[Light Screen]
[The Five-Deck Tower Ship is what modern scholars refer to as the Sui Dynasty Five-Tooth Warship.
This absolute beast first hit the water during the Sui Dynasty, built under General Yang Su's supervision in Sichuan. It got its name from the five distinct decks stacked one on top of the other, and the numbers alone tell you just how insane this vessel was.
Fifty five meters long. Fifteen meters wide. Draft of 2.2 meters. From waterline to the top observation deck, it stood nearly thirty meters tall.
For perspective, that's about as high as a ten story building. Made entirely of wood. Floating around like it's no big deal.
If you ever need to show someone what an ancient Chinese floating fortress looked like, just point at this ship and say, "That. That right there."
The top deck was strictly for calling the shots and keeping an eye on things. The four levels below? Stuffed to the gills with soldiers and weapons. It could carry up to eight hundred troops, plus it had forty long oars and two stern sweeps to get it moving where you wanted it to go.
Basically a floating apartment building, except instead of neighbors complaining about loud music, you've got enemies complaining about getting shot full of arrows.
The ship also had some clever design tricks for staying steady. Builders installed transverse bulkheads with longitudinal beams on top, covered with planks. Underneath those planks, they packed earth and stone to keep the whole thing from tipping over when the waves got rough.
Ancient engineering at its absolute finest.
Back in the Sui Dynasty, there weren't many serious threats out at sea. Most enemies were tooling around in tiny boats that looked like they'd been cobbled together by kids playing with blocks. So the original weapons on the Five-Deck Tower Ship were built to deal with exactly that kind of target.
Light targets. Small boats. Easy pickings.
Every deck had defensive walls and firing holes, so rows of soldiers could hide behind cover and rain arrows down on anyone dumb enough to get close. But the real ship killer on this bad boy was the Striking Pole.
Here's how it worked: think of an oversized mast with a huge boulder strapped to the end. It was actually adapted from the simple well sweep you'd use to draw water from a well, just way more violent.
During close combat, the crew let go of the ropes. Gravity did the rest. The boulder came crashing down and turned whatever poor boat was underneath into matchsticks.
Simple. Brutal. And it got the job done.
Once the strike was over, soldiers on the main deck cranked heavy wooden winches to haul the whole thing back up. Then they aimed again and dropped it once more.
Repeat until there's nothing left floating.
Early models carried six of these poles, one at the front, one at the back, and two on each side. Each pole was about sixteen meters long. In a fight, the ship would just plow straight into the middle of the enemy fleet and let all six poles go to work in a never ending cycle of destruction.
Records from back then say nothing could stand up to its power.
If you saw it from a distance, it probably looked like some giant angry bug thrashing its legs around. A very, very lethal bug. The kind that haunts sailors' dreams for years.
The Tang Dynasty got hold of the blueprints and immediately saw ways to make it even better. Their military engineers looked at all that empty deck space and thought "What a waste!" so they started bolting on heavy winched crossbows and siege trebuchets.
With those upgrades, this thing finally went from "really angry floating fortress" to "proper battleship."
Archaeological records let us track how these weapons evolved over time. The earliest repeating crossbows showed up in the late Warring States period. They could fire multiple bolts, but they were clunky as hell. Took a whole team of guys cranking a winch just to pull the string back.
Not exactly what you'd call user friendly.
Then the Han Dynasty came along with the bed crossbow. No subtlety here. This weapon was all about using pure mechanical force to hurl heavy projectiles at crazy speeds. Basically the medieval version of a cannon.
Tang artisans took the best parts of both. They combined the multi shot feature of the repeating crossbow with the raw power of the bed crossbow. They swapped out the Han design's single bow arm and replaced it with a composite multi arm system.
The result was the Tang Winched Crossbow, also known as the Three Bow Bed Crossbow or the Eight Ox Crossbow. The name came from just how much strength you needed to pull it back.
This was a massive artillery piece mounted on a wheeled carriage. The crew used a heavy winch to draw the bowstring back. The firing track had one main slot and six smaller ones. A huge armor piercing spear went in the center, with slightly smaller heavy bolts on either side.
When you pulled the trigger, all seven projectiles flew out at once.
Effective range: seven hundred paces. Since one Tang pace is roughly one and a half meters, that's a maximum range of about one kilometer. To put that in perspective, it's like shooting an arrow from one end of a big shopping mall to the other.
