May 29, 2025 • 48 mins
In this invention-themed episode of Stuff to Blow Your Mind, Robert and Joe discuss the origins and physics of skating on ice.
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Speaker 1 (00:03):
Welcome to Stuff to Blow Your Mind production of iHeartRadio.
Speaker 2 (00:12):
Hey you welcome to Stuff to Blow your Mind. My
name is Robert Lamb, and I am Joe McCormick, and
we're back with another Invention themed episode. Some of you
may notice Joe and I were just chatting about this.
We were doing an episode here on ice skating. It is,
of course the very beginning of summer.
Speaker 3 (00:29):
Most of the articles you find about this come out
in December, so actually you might be much more familiar
with the seasonal mismatch if you live in the Southern Hemisphere.
But yeah, I guess for the majority of readers in
the Northern hemisphere reading, I guess they're only going to
click on an article about ice skating in December. I
don't know. I'm against that kind of thing. I believe
(00:51):
in anti seasonal topicality.
Speaker 2 (00:54):
Yeah, I mean, plus, people are ice skating somewhere year around.
There are of course indoor ice skating rinks. And I
should also mention that the way we're getting to ice
skating is because my initial inspiration here was to do
an episode on roller skating. This is of course, the
past time that initially boomed during the so called Golden
Age of roller skating, This is roughly nineteen thirty seven
(01:17):
through nineteen fifty nine. I think there's a lot of
you know, escaping from the darkness of the world in
that period and finding a little lightheartedness on the roller
skates in the skating rink. But you know, it's something
that's never completely gone out of fashion either, and it's
experienced sustained popularity in various parts of the world and
(01:37):
saw a major boost during the global pandemic.
Speaker 3 (01:40):
Can I ask a question to older listeners if you
watch movies about the fifties, you often see people roller
skating down the hallway in high school or in another
setting that's not a dedicated roller skating environment like a
rink or something, and people just roller skating on the
sidewalk at school going from class to class. Is that
a thing people?
Speaker 2 (01:59):
Actually, I don't know they're doing it now because roller
skating is not only going strong, but it's I think
it's getting stronger. We may get into this in a
in another episode, but there are a lot of like
financial I saw some financial papers talking about how the
roller skating industry is just going to continue to grow
(02:19):
over the next decade or.
Speaker 3 (02:21):
So I do think we should bring back the roller
skate mounted server at the drive in restaurants, because that's interesting.
It adds an element of danger and theatrical athleticism to
the dining out experience that you don't usually get.
Speaker 2 (02:37):
Well, I don't know how dangerous it is, but yes
it is. There is kind of a neat charm to it.
But yeah, I've been seeing a lot of roller skaters recently.
My kid is involved in a local vibrant skating club,
and it really made me reconsider what I thought I
knew about skating and skating culture. So I figured, hey,
well let's let's do a nice summer episode about roller skating.
(02:59):
But the thing is, before you can even begin to
cover the invention of roller skates, you have to explore
their cold weather predecessor. You have to talk about ice skates.
Speaker 3 (03:08):
I assume there's no disputing this at all, which came first.
The ice skate is definitely older than the roller.
Speaker 2 (03:14):
Skate, definitely, definitely by a considerable margin. Yeah, nobody's even
making the case, even if you were getting into potential
possible examples of somebody designing something like a roller skate
that just wasn't usable. Anywhere, because maybe you lacked the
places for I've I've seen no arguments that this is
(03:35):
the case. If anyone out there is aware of even
any just unhinged theories about the roller skate coming before
the ice skate, send it our way and we will evaluate.
But as far as I can tell, nobody's making this case,
and so we're going to stick to what seems to
be the established lower here. We're going to talk about
ice skating now, and then I think maybe an episode
(03:58):
later in June, we'll come back and discuss roller skating
in more detail. Fair enough, Okay, So, as is generally
the case when we're talking about an invention, we like
to talk about what comes before, so we can appreciate
the invention. What came before skating on the ice using
(04:18):
some sort of an ice skate. Well to properly consider
ice skates. Oh wait, you already have an answer. Let's
have it.
Speaker 3 (04:25):
No, I was going to slipping on the ice, slipping
and falling game first.
Speaker 2 (04:29):
Well, it always does in ice skating, doesn't it. You
could and you could make an argument that skating on
the ice one way or another is slipping in style.
It is a controlled slip.
Speaker 3 (04:40):
Exactly controlled slipping.
Speaker 2 (04:42):
Yeah, I think the most important thing that I quickly
realized looking at the history of the ice skate is
we think of ice skating more as novelty, or perhaps
you think of it as part of sport, but we
really have to view ice skates not as an item
of recreation, but as a mean of conveyance, of moving
(05:02):
the human body from one point to another. And so
before humans skated across ice as a means of conserving
energy and maximizing speed, they did a few different varied
things on ice, including slipping and falling down. Of course,
walking across the ice is of course the oldest forerunner,
obviously requiring no technology, but certainly benefiting from a variety
(05:24):
of innovations that would occur over human history, including the
leather shoe I believe, the oldest surviving example being a
some five five hundred year old arny one shoe from
Armenia or what is now Armenia. But obviously such footwear
was biodegradable by its very nature, so who knows what
we lost though?
Speaker 3 (05:45):
Of course, when we think about ice skates, these are
obviously tools designed to decrease friction on the ice and
allow you to glide more easily. I would tend to
think that the earliest ice traversal technologies were exactly the opposite.
They would be things disa to help you better grip
the ice to avoid slipping and falling while you walked.
Speaker 2 (06:05):
Yeah, which brings our mind to things like spiked cleats.
I was looking around. Let's say there's some examples that
survive from the first and second millennium CE, But again
there's no telling what was lost as well in our
ability to figure out how to make grippier footwear for
walking around on the ice. And then, on top of this,
(06:26):
we should also point out that a certain understanding of
the different types of ice and how it responds to
your weight would also have been important for moving across
the ice. The examples of the oldest surviving cleats that
I was finding my research were things from the Viking era,
So it's very possible there are older examples of this
that didn't survive, and possibly something that didn't come up
(06:49):
with my research. So as always, if anyone knows of
an earlier example of some sort of grippy footwear technology,
send it our way. Furthermore, before humans turn to ice skating,
proper they make use of sleds, a variation of the sledge,
which itself is a predecessor to the cart. And these
of course are ancient and widespread innovations which, depending on
(07:09):
the environment and you know where they were constructed, they
might have entailed bone, ivory or wood. So we can
easily imagine that the idea for the ice skate perhaps
comes together from ruminations on existing sled technology, you know,
like what if ice strapped a sled to my foot,
as well as experiences walking, sliding, slipping on ice covered lakes, rivers,
(07:34):
and so forth. Couple that with a need for such
skates for a conveyance, such as areas where human communities
are separated by expansive frozen over bodies of water. And
it's only a matter of time till someone tries to
miniaturize the whole affair and place it on a boot.
Those will discuss the physicality and indeed physics of ice
(07:54):
skating differs significantly from either of these pre existing technologies.
So here in a bit we're going to go back
and look at the most ancient known examples of ice skates,
how they worked and didn't work, and how they evolved.
But let's go ahead and move towards our current understanding
of the ice skate and just talk about how it works.
Speaker 3 (08:16):
As in, what physics principles does the ice skate take
advantage of?
Speaker 2 (08:21):
Yeah, because we can all sort of have innate understanding
of out works. But yeah, let's get into the physics. Yeah.
Speaker 3 (08:27):
So this is one of those things that seems like
a question that would have a fairly simple, well understood,
well agreed upon answer, But surprisingly, no, the physics of
ice skating are quite complicated. The issue is still being investigated.
Some explanations that you see all over the place and appearing,
I think even in fairly recent physics textbooks are actually
(08:51):
disputed by experts, and from what I can see, new
papers on the physics of ice skating still appear regularly
in scientific journals, at least as of a couple of
years ago.
Speaker 2 (09:02):
That's crazy. It's not settled science yet.
Speaker 3 (09:05):
Yeah, there is a lot we do know now, but
a lot of that was established rather recently, and then
there are still a bunch of questions that we don't
have answers to yet. But I always think it's interesting
when you come across something like this, one of those
things that you assume would have a short, simple, non controversial,
one paragraph answer in the physics textbook, and actually it's
(09:27):
like a super complicated unsolved question. But anyway, so the
main thing that we need to explain when looking at
the physics of ice skating is why can an ice
skater glide with such low friction? That's the main physics question.
To illustrate this, you can quite well imagine the scenario.
You don't really need to do the experiment. We know
(09:49):
well enough from walking on various services how this would work.
Imagine you put on a pair of ice skates, you
stand on a flat stretch of parking lot, and you
get somebody to stand behind you and give you a push.
Is that gonna work? Are you going to glide? No,
that's all right. The blades will not glide smoothly over
the surface of the pavement the way they would over
(10:10):
the ice. They will know, I wrote here on my
notes that they will I was gonna say, grind to
a stop, but they probably won't even grind to a stop.
They're just not going to move at all. They will
be clamped to the ground where you are standing, and
any forward momentum you had from the push somebody gave
you will cause you to fall in your face because
the blades are not going to go anywhere. They will
(10:30):
grip the ground and the top half of your body
will go forward. The friction defeats the momentum, so the
friction is the problem. The physical principles that make low
friction skating possible on ice are still under investigation. That said,
the best and most up to date core research that
I could find on this was summarized in a December
(10:53):
twenty nineteen there's December again. December twenty nineteen review article
in the journal Nature by Daniel Bond called the Physics
of Ice Skating and a bit of background on the
author here. Daniel Bond is a physicist affiliated with the
Institute of Physics at the University of Amsterdam. Bond specializes
(11:13):
in fluid mechanics, among other things, so you'll see him
writing articles on these kinds of topics, sometimes aimed at
a more popular audience. But a couple of notable achievements
that I wanted to mention of his because they're kind
of indirectly connected to this topic. This will take us
a little bit of field, but I think it's an
interesting parallel. Bond was involved in research you might remember
(11:35):
from roughly a decade ago, building on some earlier research
about how the massive stone blocks that were used to
build the pyramids were probably transported across the ground to
the building site. Of course, this was a serious question
because each stone piece is enormous. The amount of force
required to move it across the ground, it's hard to
(11:56):
imagine you would have had tons and tons of workers pulling.
