SpaceX's Crew Dragon was the first crewed spacecraft piloted by touchscreen

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

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.

As part of the up to 15 pounds of seafood they consume daily, sea otters eat urchins that feed on kelp forests—sources of shelter and food to over 800 species—thereby making the marine mammal a keystone species.

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

Watch President John F. Kennedy's speech on going to the moon

Watch a two-year time-lapse of a pinecone seed transforming into a pine tree.

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

Emanuel Leutze's painting 'Washington Crossing the Delaware' is one of the defining images of the Revolutionary War.

Stonehenge was built using giant wooden rollers and precisely carved tongue-and-groove joints to lock the stones in place.

This short animation shows how human beings managed to lug 30-ton stones over miles of prehistoric English countryside and stand them up The Stone Age engineering involved using giant wooden rollers and carving precisely interlocking tongue-and-groove joints to hold the heavy stones in place.

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

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.

See a 3D reconstruction of Tenochtitlan, the Aztec capital

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

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

Watch Dr. Laurence Peter explain his 'Peter Principle,' which states that people are promoted to their level of incompetence and explains why bosses aren't always good at their jobs.

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.

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

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

Find out how important you are to AI tools when they generate text responses with this tool, which estimates the weights of people's names.

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

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

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.

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

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

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.

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

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.

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

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.

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.

'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.

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.

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

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.

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

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

Lake Sørvágsvatn sits about 32 meters (105 feet) above sea level, but the taller surrounding cliffs create an optical illusion that makes it appear to float much higher above the ocean.

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

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

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.