00:017 billion people.
00:02Every single day.
00:03They all do the same thing everyone has done since the dawn of time.
00:06And you would think the planet would be buried under it all.
00:09But it's not.
00:10And the reason why.
00:11It depends entirely on where you were born.
00:13In ancient China, you couldn't drown in it, even if you wanted to.
00:16Because every bit of it was someone's treasure.
00:18Drop it in the soil, and your harvest could multiply a hundredfold.
00:22Meanwhile, in the same era, Europe could barely triple its crops.
00:25The Europeans didn't know how to use it.
00:27So they just opened their windows and threw it into the street.
00:29And in the end, whole cities were literally swallowed by plague.
00:32The perfume you wear today.
00:34The high heels on your feet.
00:35Both of them were invented because of this one thing.
00:38Here's the strange part.
00:39The same exact substance.
00:41In Europe, it turned entire cities into graveyards.
00:44In China, every family fought to get their hands on it.
00:47Why?
00:47The answer comes down to two words, fermentation.
00:50You might think, it's just waste.
00:52Bury it in the field and it becomes fertilizer.
00:55Wrong.
00:55Fresh waste, straight into the ground, doesn't feed the crops.
00:58It burns them alive.
01:00It has to be piled up first.
01:02Covered.
01:03Left to sit.
01:04Let the heat and the ammonia ferment away.
01:06Only then does it become fertilizer a plant can actually absorb.
01:09The Chinese figured this out 2300 years ago.
01:12During the warring states period, the philosopher Xuanzi wrote four characters that literally mean, more manure, richer soil.
01:17That's it.
01:18One sentence.
01:20And it took Europe over a thousand years to catch up.
01:22So how much difference does one pile of manure actually make?
01:25Let's break down the numbers.
01:27According to the records, in ancient China, one seed planted could bring back 200 grains.
01:31You took a handful of seeds out the door, and you could come home carrying two full baskets of food.
01:35In England at the same time, you planted one and got three back.
01:38That was considered excellent.
01:40Feel the gap.
01:41The exact same feel.
01:42In Europe, it barely kept one family from starving.
01:46In China, those extra crops could feed an entire village.
01:49Over there, people were killing each other over a mouthful of food.
01:52Over here, the granaries were overflowing.
01:54And the thing standing behind all of it.
01:56That same substance the Europeans held their noses at.
01:59In ancient China, it was never filth.
02:01It was currency.
02:02How valuable.
02:03In the Tang Dynasty capital of China, there was a man named Luo Hui.
02:07He made his fortune by walking the streets, collecting waste from the city's cesspits.
02:11He started with nothing.
02:12And he built himself into one of the wealthiest men in the city.
02:15Everyone else started from scratch.
02:17He started from a pile of dung.
02:18And he wasn't the only one.
02:20The history books record another man who collected all the city's unwanted refuse, scrap by scrap, until he had amassed
02:25a fortune.
02:26In those days, what sat in your latrine wasn't waste.
02:28It was a chicken that laid golden eggs.
02:30And it gets stranger.
02:32The Chinese didn't just use it for the fields.
02:34They fed it to pigs.
02:36Many ancient households built their latrine directly on top of the pig pen.
02:39You'd squat down to do your business, and below you, the pig would open its mouth and catch it.
02:43Your waste.
02:44Turned into the pig's dinner.
02:46The pig got fat.
02:47And then the pig went right back onto the family's dinner table.
02:50I'm not making this up.
02:52Archaeologists have dug up a complete set of Han Dynasty pottery models, showing the latrine perched directly above the pig
02:56pen, laid out for you one to one.
02:58Follow the loop.
02:59People eat grain.
03:00Grain needs manure.
03:02Manure comes from people.
03:03People eat pigs.
03:05Pigs eat manure.
03:06And the manure still comes from people.
03:08A lump of waste leaves your body.
03:10It circles through the fields, through the pig pen, and finally comes right back to your table as a feast.
03:14This whole system, today, has a fancy name.
03:17Circular economy.
03:18It's the kind of thing that gets exhibits in environmental museums, and they charge you for the ticket.
03:22But our ancestors, over a thousand years ago, just swatted down and did it for free.
03:27So back to the opening question.
03:28Seven billion people, doing it every day.
03:31Why hasn't the planet drowned?
03:32In ancient China, the answer was simple.
03:35It could never pile up.
03:36The moment it left your body, someone grabbed it for the fields.
03:39Or fed it to the pigs.
03:41Or traded it for money.
03:42And it all circled back into the rice on your plate.
03:44Clean.
03:45Not a drop wasted.
03:47But Europe.
03:48Europe never got the hang of it.
03:50And don't be too harsh on the Europeans.
