnatural about this,
this hybrid being that is not even just part animal
and part human or part of this animal and part
that animal, but part flesh being and part cosmic or
technological entity. Now then again, in nature and biology, you

(11:56):
do find all kinds of round mechanism and round bodies
and even rolling forms. You know, lots of animals can
roll up into a round shape and then roll their
whole body. What you what really seems to be unusual
in nature, And again maybe you can only find a
few examples here and there that would seem to fit.
This is a freely rotating wheel that somehow transfers energy

(12:19):
within a broader context. So like the wheel and axle
on a car that moves the car body the car,
you know, the chassiss stationary and then the wheel turns
to propel it forward. That's what you really don't find
much of in nature. But if you're content with just
like something round that rolls, you can have a wheel
spider rolling down a dune. You can have bugs that
roll up into round shapes and roll all over the place.

(12:41):
Even some mammals do that. Yeah, there are some examples
of creatures that that form rolling shapes, granted if the
topography is correct. Uh. There's also, of course, the example
of goat poop I've seen brought up. Granted, goat poop
is not itself alive, but it is the product of
of a biological organism. And the idea here is that

(13:04):
the goat poop is nice and rounds so that it
can roll away and hide itself. Uh in these kind
of environments. But I advocate for goat poop personhood, okay, um.
But but of course, one of the things about any
of these rolling creatures is, of course, if it's gonna roll,
it's everything's gonna roll. There's not gonna be a stationary
part all of the rolling creature as in the same

(13:26):
way that say, there would be the cart portion of
an ox cart would remain the same. Uh. But when
we look to some of our supernatural models, we do
see things that work like this, of course in a
very supernatural form. Uh. There's a wonderful wheel creature in um.
In Japanese traditions, there's a yokai known as one you know,

(13:47):
the fire wheel, and he's a he's a pretty famous yokai.
You've you've probably seen images of him, especially if you
partake of various like anime um products, because he pops
up in a lot of things. I think he pops
up in some video games as well. He looks like
a grumpy, giant human head sort of haloed by a burning,

(14:08):
smoking ghost wheel, and we get the impression that the
wheel is moving in the head is remaining stationary. He
said to guard the gates of Hell, and I've also
read that in life he said to have been a
cruel ruler who burned people on the wheel, so this
is kind of his punishment. He haunts them the roads
at night. He made drag souls back to Hell. And

(14:28):
there's also a female variation called Catawaga. Okay, so this
would seem to be more like that mechanism you don't
really find in nature, if the head stays stationary while
the wheel turns around it right. And of course in
this too we have just a it's not even pretending
to be an entirely organic creature. It is this supernatural

(14:48):
um combination of two or three different things. Um. But yeah,
this is a pretty popular figure. The Power Rangers have
even fought him on occasion. Um shows up in very
his anime titles, and I have to say sometimes he
looks a little bit like Dr robot Nick from The
Sonic games. So I wonder if Dr Robotnick was at

(15:09):
all inspired by this Yokai you know, a grumpy faced
man machine with kind of a spherical design. Because Dr
Robotnick is he's the Eggman, you know, so he's often
in some kind of little like little circular pod. Why
do I want to say that the the Dr Robotnick
was supposed to be based on the appearance of Theodore Roosevelt.
Do you know what I'm talking about? He does look

(15:30):
like Theodore Roosevelt. Yeah, so that might be it instead.
I don't know. I couldn't. I briefly looked around. I
couldn't find anything that connected at Dr Robotnick. There's not
a lot of scholarship on Dr Robotnick, it seems unless
I'm missing it. And if I am missing it, please
send it to me. I want to read your your thesis, Okay.
Our new podcast is an oral history of Dr Robotnick. Um,

(15:54):
now there's a there's another throw some I am the Walrus,
and some Teddy Roosevelt and little Blender and then there
you go, oh, yeah, there's definitely a It seems like
there's definitely a Beatles connection there as well. Now, um,
I was I was reading about this, particularly Yokai, and
there's one more little story I ran across it. I
have to share. This was I found this on Matthew Myers.
Yokai dot com has a profile of when Udo and

(16:16):
shares a brief story that I haven't found anywhere else.
But it's it's too good not to share, and I'm
probably just missing accounts of it elsewhere. But quoting this website,
one famous story from Kyoto tells a woman who peeked
out her window at one Udo as he passed through town.
The demon snarled at her, saying, instead of looking at me,
have a look at your own child. She looked back

(16:37):
at her baby, who was screaming on the floor in
a pool of blood. Both of its legs had been
completely torn from its body. When she looked back out
at one Udo, that child's legs were in its mouth,
being eaten by the mad, grinning monster. What so it
did he teleport that? I don't Okay, yeah, yeah, I
don't know. He's eating those baby legs. He's a bad dude.

