Ihtesham Ali

The US government spent decades building language courses to train its diplomats, and you can download them for free.

They come from the Foreign Service Institute, the school that trains American diplomats.

It's the same place behind that "world's hardest languages" chart going around this week.

By their numbers, Spanish or French takes about 24 to 30 weeks of full-time study. Japanese, Mandarin, Arabic and Korean take 88.

The old FSI courses were made by the government, so they're public domain.

Full textbooks plus the audio, for around 50 languages. Swahili, Hungarian, Korean, Yoruba, Tagalog, Turkish, Thai.

Diplomats learned from these before they were sent abroad. The same material costs you nothing.

Link in the comments.

Michel Siffre was 23 when he climbed 130 meters down into a cave under the Alps. He had no watch, no clock and no daylight.

He planned to stay two months, and there was one rule. Every time he woke up, ate or went to sleep, he phoned a team on the surface. They wrote it down. They never told him the time.

The cave sat at 98% humidity, so his feet were always wet. His body temperature dropped to 34°C. Some days he cried.

He ran one test on himself over and over. Count to 120, one number per second. That should take two minutes.

It took him five.

Five real minutes felt like two to him, and nothing about it seemed strange.

On September 14, the surface team called down and told him the experiment was over.

He didn't believe them. By his count it was August 20, and he thought he still had weeks to go.

He had been underground for 63 days. In his head he'd lived about 35. Almost a month of his life was gone, and he had no memory of losing it.

His body never lost track, though.

With no sun at all, his sleep and wake cycle settled at about 24 and a half hours. Something inside him kept time while his mind lost it completely.

That was the discovery. Siffre's cave helped build a new field of science, the study of the clock inside your body. NASA and the French military both studied his results, because they needed to know how people stay sane in space and in submarines, where there's no sunrise.

He kept going back down.

In 1972, at 33, he spent 205 days alone in a cave in Texas. His body slipped into a rhythm of 36 hours awake and 12 hours asleep. He came out $100,000 in debt.

He died in 2024 at 85.

Your sense of time is a guess your brain makes from sunlight. Take the sunlight away and the guess is off by a month.

How long do you think you'd last in that cave before you lost track of the days?

In 1904, 13 experts signed a report saying a horse in Berlin could do math.

They checked for tricks and found none.

The horse was called Hans. His owner, Wilhelm von Osten, was a math teacher who had trained him like a schoolboy.

Ask Hans what 3 plus 5 was and he tapped his hoof 8 times. Ask him "If the eighth day of the month falls on a Tuesday, what is the date of the following Friday?" and he tapped 11. He told the time. He kept track of the calendar. He spelled words. The New York Times wrote about him. Von Osten never charged a cent to watch.

Germany's board of education wanted an answer, so a commission of 13 was formed. A vet. A circus manager. A cavalry officer. Schoolteachers. The director of the Berlin zoo.

In September 1904 they announced their verdict: no tricks were involved.

Then the case was handed to a young assistant named Oskar Pfungst.

Pfungst didn't try to catch a cheat. He changed one thing at a time.

He let strangers ask the questions. Hans still got them right. So it wasn't von Osten.

He put blinders on the horse. The answers fell apart.

Then he ran the test that ended it. He had people ask questions they didn't know the answer to themselves.

When Hans could see someone who knew the answer, he got 89% right.
When he couldn't, he got 6%.

Hans couldn't count. He was reading faces.

As his hoof got close to the right number, the person asking tensed up without realizing it. On the final tap, they relaxed. A tiny lift of the head. Hans stopped right there, every time.

Von Osten wasn't a con man. He never accepted the result and kept showing Hans to cheering crowds until he died in 1909.

The strangest part came later. Pfungst learned the cues so well that he could perform the act himself, and he found he kept giving the cues even when he tried not to.

It's one reason experiments on people are run double-blind today.

And it never went away.

In 2011, researchers at UC Davis sent 18 certified drug and bomb dog teams through rooms with no drugs and no explosives in them at all. Handlers were told red paper marked where a scent was hidden.

The teams made 225 alerts. Most of them landed where the handlers believed the scent was.

The dogs smelled nothing. They read the person holding the leash.

Thirteen experts watched a horse for months and never once looked at the humans standing next to it.

What's something you were sure you understood, until you realized you were just reading the room?