They were probably mounted on these sledges and moved along
with great difficulty. But Bond and colleagues discovered that you
could greatly decrease the friction between the sandy ground and
a sledge used to transport a stone block by slightly
(12:17):
wetting the sand in front of the sledge. They found
that you want to add something like two to five
percent water per unit of sand by volume, and this
can reduce roughly by half the amount of force and
thus the number of workers needed to pull the stone
along the ground. Now why would the water do that? Essentially,
(12:38):
the water here helps the sand grains stick together rather
than flow, so the sand functions more like a solid,
flat surface when you wet it this way dry sand
when you're pushing something really heavy through it, it tends
to get kind of pushed out in front of the load,
forming this mound that then takes more force to pull past.
(12:58):
You can kind of imagine this. It's like as you're dragging,
you're constantly like building a little mountain in front of
where you're trying to go.
Speaker 2 (13:05):
Yeah, yeah, that makes sense.
Speaker 3 (13:07):
But when you wet the sand, it doesn't do that
as much. It forms more of a solid flat surface
and you can drag it over the top more easily.
Bond compared the benefits of wet sand here to the
reason that you want to use wet sand to build
a sand castle. It sticks together and holds its shape better.
Another cool at side about that discovery about the wet
sand is that this process of pouring out water on
(13:29):
the sand in front of a stone work during transport
was actually depicted in ancient Egyptian art. So this is
not really even a hypothetical process. It was instead investigating
the physics principles of a process that ancient Egyptians depicted
themselves doing. So there's like one example here is there's
(13:50):
a tomb from the Middle Kingdom twelfth dynasty about nineteen
hundred BCE. Belonging to a governor called Jehudi Hotap. That
shows teams of workers sporting this big statue and they're
pulling it with ropes as it's mounted on a sledge,
and then it shows workers pouring water out of jars
on the ground right in front of the load. This
(14:12):
was previously interpreted as a libation, like a ceremonial pouring
out of liquid as an offering to the gods, but
this discovery completely reframes that pouring out of liquid as
something that was very likely functional in nature, whether or
not it had ritual significance, which it might also have had.
Speaker 2 (14:29):
Yeah, you can very well imagine it having both, and yeah,
then it makes the ritual even more potent by knowing
that you can see the results right away.
Speaker 3 (14:37):
Yes, so Bond was involved in that research. But one
more funny thing about him. He was part of the
team that won the twenty twenty four Igno Bell Prize
for chemistry. We didn't talk about the chemistry prize in
our in our last episodes.
Speaker 2 (14:50):
Did we?
Speaker 3 (14:51):
But this was quote for using chromatography to separate drunk
and sober worms. I feel kind of sad we didn't
cover this anyway. I looked it up to figure out
what this was about. The issue is it was not
really about worms. Instead, the worms were being used as
a model to test different methods, different methods of sorting
(15:13):
different kinds of polymers. So the sober worms represented what
are called active polymers that can move around, and the
drunk worms were non active polymers because they just kind
of chill anyway. All that was an aside on Bond's
(15:37):
previous work. Here Bond is writing an article reviewing recent
ice skating research. It's a short review in the journal Nature,
summarizing both the previous state of research on ice skating,
as well as especially a new paper published in the
journal Physical Review X by Canali at All from that
(16:00):
same year, from twenty nineteen. So Bond begins by talking
about the explanation that has long been given sort of
the older textbook explanation for why ice skating works, and
that is that at the interface between the blade and
the surface of the ice, there is a thin layer
not of ice, but of liquid water, and this thin
(16:24):
layer of water lubricates the contact between the two solid objects,
between the blade and the ice. Now, why would that happen,
Why would that liquid water be there. There are several
different explanations that have been offered throughout the years. One
is the idea of surface melting. This is the concept
(16:45):
that there's sort of a quasi liquid layer of water
that exists on the surface of ice, generally primarily at
higher temperatures, though still below freezing, and this is sometimes
called pre melt. Another idea, this is commonly sighted but
now disputed by Bond and by many others. And I'll
get to the reason why in a second. But this
(17:07):
idea is pressure melting at the contact point. So under
this hypothesis, like the weight of a human body distributed
over the small surface area of the bottom edge of
a skate blade creates so much pressure at that contact
point that it causes the ice crystals to melt and
(17:28):
become water. And thus you get your lubricating layer of water.
And then the final possible explanation for that layer is
frictional heating. So we know what frictional heating is. When
you rub things together, the friction generates heat. This idea
here says that this kind of frictional heating happens between
the skate and the ice. The heat melts the ice
(17:50):
and the thin layer of slippery melt water is formed.
I've come across sources, especially older ones, that favor the
explanation based on pressure melt melting, but Bond says this
is now widely thought to be incorrect because apparently this
would not work at temperatures below negative twenty degrees celsius.
(18:11):
And we can see that ice skating regularly works well
at temperatures lower than that, So just the observation of
ice skating does not match that explanation. So then maybe
is it surface melting that pre melt the quasi liquid
layer on the outside, or is it frictional melting leading
to a liquid layer on top of the ice. Strangely,
Bond says, neither of those seem to fully explain what's
(18:35):
going on either, especially not in the idea that they
could just create a layer of liquid water, because, for
one thing, these mechanisms would be equally present at the
surface of other various solids that you cannot skate on.
So there must be something else at place, something special
about water ice compared to other solids. Another interesting question,
(19:00):
what exactly are the mechanical properties of this lubricating layer
of water. Bond points out some things that are not
really consistent with the idea that water lubricates the interface
between the skate and the solid surface. For one thing,
you can't skate on a flat, solid surface covered in water.
(19:20):
You think about this like imagine a flat basketball cort
or something. You drench the floor with a thin layer
of water, put on some ice skates and try to
skate on it. That does not work.
Speaker 2 (19:31):
Yeah, yeah. Your only hope is if the heat the
floor that is being covered by the water is ice. Yeah.
Speaker 3 (19:37):
Yeah, so there's something special about ice. It's not enough
to just have liquid water underneath your skate blade. Another
interesting thing he mentions water is generally not a great lubricant,
in part because it is too thin. When it gets
pressed between two solids, water is easily squeezed out of
(19:59):
the space between them like a grippier. Stickier fluid like
oil or grease, makes a better lubricant because it clings
to the space between the solids and doesn't get pressed
out as easily. So curious questions confounding observations here.
Speaker 2 (20:15):
So you would see oil skating would be more likely
to take off than this water skating.
Speaker 3 (20:20):
I mean, I would imagine if you coat a floor
with oil. You can probably do some good slipping and
sliding on it. I don't know exactly what the skate
blade but maybe but anyway, so whatever the mechanism, the
idea has long been that ice skating is possible because
instead of skating on solid ice crystals, you are actually
gliding over a microscopic, invisible layer of liquid. What Kanali
(20:45):
and co authors found in their paper is that this
is half true. When you skate over the ice, there
is a lubricating layer of something, but it's not simply
liquid water. It's actually a unique water based substance that
has some properties of liquid water and some properties of
solid ice. So to show this, the authors of this paper,
(21:08):
Canali and co authors created an experiment where they were
able to measure the coefficient of friction of both the
ice and the lubricating layer on top of the ice
at the same time. And they did this with a
device that Bond compares to a tuning fork. Here I'm
going to quote from Bond's description of their experiment. Quote.
(21:29):
The fork was made to vibrate so that a millimeter
scale glass bead attached to one of its prongs oscillated
across an ice surface. The bead thus functioned as a
tiny ice skate, gliding for distances of the order of
tens of micrometers across the same region of ice. An
accelerometer attached to the same prong of the fork as
the bead measured the amplitude of the bead's oscillations parallel
(21:54):
to the surface and compared them with the amplitude of
the driving force. Canali at all use the difference in
amplitude to calculate the friction force between the bead and
the ice, So they did that, and then at the
same time also they were measuring the oscillation of the
bead perpendicular to the ice surface. Essentially that would be
(22:16):
sort of how it was bouncing up and down to
learn things about the lubricating layer underneath the bead. And
then by comparing these two different measurements based on the
parallel oscillations and the perpendicular oscillations, the authors could figure
out the friction coefficient between the bead and the ice
and could figure out flow properties of the lubricating layer
(22:37):
in between them. And what they found was weird and interesting.
The lubricating layer has some viscous properties, so like a thicker,
stickier fluid compared to regular water, and it also had
elastic behavior, meaning it can have its shape squeezed or
stretched and then bounce back to its original shape like
(22:58):
a rubber ball. It behaved neither like water nor like ice,
but like a hybrid of the two.
Speaker 2 (23:04):
Quote.
Speaker 3 (23:05):
The author suggests that repeated sliding over the same spot
generates a mixture of ice and water, which displays both
elastic behavior from the ice and viscous behavior from the water.
In response to a load. The resulting layer of material
would be more difficult to squeeze out of gaps than
ordinary water. This could, at least in part explain the
(23:27):
layer's excellent lubrication properties. So it has something to do
with the special characteristics of the outer layers of water. Ice.