Fun fact: the Mongols later used a similar weapon called the "ox bow" during their 1256 campaign against the Hashashin fortress of Maymun Diz. Historical records say they fired fire arrows that could burn enemies alive. Persian historians had never seen gunpowder before, so they described the arrowheads as carrying "poison."
Compared to all that mechanical complexity, the Tang naval trebuchet was almost simple. It ran on a basic traction system, basically a giant lever.
You put a heavy rock in a basket on one end of a beam. A team of soldiers grabbed ropes on the other end and pulled down as hard as they could.
Not exactly high tech efficiency. But boy, was it cheap. Ridiculously cheap to build, and easy to make in huge numbers.
Because quantity has a quality all its own.
So you take this massive warship. Add winched crossbows. Bolt on traction trebuchets. Load up incendiary arrows. Then sail it straight into battle against the Japanese fleet.
It wasn't a fight. It was a technological beatdown. The enemy never stood a chance. Total annihilation was the only possible end.
Now here's the part that actually hurts.
The Song Dynasty inherited all this incredible military tech from the Tang. And what did they do with it?
Tweaked it a little. Made some small, boring improvements. Never touched the fundamentals. It was like inheriting a Ferrari and only changing the paint color.
Take the Eight Ox Crossbow, just a Tang winched crossbow that was slightly bigger, with an extra five hundred meters of range. Same idea, just bigger numbers.
Same deal with the trebuchet. The Song just made the payload heavier. Their masterpiece was the Seven Whirlwind Trebuchet. This ridiculous machine needed over two hundred men pulling ropes in perfect sync just to hurl a sixty four kilogram rock about one hundred meters.
The energy conversion rate on that thing was so terrible it'd make a modern physics professor want to scream. And trying to drag this monster around a battlefield? Let's just say practicality wasn't exactly its strong suit.
That lack of innovation eventually came back to bite them hard. When the Mongols showed up, they brought in engineers from Western Asia who completely reworked the design. Specifically, in 1271, Kublai Khan sent envoys to his cousin Abaqa, the Ilkhan in Persia, asking for skilled siege engineers.
The Ilkhan sent two Iraqi experts named Ismail and Ala al Din, along with their families, to China.
These engineers built massive counterweight trebuchets for the Mongols. The Counterweight Trebuchet made its grand entrance during the 1273 siege of Xiangyang. According to records, the one Ismail built was set up at the city's southeast corner. When it fired, the noise was said to shake heaven and earth. It smashed everything in its path and drove projectiles seven feet into the ground.
The Southern Song commander Lü Wenhuan was so scared he surrendered on the spot.
Here's the kicker: the Mongols built about twenty of these counterweight trebuchets. They could launch projectiles weighing over three hundred kilograms to a range of about five hundred meters. The Chinese called them "Muslim trebuchets" because of where they came from.
The crazy thing is, counterweight trebuchets weren't even new in the West by then. Arab engineers had already perfected hybrid versions centuries earlier.
Not to mention, the Western world had been using classical torsion catapults since ancient times. The Roman onager, for example, was a torsion powered siege engine that could throw a forty five kilogram rock over three hundred meters. It first showed up around 353 AD and stayed in use until the 6th century. After that, torsion tech mostly disappeared from the West, replaced by the simpler traction trebuchet.
If you're looking for real, game changing military innovation in Chinese history, you've got to jump ahead to the Ming Dynasty. They threw out all the old throwing arms entirely and went all in on gunpowder and cannons.
Finally, someone decided to try something new.]
Inside the lush imperial garden of Bianliang, the air was thick with unspoken tension. Also, the sound of a grown emperor playing in the dirt with a fancy toy.
Zhao Kuangyin was huddled on the ground, his right hand clutching a tiny ceremonial jade axe. This thing was worth more than most people's entire villages, and he was using it like a stick to scratch a rough diagram of the Mongol counterweight trebuchet into the soil.
He stared at his masterpiece for a solid minute. The lines were wobbly. The proportions were way off. Honestly, it looked less like a deadly siege weapon and more like a kid's first attempt at drawing a giraffe that forgot how legs work.
Finally, he let out a soft sigh, stood up, and dragged his boot right over the whole thing. Poof. Lines gone. Along with any reminder of the weapon that would one day tear his dynasty to pieces.
