The Fact Ledger

Squirrels can survive a fall from any height.

A squirrel's low terminal velocity of about 23 mph is too slow to be fatal. Their light bodies and bushy tails create enough drag to act like a parachute, while flexible joints abs...

Squirrels help plant thousands of new trees every year by forgetting where they bury their nuts.

Squirrels hide acorns and walnuts in the ground to prepare for winter. Since they fail to recover many of these caches, the forgotten seeds sprout and grow into trees. This process...

Camel dung is so dry that it can be used as fuel for fire immediately.

To survive harsh deserts, camels extract nearly every drop of moisture from their food. Their long intestines absorb so much water that their waste is almost completely dry. This f...

Camels have a built-in moisture recycler in their noses to survive the desert.

A camel's nasal passages trap water vapor from its breath during exhalation and return it to the body. This unique system prevents dehydration and humidifies dry air before it reac...

Camels can change their body temperature by 11°F to survive extreme desert heat without sweating.

Most mammals maintain a steady temperature, but camels let theirs rise from 93°F at night to 104°F during the day. This prevents water loss by delaying sweat until it is absolutely...

Camels originally evolved in North America and lived in snowy forests for millions of years.

Modern camels are famous for desert life, but their ancestors first appeared in North America 45 million years ago. Their signature traits, like fatty humps and wide feet, were ori...

Camels have oval-shaped red blood cells that keep flowing even when severe dehydration thickens their blood.

Most mammals have round red blood cells that clump together when water is scarce. A camel's oval cells are flexible and glide through tiny vessels even in 104°F (40°C) heat. These...

A thirsty camel can drink 113 liters of water in just 13 minutes.

This rapid rehydration is possible because camels have unique, oval-shaped red blood cells. These cells can expand to 240% of their original size without bursting, allowing the ani...

A camel's hump stores fat, not water, to serve as a vital energy reserve.

Storing fat in a concentrated hump instead of under the skin prevents the camel from overheating in the desert sun. This reserve can weigh up to 80 pounds and provides energy when...

Vultures use a 'follow the leader' strategy to find food across thousands of miles.

Vultures scan the ground while watching other vultures in the sky. When one bird dives toward a carcass, others nearby notice and follow. This creates a massive, living surveillanc...

Vultures prevent deadly disease outbreaks by eating rotting carcasses.

Their stomach acid is powerful enough to destroy pathogens like anthrax, cholera, and botulism. By consuming decaying remains, vultures stop these diseases from spreading into the...

Vultures can soar for hours without flapping their wings.

They stay aloft by riding thermals, which are rising columns of warm air. By circling within these currents, vultures gain altitude and glide long distances while using very little...

The Rüppell's vulture is the world's highest-flying bird, reaching altitudes of 37,000 feet.

In 1973, a Rüppell's vulture collided with a commercial jet over the Ivory Coast at 37,000 feet. These birds survive at such extreme heights thanks to a specialized hemoglobin that...

Vultures have bald heads to stay clean while eating and to regulate their body temperature.

A featherless head prevents blood and bacteria from sticking to the bird while it feeds on carcasses. Bare skin is easier to keep clean and dries quickly in the sun, which helps ki...

The Bearded Vulture is the only bird that survives almost exclusively on a diet of bones.

Bones make up 70% to 90% of this bird's diet. If a bone is too big to swallow, the vulture drops it from high altitudes onto rocks to shatter it. Its powerful stomach acid can comp...

Vultures have stomach acid so powerful it can dissolve bones and neutralize deadly diseases like anthrax.

A vulture's stomach acid is up to 100 times stronger than a human's. This extreme acidity allows them to safely eat rotting carcasses infected with rabies, botulism, and anthrax. B...

Vultures cool themselves down by urinating on their own legs.

This process, called urohydrosis, uses evaporation to lower the bird's body temperature, similar to how humans sweat. The highly acidic waste also acts as a disinfectant, killing b...

Chewing gum helps prevent ear pain during flights by equalizing air pressure.

Rapid altitude changes create a pressure imbalance between your middle ear and the airplane cabin. Chewing gum triggers frequent swallowing, which opens the Eustachian tubes. This...

Ancient Greeks used mastic resin as a natural chewing gum to clean their teeth and freshen their breath.

Harvested from the mastic tree on the island of Chios, this resin has natural antibacterial properties that fight plaque. It was so popular that the English word "masticate" comes...

Most modern chewing gum is made from synthetic rubber used in tire inner tubes.

Manufacturers use food-grade synthetic rubbers like polyisobutylene to give gum its stretch. This material is more durable and consistent than natural tree resins. Most brands swit...

Swallowed chewing gum does not stay in your stomach for seven years.

Your body cannot digest the synthetic rubber base, but it doesn't get stuck. Your digestive system moves gum through your intestines using muscle contractions. It typically passes...

The world's largest chewing gum company originally started by selling soap and baking powder.

In 1891, William Wrigley Jr. founded his company in Chicago selling soap. To boost sales, he offered free baking powder as a gift. When the baking powder became more popular than t...

Chewing gum can significantly boost your memory and focus.

Chewing increases your heart rate and delivers more oxygen to the brain. This surge in blood flow can improve short-term memory by up to 35% while reducing stress hormones like cor...

During World War II, chewing gum nearly vanished from American stores because the military bought almost the entire supply.

The U.S. military included gum in every soldier's rations to reduce stress and keep teeth clean. Demand was so massive that companies like Wrigley stopped selling to civilians to p...

Bubble gum is pink because its inventor only had pink food coloring on hand during his first successful batch.

In 1928, accountant Walter Diemer created a stretchy, non-sticky gum that was originally a dull gray color. The only food coloring he had in a large enough quantity was pink. This...

Modern chewing gum was born from a failed attempt to create rubber tires.

