Autoimmune diseases affect between 5% and 10% of people worldwide, but their causes remain unknown

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.

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

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.'

See a 3D reconstruction of Tenochtitlan, the Aztec capital

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.

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

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.

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

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.

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.'

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.

The US jobs projected to shrink the fastest over the next decade include typists and word processors.

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.

Author David Foster Wallace's 'This Is Water' speech provides guidance for adulthood.

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.

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.

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

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

'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.

Explore the wineries of Napa Valley with an interactive map of its hundreds of wineries, vineyards, and tasting rooms.

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

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

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

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

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

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.

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.

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.

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

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

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.

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

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

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

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

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.

Although the moon passes between the sun and Earth each month, its orbit is tilted by five degrees, preventing Earth from experiencing a solar eclipse each month.

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

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.