Zhao Guangyi, standing a little ways off, saw the whole thing and quickly wiped that "what in the world are you doing, bro?" look off his face. He walked forward with an expression of pure, practiced sincerity, the kind you only master after years of being the emperor's little brother.
"Elder brother, let me take charge of the Directorate for Imperial Manufactories. I will manage the artisans personally and share your burdens!"
Zhao Kuangyin turned his head slowly. His eyes were as unreadable as a book written in a dead language. He paused for a moment, then reached out and placed his left hand firmly on his brother's shoulder.
"Your heart is in the right place, I know that," he said, his voice smooth as silk. "But all you saw was a quick little sketch on that screen. You do not know the first thing about digging foundations, cutting wood, or how any of this mechanical stuff actually works. What exactly would you even do there?"
Zhao Guangyi ducked his head. His eyes flicked down to the fancy jade axe still clutched in his brother's right hand. Yeah. Okay. Time to back off.
He nodded obediently and swallowed whatever else he was about to say. Smart man.
Returning to his stone seat, Zhao Kuangyin felt a new strategy crystallizing in his mind.
One piece of technology could make a nation rise. One piece of technology could turn a capital into rubble. Maybe it was time to crack down hard on the merchant class. Any trader caught smuggling blueprints or engineering tools to the northern tribes? Straight to the executioner. No second chances. No "oops, my bad" allowed.
He also needed to pay way more attention to those future broadcasts. He quietly mumbled that strange name under his breath. Torsion catapult. He needed to lock every single detail about that thing in his brain.
Mental note to himself: find some palace eunuchs who were actually good at drawing. Station them nearby during the next broadcast with brushes and paper ready to go. Trying to reverse-engineer future weapons just by memory was like trying to bake a cake after only seeing a picture once. Way too risky.
He was an emperor, after all. Not a guy who built things for a living.
And as for letting his little brother run an engineering bureau… Zhao Kuangyin almost burst out laughing.
He knew exactly what kind of person Guangyi was. No illusions there at all. His brother's brain was full of schemes and plots, not gears and blueprints. What good would a schemer do in a workshop full of artisans? The man would probably try to backstab the sawmill into submission.
---
Meanwhile, in Chengdu's government office, Zhuge Liang was practically buzzing with excitement.
He was putting on a masterclass of skill right now. With nothing more than a stick of charcoal, he was sketching the mechanical diagrams from the magical screen with near photographic accuracy. Across the table, Pang Tong watched and felt a deep, gut wrenching wave of pure jealousy wash over him.
Pang Tong had always known Zhuge Liang was an insufferable polymath.
Back when they both lived in Nanyang, he'd seen it firsthand. Zhuge Liang casually mastering complex calligraphy styles like it was nothing. Playing the zither with the skill of a professional musician. Painting landscapes that belonged in the finest galleries. On brutally hot summer days, he'd swim laps across the local river without even breaking a sweat.
Even back then, Pang Tong had wondered where the man got his endless energy and focus. Was he even human? Or just really good at pretending he wasn't some kind of machine?
And now he had to watch as Zhuge Liang pulled out a carefully trimmed slate ruler. With a few swift, impossibly precise strokes, he drafted a flawless, perfectly scaled blueprint of the torsion catapult onto parchment.
As if that wasn't enough to make Pang Tong's teeth grind, Zhuge Liang calmly swapped his charcoal for a fine calligraphy brush, dipped it in ink, and wrote the characters for "Torsion Catapult" next to the diagram in elegant, flowing script.
Pang Tong felt a sharp, almost physical pang in his chest.
The man was definitely showing off. There was no other explanation. Who just casually draws perfect blueprints and then adds fancy handwriting for fun?
"What are your thoughts on this device, Shiyuan?" Zhuge Liang asked, his eyes gleaming with genuine curiosity.
The question jolted Pang Tong out of his envy fueled spiral. He took a deep breath, forced his mind back on track, and leaned closer to the table. His sharp eyes zeroed in on the core mechanical challenge instantly.
"The destructive power depends entirely on the material quality of this central twisting bundle," he said, tapping the drawing firmly.
He stroked his chin, running calculations through his head. "Even if we replace it with heavily braided hemp rope, I doubt it'll hold up under the tension we'd need."
