Augustin Jean Fresnel

Episode Transcript
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Speaker 1 (00:01):
Welcome to Stuff you missed in History Class, A production
of iHeartRadio. Hello, and welcome to the podcast. I'm Holly
Frye and I'm Tracy V. Wilson. Hey. This is yet
another instance of one episode tangentially inspiring another that happens

(00:22):
a lot. It does lately, it happens a lot more
than usual. I don't know why that is. I first
came into contact with Frenelle lenses in college, but then
because I worked, you know, I have a theater degree,
and they come up in lighting, right, which you had

(00:43):
to do. Even though I was largely working in acting,
I did a lot of set stuff as well. But
then while I was working on our episode on TV remotes,
Fornelle lenses came up again in relation to one of
Eugene Polly's patents, and that, of course reminded me of him.
Because August Stint Franelle is pretty interesting to me. He
did not live a long life, but in his relatively

(01:06):
short life, he contributed significantly both to the understanding of
light and related to that, to the safety of coastlines.
But what I love most about his story is that
neither of those accomplishments had anything to do with his
chosen career that you can talk about a little more
behind the scenes. But we're going to talk about Augustin

(01:26):
Franell today. Augustin Jean Frenelle was born on May tenth,
seventeen eighty eight, in Brolyi, France, which sits roughly seventy
five miles or one hundred and twenty kilometers west of Paris.
His mother was Augustine Mary May and his father was
Jacques Frenelle, who was an architect, and Jacques was very successful.

(01:48):
He took on projects like restoring and expanding chateau for
the aristocracy. After Augustin was born, the Frenelles moved to Scherbourg,
which sits on the northern point of the coast line
bordering the English Channel. This was being built up as
a port city and Jacques Frenelle was part of that
expansion project. If you have ever seen the movie Parapluis

(02:12):
de Cherbourg, which was spectacular, Catherine din a vehicle. You
like me, hear that name and go ja tem gee,
I can't help it forever forever. Augustin was born at
a pivotal point in French history. He was still a baby.
For example, when the Bastille was stormed in seventeen eighty nine,
and he was not yet five years old when Louis

(02:34):
the sixteenth was beheaded and the Reign of Terror began,
And although his parents were not directly involved in the revolution,
the family was of course impacted by it. The most
obvious result was that the work at Cherbourg stopped and
Jacques took Augustine and Augustin to live in a small
village north of cont called Matthieu. After the family moved there,

(02:56):
Jacques and Augustine had two morph sons, Leonard and Fauje.
This was a deeply religious family. The Frenelles were followers
of the teachings of sixteenth and seventeenth century Dutch Catholic
bishop Cornelius otto Jansen, who led the Jansenist reform movement
in the Roman Catholic Church. Yansonism focused on ideas of

(03:18):
free will and God's grace, and that the fate of
humans is largely out of their hands, as those who
God gives grace to will be saved by it, and
those without it are doomed to sin. This faction of
the church was controversial. A lot of Catholics rejected it
as not really being part of the denomination at all,

(03:41):
although that sentiment may have had less to do with
theology and more to do with power struggles within the church.
But the Frenelles were devout, and Augustin remained so for
the rest of his life. As a young child, Augustin
was educated at home. Although he was not considered to
be especially smart by his parents because he struggled with

(04:03):
his studies and he actually couldn't read at all until
he was about eight years old, other children thought he
was absolutely a genius. All of the energy that he
was not putting into his studies seemed to go into
his own experiments and to sometimes building dangerous toys like
projectile shooters for the village children. There's a story that
he built them all canons to play with, to the

(04:25):
point that parents were like, oh my goodness, hey, for nels,
can you control your kids? I was wondering when I
read this, like, what kind of projectiles are we talking
about here? Yeah, they weren't like fuse lit canons. They
were more like, you know, simple machine type things that
could shoot things. But yeah, he was apparently a little
scamp in that regard, and when he was twelve he

(04:46):
started studying AT's Eco Central School, and he got his
first taste of science and mathematics there and he really
loved it, and with subject matter that engaged his brain,
he actually did very well in school. He pretty quickly
decided that an engineering career was his goal, as it
incorporated both of those things. So at the age of sixteen,

