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

'Golden blood' is the rarest blood type in the world—fewer than 50 people are known to have it.

Hear 50 years of iconic hip-hop samples, the genre's foundational looped tracks.

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

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

Listen to audio clips from Hoover, a harbor seal named after its insatiable appetite, who learned to say English phrases such as 'hello there' and 'come over here.'

On planets in systems with two stars, such as the fictional Tatooine from 'Star Wars,' observers would see overlapping rainbows and double rainbows.

Explore the history of American restaurants through an archive of menus dating back to the early 1800s.

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

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

Explore an interactive forecast of the future of the universe, from the return of Halley's Comet to the last light in the cosmos.

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

'Bibliotherapy' is of increasing interest as a way to improve mental health and help navigate complex life situations—with people immersing themselves in the experiences of fictional characters or nonfiction and self-help books to find relief and gain personal insights.

On a cruise ship, the average person uses about 50 gallons of water a day, which is treated by bacteria and onboard filtration systems, then stored until the ship can legally discharge the wastewater.

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

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.

Explore the 2025 Uber Lost & Found Index to find out the weirdest items that passengers left behind in Ubers last year, from ten live lobsters to a mannequin head with human hair.

Check out some of the best books that can be read in a single day, with titles from Han Kang, Denis Johnson, Muriel Spark, and more.

Watch what would happen if you literally had all the money in the world.

See a 3D reconstruction of Tenochtitlan, the Aztec capital

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.

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

Explore Lewis and Clark's 8,000-mile journey in Google Earth.

Watch the many different civilizations around the Mediterranean shift power from the year 2500 BCE to 0 BCE in this animated map.

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

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.

You may be better at spotting a lie when listening to a speaker's voice inflections rather than watching for facial and body cues.

Rapid intensification is the increase in a hurricane's sustained wind speed by at least 35 miles per hour within 24 hours, which can strengthen it by up to two categories.

If a source of music traveled past someone at twice the speed of sound, assuming sufficiently sensitive hearing and powerful equipment, they would hear the music backward.

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.

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

Explore the known asteroids, comets, and spacecraft involved in asteroid studies within our solar system with 'Eyes on Asteroids,' a 3D visualization from NASA.

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.

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

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.

See where your state ranked in an analysis of the best public school systems in the US.

Watch 4-plus decades of Pixar's opening logos.

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.

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

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.