Imagine making a mathematical error at your job,
and your boss comes up to you and tells you that
if you don't find a way to fix it, you are going
to be crucified. Right, literally crucified on
the job site. Not fired, not demoted. You're
a criminal. Crucified. It's intense. Yeah, welcome
to today's Deep Dive. We are traveling back to
the Islamic golden age in ninth century Baghdad.
Right. And we're going to explore the brilliant
minds, the unprecedented inventions and the truly
perilous workplace environment of the Bonamusa
Brothers. It is a story that, honestly, it forces
us to completely rethink how scientific progress
actually happens. Absolutely. Because we tend
to picture the history of science as this, like,
orderly, civilized march forward in pristine
laboratories, you know? But the reality here
is scorching deserts, cutthroat palace intrigue,
and literal highway robbery. OK, let's unpack
this. Today we are pulling from a comprehensive
Wikipedia article detailing the biographical
timeline of these three brothers, Muammar, Ahmad,
And also on the bun. Exactly. We're going to
look at their surviving texts and how they managed
to bridge ancient Greek theoretical math with
like hand on physical engineering. They essentially
built what might be the world's first programmable
machine, which is just mind blowing for the ninth
century. Right. But to understand how they achieved
any of this, you really have to look at their
origin story because their father. Musa ibn Shaqir
was a bandit. He started his career as a highwayman
in Khorasan, just robbing travelers. Which is
an incredibly rare starting point for a family
of legendary polymaths. I mean, yeah. We don't
have the exact historical record of how he managed
this pivot, but somehow this highway robber puts
down his sword, studies the stars, and becomes
a recognized astronomer. That's wild. And more
importantly, he manages to befriend a man who
would eventually become the Abbasid caliph And
that friendship is the catalyst for everything.
Because when the father dies, his three sons
are left orphaned. But the caliph remembers his
friend. He steps in, takes these three boys under
his wing, assigns a senior Baghdad official as
their guardian, and enrolls them in the House
of Wisdom. The intellectual center of the world
at that time. Yeah. I'm trying to think of a
modern equivalent for you listening. And the
closest thing would be if a superpower government
scooped up three orphan kids and just drop them
into a top -secret elite tech incubator with
an unlimited black budget. That's a great way
to put it. Right. They were handed every conceivable
resource and trained by senior court astrologers
in geometry, mechanics, music, and mathematics.
Well, if we connect this to the bigger picture,
you have to understand the environment they were
dropped into. The Abbasid Caliphate at this time
was completely obsessed with acquiring knowledge.
Right. The translation movement. Exactly. This
was the peak of the Great Translation Movement.
The state's primary goal was to gather ancient
Greek texts from Byzantium, you know, works of
philosophy, mathematics, engineering, and translate
them into Arabic. And the Bani Musa brothers
didn't just sit in a classroom reading these
texts. As they grew older and acquired immense
state -sponsored wealth, they became major power
players in this movement. Yeah. The sources say
they were personally paying translators 500 dinars
a month. Which is a staggering fortune. To put
that in perspective, yeah, it was massive. They
were funding these massive expeditions just to
hunt down ancient manuscripts. Oh, totally. They
even traveled to Byzantium themselves to find
these books. what stands out to me is their eye
for raw, unconventional talent. Yes, the Thabit
Dibbinkora story. Exactly, there's this one specific
story where the eldest brother, Muthamad, is
traveling back to Baghdad, and he happens to
stop at a currency exchange stall in Haran. He
starts talking to the money changer, a man named
Thabit Dibbinkora. And a money changer is someone
dealing constantly in fractions, conversion rates,
rapid mental arithmetic. Right, exactly. So Momod
recognized that the man wasn't just doing basic
commerce, you know. He had a profound intuitive
grasp of complex mathematics. So Momod just recruits
him on the spot. Literally just takes him. Yeah,
he pulls him out of the market and brings him
into their inner circle. and that money changer
goes on to make massive historical discoveries
in algebra and geometry. It's incredible. It
really proves that genius isn't confined to academic
institutions. If you have the vision and, well,
the funding to look for it, you can find brilliant
minds working at a currency exchange stall. Absolutely.
And that wealth gave them the freedom to not
just archive knowledge, but to aggressively test
it in the real world. Right. They were working
alongside titans of the era, like Al -Khorizmi
and Al -Kindi, but the brothers were unique because
they weren't satisfied with merely translating
what the ancient Greeks thought about the universe.