(17:00):
That that's a bad dude. So anyway, I'll stop there
with my wheel creatures. But this suffice to say, just
just bringing these up to drive home the fact that
that I think we we have long not expected to
find wheels and gears in the natural world. They are

(17:21):
things of our creation. We are the people of the wheel,
well especially the gear. So that that was my original
idea for the episode, was to focus on the idea
of artificial gears versus possible examples of gears in nature.
And while you can make arguments for a few examples
of wheels in nature, the gear is really a different
kind of story, except for this one really cool example

(17:43):
that we're gonna be looking at today. So what is
a gear? Well, you've seen gears before, but to actually
define the concept what counts as a gear, I think
I think you could say a gear is a set
of rotating machine parts with interlocking teeth. So these can
often take the form of a kind of flat circular plate,

(18:04):
but they can also take the form of, say like
a long shaft that has teeth on the shaft, or
they can even be non circular. There are more kind
of square shaped gears and gears of all different kinds
of shapes and sizes, but what's common to all of
them is that they have teeth that interlock with each other,
and they use those teeth and rotation to transfer force

(18:27):
rotational force known as torque, So they can transfer torque
from one place to another, and they can also sometimes
transform that force in some way as it is transferred.
So gears can change the direction of rotational force. Like
if you picture two interlocking wheel shaped gears, you rotate
one of them clockwise, will actually rotate the other one counterclockwise,

(18:49):
so that'll that'll perform one kind of change. Or you
can change the orientation of the torque by having the
gears interlock at an angle. So think of for example, well,
how if you imagine a car that has the engine
sending its rotational force its torque through a drive shaft
that runs along the length of the car, then that

(19:11):
energy has to be transferred to the wheels to get
them rotating in the direction that's parallel to the car's motion.
So there are gears that interlock at angles there to
transfer that force eventually to the wheels. But gears can
also be used to gain mechanical advantage or change the
speed of a rotational force in a mathematically predictable way. So,

(19:33):
for example, if you use a bigger gear with more
teeth to spin a smaller gear with fewer teeth. The
smaller gear will spin faster than the larger one, and
the change in speed will be proportional to the ratio
of the tooth counts between the two differently sized gears.
In other words, if you use a gear to drive
a second gear with half as many teeth as the

(19:54):
first gear, it will spin exactly twice as fast. To
a certain extent, it almost feels like like wheel wizardry,
because the wheel is doing its thing and and and
if you're not going to do anything else, you can Okay,
you can do various tasks and carry out various acts
by interacting with that wheel on its terms. But by

(20:15):
the use of gears, you can transform it. You can
you can make the gear work in other ways. Um,
and I think that's that's one of the fascinating things.
So when we're when we're talking about sort of that
lead from from wheel to gear, and of course, and
this could be just as simple as well. I don't
want horizontal rotation, I want vertical rotation, that sort of thing, right,

(20:36):
But it can also this last thing I mentioned about
the predictable mathematical relationships between the intervals of rotation of
tooth to gears. The fact that toothed gears are quantized
right that you can like put a number to the
number of teeth on a rotation that allows you to
tightly control the ratios you know, how fast one spins

(20:57):
in relationship to another one. That actually has made gears
useful not just for say, applying force to things like
you know, powering a machine or something, but also for
tasks related to more abstract types of work, like measurements
such as measuring intervals of time UM, and not just
in straightforward timekeeping devices like clocks. Of course, gears are

(21:20):
very important in in UM analog clocks, but even more
complex applications like we see in one of the most
intriguing artifacts from the ancient world, known as the Antiquothera mechanism,
which is widely considered the first known computer not a
digital computer, but an analog computer, a computer that uses

(21:42):
gears instead of semiconductors for information processing. UH. The Antikothera
mechanism was discovered in a Roman era shipwreck in the
Mediterranean around the r nineteen hundred UH, and this shipwreck
traced back to a ship that sank probably in the
first since chere ce rob. I've got an image for
you to look at here that shows the actual remains

(22:05):
of the mechanism alongside a modern reconstruction that was sort
of reverse engineered and built by some experts who had
studied this machine. The mechanism is now understood to have
been an ancient mechanical or ory. An oorory is a
is a working model of the movement of heavenly bodies,

(22:25):
and this one would have been powered by a hand
crank that operated gears. And this or ory would allow
you to calculate the relative positions of heavenly bodies like
the Moon and the Sun as they traveled through the
zodiac out to specific future dates. Uh. And I think
it may it may also have tracked planetary motion as well,