A 17-year-old once stayed awake for 264 hours straight to prove that going without sleep doesn't hurt you.

On day 10, he beat a Stanford sleep scientist at pinball.

On day 11, he couldn't count backwards.

His name is Randy Gardner.

In late 1963, he and his friend Bruce McAllister needed a project for their high school science fair in San Diego. They decided to break the world record for staying awake. The record was 260 hours.

Back then, nobody really knew what that would do to a human brain. His parents were scared it might do real damage.

Then a young researcher named William Dement read about the attempt in a San Diego newspaper and showed up. Sleep science was a brand-new field. Dement later said he was probably the only person on the planet at the time who had actually done sleep research.

A doctor, Lt. Cmdr. John J. Ross, checked on Randy's health. Two classmates kept a log.

The pinball game became the famous part of the story. The kid who stayed awake for 11 days and was fine.

He wasn't fine.

Ross's notes describe mood swings, trouble concentrating, short-term memory problems, paranoia and hallucinations.

On day 11, they asked him to start at 100 and keep subtracting 7.

He stopped at 65.

When they asked why, he said he'd forgotten what he was doing.

On January 8, 1964, he passed the record: 264.4 hours, 11 days and 25 minutes. He held a press conference looking healthy. Then he slept for 14 hours and 46 minutes.

For years, his case was quoted as proof the body can take extreme sleep loss. Guinness later stopped accepting attempts at the record, because it was too dangerous to encourage.

Then, in 2017, Randy said something nobody expected.

Around 2007, more than 40 years after the experiment, he had started getting serious insomnia. He believed those 11 days were to blame.

He stayed awake to prove sleep didn't matter.

Decades later, sleep stopped coming.

How long is the longest you've ever stayed awake and why?

On the night of August 21, 1986, a lake in Cameroon killed 1,746 people in their sleep.

Nothing exploded over the villages. Nothing burned. No one came to attack them.

The lake breathed out.

Lake Nyos sits in the crater of an old volcano in the hills of northwest Cameroon. Blue, quiet and very deep. It looks like any other mountain lake.

But for a very long time, carbon dioxide from the magma below had been seeping into the bottom of it.

Cold, deep water under pressure can hold a huge amount of dissolved gas. Think of a bottle of soda that has never been opened. And this lake barely mixed. The heavy, gas-loaded water stayed at the bottom, getting closer and closer to its limit.

That night, something disturbed it. Scientists still don't agree on what. A landslide. A small eruption on the lake bed. Cold rain on one side. Some think nothing was needed at all.

Some of the deep water moved up. The pressure on it dropped. The gas came out as bubbles. The bubbles dragged more deep water up behind them, which released more gas, which dragged up more water.

The whole lake turned itself over.

A column of water and foam about 100 meters high burst out of the surface. A wave at least 25 meters tall hit one shore. Around 1.2 cubic kilometers of carbon dioxide poured into the air.

Carbon dioxide is heavier than air. So the cloud didn't drift away.

It rolled downhill.

A layer of gas about 50 meters thick flowed down the valleys at 20 to 50 kilometers an hour, into the villages of Nyos, Kam, Cha and Subum. It pushed the air out of every house. Up to 25 kilometers from the lake, people suffocated where they lay. About 3,500 animals died with them.

One survivor, Joseph Nkwain, woke up unable to speak. He heard his daughter breathing in a terrible, abnormal way, tried to get to her and collapsed. When he came round the next morning, she was dead. So were his neighbors. Riding his motorcycle through Nyos, he didn't see a single living thing.

When scientists reached the lake, the blue water had turned deep red. Iron-rich water from the bottom had come up and rusted in the air.

It's one of only two eruptions like this ever recorded. The other happened two years earlier at Lake Monoun, also in Cameroon, and killed 37 people.

The fix is the strangest part of the story.

In 2001, a French and Cameroonian team lowered a long pipe from a raft into the deepest water. They pumped a little water up to get it started. As the water rose, the gas came out, the bubbles pushed it up faster, and the pipe started pulling up deep water on its own.

A fountain of gas and water shooting out of the lake, with no motor.

It's the same chain reaction that killed 1,746 people. Just squeezed through a pipe, slowly, under control.

Two more pipes went in in 2011. By 2019, researchers said a single pipe could keep the lake safe indefinitely, with no outside power.

The only way to stop the lake from erupting was to make it erupt on purpose, a little at a time, forever.