They wanted to prove it. Exactly. They demanded
empirical proof. Which brings us to a project
that sounds like an absolute logistical nightmare.
So the ancient Greeks had theorized that the
circumference of the earth was roughly 25 ,000
miles. Right. Eratosthenes. Yeah. And the Caliph
Alma Moon basically issues a challenge. He's
like, go verify that. Now, imagine you are tasked
with measuring the entire planet, but you are
living in the ninth century. Good luck. Right.
You don't have satellites. You don't have lasers.
The brothers' solution was to travel out to the
desert near Sanjar in northern Mesopotamia, equipped
with essentially nothing but wooden pegs, long
ropes, and the night sky. Their methodology was
brilliantly elegant, though. Walk us through
it. So they waited until nightfall and measured
the exact altitude of the pole star in the sky.
Then they started walking due north. Okay. As
they walked, they drove wooden pegs into the
hard desert ground and stretched a rope tightly
between them to ensure they were walking in a
perfectly straight line, measuring the exact
distance they covered. Right. They kept walking
north until the altitude of the pole star changed
by exactly one degree. Then they returned to
their starting point and did the exact same thing,
walking due south. See, I'm trying to picture
the sheer physical toll of this. You're in the
Mesopotamian desert. Whoa, it would have been
grueling. But beyond that... I just have to challenge
the accuracy here. You're telling me they used
a giant protractor and a long piece of string
to measure a planet? Essentially, yes. Wait,
how do you account for a rope stretching in the
midday heat or just the fact that humans naturally
drift and don't walk in perfectly straight lines,
especially over dunes and uneven terrain? Well,
those are the exact variables that ruin scientific
experiments, right? Yeah. And the brothers knew
it. That is why they didn't just do it once.
The brilliance of their work lies in the rigorous
repetition. By walking both north and south,
they averaged out local topographical errors,
but they went further. They packed up the entire
expedition, traveled to a completely different
geographical location, Al -Kufa, and repeated
the entire grueling process all over again. Wow.
Okay, so they were verifying their own data.
Exactly. They were actively trying to control
four environmental variables. By measuring the
physical distance on the ground that corresponded
to a one -degree change in the star's altitude,
they knew they had measured exactly one 360th
of the Earth's circumference. Multiply that distance
by 360. and they arrived at their answer, 24
,000 miles. Which is astonishingly close to the
actual figure of about 24 ,900 miles. It's incredible.
They achieve that precision using sticks, string,
and exhaustion. Pretty much. And you can see
that transition from theoretical to hyper practical
in their mathematical text too. Specifically,
Their treat is called the book on the measurement
of plane and spherical figures. Oh, that specific
book was foundational. Medieval mathematicians
like Fibonacci used it centuries later. Wow,
really? Yeah. The reason it was so revolutionary
is that it fundamentally broke away from the
Greek tradition of geometry. Think about Euclid
or Archimedes. When the Greeks did geometry,
they thought in terms of abstract ratios. OK,
like how? They would say that the area of a circle
relates to its radius in a specific proportional
relationship. It was a philosophical way of looking
at shapes. But the Banu and Musa brothers needed
something more concrete. They shifted that paradigm
by expressing area and circumference as actual
hard numerical values. It is the difference between
reading a recipe that says use twice as much
flour as sugar versus a recipe that says pour
in exactly 500 grams of flour. That's a perfect
analogy. One is relational concept. The other
is an actionable blueprint. And that shift is
the critical leap between a philosopher and an
engineer. If you want to actually build a physical
machine, ratios aren't enough. You need exact
numbers. You need exact numbers to know how much
brass to cut or exactly how much water a cylinder
can hold. Because they had finally nailed down
how to use exact, concrete numbers, they could
start building physical working mechanisms. Which
perfectly explains the middle brother, A -mad.
He is the author of the book of Ingenious Devices,
a manuscript detailing a hundred different physical
inventions. Yes. And looking at the breakdown
of this book is hilarious because it highlights
the dual nature of engineering. Out of the hundred
inventions, about 25 are highly practical, life
-saving tools. We are talking about genuine industrial
innovation here. They designed a gas mask for
workers exploring polluted underground wells.