In particular, other melting solids would not necessarily behave this way,
and as we observe, many other melting solids do not
behave this way. There's something special about H two zero
(23:49):
bond rights quote. Few materials can form a viscoelastic liquid
solid third body in response to friction and wear. That's
something that makes water special. Also, Bond mentions at the
end of this review that there are plenty of questions
about the physics of ice skating that remain. The lots
of things we still don't know, For example, like why
(24:11):
does the ideal temperature for reduced friction on the ice
seem to be like negative seven degrees celsius. That that's
a finding, but we don't know why that temperature. And
another thing he points out which I hadn't quite considered,
but I think is worth the certainly worth understanding. Having
a complete science of lubrication is not just trivia. This
(24:32):
is not just like, you know, somebody goes ice skating
and wonder how does this work. It's not just to
satisfy our curiosity. Understanding lubrication is hugely important to human
economics and technology. Bond Site's an estimate that something like
twenty percent of the world's total energy consumption is lost
(24:53):
to friction, meaning it's turned into heat and wear on
components from things rubbing together. Generally that that is not
useful to us as a type of energy. Thus, better
lubrication technologies could represent big improvements in energy efficiency and
in the performance and durability of our machines.
Speaker 2 (25:12):
Yeah, that's a great point, I thought so too.
Speaker 3 (25:14):
So let no one, Let no one snicker at the
idea of lubrication science is it is serious business. But
anyway to bring it back around, I would summarize what
I've read on this subject by saying that it seems
ice skating works because the surface of regular ice, regular
hexagonal crystal and ice can and usually does, become coated
(25:40):
in a quasi liquid layer of H two oz made
of some interesting mixture of liquid melt and tiny ice crystals.
And this quasi liquid layer does not act like regular
liquid water, but instead has a sticky bouncy quality or
what are called in the paper visco elastic qualities, and
(26:02):
these qualities make it an amazing lubricant between solids. This
lubricating layer is not primarily created by pressure from the
skater's body weight as physics as people used to say,
especially a long time ago, though pressure could play some
small role, it seems frictional heating between the blade and
(26:23):
the ice probably does play some role, maybe a major one,
though some of this quasi liquid layer is already naturally
there on the ice within the normal temperature range for
ice skating, and then beyond that, of course, you have
to think about the physical characteristics of the blades themselves.
The smooth blades of the skates allow the skater to
(26:45):
further decrease friction, more so than say the relatively rough
and grippy soles of shoes or of the bottoms of
your bare feet, and the blades also allow the skater
to control movement. There's greater control because they allow you
to both do a pushing motion when applied to the
ice one way, and a gliding motion when applied in
(27:07):
a different way.
Speaker 2 (27:08):
Which of course is the great that's part of the
great fun of ice skating, this gliding sensation, the pumping
your legs side to side. I don't get out and
ice skate all that often. Generally, like once a year,
I'll go ice skating. Oh and it's cold enough here
in Atlanta, and they have some outdoor ice skating rinks.
But generally I spend at least half the time i'm
(27:29):
there relearning how to ice skate and getting my balance,
and then it gets pretty fun. You know.
Speaker 3 (27:35):
I haven't done it since I was a kid. There
was an ice skating rink in town when I was
a kid, and we would go a number of times.
It's one of those things where I think I only
ever did it enough to just get to the edge
of not being terrible at it, and then never proceeded
to go into like being able to do it.
Speaker 2 (27:57):
Yeah. Yeah, I mean, like I say, I always have
to relearn. At least half the time, I'm just getting
my balance right and figuring out how I'm supposed to
do this, allowing my confidence to build up enough, and
then I'm finally in a place where I can dodge
all the children out there on the rink and make
a few laps that feel pretty satisfied.
Speaker 3 (28:16):
This is a tangent, but this makes me think I
don't know if there's a name for this phenomenon, but
I would be interested in doing something on the show
about these kinds of endeavors where you get stuck in
the perpetual beginner zone, where you're always just like retreading
or reviewing the beginner material and you never break out
into actual competence of it.
Speaker 2 (28:38):
Yeah, there are probably a lot of things like that, though,
of course, one of the great things about hobbies is
you don't actually have to be good or even competent
at them. They are your hobbies, after all. But yeah,
I think there are a lot of things like this
where we can look to our own experiences and say, well,
I almost did that, I almost served once.
Speaker 3 (28:57):
Well, I feel like there are some hobbies that are
more fun to spend time in the beginner zone in
than others. Like with ice skating, you know, you can
imagine that you'd be having more fun once you were
able to feel some amount of mastery over it, whereas
other things you can just be messing around in the
you know, total beginner zone and it's already pretty fun
(29:19):
to be right there.
Speaker 2 (29:30):
All right, well, let's get back into the history of
ice skating, and again we'll stress the caveat that the
earliest examples of any given technology don't always survive or
have yet to be found, especially if their biodegradable materials
bound up in their production. But the oldest ice skates
that I think we know of date back to roughly
(29:51):
eighteen hundred BCE in Scandinavia, where the ancient Scandinavians seemingly
invented the technology. Some three thousand years ago, I was
reading a paper by Frederico Formenti and Alberto E. Minetti.
Formenti in particular has written numerous papers dealing with recreating
(30:13):
old examples of ice skates and comparing them to other models.
This particular two thousand and seven paper was titled human
locomotion on ice and it was published in the Journal
of Experimental Biology, and he mentioned that there's also a
case to be made for Bronze Age invention of skates
in what is now Northern Russia. And I also am
(30:36):
going to come back around to some arguments here in
a bit that also point to parts of modern day
China where we have some evidence of ice skating, and
then also some things like ice skating I'll get into,
but it seems like universally, the earliest skates that we
know of they were not made of metal. They were
not even made of wood entirely. They were made of bone,
(31:00):
which makes a lot of sense. Bone is a dense,
dependable construction material for human tool use. And yeah, you
can look up some images of this. In particular, I
would say that Science Friday has a really good article
about the paper in question here that I'm referencing, and
it has some nice color images of for Minty's reconstructed
(31:21):
ancient skates that you can look at. They're the same
images in the original paper, except in this case they're
in color, and so I included one here for you, Joe,
of reconstruction of an ancient bone ice skate, and it's
pretty simple.
Speaker 3 (31:35):
It looks like a bone with two belts looped through it.
Speaker 2 (31:38):
That's right. Yeah, this would be a bone from a
horse or a cow. Generally the metatarsal bone strapped to
a boot via leather straps that are worked through slits
in the bone. Oh, I meant to mention that. Formenti
also notes that the ancient Scandinavian sagas suggest that the
first ice skates were made of wood, but this is
(32:00):
something that is present in textual evidence, but there's no
archaeological findings to support this currently, so as far as
we can tell, it was bone all the way back.
Speaker 3 (32:11):
This reminds me of our Bone Punk episodes where we
were talking about those Ice age dwellings with the huts
made out of mammoth bones.
Speaker 2 (32:19):
Yeah.
Speaker 3 (32:19):
Yeah, I believe part of the idea there was that
those were in places where wood was actually in quite
short supply or would have been precious for other reasons,
and thus the bone was like it made sense economic
sense to use mammoth bones as a building material. I
don't know if there was a similar thing in here.
It might just be that the bone had properties that
(32:39):
you would prefer for skating.
Speaker 2 (32:41):
I think a lot of it comes down to those properties. Yeah,
So it's thought that these would have been the first
variety of ice skates that humans used. And the crazy
thing is these remained in use up into the eighteenth
century CE, so until fairly recently folks were still known
to strap some bones to their feet and hit the ice. Now,
(33:04):
the authors here note that these ice skates lacked the
edge that you find on modern metal skates, so you
couldn't just pump along on these with your legs. That
kind of that sliding and gliding motion that we were
just talking about being so fulfilling. You would not be
doing that on these ice skates. You wouldn't be doing
a lot of tricks I'm guessing either, and whirls and
(33:25):
whirls and so forth, because your locomotion depended pretty much
entirely on your upper limbs working a pair of poles
to push you along. Oh interesting, Okay, So in that
it has more in common I would imagine with skiing,
which we're not really getting into today. It's going to
be a separate episode at some point. Now. From and
(33:48):
his co author point out that skates such as these
would have been used for accompanying animal driven sleds or sledges.
They would have been used in ice fishing or fishing
from positions further out on the ice, but especially among
the Dutch people, the technology soon became essential for winter
transportation via frozen rivers, lakes, and eventually canals. So think
(34:10):
of a region where you know, where you have a
bunch of frozen over rivers and or canals that are
ultimately connecting different human populations, or situations where you have
a completely frozen lake and you have human populations at
different points across from each other across said lake. It's
ultimately faster and more energy efficient to use some sort
(34:32):
of skating technology. And yeah, for Menty stresses that it
was highly efficient. This was no mere novelty. They weren't
doing this. You know, maybe it was fun, but they
weren't doing it because it was fun, He writes, quote
from its very conception, skating on ice was a form
of human powered locomotion that was simple and effective, very cheap,
(34:54):
and thus accessible to a large part of the population,
and allowed people to reach more distant destinations than they
could do by walking or running. In fact, unless more
expensive means of transport such as horses or later trains
were used, ice skates were probably the most convenient locomotion
tool until bicycles were built. That would have been the
(35:14):
nineteenth century, the latter probably not being very safe on
slippery roads in winter.
Speaker 3 (35:20):
That's interesting, Well, I would not have thought about it
that way.
Speaker 2 (35:23):
Yeah, so not everywhere and certainly not year round, but
that there would be places where this was just highly efficient.
It was just the most the most sensible way to
move from point A to point B if conditions were
just right. Now, while again bone skates were ultimately a
(35:43):
long lasting technology against superior to mere wood, it would
seem by the thirteenth century CE in the Netherlands, skaters
returned to wood to make use of metal in their skating,
constructing wooden skates that had metal blades. Now, these were
still things that you would strap to the bottom of
your shoes, and I included an image of one of
(36:03):
these for you here, Joe. It is also not very fancy.
If you didn't know you were looking at an ice skate,
you might not know you were looking at an ice skate.
It's like a imagine a wooden skate but with a
thin metal blade, and then it is strapped or tied
to your shoes.
