Convertible notes represent loans that startups owe investors

Humans may have as many as 100,000 to 150,000 individual hairs on our scalps, growing at a rate of roughly 1 centimeter per month.

Lesser-known phobias include turophobia, or the fear of cheese, and nomophobia, the fear of being without your cell phone.

Joan Didion interviewed The Grateful Dead in 1967, before they became music icons.

Explore (and debunk) the world's most contagious misconceptions—from the 5-second rule to sugar rushes—on this interactive site. Click on each misconception for further evidence.

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

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.

Light takes approximately eight minutes to travel from the sun's surface to Earth, but it takes thousands of years to reach the star's surface from its core—a distance more than 200 times shorter.

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.'

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

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.

Semaglutides, which belong to a class of drugs called GLP-1s, are prescribed for weight loss in combination with diet and exercise because they trigger the release of the appetite-suppressing hormone incretin.

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

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.

Explore the history, structure, and species of Australia's Great Barrier Reef with this interactive journey narrated by Sir David Attenborough.

The final shots of the Civil War were fired in the Arctic over 2 months after the South's surrender.

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.

Located on Ross Island in Antarctica, Mount Erebus is the southernmost active volcano on Earth and features a lava lake—one of eight known worldwide as of 2026—that erupts regularly.

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

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.

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.'

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

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

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

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

Experience 14 billion years of important moments in world history with this scrollable interactive timeline.

Here are some tips from Pew Research to help you distinguish between a good poll and an unreliable one.

Explore how temperatures compare to historical averages in cities worldwide with this interactive global monitor.

Robert Smalls escaped slavery by piloting a stolen Confederate ship to freedom, then became an influential Black political leader during Reconstruction.

Fecal transplants can help treat infections by transplanting healthy gut bacteria from a donor into a patient's gastrointestinal tract using samples of human waste, which are turned into a liquid mixture and often delivered via a colonoscopy procedure.

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.

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

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.

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.

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

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.

A dog's nose can be up to 100,000 times more sensitive than a human's, and each possesses a secondary organ for smelling, which helps learn about other dogs when they sniff each other's butts.

Metamorphosis evolved over millions of years as species that hatched as smaller versions of adults started exhibiting genetic mutations that differentiated juvenile and adult bodies.