How do we search for alien life if it's nothing like the life that we know? Christoph Adami shows how he uses his research into artificial life -- self-replicating computer programs -- to find a signature, a "biomarker," that is free of...

This week on Crash Course Theater, Mike and Yorick take us to beautiful Spain, and look at its Golden Age. Spain was having kind of a moment in the 16th and 17th centuries. They had this big empire, the culture was really flowering, and...

In this video Paul Andersen explains how the wave speed measure the speed of a wave through a medium. The medium determines the speed of the wave. The velocity of the wave is equal to the product of the wavelength and the frequency of...

Hannah Brencher's mother always wrote her letters. So when she felt herself bottom into depression after college, she did what felt natural -- she wrote love letters and left them for strangers to find. The act has become a global...

How to think about implicit differentiation in terms of functions with multiple inputs, and tiny nudges to those inputs.

The task sounds like it should be pretty easy, but the Stroop task is a fantastic, and very well studied, example of how your brain’s automatic processing can trip you up!

Divergence, curl, and their relation to fluid flow and electromagnetism

History is written by the victors, as the saying goes -- but what would it look like if it was written by everyone? Journalist and TED Fellow Mikhail Zygar is on a mission to show us with Project1917, a "social network for dead people"...

Everyone knows the name Charles Darwin, but his lesser known frenemy, Alfred Russel Wallace, was developing a lot of the same ideas around the same time.

1, 11, 21, 1211, 111221. These are the first five elements of a number sequence. Can you figure out what comes next? Alex Gendler reveals the answer and explains how beyond just being a neat puzzle, this type of sequence has practical...

Today we're going to talk about the birth of personal computing. Up until the early 1970s components were just too expensive, or underpowered, for making a useful computer for an individual, but this would begin to change with the...

Formally or informally, human societies across place and time have made rules to bind and dissolve couples. The stakes of who can obtain a divorce, and why, have always been high. Divorce is a battlefield for some of society's most...

Some people question whether Shakespeare really wrote the works that bear his name _ or whether he even existed at all. Could it be true that the greatest writer in the English language was as fictional as his plays? Natalya St. Clair...

So we ended last episode with programming at the hardware level with things like plugboards and huge panels of switches, but what was really needed was a more versatile way to program computers - software! For much of this series we’ve...

If you want to make a movie, generally you're going to want to start with a script. In this episode of Crash Course Film Production, Lily Gladstone talks about the basics of screenplays and how to get started thinking about and actually...

You've heard about slow food. Now here's slow ... TV? In this very funny talk, Norwegian television producer Thomas Hellum shares how he and his team began to broadcast long, boring events, often live -- and found a rapt audience. Shows...

Daily, Americans exercise their rights secured by the Constitution. The most widely discussed and debated part of the Constitution is known as the Bill of Rights. Belinda Stutzman provides a refresher course on exactly what the first ten...

Film has the power to change the way we think about ourselves and our culture. Documentarian and TED Fellow Sharmeen Obaid-Chinoy uses it to fight violence against women, turning her camera on the tradition of honor killings in Pakistan....

In this video Paul Andersen explains how plate tectonics explains the large-scale system interactions on our planet. Large plates float on the mantle and interact to form the major landforms on the planet. Evidence for plate tectonics...

If Fermat had a little more room in his margin, what proof would he have written there?

With almost 100 mystery novels, each one a cleverly constructed puzzle box of clues, misdirection, and human drama, Agatha Christie is the best-selling novelist of all time. Her eccentric detectives, clever clues, and simplified suspects...

In which John Green teaches you about Chinua Achebe's 1958 novel, Things Fall Apart. You'll learn about Igboland, a region in modern day Nigeria, prior to the arrival of the British Empire. Achebe tells the story of Okonkwo, an Igbo...

In which John Green teaches you about Vikings! That's right, one of our most requested subjects, the Vikings, right here on Crash Course. So what's the deal with Vikings? Well, the stuff you've heard about them may not be true. The...

In this video Paul Andersen explains how Kirchoff's Loop Rule can be used to calculate the voltage of different components of a circuit. The sum voltage throughout an entire loop will sum to zero following the law of conservation of...