They built a hurricane lamp designed to withstand
high winds without blowing out. They even engineered
a mechanical grabbing tool for recovering heavy
objects underwater. Right. The clamshell design.
Yeah. The source material notes that it was constructed
using two hinged toothed buckets that snapped
together under rope tension, which is the exact
same mechanical principle as the clamshell grabber
you see on a modern construction excavator. It's
identical. But that leaves 75 other inventions
in the book. The vast majority of A -Man's work
was dedicated to trick -pouring vessels. Party
tricks. Pictures designed for fancy banquets
that would pour wine, then pour water, and then
pour a mixture of both, seemingly by magic. They
were essentially ninth -century parlor tricks
designed to confuse rich guests. It is easy to
dismiss those pictures as frivolous toys. But
what's fascinating here is that the significance
for the history of engineering isn't what the
pitchers did, it is how they functioned. Okay,
explain that. The trick pitcher was merely a
physical shell hiding a labyrinth of fluid dynamics.
To make a pitcher pour two different liquids
automatically without the user doing anything,
Ahmad had to invent automatic one -way and two
-way valves. He built concentric siphons. Wait,
break that down for me. How do you build a mechanical
delay? out of just water and gravity. Okay, imagine
a hidden secondary tank inside the pitcher. As
you pour the first liquid, water is also slowly
bleeding into this hidden chamber. Inside that
chamber is a piece of cork, a float valve, very
similar to the ball floating in the back of your
modern toilet tank. Oh, I see where this is going.
Right. As the hidden chamber fills, the cork
rises. Once the water reaches a specific height,
the rising cork trips a hidden lever, which snaps
a valve shut and opens a new one, changing the
liquid being poured. That is so clever. The time
it takes for that hidden tank to fill up creates
a physical delay. It is a timer made entirely
out of fluid pressure and gravity. They were
creating even statements using water. Here's
where it gets really interesting. Because they
took those if in statements, those control valves,
and they applied them to a completely different
medium. Yes, they did. It's detailed in a separate
manuscript called The Book on the Description
of the Instrument, which sounds by itself. This
wasn't a water pitcher. It was a massive automatic
flute player. The conceptual leap here is just,
it's astonishing. They took the principles of
fluid control and used them to sequence information.
The mechanism is brilliant. Think of a child's
wind up music box. The kind of with a rotating
metal cylinder covered in little raised bumps
that pluck metal teeth to make a song. Right.
Everyone knows those. Now, scale that up and
power it with a steam engine concept. The brothers
used continuous water pressure to slowly rotate
a large cylinder covered in strategically placed
pins. As the cylinder turned, those pins pushed
against levers. The levers acted like human fingers,
dropping down to open and close the holes on
a flute, while steam or steady air pressure was
forced through the mouthpiece. and the most revolutionary
part. You could pull that pin cylinder out and
swap it for a different cylinder with a different
pattern of pins. And it would play a new song.
Exactly. The machine would play a completely
different song. That is physical coding. Yeah.
They separated the hardware, the air pressure,
and the levers from the software. The pin cylinder.
Yes. They essentially invented a programmable
machine, an early music sequencer, hundreds of
years before the Industrial Revolution. It really
is an early computer. Now you would assume that
inventing gas masks, measuring the globe, and
building the first programmable robots would
make the brothers universally beloved. You would
think so. But extreme brilliance combined with
limitless state funding often breeds extreme
arrogance. And they were incredibly arrogant.
As they accumulated wealth under successive caliphs,
they became deeply entrenched in court politics.
Very deeply. They were basically the real housewives
of 9th century Baghdad. They used their proximity
to power to ruthlessly crush anyone they viewed
as a rival. And the most glaring example of this
is their treatment of al -Kindi, who was himself
a legendary philosopher and mathematician. Yeah,
the brothers viewed him as a threat to their
monopoly on the caliph's favor. So they started
by academically bullying him. harshly mocking
his writings on the astrolabe. Just petty academic
stuff at first. Right. But academic debate wasn't
enough. They leveraged their political influence
to have al -Kindi physically beaten. Which is
just awful. They have banished from the court
and then they confiscated his entire personal
library. It's his workplace toxicity on a staggering
scale. But when your entire career depends on
the favor of an absolute monarch, playing political
games is an existential risk. If you make enemies,
you better not make any mistakes. Which brings
us to the Jafferet Canal disaster. Oh boy. The
Caliph al -Mutawakil decides to build a massive
new city, and he demands the Banu Musa oversee
the construction of a vital canal to supply it
with water. The brothers, perhaps feeling that
digging ditches was beneath their immense intellect,
delegate the actual engineering and surveying
work to a man named Al Fargani. And Al Fargani
makes a catastrophic error in fluid dynamics.