He tapped the parchment again, mentally comparing it to older designs they'd worked on. "And when you stack this up against the traction trebuchet… each has clear strengths and weaknesses."
He found his groove, slipping into the familiar rhythm of explaining his ideas. "The traction model runs on raw manpower. Building it is dead simple, anyone can learn to operate one in minutes. You only need a few custom iron parts. A small team of three to five soldiers can put the whole frame together in about fifteen minutes."
"This Western design needs precision work," he continued, pointing at the complex gear mechanisms in the sketch. "Hauling it across mountains would be a nightmare. And that torsion bundle… if you want it to store enough energy to actually do damage, you'll need huge amounts of treated cow sinew or high grade animal glue ropes."
Ever since Gongan City established its dedicated engineering academy, local artisans had faced the same recurring problem. Every time they tried to build large scale heavy machinery, they hit a wall when it came to materials. They kept needing components that were both flexible and strong enough to handle extreme tension.
In short, they needed industrial quantities of cow sinew.
Zhuge Liang and his wife Huang Yueying had spent months researching alternatives. Their best solution so far was heavily processed peach tree resin. It worked, sure, but peach resin was rare, and harvesting it in bulk was painfully expensive.
Hearing Pang Tong's analysis, Zhuge Liang sighed and offered a wry smile.
"I honestly wonder how the ancient Westerners solved this particular material problem."
As for the naval Striking Pole they'd seen earlier, the sharp minds in Chengdu had grasped how it worked right away.
Anyone traveling through their territory would spot similar pulley systems all over the place. The water powered mills along the rivers used them nonstop. Complex wooden gear systems were already in heavy use across the region.
Gongan City had even set up a dedicated gear workshop years ago, mass producing specialized bronze gears and iron cogs for advanced engineering projects.
With that industrial foundation already in place, Zhuge Liang had already mentally designed several major upgrades to the Sui Dynasty Striking Pole. He planned to draw up the full blueprints tonight and send them straight to the naval yards in Jingzhou.
The Striking Pole had its limits, no question. But like the traction trebuchet, its greatest strength was its rugged simplicity. Cheap to build. Built to last. Almost impossible to break when you're out in the field.
Those massive winched crossbows on the Tang warships had the same flaw as the torsion catapult. Devastating when they hit their mark. Brilliantly designed when everything worked as planned. But they needed constant, almost obsessive maintenance. Replacing snapped bowstrings and broken firing tracks would drain a logistics budget faster than water through a sieve.
A phrase from earlier broadcasts echoed in Zhuge Liang's mind: Industrial Productivity.
The real value of a military invention had nothing to do with how clever it looked on paper. It all came down to one question: can your society actually afford to build it, and keep using it?
The same problem held back their heavy cavalry plans. A fully armored knight was nearly unbeatable on the battlefield. But their current agricultural output just couldn't support equipping and feeding an entire army of them.
This torsion catapult was stuck in exactly the same paradox. Progress held up by nothing more complicated than a bundle of twisted rope.
The path of scientific material research stretched out ahead of them, long and daunting. They'd barely taken the first step. How many years would it take to find a cheap, easy to make substitute for cow sinew and peach resin?
Zhuge Liang rubbed his temples. He'd just picked up a brand new headache to add to his collection.
And somewhere across the table, Pang Tong was still silently fuming about the calligraphy.
---
Inside the Ganlu Pavilion, the brothers Yan Lide and Yan Liben looked like kids on Christmas morning.
This mechanical knowledge was basically a cheat code for the Tang Dynasty, and Yan Lide happened to be the empire's top engineering nerd.
He had served in the Directorate of Construction for years, but he had never felt this excited. It was like being a starving man locked inside a buffet.
Over the past two years, the magical screen had been dumping miracles on them like confetti. Better steel armor. Revolutionary saddles. Fancy warship designs. Agricultural tools that actually worked. Modern drafting methods. Structural formulas that made his brain tingle.
For a master architect like Yan Lide, it felt like the universe had finally decided to hand him the answer key to everything.
More importantly, he recognized his unique political position. The imperial court was a battlefield. Military generals fought endlessly for glory on the borders. Civilian ministers schemed against each other for administrative power. Everyone was stabbing someone in the back.
