Paxmlian

Science is more interesting when you see it for yourself.

[Paxmlian @paxmlian]

THIS PLANT PLAYS DEAD WHEN YOU TOUCH IT! PLANTS AREN'T SUPPOSED TO DO THIS!

Brush your finger across these leaves. They instantly fold inward. The entire branch droops down like it just died.

But give it a few minutes and it opens back up like nothing happened.

This is Mimosa pudica... the sensitive plant.

It has no brain. No nerves. No muscles.

Yet it reacts to touch in milliseconds.

When you touch a leaf, an electrical signal races through the plant. Special cells at the base of each leaf rapidly lose water pressure and collapse.

It's a defense mechanism. Herbivores see folded leaves as less appetizing and harder to eat.

[Paxmlian @paxmlian]

Gravity pulls everything down. But drop this metal chain from a jar, and it leaps up into the air before falling.

This is the Mould effect, or the chain fountain.

Instead of just sliding over the rim, the chain forms a tall arc, hovering above the glass as it empties.

Why does it jump? It’s not just momentum. It’s leverage.

As a rigid link of the chain is pulled upward, it pivots. The other end of that metal link smacks down into the pile of chain resting at the bottom.

The pile pushes back. That upward kick from the jar is what actually launches the chain into the air.

It isn't just falling. The pile is kicking it out.

[Paxmlian @paxmlian]

Ever wanted to see a sound wave? Watch what happens when music meets fire.

This is a Rubens' tube.

A long metal pipe with dozens of small holes is filled with flammable gas. Light them, and you get a perfectly flat row of flames.

Now turn on a speaker at one end.

Instantly, the flames rise and fall into a perfect standing wave pattern.

The sound wave creates zones of high and low pressure inside the tube. Where pressure is high, more gas pushes out and the flames burn taller. Where pressure is low, the flames shrink.

You are literally watching sound.

[Paxmlian @paxmlian]

HOW DOES A TINY PILL BIRTH A GIANT SNAKE?! This isn't CGI!

Light a small white pellet on fire. Instead of burning down, it births a giant, writhing black serpent.

This is the Pharaoh's serpent.

The pellet is mercury thiocyanate. When ignited, it decomposes in a self-sustaining exothermic reaction.

The solid products mainly mercury sulfide form a dark, expanding mass. Meanwhile, gases released by the reaction puff the material up, stretching it into a long, twisting snake that can grow meters in length.

[Paxmlian @paxmlian]

You cannot un-stir your coffee. Entropy forbids it.

But watch this dye un-mix itself.

This is a Taylor-Couette flow cell. Thick corn syrup is trapped between two cylinders with drops of dye inside.

Turn the handle, and the colors smear into a messy blur. Turn it backward the exact same amount, and the drops perfectly reform.

It looks like time running backward, but it’s just laminar flow.

The syrup is so viscous that the fluid layers never actually mix. They just slide past each other like a deck of cards.

There is zero turbulence. Reversing the cylinder simply slides every molecule exactly back to where it started.

[Paxmlian @paxmlian]

Your breakfast cereal isn't magnetic. Nothing is pulling the flakes together.

Yet they always drift across the milk, lock together, and stick to the edge of the bowl.

This is the Cheerios effect, and it's pure fluid dynamics.

Milk sticks to the flakes and creeps up around their edges, forming tiny raised collars around each piece.

When two flakes drift close, their collars merge.

The flakes move together because it reduces the total surface area of the milk it's energetically favorable.

At the bowl's edge, milk also creeps up the ceramic wall. The flakes drift there because they're floating toward that same raised surface.

[Paxmlian @paxmlian]

@devb332 Nature's undercover agent ;)

[Paxmlian @paxmlian]

Two-thirds of an octopus's neurons aren't in its brain. They're distributed throughout its arms and skin.

Watch it vanish in 0.3 seconds.

The octopus changes color, texture, and even shape to perfectly match a rock or coral.

But the decision doesn't come from the central brain.

Its skin contains light-sensitive proteins and millions of pigment cells called chromatophores, each controlled by tiny muscles.

The skin literally "sees" the environment and reacts independently, processing information without waiting for commands from the brain.

[Paxmlian @paxmlian]

Drop a basketball off a huge dam, and it falls straight down. Drop it again with a little backspin, and it flies far away from the wall.

This is the Magnus effect.

The early part of the fall looks completely normal. But as the ball speeds up, it curves sharply forward like a glider.

A spinning ball drags air around with it. This bends the airflow behind the ball and physically pushes it in the opposite direction.

