Jessi and Squeaks got a question about how submarines go underwater and explore, so Squeaks did some research!

Ragnarok! It's the end of the world, Norse style. It's got everything you want in an apocalypse. Earthquakes, destruction, armies of the dead, a giant evil wolf, giants with flaming swords, and a kind of happy ending. It's got it all....

In part 1 of our special series on human ancestry, we tour through our family tree to meet our ancestors and distant cousins, and to find out what made us human along the way. The story of human ancestry is not a simple progression from...

We're kicking off our exploration of muscles with a look at the complex and important relationship between actin and myosin. Your smooth, cardiac, and skeletal muscles create movement by contracting and releasing in a process...

The world doesn't have to be shrouded in mystery to be fascinating! Here are 6 mysteries that science has managed to solve.

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James Joyce's "Ulysses" is widely considered to be both a literary masterpiece and one of the hardest works of literature to read. It inspires such devotion that once a year, thousands of people all over the world dress up like the...

n 10 episodes John Green, Hank Green, and Emily Graslie teach you about, well, everything. It’s Big History! This course will take you on a whirlwind journey from the creation to the death of the universe and is based on the Big...

This week on Crash Course Theater, Mike is taking you to Japan to have a look at Noh theater. Noh, and its counterpart Kyogen are some of the most revered theater forms in Japan, and are still performed today. Today you'll learn how Noh...

In which John Green, Hank Green, and Emily Graslie teach you about, well, everything. Big History is the history of everything. We're going to start with the Big Bang, take you right through all of history (recorded and otherwise), and...

Doubling human life expectancy in a century is our greatest achievement, says author Steven Johnson. How did we make it happen -- and can we keep it going? Backed by fascinating historical anecdotes, he shares some life-lengthening...

In which John Green reads Zora Neale Hurston's novel, "Their Eyes Were Watching God," and talks to you about it. You'll learn about Zora Neale Hurston's life, and we'll also look at how the interpretations of the book have changed over...

There's a region of Earth's atmosphere known as the South Atlantic Anomaly, and it’s one of the most dangerous near-Earth areas of space, both for satellites and humans.

Neuroscientist uri Hasson researches the basis of human communication, and experiments from his lab reveal that even across different languages, our brains show similar activity, or become "aligned," when we hear the same idea or story....

In our continuing series on Earth's weirdest places, Hank describes the crazy place in Antarctica known as Blood Falls in all its scientifically strange majesty.

The first era of our current eon, the Paleozoic Era, is probably the most deceptively fascinating time in Earth's history. With near constant revolutions in life, punctuated by catastrophic extinctions, it is also one of the most chaotic.

Homer's "Odyssey" recounts the adventures of the Greek hero Odysseus during his journey home from the Trojan War. Though some parts may be based on real events, the encounters with monsters, giants and magicians are considered to be...

Did you know you can read the story of a tree's life? By looking at a tree's rings, you can figure out way more than just how old it is! Jessi and Squeaks are here to show you what to look for next time you're on a hike and find a tree...

Reptiles emerged from the Paleozoic as humble creatures, but in time, they grew to become some of the largest forms of life ever to stomp, swim, and soar across the planet. This Age of Reptiles was a spectacular prehistoric epic, and it...

The world of modern theater owes its roots to the tragedians of Ancient Greece. As far back as the 5th Century BCE, actors and playwrights were entertaining the masses with intriguing stories. Melanie Sirof unveils the ancient theatrical...

Who is telling a story, and from what perspective, are some of the most important choices an author makes. Told from a different point of view, a story can transform completely. Third person, first person, and second person perspectives...

The starving orphan seeking a second helping of gruel. The spinster wasting away in her tattered wedding dress. The stone-hearted miser plagued by the ghost of Christmas past. More than a century after his death, these remain...

In which John Green teaches you the history of Islam, including the revelation of the Qu'ran to Muhammad, the five pillars of Islam, how the Islamic empire got its start, the Rightly Guided Caliphs, and more. Learn about hadiths, Abu...

Adam Savage walks through two spectacular examples of profound scientific discoveries that came from simple, creative methods anyone could have followed -- Eratosthenes' calculation of the Earth's circumference around 200 BC and...

Euclid, known as the "Father of Geometry," developed several of modern geometry's most enduring theorems--but what can we make of his mysterious fifth postulate, the parallel postulate? Jeff Dekofsky shows us how mathematical minds have...