(05:08):
he moved to Paris to study at the Ecole Polytechnique.
He studied there for two years, and then he advanced
to the Ecole des Pont de Chose, the School of
Bridges and Roads, and he studied there for three years
before receiving his credentials as a civil engineer. In his
mid twenties, Frenelle settled into a career path not dissimilar

(05:29):
from his father's. He worked as an engineer on public works.
In eighteen oh four, the same year that Napoleon became
Emperor of the French, he was hired by the Corps
of Bridges and Roads to expand the country's roadways, starting
m Bondei on the west coast of France. His first
assignment was in Larouchurion, which was a town that Napoleon

(05:52):
renamed after himself and then built up as an administrative
seat of government in the region, and Frenelle's job was
to create an infrastructure of roadways that would give La
Rochetrion easier access to the rest of Vonde, and he
hated it. He liked solving problems, but he was put
in a position where he had to manage people, which

(06:16):
is the last thing on earth that he wanted to do.
So he kept himself busy studying various things that just
tickled his fancy in his free time. Yeah, his writings
back to his family are basically about how much he
dislikes management. How he's one of those people that I
suspect may not have been an amazing communicator of his

(06:36):
ideas because he talks about often having to step in
and do the work himself, which, listen, I have that
same disease, so I understand it. But I think he
just maybe wasn't always great at communicating what he was after.
In eighteen twelve, Frenell moved into another large scale public
works project, this time building a roadway that would connect

(06:57):
Spain in Italy and it had to pass through grants,
particularly through mountainous areas, and this was once again a
job assignment that came at the same time as a
significant development in Napoleon's story, and that story impacts Ranel.
So we're going to quickly review a little bit of
French history here. In the summer of eighteen twelve, the
Emperor Napoleon, acting on fears that Russia was about to

(07:20):
ally with England, invaded Russia after first parking his troops
in Poland along the border for a while. This pretty
famously did not go well. In the very simplest terms,
the Russian army mostly refused to battle, which made Napoleon's
entire effort look sort of foolish. There was only one
major battle that happened as a result of this, at Borodino,

(07:41):
which Napoleon did win, and that enabled the French to
advance to Moscow, but the city had already been sacked
by Russian forces, so that Napoleon's army would find nothing
to gain there. Furthermore, Zar Alexander the First refused to
negotiate with Napoleon, and as winter closed in, things got
dire and Napoleon was forced to retreat to Paris, where

(08:03):
he actually found rumors circulating that he was dead. He had,
in returning to Paris, left behind most of his troops,
which dwindled from a starting number estimated at seven hundred
thousand to a mere one hundred thousand by the end
of the Russian campaign. Napoleon's failure was such a complete
disaster that allies began to abandon him, and some of

(08:25):
them actually joined forces with Russia. As countries expelled French
troops and Napoleon's power shrink, he was eventually completely overthrown
and the French monarchy was restored with Louis the eighteenth
as king. Napoleon was exiled to Elba in the spring
of eighteen fourteen. That same year, Frenelle started studying the

(08:46):
area that would make his name famous, which was optics.
He had some optics education at university, but it was
pretty rudimentary and soufre Now it seemed like the principles
he was taught didn't really explained the behaviors of light
very effectively. Newton's ideas about light were included. We'll talk
more about those inan a moment, but again that felt

(09:09):
limited to him. He did not feel compelled to start
to do his own experimenting until the eighteen teens, and
he didn't actually start his scientific study as a hobby
working in light or optics. He kind of messed around
with a few different things until he landed there. For
a while, he thought that light and heat transmission might

(09:31):
happen through quote the vibrations of a special fluid. He
wrote about this idea to his brother Leonor. He was
just really excited. It seems to have projects that let
him try to solve problems creatively. He eventually worked on
various experiments to explain the behaviors of light, including reflection, refraction,

(09:53):
and polarization. And coming up, we're going to talk about
exactly how Napoleon impacted for Nell's work, but first we
will hear from the sponsors. They keep the show going.
When Napoleon returned from Elba suddenly in eighteen fifteen, everything

