Qvyre

Every equation has a picture. School skipped it.

[Qvyre @qvyrex]

Physicists spent over 300 years trying to fully explain what you're about to watch. 32 metronomes, all started at random. Watch what they do by the end

It began in 1665, when the man who invented the pendulum clock was stuck in bed, sick, staring at two of his clocks. Something was happening between them that he couldn't explain

No matter how he started them, within about half an hour they ended up swinging in perfect opposition. He called it "an odd kind of sympathy" and reported it to the Royal Society

He guessed the clocks were secretly talking through tiny movements in the wooden beam they hung from. He was right, but it took until 2002 for a team at Georgia Tech to rebuild his setup and prove it

That's what's happening here. Every metronome gives the board a tiny push, and the board passes it on to all the others. Watch the last rebels fall in line

The same thing happens with fireflies flashing together, crickets chirping in sync and the cells that keep your heart beating in time

Nobody tells them to agree. They just can't help it

[Qvyre @qvyrex]

Physicists spent over 300 years trying to fully explain what you're about to watch. 32 metronomes, all started at random. Watch what they do by the end

It began in 1665, when the man who invented the pendulum clock was stuck in bed, sick, staring at two of his clocks. Something was happening between them that he couldn't explain

No matter how he started them, within about half an hour they ended up swinging in perfect opposition. He called it "an odd kind of sympathy" and reported it to the Royal Society

He guessed the clocks were secretly talking through tiny movements in the wooden beam they hung from. He was right, but it took until 2002 for a team at Georgia Tech to rebuild his setup and prove it

That's what's happening here. Every metronome gives the board a tiny push, and the board passes it on to all the others. Watch the last rebels fall in line

The same thing happens with fireflies flashing together, crickets chirping in sync and the cells that keep your heart beating in time

Nobody tells them to agree. They just can't help it

[Qvyre @qvyrex]

@auteurtheory__ Those temps were the orbiter's heat tiles, the O-rings sat down in the boosters that only fly for about two minutes, and that morning was 36F, colder than any shuttle launch before it

[Qvyre @qvyrex]

In 1986 a Nobel physicist dropped a piece of rubber into his glass of ice water on live TV. It explained why seven astronauts died

Challenger broke apart 73 seconds after liftoff, on the coldest morning a shuttle had ever launched. The night before, the engineers who built its boosters warned the rubber seals could fail in the cold. NASA launched anyway

At the hearing Richard Feynman pulled a strip of that rubber out of a model, squeezed it in a small clamp and dropped it into his ice water. Watch his hands

He lets go and the rubber doesn't spring back. A seal that can't spring back can't seal. Turn the sound on

He didn't find it alone. General Donald Kutyna pointed him to the O-rings, and Kutyna got it from astronaut Sally Ride, who had quietly passed him NASA's own test data. He kept her name secret until she died in 2012

Feynman's final report ended with one line: nature cannot be fooled

[Qvyre @qvyrex]

@brian_t_muldoon NASS did launch outside what the seals were built for, no argument there. The satellite on board was TDRS-B though, a NASA communications relay, not a military one

[Qvyre @qvyrex]

In 1986 a Nobel physicist dropped a piece of rubber into his glass of ice water on live TV. It explained why seven astronauts died

Challenger broke apart 73 seconds after liftoff, on the coldest morning a shuttle had ever launched. The night before, the engineers who built its boosters warned the rubber seals could fail in the cold. NASA launched anyway

At the hearing Richard Feynman pulled a strip of that rubber out of a model, squeezed it in a small clamp and dropped it into his ice water. Watch his hands

He lets go and the rubber doesn't spring back. A seal that can't spring back can't seal. Turn the sound on

He didn't find it alone. General Donald Kutyna pointed him to the O-rings, and Kutyna got it from astronaut Sally Ride, who had quietly passed him NASA's own test data. He kept her name secret until she died in 2012

Feynman's final report ended with one line: nature cannot be fooled

[Qvyre @qvyrex]

Footage: the Rogers Commission hearing, February 11, 1986. Feynman tells the whole story in "What Do You Care What Other People Think?"

[Qvyre @qvyrex]

If you stood next to this tube, you'd see normal falling water. Only the camera sees it freeze in midair and crawl back up

The same trick of light can make a lathe spinning at full speed look completely still. Safety guides for factories warn about it

Nothing here is edited. The tube is attached to a speaker playing a low hum, 24 vibrations per second. The camera films at 24 frames per second

So every time the camera takes a picture, the water is at the exact same point of its wiggle. Frame after frame, it looks like it never moves

Make the sound a little lower and the water seems to flow backwards. A little higher and it creeps forward in slow motion

It's the same reason car wheels spin backwards in movies and helicopter blades look frozen on phone videos

Old fluorescent lights flicker with the power supply, and the same thing can happen to a spinning machine. That's why workshops used to hang an ordinary bulb over lathes

Your eyes see a shaking stream. The camera sees a frozen snake. So which one is lying to you

[Qvyre @qvyrex]

Video: brusspup, Amazing Water & Sound Experiment #2

Old record players used this trick on purpose. Dots on the edge of the platter look frozen under a flickering lamp only when the record spins at exactly the right speed

[Qvyre @qvyrex]

If you stood next to this tube, you'd see normal falling water. Only the camera sees it freeze in midair and crawl back up

The same trick of light can make a lathe spinning at full speed look completely still. Safety guides for factories warn about it

Nothing here is edited. The tube is attached to a speaker playing a low hum, 24 vibrations per second. The camera films at 24 frames per second

So every time the camera takes a picture, the water is at the exact same point of its wiggle. Frame after frame, it looks like it never moves

Make the sound a little lower and the water seems to flow backwards. A little higher and it creeps forward in slow motion