(22:46):
but that's less certain. I think that's a hypothetical mechanism
that may have been present but may have been lost.
When I look at it, I'm instantly reminded of those uh,
those gear devices you find at museums and zoos where
you and squash a penny and make it into a
collector's token, which which I have to say, as as
a parent, I have I have long realized the children

(23:08):
are drawn to these like like flies. Uh. To to
meet they they have to turn the crank. They have
to watch those gears operate. Um and uh and And
now that we've actually discussed gears a bit on the show,
I used to be I was. I've long been very
annoyed by it, like, oh, come on, don't mess with that.
We're here to look at something else, and you're just

(23:28):
gonna turn this gear on this machine that I'm not
going to give you fifty cents and a penny for
because it's it's a dumb invention. But at the same
time they're interacting with the gears, they're getting to see
the gears in motion and see some of that energy
transference that we're talking about. Oh well, I mean yeah,
it's a beautiful way. Actually, I think to educate kids
about mechanical advantage, about like what machines can do. Because

(23:50):
the kid, they know that they wouldn't have enough strength
to smash a penny flat with their hands alone, but
with their hands by operating a rank in a machine
that has no external power source. It's just the power
of their arm. But through the mechanical advantage created by
this crank, the lever of the gears. They can smash
a penny. That that's kind of that's that's empowering knowledge

(24:12):
that there's a wizardry to that too. Behold the power
of the gear. But anyway back to the antikotherum mechanism.
So it was able to predict the future movements of
heavenly bodies like the Sun and the moon, and also
I think predict eclipses. And it managed the different time
ratios between these these moving objects in the heavens by

(24:35):
the use of gear ratios, gear ratios to calculate the
intervals of these movements. So in a way, this was
a calculator the different ratios between the number of teeth
on the gears. We're doing math for you now. We
know in the modern world gears are useful in all
kinds of machines. You find them everywhere. They're in clocks,
they're in cars, they're in fluid pumps, they're in mills

(24:58):
and factory machines. Uh. But but you might wonder, okay, well,
where did they first appear in the technological space, Because
you wouldn't necessarily expect to have found a computer for
astronomical phenomena in the first century ce but here it
is and probably actually it's even older than that. I
think it's believed to have been uh. I don't know,

(25:18):
maybe at least a hundred years old at the time
it was lost in the shipwreck, so so clearly that
that's taking gear math way way back. UH. And I
was trying to find some good sources on the ancient
history of gears. I didn't come across anything that was
super recent, so there may be discoveries since these sources
I turned up, but um one that was interesting to

(25:40):
me because it was by Derek John Desola Price, who
was a British physicist and historian of science who was
one of the investigators who worked on the Antiko theorem mechanism. UH.
He did a chapter that was in a book put
out by the U. S National Museum Bulletin in nineteen
fifty nine called on the origin of clockwork perpetual motion

(26:02):
devices in the Compass, and in a short section on
the earliest known examples of gears and geared mechanisms, he
writes that the earliest evidence for the knowledge of tooth
to gears um. Probably it goes back at least as
far as the Greek mathematician and inventor Archimedes, who showed
clear knowledge of of toothed gears, and he lived in

(26:23):
the third century BC. But he also cites artifacts from
ancient China that may indicate knowledge of of gears even
farther back than that. He writes, quote, in China, actual
examples of wheels and molds for wheels dating back from
the fourth century BC have been preserved. One of the
interesting things he mentioned about some of these earliest examples

(26:45):
of gears in the archaeological record. Uh. He says, quote,
a remarkable feature in these early gears is the use
of ratchet shaped teeth, sometimes even twisted heliically so that
the gears resemble worms into or meshing on parallel axles.
But then he also calls attention to the fact that
throughout much of history, uh, you know, definitely before the

(27:08):
Industrial Revolution, a big use of a lot of a
major use for gears in the technological space was in mills,
in windmills and water mills, using large gears as a
way of transferring force, often at a right angle to
how these natural forces like the flow of water or
the flow of wind. We're we're moving the primary turban yeah,

(27:30):
or likewise to transition from say a horizontal paddle wheel
into a vertical millstone, that sort of thing. Yeah. Yeah,
Now another paper that you you turned up on. This
comes to us from M. J. T. Lewis Gearing in
the Ancient World, published in Endeavor seventy seventeen, number three
from UM and I was reading through this one. This

(27:52):
was pretty interesting. I'm going to be some slight retreading
of what we're vary discussed, but basically, according to this
paper we can trace the technology of of the gear
to ancient Greeks of the third century b c. Which
also according to um uh To Fagan at all in
uh the seventy Great Inventions of the Ancient World. Uh.