In the 1860s, inventor Thomas Adams tried to turn chicle—a natural tree sap—into a cheap rubber substitute. When the material proved too soft for tires, he noticed it was enjoyable...

Ancient birch bark 'chewing gum' has preserved human DNA for over 5,000 years.

Stone Age people chewed birch bark tar to clean teeth and soothe toothaches. This sticky substance acted like a time capsule, trapping the DNA of the person who chewed it. In 2019,...

Your weight changes depending on your location on Earth because gravity is not the same everywhere.

Earth is not a perfect sphere, and its mass is unevenly distributed. Variations in density, such as mountain ranges and ocean trenches, create slight differences in gravitational p...

Falling into a black hole would stretch your body into a thin strand of atoms through a process called spaghettification.

This happens because gravity pulls much harder on your feet than on your head. This massive difference in force, called a tidal force, stretches you into a vertical line thinner th...

When massive black holes collide, they create ripples in space-time that physically stretch and squeeze the entire universe.

Known as gravitational waves, these ripples travel at the speed of light and distort the fabric of reality. When they pass through Earth, they cause everything—including you—to tin...

Gravity has an infinite range, meaning every atom in your body is pulling on every galaxy in the universe.

Gravity never reaches zero. While the force weakens as distance increases, it never truly disappears. This means you exert a tiny gravitational pull on objects billions of light-ye...

Astronauts are not weightless because gravity is gone. They are actually in a constant state of freefall.

At the International Space Station's altitude, Earth's gravity is still 90% as strong as it is on the ground. The station and the astronauts inside are falling toward Earth, but th...

Gravity pulls massive space objects into spheres by squeezing them evenly from all directions.

A space object's shape is determined by the tug-of-war between gravity and material strength. When an object reaches a specific mass, its gravity becomes strong enough to crush sol...

You weigh about 0.5% to 1% less at the equator than at the North or South Pole.

Earth is not a perfect sphere. It bulges at the equator, placing you farther from the planet's center where gravity is weaker. Additionally, Earth's rotation creates a centrifugal...

Time moves faster at the top of a mountain than at sea level.

This happens because gravity warps time. The stronger the gravity, the slower time passes. Since gravity is weaker farther from Earth's center, clocks at high altitudes tick slight...

Massive objects warp the fabric of space to create natural cosmic magnifying glasses.

This effect, called gravitational lensing, occurs when a massive galaxy or black hole curves spacetime. When light from a distant source passes through this curve, it bends and mag...

Gravity is the weakest of the four fundamental forces in nature.

Even though gravity holds galaxies together, it is surprisingly weak. A small refrigerator magnet can lift a paperclip, easily overcoming the gravitational pull of the entire Earth...

London's Shard is a 'Vertical City' that stacks offices, restaurants, a hotel, and private residences into one skyscraper.

Standing 309.6 meters tall, The Shard maximizes urban space by layering different environments vertically. It uses an on-site natural gas plant to generate electricity and recycle...

It takes three to four months of non-stop work to clean every window on the Burj Khalifa just once.

The world's tallest building has 24,348 windows covering an area the size of 17 soccer fields. A team of 36 workers uses specialized tracks and machines for most of the tower, but...

In 1978, engineers discovered a design flaw in New York's Citigroup Center that could have caused the skyscraper to collapse during a storm.

To preserve a church on the site, the tower was built on massive stilts placed in the middle of its sides instead of the corners. A student's question led to the discovery that dia...

The Burj Khalifa is held up by friction between its foundation and the sand.

While most skyscrapers rest on solid rock, the Burj Khalifa sits on deep soil. Its foundation uses 192 concrete piles driven 164 feet into the ground. These piles stay stable using...

The Shanghai Tower features the world's fastest elevators, reaching speeds of 46 miles per hour.

These elevators can reach the 119th floor in just 55 seconds. To prevent ear pain from rapid altitude changes, the cabins are pressurized like airplanes. The ride is so smooth that...

Sunlight causes steel skyscrapers to expand and grow several inches taller during the day.

When the sun heats a building's steel frame, the metal absorbs energy and expands. This process, known as thermal expansion, can cause a skyscraper to grow taller or even lean away...

The Empire State Building is struck by lightning about 25 times every year.

At 1,454 feet tall, this iconic skyscraper acts as a massive lightning rod. Its steel frame and copper tip safely channel millions of volts into the ground. During one intense stor...

You can watch the sunset twice in one day at the Burj Khalifa.

Because the tower is so tall, the sun sets about three minutes later at the top than at the ground. If you watch the sunset from the base and then take the high-speed elevator to t...

A tiger's tail acts as a powerful rudder, allowing it to make sharp, precise turns at high speeds.

Measuring up to 3 feet long, a tiger's tail provides essential balance for its 500-pound body. During a high-speed chase, the tiger swings its tail in the opposite direction of its...

Siberian tigers are the largest cats on Earth, growing up to 11 feet long and weighing as much as six adult humans.

Also known as the Amur tiger, this massive predator can weigh over 660 pounds. To survive the freezing Russian Far East, they have thick fur and a layer of fat for insulation. Thei...

A tiger's night vision is six times more powerful than a human's.

Tigers have a reflective layer behind their retinas called the tapetum lucidum. This structure bounces light back through the eye to maximize what they see in the dark. It is also...

A single male Siberian tiger can rule a territory larger than 17 Manhattan Islands.

Siberian tigers are solitary hunters that require massive territories to survive. A single male's range can exceed 400 square miles to ensure he has enough food and access to mates...

Tigers are elite swimmers capable of traveling over 18 miles through water in a single day.

Unlike most felines, tigers are naturally adapted to the water. They have partially webbed toes that act like paddles, allowing them to cross rivers up to 4 miles wide. In regions...