It's the same reason car wheels spin backwards in movies and helicopter blades look frozen on phone videos

Old fluorescent lights flicker with the power supply, and the same thing can happen to a spinning machine. That's why workshops used to hang an ordinary bulb over lathes

Your eyes see a shaking stream. The camera sees a frozen snake. So which one is lying to you

[Qvyre @qvyrex]

This cup is 1,600 years old. Shine a light into it and it turns from green to red. Scientists only figured out how in the 1990s

The Romans put gold and silver into the glass in pieces far too small to see. Watch the color change

It's the Lycurgus Cup, made in the 4th century and now in the British Museum. In reflected light it's an opaque jade green. When light passes through it, it glows ruby red

Under a microscope the glass is full of particles of silver and gold less than a thousandth the width of a grain of salt

Particles that small stop looking like metal. They bounce green light back at you and let red light through

The makers probably had no idea what they'd done. It may have started as accidental contamination with metal dust, and nobody managed to recreate it for centuries

Today labs copy the same trick to build sensors. The Romans did nanotechnology by accident

[Qvyre @qvyrex]

Video: John Lawrence, filmed at the British Museum.

[Qvyre @qvyrex]

This cup is 1,600 years old. Shine a light into it and it turns from green to red. Scientists only figured out how in the 1990s

The Romans put gold and silver into the glass in pieces far too small to see. Watch the color change

It's the Lycurgus Cup, made in the 4th century and now in the British Museum. In reflected light it's an opaque jade green. When light passes through it, it glows ruby red

Under a microscope the glass is full of particles of silver and gold less than a thousandth the width of a grain of salt

Particles that small stop looking like metal. They bounce green light back at you and let red light through

The makers probably had no idea what they'd done. It may have started as accidental contamination with metal dust, and nobody managed to recreate it for centuries

Today labs copy the same trick to build sensors. The Romans did nanotechnology by accident

[Qvyre @qvyrex]

For almost 100 years pilots reported red lights shooting up from storms toward space. Nobody believed them

Until one night in 1989, when a University of Minnesota team testing a camera for a rocket launch caught two frames of it by accident

These are red sprites. They flash about 50 miles up, high above the clouds, and they're gone in a few thousandths of a second. That's how they hid for a century

The second clip was filmed at 100,000 frames per second. Watch the dots falling from the top. Each one is a ball of glowing plasma dropping at up to a tenth of the speed of light, right before it bursts into a jellyfish. The bar in the corner is one kilometer

Some pilots never filed a report. Scientists, the Air Force and the airlines didn't believe in "upward lightning", and nobody wanted to sound crazy

They've been filmed thousands of times since. Nobody can yet say why some storms make them and most don't

[Qvyre @qvyrex]

Footage: Paul M Smith over Oklahoma, and Matthew McHarg, Jacob Harley, Thomas Ashcraft and Hans Nielsen at 100,000 fps via NASA's Astronomy Picture of the Day

[Qvyre @qvyrex]

For almost 100 years pilots reported red lights shooting up from storms toward space. Nobody believed them

Until one night in 1989, when a University of Minnesota team testing a camera for a rocket launch caught two frames of it by accident

These are red sprites. They flash about 50 miles up, high above the clouds, and they're gone in a few thousandths of a second. That's how they hid for a century

The second clip was filmed at 100,000 frames per second. Watch the dots falling from the top. Each one is a ball of glowing plasma dropping at up to a tenth of the speed of light, right before it bursts into a jellyfish. The bar in the corner is one kilometer

Some pilots never filed a report. Scientists, the Air Force and the airlines didn't believe in "upward lightning", and nobody wanted to sound crazy

They've been filmed thousands of times since. Nobody can yet say why some storms make them and most don't

[Qvyre @qvyrex]

Every textbook says Galileo dropped two balls from the Leaning Tower of Pisa. Most historians think he never did

Someone did it years earlier in a Dutch church. And the most famous drop happened in 1971, on the Moon

This is Apollo 15 commander David Scott with a hammer in one hand and a feather in the other. Watch them land

On Earth the air slows the feather down. On the Moon there's no air, so both fall at the same speed

The feather came from the Air Force Academy's falcon, because their lunar module was called Falcon

And Pisa? Galileo never wrote about it. The story comes from a biography his student wrote after Galileo died

The real drop was in 1586. Simon Stevin and Jan de Groot dropped two lead balls, one ten times heavier, from a church tower in Delft. They hit the ground at the same moment

Turn the sound on for Scott's last line. Mr. Galileo was correct. He just probably never climbed the tower

[Qvyre @qvyrex]

Footage: NASA, Apollo 15, August 2, 1971. Stevin wrote up the Delft drop in 1586 in "De Beghinselen der Weeghconst"

[Qvyre @qvyrex]

Every textbook says Galileo dropped two balls from the Leaning Tower of Pisa. Most historians think he never did

Someone did it years earlier in a Dutch church. And the most famous drop happened in 1971, on the Moon

This is Apollo 15 commander David Scott with a hammer in one hand and a feather in the other. Watch them land

On Earth the air slows the feather down. On the Moon there's no air, so both fall at the same speed

The feather came from the Air Force Academy's falcon, because their lunar module was called Falcon

And Pisa? Galileo never wrote about it. The story comes from a biography his student wrote after Galileo died

The real drop was in 1586. Simon Stevin and Jan de Groot dropped two lead balls, one ten times heavier, from a church tower in Delft. They hit the ground at the same moment

Turn the sound on for Scott's last line. Mr. Galileo was correct. He just probably never climbed the tower

[Qvyre @qvyrex]

@Shattubatu Aahahha that wow is a premium feature, full video only