Speaker 3 (36:19):
Yeah, yeah, it looks It looks like the wooden bottom
of a boat, or like a boat keel with a
tiny little strip of metal blades sticking out of the bottom.
Speaker 2 (36:26):
Yeah. And so for Mantiene's co author point out that
the wood here would have been easy to work, the
metal that they use was very durable. An interesting thing
here is that these skates would apparently according to their
reconstructions and their tests, would have suffered from greater friction
compared to bone skates. But their big advantage was that
(36:47):
they allowed the user to finally propel themselves with their
lower limbs, so you could seemingly throw away the poles,
free up your arms, and depend almost entirely on leg power.
And as such, this is really when we begin to
see skating as we know it today entering the world,
Because if you go to any ice skating rink, and
(37:08):
certainly if you go to a roller skating rink, you're
not going to see people pushing around on poles. I mean,
maybe there's some sort of scenario where you use poles
to get your feet underneath you. But I've never seen
anything like that.
Speaker 3 (37:20):
Right, So I imagine it's like the thinness of the
blade that allows you to just use your legs because
of the way that you can angle the foot to
push versus gliding, and you can't really do that with
the more rounded edge of a bone.
Speaker 2 (37:35):
Yes, that's my understanding. So at this point, yeah, we're
kind of off to the races. We're really not purely
inventing something new, but we've innovated to a very interesting
place in the development of the ice skate. And during
the fifteenth and eighteenth century ice skates they retain their
metal wood construction, but they became about thirty percent lighter.
(37:55):
According for Mente, Dutch skates of the time were shorter
compared to modern skates and therefore more difficult to balance
on compared to what we have today, but they would
have proven especially useful to them during the Little Ice
Age of the sixteenth through nineteenth centuries, during which the
system of rivers and canals would have proven ideal skate
(38:16):
routes connecting different populations and different different destinations. And then
during the eighteenth century, skates on the whole became longer
and enabled easier balance and resulted in lower resistance the
weight spread out across longer blades. And I've included another
photo Formenti's work here reconstruction. This is still something you
(38:40):
strapped your existing footwear, but it is even more identifiable,
I think as an ice skate.
Speaker 3 (38:46):
Oh yeah, totally.
Speaker 2 (38:47):
And then during the nineteenth century we finally ended up
with specialized ice skates, with the skates permanently affixed to
a boot of some sort screwed into place, an ice
skate that has shoe ices so forth, like you would
identify now when you go in like rent ice skates
to go ice skating. And the blades were even longer,
(39:09):
apparently up to twice the length of the old thirteenth
century skates, enabling even greater balance and maneuverability. And then
a whole host of additional innovations have been made and
continue to be made, producing skates that are ever more ergonomic, speedy,
and effective. Different breaking mechanics were added, blades that ultimately
(39:33):
like have a mechanical aspect to them and can shift
and so forth. Saw a Fermente quoted in an article
I believe it's the Science Friday, where he basically says
that we probably haven't seen as long of a skate
as is ideal, like, skates are probably going to keep
They're going to keep evolving. They're still evolving, They're becoming
(39:54):
more and more efficient, and they may get longer. We
have not reached peak ice skate length yet.
Speaker 3 (40:00):
Wait, does he have a specific peak length in mind?
Speaker 2 (40:04):
Now he's just saying that we're still like fine tuning everything.
And I guess the other interesting thing here is that
there's not just one purpose for ice skates. There are
a lot of highly specialized purposes for ice skates. So
you know, we have a whole host of skate based
sporting activities and they range from figure skating to ice hockey.
Speaker 3 (40:23):
Yeah, I was reading about that too, And an interesting
thing there is that apparently different ice temperatures are preferred
for the different sports. I think the way I was
reading it is that usually they want the temperature a
little bit higher for figure skating because figure skaters, I
think a softer ice gives them more control over precise movements,
(40:46):
whereas with ice hockey, I think they like a slightly
colder ice because that allows them to achieve like a
higher top.
Speaker 2 (40:53):
Speed okay, interesting, Okay, So with hockey it's more about speed,
and with figure skating it's maneuverability, which makes it now
Fomenty and his co author in the aforementioned paper, they
compare the effectiveness of the four main eras of ice skates,
and the results illustrate this continual improvement process that we're
looking at here. I'm not going to roll through the
(41:14):
entire chart. You can find it in the original paper,
but you can see here he breaks things out by speed,
stride frequency, stride length, and so forth, and Fermenty points
out that with the same metabolic power, skaters today have
a speed four times that of our ancestors, and again
(41:34):
it's only increasing as we find tune our skate design.
Speaker 3 (41:38):
This might not actually be an issue, but I just
had the thought. Do skaters on rink ice have higher
speeds as well, just because they can feel safe to
go at higher speeds, whereas if you're on a natural
body of water you might be more I don't know,
cautious about like straying into an area of thin ice
(41:58):
or something like that.
Speaker 2 (42:00):
That's a good point. I mean, I guess the other
number of factors that might come into play, right, if
you're dealing with like natural ice versus zambonid ice, right.
Speaker 3 (42:09):
Yeah, And I know that the zambonid ice, like the
rink ice, is laid down one layer at a time
to give it special properties, to kind of make it
perfect for skating, whereas, of course natural ice on a
body of water, I mean, it might be great for skating,
but it doesn't have whatever refined quality they're looking for
on that rink ice.
Speaker 2 (42:28):
Now, I want to come back to ice skating in
China because as I was hitting like the core data here,
I kept finding various references to Chinese ice skating, and
I'd read that ice skating in China might date back
to the Song dynasty, so nine sixty to twelve seventy nine.
See that is, of course in addition to possibly connected
(42:50):
or independent developments in the north of Russia as I
referenced earlier. But certainly I looked into this a little
bit more, and you have these ice festivals the Bingshe,
which I think means ice amusement festivals that seem to
date back to the Song dynasty in China and consisted
of various winter sports and performances. Among the many festivities
(43:13):
there was a downhill skating event that involved kind of
a leather ice skate. I wasn't able to find any
images of reproduction of this, but I found some various
modern illustrations of what these might have consisted of. And
these these are kind of like curved leather shoes that
seem to have been made expressly for sliding across the
(43:38):
ice and or snow.
Speaker 3 (43:40):
If this is what's depicted in the illustration you put
in our outline that kind of curled up at the
toe like elf shoes.
Speaker 2 (43:45):
Yes, yes, think like leather elf shoes designed for sliding
around on ice. It's not skating in the sense that
we've been talking about skating, I think from the physics standpoint,
But these would have been things that would have been
you would have worn for like this downhill skating competition
or something that I've seen translated as ice football, in
(44:06):
which people were skating around on the ice in these
leather shoes throwing some sort of a ball back and forth.
The illustration here that I found is from the Beijing
based World of the World of Chinese website, So my
understanding is like these are similar but a little bit different.
These would have also the examples we're looking at here
would have definitely been novelty based skates. These were not
(44:29):
about locomotion, These were about amusement. However, in other parts
of modern China you do find ancient examples of bone skates.
I was reading that in twenty twenty three, Chinese archaeologists
found an example of a bone ice skate in a
Bronze Age tomb from roughly three thy five hundred years ago,
(44:52):
possibly of the Andronova culture of cattle herders that lived
in China's western Shijang Weaker Autonomous Region. These would have
been very much akin to what we were talking about,
like the bones scrapped to a boot or to a
shoe that enabled one to move across naturally frozen bodies
(45:14):
of water. But again, it does seem to come back
to bones. It comes back to horse and cow bones
strapped to the bottom of your feet, enabling you to
at least push yourself across the ice with a big
with a pair of poles or sticks.
Speaker 3 (45:29):
Well, Rob, you've talked me into it. If I if
I take my child ice skating this year, I'm gonna
I'm gonna have to get some bone skating to try
out see how they do.
Speaker 2 (45:39):
You know, I don't think it would be a good idea.
I think this would not in the long run, this
would be a failure. But I could imagine someone trying
to market this. You know, why settle for ice skating
when this year when you could do primal ice skating,
bone ice skating, and people would be like, yeah, you know,
I'm kind of a little over three own axes at
(46:00):
the local acts throwing range. I want to try something
else that has this kind of like, you know, ancient
vibe to it. Let's strap on some bones and see
how it goes. I think you would find it. Would
it would? It would be harder. It sounds like every
everything I've read about it, it would have been a
much harder and clumsier thing to do. We're much better
off with modern ice skates, but for.
Speaker 3 (46:20):
The metal of it, maybe you use the non metal.
Speaker 2 (46:24):
Yes, bone ice skates are very metal. We'll definitely say that.
Speaker 3 (46:28):
All right.
Speaker 2 (46:29):
Should we wrap up there, Yeah, We're going to go
ahead and close out this episode. However, again, definitely tune
in later in June when we come back and talk
about roller skating on its own again directly connected to
the invention of ice skating, but very much its own
thing as well. In the meantime, would of course love
to hear from everyone out there. Do you have experiences
(46:50):
or thoughts related to ice skating? Is there anyone out
there who has tried a more archaic version of the
ice skate? If so, definitely right into it because we
would love to have your feedback. As always, we'd like
to remind you that Stuff to Blow Your Mind is
primarily a science and culture podcast, with core episodes on
Tuesdays and Thursdays. On Fridays, we set aside most serious
concerns to just talk about a weird film on Weird
(47:12):
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Speaker 3 (47:32):
Huge thanks as always to our excellent audio producer JJ Posway.
If you would like to get in touch with us
with feedback on this episode or any other. If you
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Speaker 1 (47:56):
Stuff to Blow Your Mind is production of iHeartRadio. For
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(48:23):
M
Welcome to Stuff to Blow Your Mind production of iHeartRadio.