(28:16):
You know this is this is also the time and
place where we see, at least according to ancient Greek
and Latin technical authors, the birth of water powered milling uh,
a technology that of course would be highly effective. But
according to to uh To Lewis, here in Alexandria, the
Greek kings of Egypt at the time the Ptolemy's, they
set up a research center called the Museum. I think

(28:38):
we've talked about the Museum in the past, right, perhaps
even in our episode the invention of the museum about
the sort of the original usage of this word that
sounds familiar, Yeah, yeah, So basically, various technological innovations were
said to have emerged from this this sort of lab
this kind of technological think tank and laboratory. Uh and,
according to such writers as hero Vitruvius and Phillow of Byzantium,

(29:03):
they all point to the work of Descibius, who would
have lived to five through two twenty two b c E.
None of his actual writings survived, but he's said to
have written various works on compressed air and hydraulics, and
hero Vitrucius and Philo would all go on to write

(29:24):
at length on these various machines and uh and and devices,
various gear arrangements. Other great minds of that age and region,
such as Archimedes, would also expand on these ideas as well. Now,
Lewis explains that we ultimately don't know where and when
the earliest gears pop up in human history UH tooth gears,

(29:46):
he writes, already existed in the form of ratchet wheels
that were used to hold a windlass against a load,
and these might date back to Greek crane innovations from
around five b c. E um. He He also points
that a bronze example of this has been found from
about a century later, and this might have been used
for hauling ships up a slipway. After this point, ratchets

(30:10):
were widely used on catapults as a way of holding
back all that potential firing energy. Um. But he writes, quote,
but the first toothed wheel for transmitting motion may have
been a sprocket wheel driving a chain. This is attested
by two machines described by Philo. One is a chain
of buckets powered by a water wheel. The other is

(30:31):
a repeater catapult built in roads by certain Dionysius of Alexandria,
who cannot be precisely identified, but may have well worked
before two eighty two b c. E. So the Greeks
and the Romans obviously applied the subsequent technology to a
number of tasks. But but Lewis raises the question did

(30:51):
they invent all of this themselves or did they borrow
or pick up on the ideas of others, And he
writes that one possibility would be the they somehow got
these ideas from China. In fact, he writes this would
be seemingly the only other alternative. UM. However, one of
the limiting factors here is that accounts of the gear

(31:13):
in China largely come later, from the first century CE,
but he writes, quote the only earlier examples in China
so far recorded, and I do want to stress this
was like UM are a number of very small bronze
gears and ratchets found in tombs and dating from around
two b c E to fifty C. They include extraordinarily

(31:35):
what looked like chevron or double helical gear wheels of
tiny size. All seemed too small and too early to
belong as has been suggested to windlasses for drawing crossbows,
and we have no idea what they were for gear mystery.
And I include of uh images of these uh, these
mysterious gears below. So yeah, I haven't haven't had a

(31:58):
lot of time to investigate further to see if any
additional scholarship has emerged on these little gears and what
they might have been used for UM. And I don't
know if if ultimately there are stronger arguments that have
been put put forth regarding their use or possible use
and crossbow technology. But it's fascinating Oh, one of these
pictures you attached. I wonder if this is what Derek J.

(32:22):
To sell a Price was referring to when talking about
ratchet shaped teeth that are twisted helickally so that they
look like worms intermeshing on parallel axles. That I can
see at least one of the images you include from
the Chinese example could could be what he's talking about there. Yeah,
that's where my mind went when you read that that debt.
Having having looked at these examples, Yeah, it has kind

(32:44):
of a worm like quality to it. Um. Now, Ultimately,
Lewis and his writing, he contends that gearing was either
invented independently in China and in the Greek world, or
that it was actually transmitted from the West to the
East rather than vice versa. But but, but, like I said, that,
there may be additional scholarship that we just haven't come

(33:06):
across yet regarding this. But it does raise the question
what kind of gears would one be entombed with? You know, what,
what bit of technology would it make sense to to
to go to the grave with. I mean, certainly a
very nice crossbow seems like the sort of thing you
might bring with you. Um, I don't know if it
would make sense for there to be some sort of

(33:27):
like purely novelty gear device, like something that was more
of a curio that maybe wasn't fully utilized or you know,
analog computer. Yeah, it could be. I guess if your
journey in the afterlife really depends on knowing when an
eclipse is coming, yeah, I wonder yeah, yeah, and then
of course, but then of course, just interlocking gears and

(33:47):
turning things are just are interesting. They they they make
us think about about motion and uh, interlocking energy. So
I don't know, it seems like they're there's just a
few different directs it could go in that I could
I could imagine somebody saying, uh, that is something I
want to be buried than now. I want to come

(34:13):
back to the concept of gears in biology because for
a long time, while there was probably no known example
of a working gear in the in the biological world,
there have been observations before of animals having appendages certainly
look like tooth to gears. And my favorite, uh instance