The force grows with speed. A tall drop gives the ball enough time for this aerodynamic push to build up and take over.

Watch the video.

[Paxmlian @paxmlian]

A person lies down on a bed of sharp nails.

Hundreds of metal points press directly against their bare skin. Not a single one pierces it.

It all comes down to how pressure works.

If you lay on one single nail, your entire body weight is focused on that tiny point. That is enough pressure to easily break the skin.

A bed of nails has hundreds of points sharing the exact same weight. Each individual nail only carries a very small fraction of the total load.

The force pressing down on any single point drops way below what it takes to puncture human skin.

The person is completely safe simply because their weight is spread out.

Watch the video.

[Paxmlian @paxmlian]

@devb332 your brain really falls for it

[Paxmlian @paxmlian]

A man and a small child stand in the same room.

They look about the same height.

Then they switch places.

The sizes flip.

This is an Ames room.

From one viewpoint the walls and floor look normal. In reality the room is distorted. One corner is closer and lower. The other is farther and higher.

The brain expects a regular rectangular room. It treats the distances as equal and changes how big the people look instead.

When they switch corners, their apparent sizes change.

Move your head and the illusion weakens. The room was never rectangular.

[Paxmlian @paxmlian]

@gosh_sol_eth that is a great way to explain it

[Paxmlian @paxmlian]

Drop a stretched Slinky. The bottom hovers completely motionless in mid-air.

The top falls, but the bottom just waits there until the top crashes into it.

When you hold it stretched, two forces act on the bottom ring. Gravity pulls it down. The tension of the coil pulls it up. They cancel perfectly.

When you let go, the bottom doesn’t instantly know it has been dropped.

Physical information does not travel instantly. It moves as a mechanical wave through the metal.

Until that collapsing wave reaches the bottom, the tension keeps pulling upward exactly as hard as gravity pulls downward.

[Paxmlian @paxmlian]

This is an ant mill, also called a death spiral.

Army ants are blind. They navigate by following pheromone trails left by the ant ahead.

When a group gets separated from the main colony, they can accidentally form a closed loop. Each ant follows the one in front, which follows the next, creating an endless cycle.

The system that makes them perfect cooperative hunters becomes a deadly trap. They will keep marching until they collapse from dehydration or exhaustion.

It's an evolutionary glitch, a behavior that works flawlessly until it kills them.

[Paxmlian @paxmlian]

Thousands of ants march in a perfect circle.

They walk for hours, sometimes days, until they drop dead from exhaustion.

Nobody is in charge. They are just marching to nowhere.

Every ant is just following the one in front of it. So why can't they break the circle?

[Paxmlian @paxmlian]

This is the famous Apollo 15 experiment from 1971.

The hammer and the feather hit the lunar surface at the exact same time.

The Moon has almost no atmosphere. There is zero air resistance to slow the feather down.

Gravity does pull the heavy hammer with more force. But a heavy object is also much harder to speed up.

Those two physical effects perfectly cancel each other out.

Take the air away, and gravity forces everything to fall perfectly together.

[Paxmlian @paxmlian]

An astronaut stands on the Moon. He holds a heavy metal hammer in one hand and a light falcon feather in the other.

He drops them from the same height at the exact same moment.

Which one hits the dust first?

Watch the video to find out. The explanation is in the comments.

[Paxmlian @paxmlian]

Mix two clear liquids. Swirl them together. For a few seconds, nothing happens.

Then, in a fraction of a second, the entire glass turns pitch black.

This is the iodine clock reaction.

Inside the glass, two invisible chemical reactions are racing. Reaction A is constantly creating iodine. Reaction B is instantly consuming it.

As long as Reaction B has its chemical fuel, the liquid stays completely clear. But the exact moment it runs out, the leftover iodine has nowhere to go. It immediately binds with starch in the water, turning the mixture dark blue or black.

The color change doesn't happen gradually. It waits in the background, and triggers the millisecond the first reaction wins the race.

By changing the amount of chemicals, chemists can set the "timer" to trigger exactly when they want.

[Paxmlian @paxmlian]

A wing nut floats and spins in zero gravity. Suddenly, without anything touching it, it flips completely upside down.

This is the Dzhanibekov effect.

It holds the new position for a few seconds, still spinning at the exact same speed. Then it violently tumbles back to where it started.

Every rigid body has three axes it can spin around. Rotating on the heaviest or lightest axis is perfectly stable.

Rotating on the middle axis is mathematically unstable. The tiniest disturbance instantly magnifies, forcing the entire object to turn over to conserve momentum.