Speaker 2 (00:12):
Hey you welcome to Stuff to Blow your Mind. My
name is Robert Lamb, and I am Joe McCormick, and
we're back with another Invention themed episode. Some of you
may notice Joe and I were just chatting about this.
We were doing an episode here on ice skating. It is,
of course the very beginning of summer.
Speaker 3 (00:29):
Most of the articles you find about this come out
in December, so actually you might be much more familiar
with the seasonal mismatch if you live in the Southern Hemisphere.
But yeah, I guess for the majority of readers in
the Northern hemisphere reading, I guess they're only going to
click on an article about ice skating in December. I
don't know. I'm against that kind of thing. I believe
(00:51):
in anti seasonal topicality.
Speaker 2 (00:54):
Yeah, I mean, plus, people are ice skating somewhere year around.
There are of course indoor ice skating rinks. And I
should also mention that the way we're getting to ice
skating is because my initial inspiration here was to do
an episode on roller skating. This is of course, the
past time that initially boomed during the so called Golden
Age of roller skating, This is roughly nineteen thirty seven
(01:17):
through nineteen fifty nine. I think there's a lot of
you know, escaping from the darkness of the world in
that period and finding a little lightheartedness on the roller
skates in the skating rink. But you know, it's something
that's never completely gone out of fashion either, and it's
experienced sustained popularity in various parts of the world and
(01:37):
saw a major boost during the global pandemic.
Speaker 3 (01:40):
Can I ask a question to older listeners if you
watch movies about the fifties, you often see people roller
skating down the hallway in high school or in another
setting that's not a dedicated roller skating environment like a
rink or something, and people just roller skating on the
sidewalk at school going from class to class. Is that
a thing people?
Speaker 2 (01:59):
Actually, I don't know they're doing it now because roller
skating is not only going strong, but it's I think
it's getting stronger. We may get into this in a
in another episode, but there are a lot of like
financial I saw some financial papers talking about how the
roller skating industry is just going to continue to grow
(02:19):
over the next decade or.
Speaker 3 (02:21):
So I do think we should bring back the roller
skate mounted server at the drive in restaurants, because that's interesting.
It adds an element of danger and theatrical athleticism to
the dining out experience that you don't usually get.
Speaker 2 (02:37):
Well, I don't know how dangerous it is, but yes
it is. There is kind of a neat charm to it.
But yeah, I've been seeing a lot of roller skaters recently.
My kid is involved in a local vibrant skating club,
and it really made me reconsider what I thought I
knew about skating and skating culture. So I figured, hey,
well let's let's do a nice summer episode about roller skating.
(02:59):
But the thing is, before you can even begin to
cover the invention of roller skates, you have to explore
their cold weather predecessor. You have to talk about ice skates.
Speaker 3 (03:08):
I assume there's no disputing this at all, which came first.
The ice skate is definitely older than the roller.
Speaker 2 (03:14):
Skate, definitely, definitely by a considerable margin. Yeah, nobody's even
making the case, even if you were getting into potential
possible examples of somebody designing something like a roller skate
that just wasn't usable. Anywhere, because maybe you lacked the
places for I've I've seen no arguments that this is
(03:35):
the case. If anyone out there is aware of even
any just unhinged theories about the roller skate coming before
the ice skate, send it our way and we will evaluate.
But as far as I can tell, nobody's making this case,
and so we're going to stick to what seems to
be the established lower here. We're going to talk about
ice skating now, and then I think maybe an episode
(03:58):
later in June, we'll come back and discuss roller skating
in more detail. Fair enough, Okay, So, as is generally
the case when we're talking about an invention, we like
to talk about what comes before, so we can appreciate
the invention. What came before skating on the ice using
(04:18):
some sort of an ice skate. Well to properly consider
ice skates. Oh wait, you already have an answer. Let's
have it.
Speaker 3 (04:25):
No, I was going to slipping on the ice, slipping
and falling game first.
Speaker 2 (04:29):
Well, it always does in ice skating, doesn't it. You
could and you could make an argument that skating on
the ice one way or another is slipping in style.
It is a controlled slip.
Speaker 3 (04:40):
Exactly controlled slipping.
Speaker 2 (04:42):
Yeah, I think the most important thing that I quickly
realized looking at the history of the ice skate is
we think of ice skating more as novelty, or perhaps
you think of it as part of sport, but we
really have to view ice skates not as an item
of recreation, but as a mean of conveyance, of moving
(05:02):
the human body from one point to another. And so
before humans skated across ice as a means of conserving
energy and maximizing speed, they did a few different varied
things on ice, including slipping and falling down. Of course,
walking across the ice is of course the oldest forerunner,
obviously requiring no technology, but certainly benefiting from a variety
(05:24):
of innovations that would occur over human history, including the
leather shoe I believe, the oldest surviving example being a
some five five hundred year old arny one shoe from
Armenia or what is now Armenia. But obviously such footwear
was biodegradable by its very nature, so who knows what
we lost though?
Speaker 3 (05:45):
Of course, when we think about ice skates, these are
obviously tools designed to decrease friction on the ice and
allow you to glide more easily. I would tend to
think that the earliest ice traversal technologies were exactly the opposite.
They would be things disa to help you better grip
the ice to avoid slipping and falling while you walked.
Speaker 2 (06:05):
Yeah, which brings our mind to things like spiked cleats.
I was looking around. Let's say there's some examples that
survive from the first and second millennium CE, But again
there's no telling what was lost as well in our
ability to figure out how to make grippier footwear for
walking around on the ice. And then, on top of this,
(06:26):
we should also point out that a certain understanding of
the different types of ice and how it responds to
your weight would also have been important for moving across
the ice. The examples of the oldest surviving cleats that
I was finding my research were things from the Viking era,
So it's very possible there are older examples of this
that didn't survive, and possibly something that didn't come up
(06:49):
with my research. So as always, if anyone knows of
an earlier example of some sort of grippy footwear technology,
send it our way. Furthermore, before humans turn to ice skating,
proper they make use of sleds, a variation of the sledge,
which itself is a predecessor to the cart. And these
of course are ancient and widespread innovations which, depending on
(07:09):
the environment and you know where they were constructed, they
might have entailed bone, ivory or wood. So we can
easily imagine that the idea for the ice skate perhaps
comes together from ruminations on existing sled technology, you know,
like what if ice strapped a sled to my foot,
as well as experiences walking, sliding, slipping on ice covered lakes, rivers,
(07:34):
and so forth. Couple that with a need for such
skates for a conveyance, such as areas where human communities
are separated by expansive frozen over bodies of water. And
it's only a matter of time till someone tries to
miniaturize the whole affair and place it on a boot.
Those will discuss the physicality and indeed physics of ice
(07:54):
skating differs significantly from either of these pre existing technologies.
So here in a bit we're going to go back
and look at the most ancient known examples of ice skates,
how they worked and didn't work, and how they evolved.
But let's go ahead and move towards our current understanding
of the ice skate and just talk about how it works.
Speaker 3 (08:16):
As in, what physics principles does the ice skate take
advantage of?
Speaker 2 (08:21):
Yeah, because we can all sort of have innate understanding
of out works. But yeah, let's get into the physics. Yeah.
Speaker 3 (08:27):
So this is one of those things that seems like
a question that would have a fairly simple, well understood,
well agreed upon answer, But surprisingly, no, the physics of
ice skating are quite complicated. The issue is still being investigated.
Some explanations that you see all over the place and appearing,
I think even in fairly recent physics textbooks are actually
(08:51):
disputed by experts, and from what I can see, new
papers on the physics of ice skating still appear regularly
in scientific journals, at least as of a couple of
years ago.
Speaker 2 (09:02):
That's crazy. It's not settled science yet.
Speaker 3 (09:05):
Yeah, there is a lot we do know now, but
a lot of that was established rather recently, and then
there are still a bunch of questions that we don't
have answers to yet. But I always think it's interesting
when you come across something like this, one of those
things that you assume would have a short, simple, non controversial,
one paragraph answer in the physics textbook, and actually it's
(09:27):
like a super complicated unsolved question. But anyway, so the
main thing that we need to explain when looking at
the physics of ice skating is why can an ice
skater glide with such low friction? That's the main physics question.
To illustrate this, you can quite well imagine the scenario.
You don't really need to do the experiment. We know
(09:49):
well enough from walking on various services how this would work.
Imagine you put on a pair of ice skates, you
stand on a flat stretch of parking lot, and you
get somebody to stand behind you and give you a push.
Is that gonna work? Are you going to glide? No,
that's all right. The blades will not glide smoothly over
the surface of the pavement the way they would over
(10:10):
the ice. They will know, I wrote here on my
notes that they will I was gonna say, grind to
a stop, but they probably won't even grind to a stop.
They're just not going to move at all. They will
be clamped to the ground where you are standing, and
any forward momentum you had from the push somebody gave
you will cause you to fall in your face because
the blades are not going to go anywhere. They will
(10:30):
grip the ground and the top half of your body
will go forward. The friction defeats the momentum, so the
friction is the problem. The physical principles that make low
friction skating possible on ice are still under investigation. That said,
the best and most up to date core research that
I could find on this was summarized in a December
(10:53):
twenty nineteen there's December again. December twenty nineteen review article
in the journal Nature by Daniel Bond called the Physics
of Ice Skating and a bit of background on the
author here. Daniel Bond is a physicist affiliated with the
Institute of Physics at the University of Amsterdam. Bond specializes
(11:13):
in fluid mechanics, among other things, so you'll see him
writing articles on these kinds of topics, sometimes aimed at
a more popular audience. But a couple of notable achievements
that I wanted to mention of his because they're kind
of indirectly connected to this topic. This will take us
a little bit of field, but I think it's an
interesting parallel. Bond was involved in research you might remember
(11:35):
from roughly a decade ago, building on some earlier research
about how the massive stone blocks that were used to
build the pyramids were probably transported across the ground to
the building site. Of course, this was a serious question
because each stone piece is enormous. The amount of force
required to move it across the ground, it's hard to
(11:56):
imagine you would have had tons and tons of workers pulling.