(34:36):
I came across here is a creature called the wheel
bug or eralists cristatas. This is a type of predatory
assassin bug that preys on all kinds of insects, including aphids, caterpillars, beetles,
and bees. I found some very gnarly looking images of
of caterpillar mutilation. Yeah, I don't think i'd really seen

(34:59):
this species before, these creatures before, but yeah, they're quite
cool looking. It kind of looks like it has some
sort of a gear emerging from its back. Also, it
reminds me of a buzz saw or perhaps to some
degree of something like a stegasaurus or or or demetrodon
or something. Yeah, so it's called the wheel bug, but

(35:21):
I think maybe a better name would be the gear bug,
because it really does look like it's it's got this
toothed gear poking up out of the back of its carapace,
right sort of behind where the head is up on
the thorax. And so I was reading about this insect
on the University of Florida Department of Intropology's website. They've
got a good profile on it there and they say

(35:41):
in adulthood, this insect tends to measure about one to
one and a quarter inches long, and then quote, this
assassin bug is a dark, robust creature with long legs
and antennae, a stout beak, large eyes on a slim head,
and a prominent thoracic semicircular crep ust that resembles a
cog wheel or a chicken's comb. This is the only

(36:05):
insects species in the United States with such a crest.
The number of teeth or tubercles in the crest varies
from eight to twelve. Now immediately you're you're probably wondering,
as I was, what does it do? What? What is
the gear on its back? Do? I could not find
any solid research alluding to a purpose of this cog

(36:25):
wheel crest. That there may be something out there that
I couldn't come across, or it may just be unknown.
I think it's more likely unknown at this point what
this gear crest is for, in which case, barring other knowledge,
I guess you might assume that its purpose might have
something to do with appearance rather than any mechanical function.
Maybe it plays a visual role in interactions with predators

(36:48):
or prey or mats, or maybe it's defensive somehow. It's
hard to tell um but apparently Another interesting fact is
that the wheel is absent in juvenile So if you
look at nymphs of this assassin bug, they don't have it.
It only appears in adults after the insects final molting,
so once it reaches its ultimate form, then it's got

(37:09):
the gear. But whatever it's for, it does not appear
to be a functional gear. It just looks like one.
I mean, for one thing, it can't rotate, and there's
nothing really that it could clearly be rotating against locking
its teeth with. It's just a crest that kind of
looks like a gear or like a like a chicken's comb. Now,
as amazing as these insects look, one thing I should

(37:31):
probably note is that you don't want to try to
handle it, because apparently wheelbugs can produce an extremely painful
bite that that lingers for days. But but anyway, this
animal is worth looking up. There are actually a few
other interesting things about them. For one thing, they do
appear to practice some amount of sexual cannibalism. Also, they

(37:52):
there is another mystery about them where they produce a vocalization.
I think they create a chirping sound by a certain
type of a friction mechanism where they rub one part
of their body on another. I think maybe they're rubbing
some uh, they're either their beak or four legs. I
think it was the beak on an on a part
on the underside of their carapacet and it creates this chirping.

(38:13):
And scientists, as far as I could tell, don't know
what this is for yet. But coming back to the
idea of an actual mechanically functional gear in biology, as
of a study published in the year in the journal Science,
there actually is at least one known animal that does
contain working toothed gears within its body, and as far

(38:35):
as I could tell, this is also still the only
animal that has this feature that that's known, and this
animal is a type of plant hopper insect known as S. S.
Colliup tratis. The paper that reported the discovery of this
animal gear was, like I said, published in Science in
by authors Malcolm Burrows and Gregory Sutton, who both at

(38:58):
the time worked in the biological sciences at Cambridge University,
and it was called interacting gears synchronized propulsive leg movements
in a jumping insect. Now, Rob, I've got some images
that you can that you can look at here while
I'm talking about this. There's some really interesting electron micrographs
of of these these gear pieces. They truly don't really

(39:21):
look animal, right, you know, they do look like a machine.
And I always love that when you like zoom way
in on the parts of an insect or something and
you get that hr Geeger space where you can't tell
if what you're looking at is is natural or artificial. Yeah,
because there's one image here of believe a nymph um
of of this uh, of this species, and you know

(39:42):
it's it's cute, but it doesn't really look like anything
other than some sort of a fly or insect um.
But yeah, when you start looking at these these electron
microscope images, yeah, then then it takes on this bio
mechanical kind of reality and it's, uh, yeah, it's quite
unlike anything else I've seen. So it is this animal,
the the S. S. Coleopterus. Well, this is an insect

(40:04):
that is again known as a plant hopper. I think
you'll normally find them crawling around on bits of ivy
in Europe and North Africa, and so they're they're very
very small. They're usually just about three millimeters long at
maturity um and so they'll go around grazing on ivy leaves.
And the discovery that's announced in this report is that

(40:25):
the juveniles of this species, so not the adults, but
the nymphs. The juveniles, they have these interlocking gear teeth
on their back legs which allow them to rotate their
legs in perfect synchronization when they are setting up a jump.
So these tiny insects have have their main defense against predators.