But in the realm of industrial engineering and architecture? The Yan brothers stood alone at the peak. No competition. Total monopoly.
Before the screen appeared, both Yan Lide and Yan Liben had planned to use their political connections to land their sons comfortable bureaucratic positions. You know, the usual route. Memorize some poems, pass the exams, become a mid-level paper pusher who complains about his boss.
But after seeing where the future was heading, the two brothers had a serious talk behind closed doors.
Why force their kids to memorize dusty old poems when they could be learning drafting? Geometry? Mechanics?
In this new, technologically awakened Tang Dynasty, becoming a grand master engineer was the real path to wealth and power. Forget the civil service exams, the future belonged to people who could build things.
The Yan brothers had basically become ancient tech bros overnight.
While his ministers plotted their family legacies, Emperor Li Shimin took a deep breath. He stood before his massive map table, scanning the topography of Liaodong and the Korean Peninsula.
As one of the finest military commanders in human history, Li Shimin understood the tactical reality immediately. Now that he possessed the blueprints for the counterweight trebuchet, those fortified mountain castles of Liaodong were basically obsolete. They could no longer stall the Tang army's advance. He could shatter Goguryeo whenever he wanted. He could march his legions down the peninsula tomorrow if he felt like it.
But the real nightmare came after the conquest. How do you govern a foreign people?
How do you make sure that territory stays a loyal Tang province for all eternity? That was the real puzzle.
Now that he had the luxury of foresight, Li Shimin wanted to solve this permanently. He wanted to rip out any possibility of future rebellion by the roots.
The screen had already taught him a bitter lesson. He had watched future Tang generals let their troops run wild, looting and pillaging. That total lack of discipline turned the local population of Baekje into permanent enemies. Liu Rengui eventually showed up and crushed the insurgency with extreme violence, but Li Shimin knew violence was a temporary fix. He saw no evidence that the underlying hatred had ever been resolved.
Suppressed anger always explodes eventually. Li Shimin knew this from painful personal experience. He still remembered his own disastrous attempts to manage the Eastern Turkic Khaganate after conquering them. That had been a mess.
And the bad blood between the Central Plains and Goguryeo ran deep. It stretched from the era of Sui Emperor Yang all the way to the future reign of his own son, when Li Shiji finally wiped them out. Decades of relentless war. Hundreds of bloody battles. Mountains of corpses and oceans of hatred between the two cultures.
How do you pacify that level of generational trauma? You don't. Not easily.
Li Shimin's assessment of long-term administration in Liaodong grew increasingly pessimistic.
Then there was Silla. By smashing their enemies, the Tang Dynasty had accidentally cleared the path for Silla to unify the peninsula and grow into a potential threat. Classic case of unintended consequences.
His mind raced through countless strategic permutations. The Liaodong region was neither as wealthy nor as militarily terrifying as the nomadic tribes of the northern steppes. But the sheer complexity of the political and cultural dynamics there made the steppe nomads look simple by comparison. At least with nomads, you just had to worry about horses and arrows. Here, you had to worry about centuries of grudges, cultural differences, and geopolitical chess.
Expanding an empire's borders was a matter of logistics and violence. Establishing a cultural hegemony that lasted ten thousand generations was an entirely different beast.
[Lightscreen]
[During the Battle of Baekgang, Liu Rengui crushed the Japanese army with almost casual ease. The massive gap in military hardware played a huge role, but the disparity in scientific knowledge was just as decisive.
Japan's own historical records reveal that before the battle, their commanders studied the weather conditions. They genuinely believed the wind gave them a decisive tactical advantage.
Their reasoning was straightforward. The Japanese ships have the wind at their backs. The Tang fleet is facing a harsh headwind. The Tang ships might be huge, but they cannot possibly move against the wind. What is there to worry about?
When the battle actually started, the Japanese commanders suffered a complete psychological collapse. They could not understand what they were seeing. Tang ships, facing a direct headwind, were actively sailing forward. Maneuvering aggressively. Surrounding their entire fleet.
The Japanese were basically watching ships defy physics.
The physics are actually quite simple. When a ship faces a headwind, the crew adjusts the angle of the hull and sails. By maintaining roughly thirty-five to forty-five degrees relative to the wind, the ship can sail forward in a zigzag pattern.
