Long before Major League Baseball began allowing instant replay for balls and strikes, an umpire reluctantly used the technology to determine whether a hit was a home run, a move that inadvertently ushered in a new era for the sport.

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

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.

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.

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.

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.

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

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

Explore 3D models of some of the most dangerous viruses, allowing us to understand these and other pathogens in new ways.

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

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

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.

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

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

Simulations suggest that a paper airplane launched from the International Space Station would maintain its orientation and gradually descend for 3.5 days before chaotically tumbling down and burning up.

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

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

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

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.

'Tulip mania,' the 1630s Dutch craze where rare bulbs were briefly traded like luxury assets, may have been the first financial bubble—and it still shapes markets today.

Watch footage from the moments the Titanic wreck was discovered by a joint US-French research team in 1985.

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

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

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

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.

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.

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

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

Washing dishware before putting it in a dishwasher may reduce the appliance's effectiveness because it dynamically adjusts wash time and temperature based on a sensor that detects dirtiness.

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

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.

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

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.

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.

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

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.

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

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

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

Peek into the love lives of thousands of strangers whom Stanford University researchers have been tracking since 2017 on this interactive page.