(40:49):
And it's not clear exactly what predator this is most
adapted against, so I don't know if this would be,
you know, against the possibility of being eaten by a
large mammal that's grazing on foliage, or being pounced on
by a parasitic wasp or some other kind of smaller
insect predator or spider or something that's not quite known
for sure, but but there it is probably some kind

(41:12):
of survival defensive adaptation that this creature needs to be
able to jump far and jump fast, and they are
one of the most amazing jumpers in all of nature.
I was watching an interview with one of the authors
of the study, Malcolm Burrows, in which he talks about
the jumping mechanism, and so the s s insect will

(41:33):
take off at a at a jump of about five
meters per second or more than eight miles per hour,
which for a tiny insect like this is pretty fast.
It accelerates to its jumping speed in less than a millisecond.
And so the way Burrows explain this is that this
insect experiences absolutely unfathomable G forces as it takes off

(41:57):
because its acceleration is so fast. He puts it at
five hundred or even seven hundred g's, which if you
look at the amount of g's that humans are able
to tolerate, it's like the amount you can tolerate is
a factor of how long you are subjected to them.
But you know, usually for humans, the the the acceleration

(42:19):
we can tolerate in gs, the maximum is like a
factor of a few tens, you know, but this would
be hundreds. Yeah, this is impressive. So this insect has
this amazingly fast, amazingly powerful jump that can just catapult
It's like it's shooting itself out of a cannon using
the power of its two hind legs. And what was

(42:40):
documented in this paper by by Burrows and Sutton is
that they they captured imagery of gear mechanisms on the
hind legs interlocking using electron microscopy and high speed video recording. Uh,
and and again, the purpose that they found is that
these interlocking gear teeth are useful for synchronizing the motion

(43:04):
of the legs. Now, why would synchronization of the leg
movement be so important that it would have its own
evolved mechanism, which is, as far as we know, unique
in the animal kingdom. Well, apparently it's because coordination of
the timing on the two legs is necessary for this
incredibly powerful sort of cannon shot jump to be effective.

(43:27):
So I was reading about this in one of the
press releases about the about the study, and what the
author's here found is that a lack of synchronization between
the legs at launch could cause an uncontrolled what they
call yaw rotation. So if you if you picture an airplane,
you know you've got the different uh, the different ways

(43:48):
that you can change the motion of the airplane. You've
got pitch, role and yaw. So pitch would be tipping
the nose of the airplane up or down. Role would
be raising. That would be rolling the airplane. You know,
ray s the wings relative to each other, and then
yaw is twisting side to side. If you can imagine
an insect, that's sort of catapulting itself in this spectacular

(44:10):
jump with two with pushing off with the two hind
legs at the same time. If one leg pushes off
faster than the other one, you can imagine that it's
going to send the insects sort of twisting out of
control in its path, which obviously interferes with landing where
it's trying to land. Now, one question would be why
the need for a mechanical gear for synchronization. What why

(44:33):
does this need to be on the insects exoskeleton. Why
wouldn't the insect just synchronize the action of its legs
through the nervous system like pretty much any other animal would, Right, Like,
if you are jumping, you are able to synchronize the
motion of your legs through neural mechanisms with your brain
and your nervous system sort of trying to control them

(44:55):
through normal motor function, and then getting feedback from the
feelings of your legs from like your appropriate reception and
stuff and and tactle sensations to to try to time
the jump together and correct for any imbalances in real time. Well,
apparently the insect can't do that because the problem is
it's jump is too fast to synchronize through the nervous system.

(45:19):
The acceleration leading into the jump happens so quickly that
the nervous system cannot do real time feedback to coordinate it,
so it needs this mechanical lock on the legs themselves
to make sure synchronization is happening, because the insects nervous
system can't talk to itself fast enough to make sure
that the that the jump is on target. In their

(45:41):
In their press release, author Malcolm Burrows summarized it like
this quote. The precise synchronization would be impossible to achieve
through a nervous system, as neural impulses would take far
too long for the extraordinarily tight coordination required by developing
mechanical gears, the can just in nerve signals to its
muscles to produce roughly the same amount of force. Then,

(46:04):
if one leg starts to propel the jump, the gears
will interlock, creating absolute synchronicity and is the skeleton is
used to solve a complex problem that the brain and
nervous system can't. This emphasizes the importance of considering the
properties of the skeleton in how movement is produced, and