He digs the origin of the canal deeper than the
destination. Water does not flow uphill. No,
it does not. Once the canal is completed and
the water is let in, it isn't going to flow into
the new city. It is going to drain away completely
into the desert. Exactly. The ultimate masters
of fluid pressure somehow oversaw a project that
fundamentally failed at moving water. And the
caliph finds out. And the caliph's response is
swift and brutal. He decrees that on the day
the canal is opened, if the water fails to reach
the city. the Banu Musta brothers will be crucified
on crosses erected right beside the dry riverbed.
I just marvel at the absolute terror of that
four -month waiting period. Imagine standing
on a construction site, looking at a dry ditch,
knowing a mathematical error is going to end
with you nailed to a piece of wood. They needed
a miracle, or they needed someone willing to
risk their own life to cover for them. And the
person who steps in to save them is a consultant
engineer named Sanad Binah. But here is the massive
twist. Sanad Binah was close friends with Al
-Kindi. The same scholar the brothers had beaten
and robbed. The irony is thick. The brothers'
lives are entirely in the hands of a man whose
best friend they destroyed. It's like something
out of a movie. Right. Sanad Binah approaches
the terrified brothers and offers a deal. He
says, I will save your lives, but my condition
is that you immediately return Al -Kindi's library.
And they agree instantly. Oh, of course they
do. So Sanad goes to the Caliph. Now, Sanad knows
the canal is a total failure, but he also knows
a piece of court gossip. Ah, the astrologers.
Yes. The royal astrologers have recently predicted
that the Caliph only has a few months left to
live. He decides to gamble his own life on a
horoscope. He lies directly to the Caliph's face.
He proclaims that the canal is perfectly engineered.
buying the brothers time. Wow. For months, Sanad
and the brothers sweated out, waiting to see
if the water will drop before the caliph drops.
Talk about high stakes. Right. And incredibly,
the gamble pays off. Just months before the canal's
failure would become undeniable, the Caliph al
-Nutawakil is assassinated. This raises an important
question about the reality of state -sponsored
science in the ancient world. What do you mean?
Well, we love to romanticize the house of wisdom
and the endless flow of gold for translation
and research, but the sword cuts both ways. The
Banu Musa brothers had limitless funding, but
their genius, their research, and their literal
survival were entirely subject to the unpredictable
moods, the whims, and the lifespans of absolute
rulers. Yeah, it was a perilous way to innovate.
But innovate they did. They escaped execution,
the library was returned, and they went right
back to their work. The eldest, Muthamad, even
ended up negotiating military sieges later in
his life, just continuing this relentlessly chaotic
existence until his death in January 873. They
lived large. But when you strip away the political
madness, their legacy is undeniably monumental.
They took abstract Greek theory, forced it into
concrete numerical values, and used those numbers
to manipulate the physical world in ways no one
had ever seen. They are the vital bridge. They
pushed humanity past philosophical observation
and into the realm of automated control. So what
does this all mean? Why should you care about
three chaotic brothers from 9th century Baghdad?
Oh, right. Because the next time you set up a
smart home routine on your phone to turn on your
lights at sunset, or you watch an automated sprinkler
system adjust its own water pressure, or even
if you just drop a coin into a claw machine at
a local arcade to grab a stuffed animal, you
are experiencing the distant echoes of their
work. You really are. You are interacting with
the legacy of three orphan boys who use ropes
and pegs to measure the planet, and who forced
water to become the world's first computer. And
it leaves us with one final, profound thought
to consider. What's that? When we look back at
the book of ingenious devices, the vast majority
of those incredible mechanical leaps, the automated
valves, the mechanical delays, the feedback loops,
they weren't built for industry. Right, they
were for the parties. They were originally designed
simply to entertain party guests. They were frivolous
toys. It makes you wonder... What obscure video
game mechanics or seemingly pointless digital
toys being developed right now just for entertainment
are secretly laying the invisible functional
foundations for our most critical future technology.
From a magic trick at a party to the future of
engineering. Thanks for joining us on this deep
dive.