(10:17):
in the French government was upended, including public works projects.
Frenelle was very dismayed. When Napoleon landed at cann on
March first, eighteen fifteen. The exiled emperor had seven ships
of soldiers with him and intended to reclaim France. Frenelle
thought this was literally an attack on civilization, that is

(10:38):
what he called it, and he left his job to
go fight for the king. But Napoleon did manage to
make his way to Paris, with people joining his military
as he passed through the country, and on March twentieth
he walked into Tuilerie and began his second rule, which
of course famously lasted exactly one hundred days. Because Frenelle

(10:59):
had against Napoleon, his position as a civil engineer was
of course no longer available to him, so he was
unemployed and viewed as an enemy of the state, and
so he was also surveilled. He moved back to his
village of Matthieu and took advantage of his unemployed free
time to continue his study of optics. One of the

(11:22):
things that he wanted to figure out was why the
shadow around a thin edged object like a knife would
have a fringed edge, or why light that passed through
a slit in a card would have dark spots in it.
He was after the cause of light diffraction. In some ways,
he had to catch up to the contemporary discussions already

(11:45):
happening in the science of light. He had no idea
about the work and the controversy around Thomas Young and
Young's wave theory of light. Thomas Young was an English
physician and physicist originally from some England, and Young achieved
a lot of noteworthy things in his life. He could
easily be an episode in the future. But germane to

(12:07):
Frenelle's story is his wave theory of light. He developed
this theory through an experiment that involved sunlight passing through
two small slits in a card, and when Young observed
the light that had passed through the card onto the
wall beyond it, he noted that it appeared not as
two spots of light, but as a series of vertical lines,

(12:29):
and that evidenced an interference pattern, and that was important
because it supported the idea that light traveled in waves.
This challenged the idea that had been put forth by
Sir Isaac Newton that light traveled as a particle, what
was known as the corpuscular theory. The corpuscular theory of
light came about as the scientific world was struggling to

(12:52):
get a handle on what exactly light was and how
it moved throughout the world. In seventeen oh four, or
Sir Isaac Newton proposed the corpuscular theory. Newton's take on
light was that it was made up of tiny particles
what he called corpusals. These particles were emitted from various sources,

(13:12):
obviously the sun, but also things like candles, stars, et cetera.
Different luminous objects produce differently sized corpusles, and that accounts
for different colors of light, and per Newton's theories, these
particles moved at a very high velocity and always in
a straight line. So if one hit an opaque object

(13:34):
and could not pass through it, it would be reflected
away at an angle and continue to travel in a
straight line. That's reflective light. But if light hits a
medium it can pass through. These particles are attracted at
the surface, and if the medium is denser than the
medium that the light had been traveling through, like traveling

(13:56):
from air into a prism, the dense nature of the
prism will speed up the light and cause the directional shift.
And in this theory, vision is explained as light hitting
the eye to produce imagery. Yeah, so that was Isaac
Newton's take. Obviously some of that is incorrect. I'll talk
about that some more. Frenell had started his own experiments

(14:21):
in this area even before he knew about Young's work.
He wasn't entirely flying blind though he was basing his
experiments on the work of another scientist, Danish mathematician and
astronomer Chris John Huygens, who he had learned about in school.
Huygen's principle regarding wave motion states quote, every point on
a wavefront is in itself the source of spherical wavelets,

(14:43):
which spread out in the forward directions at the speed
of light. The sum of these spherical wavelets forms the wavefront,
and Forrenell eventually expanded on Huygen's adding that these secondary
wavelets would then interfere with one another. Where Huygen's had
described those secondary wavelets as enveloping the initial wave and

(15:03):
carrying it forward, Frenell's explanations suggested that they overlapped and
interfered with one another, and that that was what formed
the wavefront. This, by the way, I should say, is
my very rudimentary understanding. Holly is not a physicist. But
this amended version of Huygen's work came to be known
as the Huygen's Frenelle principle. Frenelle also worked on explaining

(15:26):
the dark spots that appeared in pools of light. Sometimes.
He came to the conclusion that two light waves that
perfectly lined up peak to trough would yield darkness as
they interfered with one another. But if they were lined
up peak to peak and trough to trough, they would
amplify into a larger wave. The earliest of these ideas