When wind hits a curved sail, it follows the rules of fluid dynamics. In a steady flow, increased airspeed means decreased pressure. The sail breaks down the wind's force and generates a forward thrust vector.
This is Bernoulli's Principle. Modern high school physics textbooks explain it clearly. It is a common phenomenon in daily life. You can see it when a curved airplane wing generates lift.
Now, our ancient ancestors obviously did not know the mathematical equations behind Bernoulli's Principle. But generations of practical maritime experience had taught them the technique completely. Sailors call it tacking.
The Japanese commanders knew neither the science nor the technique. They got thoroughly outmaneuvered, trapped upwind, and incinerated by Tang fire arrows.
It was a masterclass in applied physics. The Japanese brought wind. The Tang brought fluid dynamics. Wind lost.
Strip away the martial romance of the Battle of Baekgang and the cold truth emerges. Between the Tang Dynasty and the Japanese nation lay an astronomical gap in social organization, troop discipline, industrial engineering, and fundamental scientific knowledge.
The Battle of Baekgang was a victory of civilization itself.
But discussing the Tang Dynasty's glorious naval history inevitably leads to a painful subject. It forces us to look at the Age of Discovery and feel a deep, frustrated sigh over China's absence from the global maritime stage.
A popular saying floats around: China invented the compass, but the compass only guided foreign robbers to our shores. There is a bitter nugget of truth in that statement.
The reality of how human civilization and modern science evolved is messy. It is the result of countless, highly improbable random events stacking together to create our current world. History is not a straight line. It is a tangled mess of accidents and coincidences.
Look at the Western world. Around three hundred years before the common era, a Greek mathematician named Euclid wrote a book called Elements in Alexandria. It is a collection of thirteen books covering geometry, number theory, and proportions.
This mathematical masterpiece introduced something revolutionary: the axiomatic method. Starting from basic definitions, postulates, and axioms, it used strict logical rules to build a rigorous deductive system. It took chaotic math and geometry and organized everything into a perfectly structured scientific framework.
It was like inventing the scientific method before anyone knew what science was.
So with this incredibly advanced theoretical foundation, did Western mathematics immediately explode into a golden age?
Not even close.
Despite having this futuristic textbook, mathematical and scientific progress in the West crawled along for centuries. It was like having a Ferrari but only knowing how to ride a bicycle.
The civilization that actually pushed modern science forward was the Islamic Golden Age under the Abbasid Caliphate.
After the Sassanid Persian Empire collapsed, Islamic influence expanded into Central Asia. This specific geographic region became a cultural sponge, absorbing the intellectual achievements of both East and West. During several centuries of relative stability, Islamic mathematics shot upward.
They took papermaking from the East to record their work. They used the rigorous logic of the Greek Elements as their guiding theory. They imported advanced astronomical data from India. This perfect storm of global knowledge produced brilliant Islamic mathematical breakthroughs, which eventually flowed back to the West as the Islamic world declined.
That imported knowledge collided with the development of eyeglasses in late thirteenth-century Italy, sparking the foundations of advanced geometry and optical physics. All these random historical threads finally ignited the Western Renaissance.
Even at that point, you could argue the East and West were simply progressing on different, parallel tracks. The exact moment the West pulled ahead permanently and created an unbridgeable technological gap was when they produced a scientific figure of almost mythical proportions. Someone comparable to Confucius, but for physics.
I am talking about Sir Isaac Newton. The Apple Celestial Venerable himself.
Set aside his endless list of world-changing discoveries for a moment. Focus strictly on navigation. His most crucial contribution to the maritime world was proposing the mathematical model for the reflecting quadrant. In 1699, Newton presented his design to the Royal Society. Based entirely on Newton's theoretical framework, the British Royal Navy successfully engineered the octant in the 1730s, thanks to the work of John Hadley and Thomas Godfrey.
With this device, humanity finally broke its ancient chains. Sailors no longer had to rely on vague astrology or hug dangerous coastlines to know where they were. They could calculate their exact latitude in the middle of an empty ocean. They could safely execute deep water, transoceanic voyages.
That was the moment global naval hegemony truly began. That was the moment the East genuinely fell behind.
In the full picture of the Age of Discovery, the magnetic compass was just one tiny piece of a massive, sprawling puzzle. China had the compass. But the West had Newton. And Newton had calculus.
It was not a fair fight.]