The collapse of gas bubbles in the joint synovial fluid causes 'cracking' knuckles.

Between 2002 and 2012, at least 12 people were killed in the Philippines in incidents related to off-key karaoke singing of Frank Sinatra's 'My Way.'

Humans tend to imagine aliens as humanlike, but that's probably unlikely. Three different hypothetical planets show how aliens' bodies could take many forms.

The world's largest waterfall is in the ocean and is more than three times the height of Angel Falls, the largest waterfall on land.

Explore a collection of famous literary maps, including original images from 'Treasure Island,' 'The Swiss Family Robinson, ' and 'Walden.'

This interactive website features nearly 40,000 photos from Wikipedia for you to create visual mosaics with.

There are up to 100 trillion microbes in the gut, and maintaining the relative balance in this ecosystem is important for our health.

Watch Bruce Springsteen's 1985 performance of Woody Guthrie's 'This Land Is Your Land,' which he calls 'the greatest song ever written about America.'

See a breakdown of how some of the most common food items are traded across the globe, including the key trade relationships for each item.

In 1962, the US detonated a nuclear weapon in space, which produced an electromagnetic pulse that disabled three low Earth orbit satellites and damaged electrical equipment in Hawaii.

Male pattern baldness accounts for more than 95% of hair loss in men and is characterized by thinning hair, hair loss, and a receding hairline.

Cats have a mutation that prevents them from tasting sweetness, and goldfish rank among the world's supertasters.

Pregnancy makes someone more attractive to the mosquito species that transmits malaria.

The US has discontinued a variety of different currency denominations over the years—including a $100K bill.

Watch a visualization of what it would look like to move along Earth's surface as fast as the International Space Station, or about 23 times the speed of sound.

Use this tool to calculate the dollar value of your parental mental load, from meal planning to coordinating after-school care, then see resources that help generate solutions.

Computer scientists first started trying to optimize dating using computers in the 1950s.

The Berlin Wall physically separated East and West Berlin for nearly three decades, preventing East Germans from fleeing to the West and earning the nickname 'the Iron Curtain.'

Explore an interactive timeline of Earth's 4.5-billion-year history to visualize shifting landmasses and oceans, view the locations of significant asteroid impacts, and learn about major geological and biological events.

The average banana produces one positron—the antimatter counterpart to an electron—every 75 minutes as its trace amounts of radioactive potassium decay.

If the moon were less than one-twelfth its current distance from Earth, the planet's tidal forces would overcome the moon's internal gravity, tearing it apart and forming a ring of debris.

Apeirophobia is the fear of everlasting life and may stem from the human brain's inability to conceptualize the concept of anything happening beyond what it can project out, such as the concept of an infinite life.

Examine this captivating animation 'building' a human—illustrating the roughly 40 weeks of fetal development.

The Aztec Empire ruled over 80,000 square miles of central Mexico for nearly a century—until a small band of Spanish conquistadors brought it down in 1521.

Sea stars are invertebrates—they lack a backbone—and while most exhibit pentametric radial symmetry due to having five arms radiating from a central disk, some can possess more than 40.

One of the most famous portraits ever taken is 'Afghan Girl' (1984) by Steve McCurry, yet the subject Sharbat Gula went much of her life without being identified or benefitting from the image's success.

One of the most famous portraits ever taken is "Afghan Girl" by Steve McCurry. Sharbat Gula, the subject of the photo, was not credited until 2002 for her role in the famous National Geographic cover, and continued to live in poverty after the photo was taken.

Plato's famous allegory of the cave is a metaphor exploring the value of truth over ignorance.

Relax to a livestream of brown bears chilling in Katmai National Park in Alaska.

The animatronic shark from 'Jaws' was a complex machine called 'Bruce.'

See a 3D reconstruction of Tenochtitlan, the Aztec capital

All rainbows are 'raincircles' caused by water droplets separating white sunlight into a spectrum of colors, but Earth's surface blocks the bottom half of the circle from our line of sight.

There are 'YouTube camps' that teach children how to create content for the video platform.

Explore a detailed map of Odysseus' fictional journey from 'The Odyssey.'

Abraham Lincoln had to sneak into Washington, DC, in disguise for his 1861 inauguration after a detective uncovered a plot to assassinate him in Baltimore.

The tallest tsunami in recorded history was 524 meters (1,720 feet) high—taller than the Empire State Building—and occurred in Lituya Bay, Alaska, in 1958 after an earthquake dislodged a rockface into the water.

Streaming service Netflix's sound logo 'Tudum' was designed as a key sonic differentiator.

Researchers generally group gut bacteria into six different categories, with varying amounts of these microbes residing in different parts of the digestive tract.

Play the role of a student as you try to navigate college and remain debt-free.

George Lucas used Joseph Campbell's 'hero's journey,' a narrative structure that encompasses the common characteristics of multiple cultures' mythologies, to revise 'Star Wars.'

Watch an animated visualization of how the Large Hadron Collider works, including how particles are accelerated through a series of machines and how collision data is collected and distributed worldwide.