(15:48):
was put into an essay which got lost, but through
an uncle, Augustin was introduced to Francois Arago, who would
become an important collaborator and front But Frenell did did
not get to work on his special interest projects forever
because he got his job with the Corps des ponte
Chaise back after Napoleon was exiled for the second time

(16:10):
to the island of Saint Helena, and Forrenell was sent
tourin to resume work on the roads. This slowed Fernelle's
scientific work quite a bit. His work in optics was
relegated to these small amounts of free time that his
work afforded him, or to times when he took vacation
or leave, and he made a lot of requests for

(16:31):
time off, each time heading to Paris to continue his
scientific studies. These frequent leaves from work would not have
been approved had it not been for high ranking members
of the scientific establishment, like Francois Arago advocating with the
Bridges and Roads Department on his behalf. Because Forrenell had

(16:51):
a strong mathematical background, he was able to back up
a lot of his ideas about lightweight theory with it.
But it also took a lot of time. As we mentioned,
he worked out a lot of his early ideas and
formulas before he even knew about other scientists working on
the problem of light The thing about Fornell's work that
was unique was that a lot of it, or work

(17:13):
closely related to it, had happened already. So in a way,
this young public works engineer was actually working in his
spare time to verify earlier theories and experiments without even
knowing it, and that was a huge challenge. He believed
that elementary waves were generated all along the arc of
the wave and interacted with one another. Okay, to a

(17:36):
lay person, that kind of makes sense, I'll be frank,
it's easier when you look at diagrams. But for me
and probably a lot of listeners, imagine having to come
up with the math that supports that idea. To me,
this seems like superhero stuff. I can't even fathom it.
And Fornell, who was very good at maths, still needed
months to puzzle it all out. In eighteen sixteen, Fornell

(17:59):
published his first paper about this work, but he acknowledged
that he was still in the early stages of working
everything out and included a plea to readers to understand
the situation. And he also for a while joined forces
with Francois Arago, who was two years older than Frenell
and was the chair of analytic geometry at the Paris

(18:21):
Ecole Polytechnique. Together the two of them studied interference as
it applied to polarized light. Frenelle may have continued to
focus on polarized light, had a high profile opportunity to
show his work in light waves not have come up,
But he learned that the Academy of Sciences was going
to make diffraction the topic of their eighteen nineteen Grand Prix.

(18:45):
And as we've just mentioned, he had worked a long
time on the mathematical side of this theory, and he
really believed that his work was solid, so he hustled
to get an entry ready. He wrote, quote, I think
I have proved that light is propagated by the unguls
of an infinitely subtle fluid diffused in space, and it
is to the demonstration of this great principle that I

(19:06):
have been particularly attached. It is the end towards which
I have directed all my efforts. Though Atrago had tried
to promote the work of Frenelle to the scientific establishment
in both France and England, most of the people who
heard about what this young civil engineer was doing assumed
that he was just copying Thomas Young, and they really
didn't give his work a whole lot of additional attention.

(19:30):
Eighteen nineteen would prove to be a big year for
Augustin Frannell, and we will talk about why after we
pause for a sponsor break. In eighteen nineteen, Augustin Frenelle
presented his work with light waves and diffraction to France's

(19:53):
Academy of Sciences under the title Natures simplexefagunda Nature simple
and Fertile, and this offered twenty five cases of ways
diffraction might appear, along with mathematical formulas to explain each
of those cases. This competition was intended to bring the
smartest minds in the country science community together to discuss

(20:16):
the true nature of light. But because Farnell's work ran
counter to the widely accepted work of Newton. There was
a lot of resistance to what he presented. The next
figure who's important to this particular part of the story
is a man named Simeon Denis Poisson. Poissant was a
mathematician who had become known for his work in probability

(20:39):
and who was very influential on France's scientific education system.
He was also one of the competition judges for the
Academy of Sciences, and he thought Frenelle was talking absolute nonsense.
One particular example in Fernell's paper really rankled Poisson, and
he pointed it out as proof that this person didn't
know what they were doing. This was an instance where

