Are we running out of clean water?
Lesson duration 05:19
Despite water covering 71% of the planet’s surface, more than half the world’s population endures...
Lesson duration 05:19
Despite water covering 71% of the planet’s surface, more than half the world’s population endures...
Lesson duration 04:32
Your professor has accidentally stepped through a time portal in his physics lab. You’ve got just...
Lesson duration 04:43
By the light of the moon, a group sneaks into the woods, where they take mind-altering...
Lesson duration 14:31
The one thing all humans have in common is that each of us wants to be happy, says Brother David...
Lesson duration 05:24
Kurt Vonnegut found the tidy, satisfying arcs of many stories at odds with reality, and he set...
Lesson duration 03:38
The family of giants you work for is throwing a fancy dinner party, but there’s a problem — the...
Lesson duration 08:43
As water travels across our planet, it shapes our environment, connects all living things, and is...
Lesson duration 03:55
Of all the species that humans have domesticated, dogs are our oldest animal friends. But how did...
Lesson duration 04:19
There is a question that has been tossed around by philosophers and art critics for decades: how...
Lesson duration 16:33
Writer James Bridle uncovers a dark, strange corner of the internet, where unknown people or...
Lesson duration 05:17
About once every century, a massive star somewhere in our galaxy runs out of fuel. No longer able...
Lesson duration 03:39
Conflict weakens national immune systems, leading to catastrophic public health emergencies....
Lesson duration 04:54
In 1987, thousands of people gathered in Saudi Arabia for the annual Hajj pilgrimage. But what...
Lesson duration 05:21
If you were to take a coffee cup, and break it in half, then in half again, and keep carrying on,...
Lesson duration 02:35
This animation is part of our series, "There's a Poem for That," which features animated...
Lesson duration 04:57
Sisyphus was both a clever ruler who made his city prosperous, and a devious tyrant who seduced...
Lesson duration 10:19
The human body is an incredibly complex machine made up of systems of organs all working together...
Lesson duration 05:25
He was a powerful king whose break with the church of Rome would forever change the course of...
Lesson duration 04:44
Humans have been on the quest for the perfect apple for hundreds of years. Farmers are now racing...
Lesson duration 14:25
Adults tend to think of kids as "future citizens" — their ideas and opinions will matter someday,...
Lesson duration 04:29
You’re on the trail of a werewolf that’s been terrorizing your town. After months of detective...
Lesson duration 04:56
Every star, black hole, human being, smartphone and atom are all constantly pulling on each other...
Lesson duration 05:15
Pristine areas with beautiful views are wonderful and amazing to visit. But over the past few...
Lesson duration 05:22
“OK” is thought to be the most widely recognized word on the planet. We use it to communicate...