They were probably mounted on these sledges and moved along
with great difficulty. But Bond and colleagues discovered that you
could greatly decrease the friction between the sandy ground and
a sledge used to transport a stone block by slightly
(12:17):
wetting the sand in front of the sledge. They found
that you want to add something like two to five
percent water per unit of sand by volume, and this
can reduce roughly by half the amount of force and
thus the number of workers needed to pull the stone
along the ground. Now why would the water do that? Essentially,
(12:38):
the water here helps the sand grains stick together rather
than flow, so the sand functions more like a solid,
flat surface when you wet it this way dry sand
when you're pushing something really heavy through it, it tends
to get kind of pushed out in front of the load,
forming this mound that then takes more force to pull past.
(12:58):
You can kind of imagine this. It's like as you're dragging,
you're constantly like building a little mountain in front of
where you're trying to go.
Speaker 2 (13:05):
Yeah, yeah, that makes sense.
Speaker 3 (13:07):
But when you wet the sand, it doesn't do that
as much. It forms more of a solid flat surface
and you can drag it over the top more easily.
Bond compared the benefits of wet sand here to the
reason that you want to use wet sand to build
a sand castle. It sticks together and holds its shape better.
Another cool at side about that discovery about the wet
sand is that this process of pouring out water on
(13:29):
the sand in front of a stone work during transport
was actually depicted in ancient Egyptian art. So this is
not really even a hypothetical process. It was instead investigating
the physics principles of a process that ancient Egyptians depicted
themselves doing. So there's like one example here is there's
(13:50):
a tomb from the Middle Kingdom twelfth dynasty about nineteen
hundred BCE. Belonging to a governor called Jehudi Hotap. That
shows teams of workers sporting this big statue and they're
pulling it with ropes as it's mounted on a sledge,
and then it shows workers pouring water out of jars
on the ground right in front of the load. This
(14:12):
was previously interpreted as a libation, like a ceremonial pouring
out of liquid as an offering to the gods, but
this discovery completely reframes that pouring out of liquid as
something that was very likely functional in nature, whether or
not it had ritual significance, which it might also have had.
Speaker 2 (14:29):
Yeah, you can very well imagine it having both, and yeah,
then it makes the ritual even more potent by knowing
that you can see the results right away.
Speaker 3 (14:37):
Yes, so Bond was involved in that research. But one
more funny thing about him. He was part of the
team that won the twenty twenty four Igno Bell Prize
for chemistry. We didn't talk about the chemistry prize in
our in our last episodes.
Speaker 2 (14:50):
Did we?
Speaker 3 (14:51):
But this was quote for using chromatography to separate drunk
and sober worms. I feel kind of sad we didn't
cover this anyway. I looked it up to figure out
what this was about. The issue is it was not
really about worms. Instead, the worms were being used as
a model to test different methods, different methods of sorting
(15:13):
different kinds of polymers. So the sober worms represented what
are called active polymers that can move around, and the
drunk worms were non active polymers because they just kind
of chill anyway. All that was an aside on Bond's
(15:37):
previous work. Here Bond is writing an article reviewing recent
ice skating research. It's a short review in the journal Nature,
summarizing both the previous state of research on ice skating,
as well as especially a new paper published in the
journal Physical Review X by Canali at All from that
(16:00):
same year, from twenty nineteen. So Bond begins by talking
about the explanation that has long been given sort of
the older textbook explanation for why ice skating works, and
that is that at the interface between the blade and
the surface of the ice, there is a thin layer
not of ice, but of liquid water, and this thin
(16:24):
layer of water lubricates the contact between the two solid objects,
between the blade and the ice. Now, why would that happen,
Why would that liquid water be there. There are several
different explanations that have been offered throughout the years. One
is the idea of surface melting. This is the concept
(16:45):
that there's sort of a quasi liquid layer of water
that exists on the surface of ice, generally primarily at
higher temperatures, though still below freezing, and this is sometimes
called pre melt. Another idea, this is commonly sighted but
now disputed by Bond and by many others. And I'll
get to the reason why in a second. But this
(17:07):
idea is pressure melting at the contact point. So under
this hypothesis, like the weight of a human body distributed
over the small surface area of the bottom edge of
a skate blade creates so much pressure at that contact
point that it causes the ice crystals to melt and
(17:28):
become water. And thus you get your lubricating layer of water.
And then the final possible explanation for that layer is
frictional heating. So we know what frictional heating is. When
you rub things together, the friction generates heat. This idea
here says that this kind of frictional heating happens between
the skate and the ice. The heat melts the ice
(17:50):
and the thin layer of slippery melt water is formed.
I've come across sources, especially older ones, that favor the
explanation based on pressure melt melting, but Bond says this
is now widely thought to be incorrect because apparently this
would not work at temperatures below negative twenty degrees celsius.
(18:11):
And we can see that ice skating regularly works well
at temperatures lower than that, So just the observation of
ice skating does not match that explanation. So then maybe
is it surface melting that pre melt the quasi liquid
layer on the outside, or is it frictional melting leading
to a liquid layer on top of the ice. Strangely,
Bond says, neither of those seem to fully explain what's
(18:35):
going on either, especially not in the idea that they
could just create a layer of liquid water, because, for
one thing, these mechanisms would be equally present at the
surface of other various solids that you cannot skate on.
So there must be something else at place, something special
about water ice compared to other solids. Another interesting question,
(19:00):
what exactly are the mechanical properties of this lubricating layer
of water. Bond points out some things that are not
really consistent with the idea that water lubricates the interface
between the skate and the solid surface. For one thing,
you can't skate on a flat, solid surface covered in water.
(19:20):
You think about this like imagine a flat basketball cort
or something. You drench the floor with a thin layer
of water, put on some ice skates and try to
skate on it. That does not work.
Speaker 2 (19:31):
Yeah, yeah. Your only hope is if the heat the
floor that is being covered by the water is ice. Yeah.
Speaker 3 (19:37):
Yeah, so there's something special about ice. It's not enough
to just have liquid water underneath your skate blade. Another
interesting thing he mentions water is generally not a great lubricant,
in part because it is too thin. When it gets
pressed between two solids, water is easily squeezed out of
(19:59):
the space between them like a grippier. Stickier fluid like
oil or grease, makes a better lubricant because it clings
to the space between the solids and doesn't get pressed
out as easily. So curious questions confounding observations here.
Speaker 2 (20:15):
So you would see oil skating would be more likely
to take off than this water skating.
Speaker 3 (20:20):
I mean, I would imagine if you coat a floor
with oil. You can probably do some good slipping and
sliding on it. I don't know exactly what the skate
blade but maybe but anyway, so whatever the mechanism, the
idea has long been that ice skating is possible because
instead of skating on solid ice crystals, you are actually
gliding over a microscopic, invisible layer of liquid. What Kanali
(20:45):
and co authors found in their paper is that this
is half true. When you skate over the ice, there
is a lubricating layer of something, but it's not simply
liquid water. It's actually a unique water based substance that
has some properties of liquid water and some properties of
solid ice. So to show this, the authors of this paper,
(21:08):
Canali and co authors created an experiment where they were
able to measure the coefficient of friction of both the
ice and the lubricating layer on top of the ice
at the same time. And they did this with a
device that Bond compares to a tuning fork. Here I'm
going to quote from Bond's description of their experiment. Quote.
(21:29):
The fork was made to vibrate so that a millimeter
scale glass bead attached to one of its prongs oscillated
across an ice surface. The bead thus functioned as a
tiny ice skate, gliding for distances of the order of
tens of micrometers across the same region of ice. An
accelerometer attached to the same prong of the fork as
the bead measured the amplitude of the bead's oscillations parallel
(21:54):
to the surface and compared them with the amplitude of
the driving force. Canali at all use the difference in
amplitude to calculate the friction force between the bead and
the ice, So they did that, and then at the
same time also they were measuring the oscillation of the
bead perpendicular to the ice surface. Essentially that would be
(22:16):
sort of how it was bouncing up and down to
learn things about the lubricating layer underneath the bead. And
then by comparing these two different measurements based on the
parallel oscillations and the perpendicular oscillations, the authors could figure
out the friction coefficient between the bead and the ice
and could figure out flow properties of the lubricating layer
(22:37):
in between them. And what they found was weird and interesting.
The lubricating layer has some viscous properties, so like a thicker,
stickier fluid compared to regular water, and it also had
elastic behavior, meaning it can have its shape squeezed or
stretched and then bounce back to its original shape like
(22:58):
a rubber ball. It behaved neither like water nor like ice,
but like a hybrid of the two.
Speaker 2 (23:04):
Quote.
Speaker 3 (23:05):
The author suggests that repeated sliding over the same spot
generates a mixture of ice and water, which displays both
elastic behavior from the ice and viscous behavior from the water.
In response to a load. The resulting layer of material
would be more difficult to squeeze out of gaps than
ordinary water. This could, at least in part explain the
(23:27):
layer's excellent lubrication properties. So it has something to do
with the special characteristics of the outer layers of water. Ice.
In particular, other melting solids would not necessarily behave this way,
and as we observe, many other melting solids do not
behave this way. There's something special about H two zero
(23:49):
bond rights quote. Few materials can form a viscoelastic liquid
solid third body in response to friction and wear. That's
something that makes water special. Also, Bond mentions at the
end of this review that there are plenty of questions
about the physics of ice skating that remain. The lots
of things we still don't know, For example, like why
(24:11):
does the ideal temperature for reduced friction on the ice
seem to be like negative seven degrees celsius. That that's
a finding, but we don't know why that temperature. And
another thing he points out which I hadn't quite considered,
but I think is worth the certainly worth understanding. Having
a complete science of lubrication is not just trivia. This
(24:32):
is not just like, you know, somebody goes ice skating
and wonder how does this work. It's not just to
satisfy our curiosity. Understanding lubrication is hugely important to human
economics and technology. Bond Site's an estimate that something like
twenty percent of the world's total energy consumption is lost
(24:53):
to friction, meaning it's turned into heat and wear on
components from things rubbing together. Generally that that is not
useful to us as a type of energy. Thus, better
lubrication technologies could represent big improvements in energy efficiency and
in the performance and durability of our machines.