(21:02):
Frenell suggested that the shadow of a circular disc would
actually have a bright spot of light in the center,
and Poisson was adamant that this just simply could not happen.
But Arago, who really believed in his friend and saw
that there was bias against his work, managed to get
the right instruments to do the experiment there with the
competition judges, so that they could see if Frenell was

(21:26):
correct and he was the shadow that he produced had
a bright spot in the center. And although the judges
who favored the Newtonian theory of light didn't exactly believe
in Frenelle's work, it had proven out and they couldn't
deny that, and so he won the prize as an aside.
Eventually it was recognized that elements of both Newton's corpuscular

(21:49):
theory and Frenelle's work were true regarding the nature of light.
Corpuscular theory is kind of the proto version of our
understanding of photon. Newton's take had some incorrect ideas, specifically
different sized light particles causing color difference, light levels, traveling
faster and denser media, and the idea that media could

(22:12):
attract or repel light. That also didn't offer an explanation
for things like polarization or diffraction. Eventually, humans came to
understand that diffraction was the result of light waves passing
through a small opening the size of or smaller than
the wavelength, or when a light wave bends and spreads
as it passes around an obstacle. Today, the idea of

(22:36):
wave particle duality is accepted to understand the nature of light.
That means that sometimes it does travel like a particle
of fox time in a straight line, but at other
times it behaves like a wave, enabling it to bend
a thing that I remember from physics class. I don't
remember a whole lot from physics class. We can talk

(22:58):
about what a weak physics student I was on Friday,
if you like. Frenelle still longed for a position where
he could work on his scientific studies full time so
he wouldn't have to juggle it in his free time
alongside a public works engineering job that he just clearly
did not like, and starting in eighteen nineteen, Frenelle did

(23:18):
begin working alongside Francois at Agau in a national project
that was intended to improve upon the lighthouses of France,
first by working to perform a series of tests on them.
And this project was precipitated by the ongoing problem of
shipwrecks being caused by vessels simply running aground unexpectedly or

(23:38):
slamming into rocks that were near the land. France had
been a buzz after a high profile shipwreck of a
French ship off the coast of Africa, and this had
led to a high level of interest in fortifying their
own coastline against similar accidents. At this time, there were
a number of ways that lighthouses provided light. Lighthouses have

(24:01):
been around since at least two eighty five BCE, maybe
even longer. That example is one of the Seven Wonders
of the World, built in Alexandria, Egypt. There were Roman
lighthouses spread throughout Europe during the time of the Holy
Roman Empire. Early lighthouses used beacon fires. Some of these

(24:22):
fires were protected by a roof and others were in
the open air. Eventually, coal and then candles, and then
oil lamps replaced the fires. In the twelfth century. Lighthouses
became more common as the dark ages ended and new
trade routes were established, fostering a need for near shore lights.

(24:42):
The earliest modern lighthouses appeared sometime around the beginning of
the eighteenth century. In seventeen eighty, Ami are Gone invented
a clean burning oil lamp that became standard in lighthouses.
These are sometimes combined with reflectors that consisted of large
glass discs with spherical coatings to reflect the light. A

(25:04):
glass cutter from London had actually created a lighthouse lens
in the seventeen eighties that was twenty one inches across
in five and a half inches thick. That glass cutter
Thomas Rogers implemented these lenses in a couple of lighthouses,
but they were made of green glass and had some imperfections,
so they did not really throw the light as far

(25:25):
as was hoped. Then there were developments that led to
rotating parabolic reflectors, a couple of which were combined with lenses.
The lenses actually made the lighthouse less effective and they
were abandoned. I kind of want to do a history
of lighthouses. It's on the list. Yeah, a lot of

(25:45):
interesting stuff there and a lot of science, So we'll
see if my brain can handle it. Because Frenelle had
already done so much study of light, he was kind
of the perfect man for this challenge, and as he
had been helping Arago performed tests on the existing lighthouse
setups in the country, he immediately began to brainstorm the

(26:06):
ways that they could be improved, although to be clear,
that was not a task he had been given. At
that point. Fornell realized that reflective mirrors could be replaced
with lenses that bent the light instead of reflecting it,
and this was something that had been tried. We just
mentioned it in some of those efforts, But Forrenell tried
to figure out ways to fix the problems that previous