(46:24):
this was really interesting to me because it also comes
back to you could maybe even consider this a case
of sort of supplementing the cognitive abilities of the nervous system,
sort of embodied cognition, allowing the body to do math
for you that your brain and nervous system can't handle. Yeah,

(46:45):
because essentially it's it's it's a physical way of solving
a problem that is beyond cognitive ability, um and and
and and really when we're talking about the g forces
pulled here, and I think this is beyond spaceflight. So
when we talk about like humans have not evolved to
travel in space or to deal with certain speeds or
or physical realities like, this is a case here where

(47:08):
this this creature is is essentially engaging in those kinds
of speeds, those kinds of rapid accelerations. Uh So it's yeah,
it's fascinating to think about here. Yeah, the body moves
too fast for the nervous system to make sense of,
so it just offloads that that computation that the motor
parts of the nervous system might do naturally, offloads that

(47:31):
onto the skeleton. Now, the exoskeleton of the insect is
doing the math for you, kind of like an analog
computer would like the antique theorem mechanism wow wow. So
to take a slightly closer look at these teeth at
the gears on the hind legs. They're located on the
backs of the strong hind legs that the s s
insect uses to jump um there on the parts of

(47:53):
the legs known as the trocanta, and it's actually a
human skeleton has trocanta to their They're sort of on
the upper part of the femur, near where the femur
would would connect to the pelvis. And these these insects
tend to have somewhere between ten to twelve teeth on
their gears. But while it seems to vary between the insects,

(48:15):
the insect always has the same amount of teeth on
each side. Within itself, each tooth is about eighty micrometers wide,
so eighty millionths of a meter. And there are some
interesting engineered features of of these gear teeth within the
body that have been created by the evolutionary process that
gives rise to them. Here, the teeth have rounded corners

(48:37):
at the point of contact, and this is useful, apparently
because it would help prevent the gears from being sheared
off or broken off if there is a slight misalignment
during a jump. And then another interesting thing about them
is that they are differently shaped than most gears we
use in the technological world, because usually gears made by

(48:58):
humans tend to have some metrical teeth, right, you know,
there's sort of curved straight out from the gear strip surface,
But in these the teeth are not quite symmetrical. They're
sort of angled out. And it's because this gear only
needs to work one way, so like, after the launch
is done, the gear teeth can just separate from each

(49:19):
other and they don't need to roll backwards in in
the direction opposite from which they came. It's a one
way gear. Yeah, and you definitely get that from looking
at the image. It feels like some sort of a
biomechanical um, you know, firing mechanism, right, A firing mechanism
is a is a good way to compare it, because again,
it doesn't go both ways and it doesn't need to
roll all the way around. It's just sort of a

(49:41):
strip of interlocking teeth that doesn't complete a full circle.
And it only and it only rolls one way only
on launch. Yeah, like it kind of looks like if
hr gear designed a flint lock. Yeah, or maybe if
David Cronenberg did you know? Yeah? Oh, but so there
was a really interesting thing about this research, the question
of how did they figure out that these gear teeth

(50:03):
locked for synchronization while launching the jump? Right? Like, how
do how did they observe that? Well, apparently the authors
here used a dead insect. They used an insect corpse,
and what they did was they they took the dead
insects legs and rotated them back into the jump launching position,
and then the researchers used an electrical stimulus to cause

(50:26):
a contraction in the jumping muscle of only one of
the legs. Okay, so they they stimulate only one leg
as if it has been told by the brain to jump.
But because the gear teeth were locked when the legs
were in jump readying position, the insects legs both performed
the launching motion, even the dead leg on the other

(50:47):
side that had not been electrically stimulated, and the insect
leapt straightforward, so you could stimulate only one of the
two legs, kind of like how an airplane can fly
with only one engine. You know, you only need to
stimulate one of the legs, and the gears keep both
legs locked in sync. Now there's another interesting question here,
why only the juveniles. I think I already mentioned that

(51:09):
the adult insects don't have these interlocking gear teeth. They've
got a feature that's more common, more like what you'd
see in a lot of other jumping insects, which is
not gear teeth, but just sort of um bumps or
friction pads, So their back legs might touch each other
and and the touching their helps keep the jump synchronized.