Speaker 2 (25:12):
Yeah, that's a great point, I thought so too.
Speaker 3 (25:14):
So let no one, Let no one snicker at the
idea of lubrication science is it is serious business. But
anyway to bring it back around, I would summarize what
I've read on this subject by saying that it seems
ice skating works because the surface of regular ice, regular
hexagonal crystal and ice can and usually does, become coated
(25:40):
in a quasi liquid layer of H two oz made
of some interesting mixture of liquid melt and tiny ice crystals.
And this quasi liquid layer does not act like regular
liquid water, but instead has a sticky bouncy quality or
what are called in the paper visco elastic qualities, and
(26:02):
these qualities make it an amazing lubricant between solids. This
lubricating layer is not primarily created by pressure from the
skater's body weight as physics as people used to say,
especially a long time ago, though pressure could play some
small role, it seems frictional heating between the blade and
(26:23):
the ice probably does play some role, maybe a major one,
though some of this quasi liquid layer is already naturally
there on the ice within the normal temperature range for
ice skating, and then beyond that, of course, you have
to think about the physical characteristics of the blades themselves.
The smooth blades of the skates allow the skater to
(26:45):
further decrease friction, more so than say the relatively rough
and grippy soles of shoes or of the bottoms of
your bare feet, and the blades also allow the skater
to control movement. There's greater control because they allow you
to both do a pushing motion when applied to the
ice one way, and a gliding motion when applied in
(27:07):
a different way.
Speaker 2 (27:08):
Which of course is the great that's part of the
great fun of ice skating, this gliding sensation, the pumping
your legs side to side. I don't get out and
ice skate all that often. Generally, like once a year,
I'll go ice skating. Oh and it's cold enough here
in Atlanta, and they have some outdoor ice skating rinks.
But generally I spend at least half the time i'm
(27:29):
there relearning how to ice skate and getting my balance,
and then it gets pretty fun. You know.
Speaker 3 (27:35):
I haven't done it since I was a kid. There
was an ice skating rink in town when I was
a kid, and we would go a number of times.
It's one of those things where I think I only
ever did it enough to just get to the edge
of not being terrible at it, and then never proceeded
to go into like being able to do it.
Speaker 2 (27:57):
Yeah. Yeah, I mean, like I say, I always have
to relearn. At least half the time, I'm just getting
my balance right and figuring out how I'm supposed to
do this, allowing my confidence to build up enough, and
then I'm finally in a place where I can dodge
all the children out there on the rink and make
a few laps that feel pretty satisfied.
Speaker 3 (28:16):
This is a tangent, but this makes me think I
don't know if there's a name for this phenomenon, but
I would be interested in doing something on the show
about these kinds of endeavors where you get stuck in
the perpetual beginner zone, where you're always just like retreading
or reviewing the beginner material and you never break out
into actual competence of it.
Speaker 2 (28:38):
Yeah, there are probably a lot of things like that, though,
of course, one of the great things about hobbies is
you don't actually have to be good or even competent
at them. They are your hobbies, after all. But yeah,
I think there are a lot of things like this
where we can look to our own experiences and say, well,
I almost did that, I almost served once.
Speaker 3 (28:57):
Well, I feel like there are some hobbies that are
more fun to spend time in the beginner zone in
than others. Like with ice skating, you know, you can
imagine that you'd be having more fun once you were
able to feel some amount of mastery over it, whereas
other things you can just be messing around in the
you know, total beginner zone and it's already pretty fun
(29:19):
to be right there.
Speaker 2 (29:30):
All right, well, let's get back into the history of
ice skating, and again we'll stress the caveat that the
earliest examples of any given technology don't always survive or
have yet to be found, especially if their biodegradable materials
bound up in their production. But the oldest ice skates
that I think we know of date back to roughly
(29:51):
eighteen hundred BCE in Scandinavia, where the ancient Scandinavians seemingly
invented the technology. Some three thousand years ago, I was
reading a paper by Frederico Formenti and Alberto E. Minetti.
Formenti in particular has written numerous papers dealing with recreating
(30:13):
old examples of ice skates and comparing them to other models.
This particular two thousand and seven paper was titled human
locomotion on ice and it was published in the Journal
of Experimental Biology, and he mentioned that there's also a
case to be made for Bronze Age invention of skates
in what is now Northern Russia. And I also am
(30:36):
going to come back around to some arguments here in
a bit that also point to parts of modern day
China where we have some evidence of ice skating, and
then also some things like ice skating I'll get into,
but it seems like universally, the earliest skates that we
know of they were not made of metal. They were
not even made of wood entirely. They were made of bone,
(31:00):
which makes a lot of sense. Bone is a dense,
dependable construction material for human tool use. And yeah, you
can look up some images of this. In particular, I
would say that Science Friday has a really good article
about the paper in question here that I'm referencing, and
it has some nice color images of for Minty's reconstructed
(31:21):
ancient skates that you can look at. They're the same
images in the original paper, except in this case they're
in color, and so I included one here for you, Joe,
of reconstruction of an ancient bone ice skate, and it's
pretty simple.
Speaker 3 (31:35):
It looks like a bone with two belts looped through it.
Speaker 2 (31:38):
That's right. Yeah, this would be a bone from a
horse or a cow. Generally the metatarsal bone strapped to
a boot via leather straps that are worked through slits
in the bone. Oh, I meant to mention that. Formenti
also notes that the ancient Scandinavian sagas suggest that the
first ice skates were made of wood, but this is
(32:00):
something that is present in textual evidence, but there's no
archaeological findings to support this currently, so as far as
we can tell, it was bone all the way back.
Speaker 3 (32:11):
This reminds me of our Bone Punk episodes where we
were talking about those Ice age dwellings with the huts
made out of mammoth bones.
Speaker 2 (32:19):
Yeah.
Speaker 3 (32:19):
Yeah, I believe part of the idea there was that
those were in places where wood was actually in quite
short supply or would have been precious for other reasons,
and thus the bone was like it made sense economic
sense to use mammoth bones as a building material. I
don't know if there was a similar thing in here.
It might just be that the bone had properties that
(32:39):
you would prefer for skating.
Speaker 2 (32:41):
I think a lot of it comes down to those properties. Yeah,
So it's thought that these would have been the first
variety of ice skates that humans used. And the crazy
thing is these remained in use up into the eighteenth
century CE, so until fairly recently folks were still known
to strap some bones to their feet and hit the ice. Now,
(33:04):
the authors here note that these ice skates lacked the
edge that you find on modern metal skates, so you
couldn't just pump along on these with your legs. That
kind of that sliding and gliding motion that we were
just talking about being so fulfilling. You would not be
doing that on these ice skates. You wouldn't be doing
a lot of tricks I'm guessing either, and whirls and
(33:25):
whirls and so forth, because your locomotion depended pretty much
entirely on your upper limbs working a pair of poles
to push you along. Oh interesting, Okay, So in that
it has more in common I would imagine with skiing,
which we're not really getting into today. It's going to
be a separate episode at some point. Now. From and
(33:48):
his co author point out that skates such as these
would have been used for accompanying animal driven sleds or sledges.
They would have been used in ice fishing or fishing
from positions further out on the ice, but especially among
the Dutch people, the technology soon became essential for winter
transportation via frozen rivers, lakes, and eventually canals. So think
(34:10):
of a region where you know, where you have a
bunch of frozen over rivers and or canals that are
ultimately connecting different human populations, or situations where you have
a completely frozen lake and you have human populations at
different points across from each other across said lake. It's
ultimately faster and more energy efficient to use some sort
(34:32):
of skating technology. And yeah, for Menty stresses that it
was highly efficient. This was no mere novelty. They weren't
doing this. You know, maybe it was fun, but they
weren't doing it because it was fun, He writes, quote
from its very conception, skating on ice was a form
of human powered locomotion that was simple and effective, very cheap,
(34:54):
and thus accessible to a large part of the population,
and allowed people to reach more distant destinations than they
could do by walking or running. In fact, unless more
expensive means of transport such as horses or later trains
were used, ice skates were probably the most convenient locomotion
tool until bicycles were built. That would have been the
(35:14):
nineteenth century, the latter probably not being very safe on
slippery roads in winter.
Speaker 3 (35:20):
That's interesting, Well, I would not have thought about it
that way.
Speaker 2 (35:23):
Yeah, so not everywhere and certainly not year round, but
that there would be places where this was just highly efficient.
It was just the most the most sensible way to
move from point A to point B if conditions were
just right. Now, while again bone skates were ultimately a
(35:43):
long lasting technology against superior to mere wood, it would
seem by the thirteenth century CE in the Netherlands, skaters
returned to wood to make use of metal in their skating,
constructing wooden skates that had metal blades. Now, these were
still things that you would strap to the bottom of
your shoes, and I included an image of one of
(36:03):
these for you here, Joe. It is also not very fancy.
If you didn't know you were looking at an ice skate,
you might not know you were looking at an ice skate.
It's like a imagine a wooden skate but with a
thin metal blade, and then it is strapped or tied
to your shoes.
Speaker 3 (36:19):
Yeah, yeah, it looks It looks like the wooden bottom
of a boat, or like a boat keel with a
tiny little strip of metal blades sticking out of the bottom.