(26:27):
lenses had. At one point he actually considered something I
found quite charming, which is creating a lens by filling
a glass container with wine. Obviously that would be a
white wine. But he abandoned it, and then he had
the idea to create a giant lens that did not
have to be impenetrably thick in the middle. Instead, it

(26:49):
would have a series of prisms that could bend and
focus the light into a beam. And he called his
design lentil Eeschlan or Lenses by Steps. But the Lighthouse
Commission was kind of a ho hum on this idea
and compared it to a similar one created by another
person some years earlier. But Frenell really thought he was

(27:11):
onto something. He knew though that he would have to
make it to show them what he was talking about.
He did manage to get some grant money from the
commission to help with the cost of construction. Like any prototype,
this one had some problems, but Frenell worked with craftsmen
to refine them. A specialist named Francois so they was

(27:33):
crucial to the construction of a glass panel that looked
like a square containing a bull's eye, with concentric rings
formed around a central circle to form a polygonal lens.
It had ninety seven different pieces of glass in it.
In an actual functioning lighthouse, he planned for there to
be eight such panels combined together in an octagonal shape

(27:56):
surrounding the light source, but for this test, one would
have to do. He combined it with a lamp that
used several small wicks instead of one large one, and
when he tested it in front of the Commission, those
in attendance were, in Frenelle's account, dazzled. But while a
full version of this design was requested, Frenelle was not

(28:18):
getting a full green light to go ahead with this project.
Two other people were also presenting fully assembled attempted solutions
to the lighthouse problem. Both of those other competitors used reflectors,
and the final test of these three models was public.
It was held at the Paris Observatory, and Forrenell was

(28:39):
the very clear winner by a mile. Nobody could deny
that what he had achieved far out shown not to
be punny. The work that everyone had been doing with
reflectors From there, he was commissioned to build a lens
for France's oldest continuously operating lighthouse, which was known as
Cordouin between the successful test of that lens and its

(29:01):
final installation, which was postponed due to winter weather, Frenell
continued to work on his work in light theory and
refining and formalizing any theoretical points that had been involved
in his earlier work with mathematics. He also wrote an
entry on refraction for Encyclopedia Britannica at the behest of
none other than Thomas Young. When the winter was over,

(29:25):
the final installation of the lens that Cordoine was completed,
and Forrenell's place in French scientific history was cemented. For
all of his work, Frenelle became an elected member of
the Academy of Sciences in eighteen twenty three. He also
received the French Legion of Honor, and the Royal Society
of London inducted Frenelle as a member in eighteen twenty four,

(29:47):
and that same year he was assigned to France's lighthouse commission.
The French government was so pleased with Frenell's lenses that
it developed a plan to illuminate the entire French coastline
with them. Arnell himself created a map of a planned
fifty one lighthouses for the country that would create a
continuous network of light. He also improved on his lens

(30:09):
design as he worked. Yeah, at that time there were
thirteen of those fifty one lighthouses that existed, so a
huge number we're going to have to be built from scratch,
and those thirteen were going to have to be significantly updated.
In eighteen twenty seven, Frenell received the Rumford Medal. That's
a metal bestowed by the Royal Society of London quote
for important discoveries in the field of thermal or optical

(30:33):
properties of matter and their applications. For some reason, just
if you go looking the Royal Society site, say this
happened in eighteen twenty four, that is the year he
was inducted. But based on ratings of other people involved
in the nomination and the award itself, this did happen
in eighteen twenty seven. Forrenell had not been especially healthy

(30:53):
at any point in his life, but as he got
into his late thirties he declined really rapidly. All through
him life, he'd been one of those people who worked
constantly up to and through the point of exhaustion. Many
biographies cite his deeply held religious faith as the source
of his drive. He believed his service to society was important,

(31:15):
and he pursued it to the exclusion of everything else.
Sometimes he characterized as being aware that he probably wouldn't
live a long life, and consequently he felt compelled to
do as much as he could in whatever time he had.
Just as his scientific work was taking off, he was
warned against overworking and had to prioritize what projects he