03:52They weren't born dirty.
03:53Back in ancient Rome, they had perfectly respectable public toilets.
03:57A row of a dozen seats, side by side, with running water flowing underneath.
04:00For a Roman, using the toilet was a genuine social event.
04:03People sat in a row, doing their business and gossiping.
04:06Of course, dignity had its limits.
04:08There was no toilet paper back then.
04:10A whole row of men shared one stick, with a sea sponge tied to the end.
04:14You wiped, rinsed it in the water, and handed it to the person next to you.
04:17In other words, an entire room of people, passing around the same rag to wipe themselves.
04:21That level of hygiene would give a modern public health inspector a heart attack.
04:24But the real disaster came after Rome fell.
04:27The Middle Ages.
04:28European cities had no understanding of fermentation, and no sewers.
04:32The waste had no value, and nowhere to go.
04:34What was the easiest solution?
04:36Open the window.
04:37Throw it into the street.
04:39I am not exaggerating.
04:40In medieval Paris, London, and Edinburgh, dumping your waste bucket from a second floor window into the street was the
04:45daily ritual of every household.
04:46The polite ones would shout a warning first, to give the people below a chance to get out of the
04:50way.
04:50Over time, that warning became a city-wide custom.
04:53In Edinburgh, the most famous phrase was, mind your head.
04:56Mind your water.
04:57It sounded like rain.
04:59But what fell from the sky was not water.
05:01And so the entire city became one giant open-air cesspit.
05:04Below your feet, mud you couldn't walk through.
05:06Above your head, a rain you couldn't escape.
05:08The smell.
05:10Imagine it.
05:11Legend has it that a filmmaker, trying to recreate the authentic smell of a medieval European street for a movie,
05:15spread tons of rotten fish and animal carcasses across the set.
05:18That gives you some idea.
05:19And it was this stench, hanging over Europe for centuries, that forced the invention of two things you still use
05:23today.
05:24Number one, perfume.
05:26The nobles stank.
05:27The streets stank.
05:28Their clothes stank.
05:30And yet there was a popular belief back then, bathing brings disease.
05:33The less you washed, the better.
05:35So what could they do?
05:36They overpowered the smell with an even stronger perfume.
05:39There's a saying that French perfume conquered the world, thanks in no small part to a mountain of Parisian sewage.
05:44Number two, high heels.
05:46Streets full of filth and mud.
05:47One step, and your shoes were ruined, your dress dragged through it, and you were done for.
05:51So a widely circulated theory says the heel was raised a few centimeters, just to keep your feet a little
05:56farther from the muck below.
05:57Today, women walk red carpets in high heels, and underneath them is elegance.
06:01A thousand years ago, Europeans raised their heels to dodge the filth.
06:04But jokes aside, this filth always demanded its payment.
06:07A city soaking in sewage is a giant breeding ground for disease.
06:10Rats.
06:11Flies.
06:12Dirty water.
06:14All of it climbing over human beings.
06:16Beyond the black death, the most direct plague was cholera.
06:18Because cholera travels through the fecal oral route.
06:21You expelled your waste.
06:22It mixed into the water.
06:24And then you drank it right back.
06:26In 1831, cholera attacked London for the first time.
06:29Within a little over a year, more than 20,000 people in England died in this plague, inseparable from the
06:33dirty water.
06:3420,000 lives.
06:35That's what it took for Europe to finally learn a lesson it was centuries late for, this stuff really cannot
06:39be wasted like this.
06:40It wasn't until the flushing toilet and the sewer system were built that this centuries long siege of filth over
06:44Europe was finally lifted.
06:46So look back.
06:47This thing we're too disgusted to even mention.
06:49For thousands of years, it has been quietly rewriting history.
06:52It stacked one civilization's granaries to overflowing.
06:55It rotted another civilization's cities into plague.
06:58It forced the invention of perfume.
06:59It raised the heels of shoes.
07:01And finally, it forced all of humanity to invent the toilet and the sewer.
07:05In the end, a huge portion of human civilization is just the history of humanity wrestling with its own waste,
07:09over and over, until it finally made peace.
07:12And today, you sit on that toilet, and you press that flush button.
07:15One second.
07:16Done.
07:17Clean.
07:18You've probably never thought about it.
07:20But for that one second of convenience, behind you, over thousands of years, people fell into cesspits.
07:24People waded through streets of filth.
07:26People died in plagues.
07:28They traded centuries of filth and chaos, just to buy you this one easy flush.
07:32So next time you flush, maybe pause for half a second.
07:35Because what you're sending away is never just waste.
07:37It's thousands of years of history, bought for you, one life at a time, by the people who came before
07:41you.
