402 facts
Early chocolate makers mixed cocoa powder and sugar into a rough paste. In 1879, Rodolphe Lindt invented a machine that stirred and ground chocolate for several days to make it cre...
This protein is called keratin. It is a strong material that protects your body from the outside world. It is also found in animal claws, hooves, and beaks.
British pilots John Alcock and Arthur Brown flew a modified bomber plane from Canada to Ireland. They completed the journey in less than 16 hours despite freezing weather and equip...
These large groups are called harems. The male seal stays on the beach for months to protect his group from other males. This behavior happens in crowded breeding areas called rook...
The city has a very small population and strict rules about how buildings must look. Residents prefer to support local businesses instead of large national chains.
Workers during the Ming Dynasty mixed sticky rice soup with lime to make a powerful glue. This mixture is stronger and more waterproof than regular cement. It has helped the wall s...
Motorola engineer Martin Cooper made the call while walking on a sidewalk in New York City. He used a prototype phone to call a rival scientist at another company. This proved that...
These tunnels can go 10 feet deep and have many exits for quick escapes. Rabbits use these shared homes to stay safe from predators and keep a steady temperature year-round.
Earlier televisions used spinning mechanical discs to create images. Farnsworth used a beam of electrons to capture and show pictures instead. This system allowed for much clearer...
This uneven placement creates a tiny delay in when sound reaches each ear. Your brain uses this time difference to figure out if a noise is above, below, or beside you.
French inventor Louis Le Prince filmed this scene in 1888 in Leeds, England. It shows four people walking in a garden seven years before the first famous public cinema shows began.
At 828 meters tall, wind is the biggest threat to the building's stability. The three wings support each other around a center point to prevent the tower from twisting or leaning....
Each eye sees a slightly different image because they are about 6.3 centimeters apart. The brain combines these two flat pictures into one 3D image. This process lets you know exac...
This behavior is called allelomimetic behavior. If one sheep moves or jumps, the rest of the flock follows immediately to stay safe. This keeps the group together so predators cann...
This organ detects tiny pressure changes and vibrations in the water. Fish feel the movement of their neighbors and adjust their own speed and direction instantly.
A scout bee moves her body in a specific pattern called a waggle dance. The angle of her body shows the direction of the sun, and the length of the dance shows the distance to the...
Each bird only watches its seven closest neighbors to decide where to move. When one bird turns, the others nearby follow instantly. This creates a ripple effect that moves through...
Chef Raffaele Esposito used red tomatoes, white mozzarella cheese, and green basil to match the colors of Italy. He created this specific combination to honor Queen Margherita duri...
Electricity flows through silver more easily than through copper or gold. It has a specific atomic structure that allows electrons to move with very little resistance.
Plasma makes up 55% of your blood volume. It carries nutrients, hormones, and proteins to every part of your body while removing waste.
The device turned his voice into electricity that traveled through a wire. His assistant, Thomas Watson, heard the message clearly in a different room.
When these plants grow next to strangers, they grow extra roots to grab as much water and nutrients as possible. If they grow next to a plant from the same mother, they limit their...
Sound moves by making tiny particles like atoms vibrate and bump into each other. Space is a vacuum with almost no particles, so vibrations have nothing to move through.
Two large eyes on the sides of their head detect movement and shapes. Three smaller eyes on top of their head help the bee find the sun and stay balanced while flying.
Most packs do not have a boss who fought to the top. The leaders are simply the mother and father wolves. The older siblings help the parents raise the younger pups and hunt for fo...
She wrote a set of instructions for a giant mechanical calculator called the Analytical Engine. She realized that machines could do more than just math and could eventually create...
Steam engines pulled wooden cars through tunnels built right under the city streets. This new system helped clear up traffic jams caused by thousands of horse-drawn carriages.
Fungi and animals share a common ancestor that lived about 1.5 billion years ago. Unlike plants, fungi cannot make their own food from sunlight. They must eat other organic matter...
Before this stamp, the person receiving a letter had to pay for the delivery. The Penny Black let the sender pay a flat rate of one penny to send mail anywhere in the country.
Nitrogen is a stable gas that does not react easily with other chemicals. It thins out the oxygen in the air so things do not catch fire too easily. This balance allows plants and...
Your brain never stops working even when you are asleep. It needs a constant supply of fuel to keep billions of nerve cells sending electrical signals throughout your body.
There are about 25 million sheep and only 5.2 million people living in the country. New Zealand has many grassy fields and a mild climate that makes it perfect for raising large fl...
It started in 1472 in Siena, Italy. The bank was first created to give cheap loans to people in need so they could avoid high-interest debt.
Rats are social animals that live and work together in large families. They use their intelligence to solve problems and help other members of their group.
These rocks, called the Acasta Gneiss, are located in Canada. Scientists found them by measuring tiny crystals trapped inside the stone that act like ancient clocks.
The coffee plant is a shrub that grows bright red fruits. Each fruit usually holds two seeds that are removed, dried, and roasted to make the coffee people drink.
A 1963 law required every home and apartment building to have a protected shelter space for its residents. This created over 360,000 bunkers across the country.
These five lakes contain enough water to cover the entire lower 48 United States in 9.5 feet of water. They are the largest group of freshwater lakes in the world by total area.
Pit vipers, pythons, and boas have these holes between their eyes and nostrils. The organs detect infrared radiation from warm animals. This creates a heat map in the snake's brain...
The body constantly breaks down old bone and builds new bone. After age 30, the body cannot build new bone fast enough to replace what is lost.
Scientists calculate this age by measuring the oldest light in space and tracking how fast galaxies move apart. They can use this movement to trace everything back to the start of...
Pilot Calbraith Perry Rodgers flew from New York to California in 1911. He crashed so often that almost every part of the airplane was replaced before he finished the trip.
Pigs have very little hair to block sunlight. They roll in mud to create a thick layer that acts like a natural sunscreen.
The only difference is how the carbon atoms are stacked. Diamonds have atoms locked in a strong 3D shape, while pencil lead has atoms in flat layers that slide apart.
These sections are called the rumen, reticulum, omasum, and abomasum. They work together to turn tough grass into energy.
During a stage called REM sleep, your brain works hard to organize memories and manage emotions. This high level of activity makes your dreams feel real and vivid.
Napoleon's staff gathered about 3,000 rabbits for a celebration. These rabbits were tame and thought the Emperor was going to feed them, so they swarmed him instead of running away...
The atmosphere is mostly carbon dioxide gas. This gas acts like a heavy blanket that lets sunlight in but stops heat from leaving. This makes the surface hot enough to melt lead.
Cacao beans were valuable because they were rare and could be turned into a special drink. People used them like coins to pay for goods and services.
Existing liver cells divide quickly to replace the missing tissue. This ability protects the body because the liver constantly filters harmful chemicals that can cause damage.