(31:36):
felt were the most important, and Forrenell did have a
short life. In the summer of eighteen twenty seven, he
was ill and was taken to a family property in
Vis d' roy in the hopes that fresh air would
help his health improve. His friend Arago traveled there to
see him and to give him the Rumford medal he
had been awarded, and Arago was quite distressed at just

(31:58):
how sick his friend was. Regarding the metal Frenelle, who
was incredibly weak, is said to have told Arago quote,
the most beautiful crown means little when it is laid
on the grave of a friend. He died of tuberculosis
on July fourteenth, eighteen twenty seven. His mother was with
him when he died, and he was thirty nine. His brother,

(32:20):
Leonor continued his work on the lighthouse project. The Frenelle
lens quickly became the standard in lighthouses around the world.
One of the ways that Frenell contributed to the world
of science, beyond his specific work in light waves and lenses,
was that his approach to his work helped to establish
the ways in which questions of physics would be examined

(32:42):
going forward. The idea of physics as a branch of
science hadn't really solidified yet when Frenelle was conducting his
experiments and developing his formulas. The word physics was kind
of a nebulous term that referred to almost any study
of the natural world. There were efforts in the decades
leading up to Augustine Farnell's birth and beyond to try

(33:05):
to formalize the more specific definition, but it had been
problematic in some ways. Other specialties had managed to carve
out their own identities, and physics was made up of
the science that was unclaimed by the other disciplines. There
were two branches of physics that developed general encompassed things
to do with the mechanics of the world and universe

(33:27):
as it was understood at the time, so things like gravity, inertia, movement,
et cetera. Particular physics dealt with the various characteristics of
matter like heat, light, and magnetism. Former podcast subject Antoine
Lavoisier had introduced the idea of physics as a recognized
branch of science to the Academy of Science just three

(33:49):
years before Frenell was born. But Frenelle's very careful methodology
of performing experiments and then developing the math to both
verify and explain the results was a huge step forward,
and it set the bar for physics, theory and proofs. Yeah,
he's interesting. I feel like we left so much out,
but I honestly can't parsel a lot of his work.

(34:11):
Don't ask me to explain the math. I love math
and theory, I'm just bad at it. I have a
listener mail that I hope won't make me cry, but
it might because it's quite beautiful. Ah. This is from
our listener Jen who writes high Holly and Tracy. I
recently listened to your behind the scenes episode on spray
Paint and I think it was Holly who was saying
in her youth, there was an area that it was

(34:31):
a rite of passage for the young people to tag
with spray paint, and that it would periodically get painted over.
It reminded me of my small town growing up. We
actually had a rather high level of deaths of high
school students for the size of our town. Death is
always hard to process, but especially for kids, and especially
when it is someone so young. Anyway, there was a

(34:52):
barn in the area that was unused, and after a
death the friends of the student would go out there
and paint a eulogy of sorts, obviously sometimes more artistically
than others, depending on who was present, but the point
wasn't really the art of it, as the grief processing
it allowed. The memorial would stay until the next high
schooler died, and then it would be covered by the
next group. It was a haunting, beautiful reminder each time

(35:15):
you drove by. The barn continued to fall into disrepair
over the years, and it has now been torn down,
but I sometimes wish something similar everywhere to allow for
this kind of public and personalized memorial in a way
for young people to work out some of their grief
as pet tax I have attached a short video of
my three year old son rolling around with our seven
year old rescue met scuttle Butt thanks to the podcast.

(35:37):
I always enjoy it. This is such a beautiful thing. Yeah,
I get very choked up over it. It's so lovely
and it is very insightful about people trying to process laws.
So Jim, thank you. I'm crying. It's lovely. If you
have an email that you would like to make me
cry with, feel free take it as challenge. It's not
a very hard one. You could do that at History

(35:59):
podcast iHeartRadio dot com. You can also subscribe to the
show wherever you listen to your favorite podcasts, including the
iHeartRadio app. Stuff You Missed in History Class is a
production of iHeartRadio. For more podcasts from iHeartRadio, visit the
iHeartRadio app, Apple Podcasts, or wherever you listen to your

(36:22):
favorite shows.

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