Speaker 2 (36:26):
Yeah. And so for Mantiene's co author point out that
the wood here would have been easy to work, the
metal that they use was very durable. An interesting thing
here is that these skates would apparently according to their
reconstructions and their tests, would have suffered from greater friction
compared to bone skates. But their big advantage was that
(36:47):
they allowed the user to finally propel themselves with their
lower limbs, so you could seemingly throw away the poles,
free up your arms, and depend almost entirely on leg power.
And as such, this is really when we begin to
see skating as we know it today entering the world,
Because if you go to any ice skating rink, and
(37:08):
certainly if you go to a roller skating rink, you're
not going to see people pushing around on poles. I mean,
maybe there's some sort of scenario where you use poles
to get your feet underneath you. But I've never seen
anything like that.
Speaker 3 (37:20):
Right, So I imagine it's like the thinness of the
blade that allows you to just use your legs because
of the way that you can angle the foot to
push versus gliding, and you can't really do that with
the more rounded edge of a bone.
Speaker 2 (37:35):
Yes, that's my understanding. So at this point, yeah, we're
kind of off to the races. We're really not purely
inventing something new, but we've innovated to a very interesting
place in the development of the ice skate. And during
the fifteenth and eighteenth century ice skates they retain their
metal wood construction, but they became about thirty percent lighter.
(37:55):
According for Mente, Dutch skates of the time were shorter
compared to modern skates and therefore more difficult to balance
on compared to what we have today, but they would
have proven especially useful to them during the Little Ice
Age of the sixteenth through nineteenth centuries, during which the
system of rivers and canals would have proven ideal skate
(38:16):
routes connecting different populations and different different destinations. And then
during the eighteenth century, skates on the whole became longer
and enabled easier balance and resulted in lower resistance the
weight spread out across longer blades. And I've included another
photo Formenti's work here reconstruction. This is still something you
(38:40):
strapped your existing footwear, but it is even more identifiable,
I think as an ice skate.
Speaker 3 (38:46):
Oh yeah, totally.
Speaker 2 (38:47):
And then during the nineteenth century we finally ended up
with specialized ice skates, with the skates permanently affixed to
a boot of some sort screwed into place, an ice
skate that has shoe ices so forth, like you would
identify now when you go in like rent ice skates
to go ice skating. And the blades were even longer,
(39:09):
apparently up to twice the length of the old thirteenth
century skates, enabling even greater balance and maneuverability. And then
a whole host of additional innovations have been made and
continue to be made, producing skates that are ever more ergonomic, speedy,
and effective. Different breaking mechanics were added, blades that ultimately
(39:33):
like have a mechanical aspect to them and can shift
and so forth. Saw a Fermente quoted in an article
I believe it's the Science Friday, where he basically says
that we probably haven't seen as long of a skate
as is ideal, like, skates are probably going to keep
They're going to keep evolving. They're still evolving, They're becoming
(39:54):
more and more efficient, and they may get longer. We
have not reached peak ice skate length yet.
Speaker 3 (40:00):
Wait, does he have a specific peak length in mind?
Speaker 2 (40:04):
Now he's just saying that we're still like fine tuning everything.
And I guess the other interesting thing here is that
there's not just one purpose for ice skates. There are
a lot of highly specialized purposes for ice skates. So
you know, we have a whole host of skate based
sporting activities and they range from figure skating to ice hockey.
Speaker 3 (40:23):
Yeah, I was reading about that too, And an interesting
thing there is that apparently different ice temperatures are preferred
for the different sports. I think the way I was
reading it is that usually they want the temperature a
little bit higher for figure skating because figure skaters, I
think a softer ice gives them more control over precise movements,
(40:46):
whereas with ice hockey, I think they like a slightly
colder ice because that allows them to achieve like a
higher top.
Speaker 2 (40:53):
Speed okay, interesting, Okay, So with hockey it's more about speed,
and with figure skating it's maneuverability, which makes it now
Fomenty and his co author in the aforementioned paper, they
compare the effectiveness of the four main eras of ice skates,
and the results illustrate this continual improvement process that we're
looking at here. I'm not going to roll through the
(41:14):
entire chart. You can find it in the original paper,
but you can see here he breaks things out by speed,
stride frequency, stride length, and so forth, and Fermenty points
out that with the same metabolic power, skaters today have
a speed four times that of our ancestors, and again
(41:34):
it's only increasing as we find tune our skate design.
Speaker 3 (41:38):
This might not actually be an issue, but I just
had the thought. Do skaters on rink ice have higher
speeds as well, just because they can feel safe to
go at higher speeds, whereas if you're on a natural
body of water you might be more I don't know,
cautious about like straying into an area of thin ice
(41:58):
or something like that.
Speaker 2 (42:00):
That's a good point. I mean, I guess the other
number of factors that might come into play, right, if
you're dealing with like natural ice versus zambonid ice, right.
Speaker 3 (42:09):
Yeah, And I know that the zambonid ice, like the
rink ice, is laid down one layer at a time
to give it special properties, to kind of make it
perfect for skating, whereas, of course natural ice on a
body of water, I mean, it might be great for skating,
but it doesn't have whatever refined quality they're looking for
on that rink ice.
Speaker 2 (42:28):
Now, I want to come back to ice skating in
China because as I was hitting like the core data here,
I kept finding various references to Chinese ice skating, and
I'd read that ice skating in China might date back
to the Song dynasty, so nine sixty to twelve seventy nine.
See that is, of course in addition to possibly connected
(42:50):
or independent developments in the north of Russia as I
referenced earlier. But certainly I looked into this a little
bit more, and you have these ice festivals the Bingshe,
which I think means ice amusement festivals that seem to
date back to the Song dynasty in China and consisted
of various winter sports and performances. Among the many festivities
(43:13):
there was a downhill skating event that involved kind of
a leather ice skate. I wasn't able to find any
images of reproduction of this, but I found some various
modern illustrations of what these might have consisted of. And
these these are kind of like curved leather shoes that
seem to have been made expressly for sliding across the
(43:38):
ice and or snow.
Speaker 3 (43:40):
If this is what's depicted in the illustration you put
in our outline that kind of curled up at the
toe like elf shoes.
Speaker 2 (43:45):
Yes, yes, think like leather elf shoes designed for sliding
around on ice. It's not skating in the sense that
we've been talking about skating, I think from the physics standpoint,
But these would have been things that would have been
you would have worn for like this downhill skating competition
or something that I've seen translated as ice football, in
(44:06):
which people were skating around on the ice in these
leather shoes throwing some sort of a ball back and forth.
The illustration here that I found is from the Beijing
based World of the World of Chinese website, So my
understanding is like these are similar but a little bit different.
These would have also the examples we're looking at here
would have definitely been novelty based skates. These were not
(44:29):
about locomotion, These were about amusement. However, in other parts
of modern China you do find ancient examples of bone skates.
I was reading that in twenty twenty three, Chinese archaeologists
found an example of a bone ice skate in a
Bronze Age tomb from roughly three thy five hundred years ago,
(44:52):
possibly of the Andronova culture of cattle herders that lived
in China's western Shijang Weaker Autonomous Region. These would have
been very much akin to what we were talking about,
like the bones scrapped to a boot or to a
shoe that enabled one to move across naturally frozen bodies
(45:14):
of water. But again, it does seem to come back
to bones. It comes back to horse and cow bones
strapped to the bottom of your feet, enabling you to
at least push yourself across the ice with a big
with a pair of poles or sticks.
Speaker 3 (45:29):
Well, Rob, you've talked me into it. If I if
I take my child ice skating this year, I'm gonna
I'm gonna have to get some bone skating to try
out see how they do.
Speaker 2 (45:39):
You know, I don't think it would be a good idea.
I think this would not in the long run, this
would be a failure. But I could imagine someone trying
to market this. You know, why settle for ice skating
when this year when you could do primal ice skating,
bone ice skating, and people would be like, yeah, you know,
I'm kind of a little over three own axes at
(46:00):
the local acts throwing range. I want to try something
else that has this kind of like, you know, ancient
vibe to it. Let's strap on some bones and see
how it goes. I think you would find it. Would
it would? It would be harder. It sounds like every
everything I've read about it, it would have been a
much harder and clumsier thing to do. We're much better
off with modern ice skates, but for.
Speaker 3 (46:20):
The metal of it, maybe you use the non metal.
Speaker 2 (46:24):
Yes, bone ice skates are very metal. We'll definitely say that.
Speaker 3 (46:28):
All right.
Speaker 2 (46:29):
Should we wrap up there, Yeah, We're going to go
ahead and close out this episode. However, again, definitely tune
in later in June when we come back and talk
about roller skating on its own again directly connected to
the invention of ice skating, but very much its own
thing as well. In the meantime, would of course love
to hear from everyone out there. Do you have experiences
(46:50):
or thoughts related to ice skating? Is there anyone out
there who has tried a more archaic version of the
ice skate? If so, definitely right into it because we
would love to have your feedback. As always, we'd like
to remind you that Stuff to Blow Your Mind is
primarily a science and culture podcast, with core episodes on
Tuesdays and Thursdays. On Fridays, we set aside most serious
concerns to just talk about a weird film on Weird
(47:12):
House Cinema. You can find us wherever you get your
podcasts and wherever that happens to be and give us
some stars and a nice rating that always helps us out.
And on top of that, you'll also find us on
various social media platforms, not all of them because they
keep adding new ones and we just can't keep up,
but hey, we're on Instagram. At least you can find
us there as STBYM podcast.
Speaker 3 (47:32):
Huge thanks as always to our excellent audio producer JJ Posway.
If you would like to get in touch with us
with feedback on this episode or any other. If you
would like to suggest a topic for the future, or
if you just want to say hi, you can email
us at contact at stuff to Blow your Mind dot com.
Speaker 1 (47:56):
Stuff to Blow Your Mind is production of iHeartRadio. For
more podcasts from my heart Radio, that's the iHeartRadio app,
Apple Podcasts, or wherever you're listening to your favorite shows.
(48:23):
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