(51:32):
But they don't actually have interlocking teeth. It's more just
kind of like pushing to surfaces together that grip each
other pretty well. In another study by Burrows, he noted
that this is achieved by quote mechanical actions between small
protrusions from each Trochantera, which fluoresce bright blue under specific
wavelengths of ultraviolet light and which touch at the midline

(51:56):
when the legs are cocked before a jump. So the
adults are touching parts of their back legs together to
help synchronize a jump, but they don't have gear teeth.
And the hypothesized explanation for the difference here is that
is this Insects go through periods of molting as they grow. Right,
So an insect, as it gets bigger and bigger, it

(52:16):
will shed its old hard exoskeleton and then it will
grow bigger and allow a new exoskeleton to harden. But
the adult exoskeleton at full maturity, it lacks these interlocking
gear teeth. And the idea is maybe the adults don't
have the teeth because if the teeth on the jumping
mechanism were to break or get sheared off but by error,

(52:39):
this would sort of break their ability to jump. And
so once the adult is in full molted form and
it's not going to shed its exoskeleton again, it needs
to have a less fragile mechanism. But the younger's, the
younger ones, the juveniles, because they will go through multiple
moltings and can grow new gear teeth if they're old
gear teeth break, they pay less of a price for

(53:01):
having this somewhat fragile mechanism. Okay, So here we see
sort of in in their early stages, the advantages of
having an an exo skeleton, and then in in later
life the disadvantages of having an exoskeleton and that you're
not going to get another one, right, And so when
you're not going to get another one, it makes more
sense for evolution to supply you with more durable mechanisms

(53:25):
that aren't going to possibly like kill you if if
they break right, there would be a survival advantage in
having a jumping mechanism that's not going to It's not
going to be like a Boba Fett's um jet pack
firing off at a weird angle and sending you into
the sarlac. Right, But that's just a hypothesized explanation for

(53:45):
the difference between the juveniles and adults. Ultimately, we don't
know for sure there and as far as I can tell,
this is still the only known toothed gear in the
animal kingdom. That there may have been something since then
that I wasn't able to track down, but it looks
like this is still the only one. Yeah, well, this
is fascinating. It kind of brings me back to the
biobmetics question earlier. You know, um an evolution solving particular

(54:09):
engineering problems over time, and this is an example where
the the engineering problem is extreme enough that and the
and the circumstances of its its lifespan enable the sort
of answer to evolve and take place. Yeah. Yeah. Can
you imagine if you had gear teeth on your inner
thighs that helps you jump, it seems uncomfortable. Yeah, yeah,

(54:32):
I'd have to have an exoskeleton too for this place.
Or yeah, I'd have to have some other kind of
weird arrangement, like you would have to be bone spurs
or keith that grow back, I guess, because that would
again you'd have to have the situation of what what
do you do about the wear and tear of this
the physical mechanics here, I mean, it doesn't really make
sense for our bodies because that wouldn't that wouldn't be

(54:52):
how we jump anyway, or like I need to work
differently for that to make sense. Yeah. Yeah, So again
we come down to a very specific, evolved answer to
a specific problem that yeah, you're just not going to
see in in in other organisms. But I am still
in memorative the idea that in a way, these these
gear teeth on the insects legs are a kind of computer.

(55:15):
They're doing a kind of mathematical processing for the animal.
This is the this is the computer of the thighs. Yeah.
And and also it's interesting too that no matter how
no matter how much you know, humanity clung to the
wheel and to gears and and saw this as their
technological achievement. Uh. Here we have an example of evolution

(55:35):
once more, beating humanity to the punch. Uh. So well,
before the Greeks of Alexandria were devising their uh their gear,
you know complexities. Uh, this creature already had the gears
right there in its thighs. These gears are hopping. Yeah. Well,
this was fun. I enjoyed talking about everything from We

(55:57):
had a little bit of an intervention episode. Uh in here,
we had some biology, we had a little bit of
mythology and folklore. So it would be interesting to come
back to this. And and we talked about potentially covering
screws and screws in nature in this episode, but perhaps
that would make for its own future episode. Oh yeah,
there are actually a few things in nature that you
could argue or screws. Yeah, and then and and of

(56:20):
course the invention of the screw and uh and so
forth is also quite interesting. All right, we're gonna go
and close it up then, but we'd love to hear
from everyone out there. UM, certainly reach out to us,
get in touch with us in the meantime, if you
want to check out other episodes of Stuff to Blow
Your Mind Core episodes publishing the Stuff to Blow Your
Mind podcast feed on Tuesdays and Thursdays, sandwich between them,

(56:41):
we have an Artifact episode or for the months of
September and October. Anyway, it's going to be the Monster Fact.
It's gonna We're gonna take on more of a monstrous
form for the holidays here and then it will likely
revert back to the Artifact. We have listener mail on Monday's.
We have a little weird house cinema on Fridays. That's
our I'm just to discuss a weird film, and then

(57:01):
we have a rerun over the weekend. Huge things. As
always to our excellent audio producer Seth Nicholas Johnson. If
you would like to get in touch with us with
feedback on this episode or any other suggest topic for
the future, just to say hello, you can email us
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(57:26):
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