In which John Green teaches you about the Crusades embarked upon by European Christians in the 12th and 13th centuries. Our traditional perception of the Crusades as European Colonization thinly veiled in religion isn't quite right. John...

Welcome to Crash Course Outbreak Science! What do pathogens actually do to us that makes us sick? Why do societies respond to outbreaks of infectious diseases the way they do? How can we stop the next outbreak? These are the kinds of...

Infectious disease has affected the human species for as long as we’ve existed, but in that time we’ve come a long way in understanding what they are and how they spread. In this episode of Crash Course Outbreak Science, we’ll introduce...

So... do plants need dirt? The truth might shock you. In this episode of Crash Course kids, Sabrina talks about how plants get energy and how that energy is transported around them. Also, she talks about dirt.

Not sleeping for days on end. Long periods of euphoria. Racing thoughts. Grandiose ideas. Mania. Depression. All of these are symptoms of Bipolar Disorder. In this episode of Crash Course Psychology, Hank talks about mood disorders and...

In this episode of Crash Course Psychology, Hank takes a look at how the treatment for Psychological Disorders has changed over the last hundred years and who is responsible for getting us on the path to getting us here. -- Table of...

In this episode of Crash Course Kids, Sabrina gives us a real world example of how the Hydrosphere and Geosphere affect each other in the form of Weathering and Erosion. Think of Weathering as the force that makes a mess and Erosion as...

Today we begin our discussion of computer graphics. So we ended last episode with the proliferation of command line (or text) interfaces, which sometimes used screens, but typically electronic typewriters or teletypes onto paper. But by...

In which John Green teaches you about the Protestant Reformation. Prior to the Protestant Reformation, pretty much everyone in Europe was a Roman Catholic. Not to get all great man, but Martin Luther changed all that. Martin Luther...

How would you measure a personality? What, exactly, is the self? Well, as you've come to expect, it's not that easy to nail down an answer for those questions. Whether you're into blood, bile, earth, wind, fire, or those Buzzfeed...

So now that we know what Properties are, how can we use them to figure things out? In this episode of Crash Course Kids, Sabrina uses them to solve the mystery of what she tripped over last night. This first series is based on 5th grade...

In which Craig Benzine teaches you about the compromises met in ratifying the U.S. Constitution. The United State’s didn’t always have its current system of government. Actually, this is it’s second attempt. Craig will delve into the...

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...

Saturn is the crown jewel of the solar system, beautiful and fascinating. It is a gas giant, and has a broad set of rings made of ice particles. Moons create gaps in the rings via their gravity. Saturn has dozens of moons, including...

Today, we're going to talk about how the Internet works. Specifically, how that stream of characters you punch into your browser's address bar, like "youtube.com", return this very website. Just to clarify we're talking in a broader...

Today we start a three episode arc on the rise of a global telecommunications network that changed the world forever. We’re going to begin with computer networks, and how they grew from small groups of connected computers on LAN networks...