Hank brings us the story of the electron and describes how reality is a kind of music, discussing electron shells and orbitals, electron configurations, ionization and electron affinities, and how all these things can be understood via...

Today we're going to talk about degrees of freedom - which are the number of independent pieces of information that make up our models. More degrees of freedom typically mean more concrete results. But something that is statistically...

We’ve discussed the four main branches of engineering but there are so many other fields doing important work, so today we’re going to explore a few of them. In this episode we’ll explore some of the history and fundamentals of...

During the Red Summer of 1919 violence against Black people broke out across the United States. Black people and neighborhoods were attacked in Washington DC, Chicago, Tulsa, and many other cities and towns across the country. Post-war...

In which John Green teaches you about the roots of the American Revolution. The Revolution did not start on July 4, 1776. The Revolutionary War didn't start on July 4 either. (as you remember, I'm sure, the Revolution and the...

During economic crises, marginalized communities are more susceptible to the harms and struggle that come with these downturns. Today we'll talk about the Great Depression, which lasted from 1929 until the US entered World War II. This...

Organic reactions are kind of like carefully choreographed fight scenes, and nucleophilic attack is a key move. This episode of Crash Course Organic Chemistry is all about nucleophiles and electrophiles, or what happens at those...

Much like a cell membrane, our atmosphere forms a protective boundary between outer space and the biosphere that allows for all life to exist on Earth’s surface. Today, we’re going to talk about its composition and layers (the...

From gnocchi and salchipapas to potato chips and french fries, it seems like every cuisine around the world has embraced the potato! And this humble tuber did not originate in Ireland or France, but near Lake Titicaca near the border of...

In which John Green teaches you about various reform movements in the 19th century United States. From Utopian societies to the Second Great Awakening to the Abolition movement, American society was undergoing great changes in the first...

Look to your left. Look to your right. Look at this video. Today, John Green is going to teach you how to read laterally, using multiple tabs in your browser to look stuff up and fact check as you read. Real-time fact-checking an help...

Carbon-carbon double bonds are pretty common in nature, but triple bonds between carbons, called alkynes, are not. When alkynes do pop up in nature, it’s usually in a compound that’s toxic to humans, however, we can synthesize alkynes...

This week we explore final ethical theory in this unit: Aristotle’s virtue theory. Hank explains the Golden Mean, and how it exists as the midpoint between vices of excess and deficiency. We’ll also discuss moral exemplars, and introduce...

In which John Green teaches you about the Market Revolution. In the first half of the 19th century, the way people lived and worked in the United States changed drastically. At play was the classic (if anything in a 30 year old nation...

Today, Andre is going to talk about the rise of Atari and with it the rise of the video game industry. So if you remember from last episode, we mentioned that the first arcade machine, Galaxy Game, happened to have a coin slot, but this...

Throughout this series we’ve mostly talked about pairs of electrons, but electrons don’t always have a buddy. An atom or group of atoms with a single unpaired electron is called a radical. In this episode of Crash Course Organic...

In which John Green teaches you about recent history. By which we mean VERY recent history. John covers the end of George W. Bush's administration presidency of Barack Obama (so far). Some people would say, "It's too soon to try to...

Our unit on the philosophy of religion and the existence of god continues with Thomas Aquinas. Today, we consider his first four arguments: the cosmological arguments.

Hank takes us through the bowels of the human digestive system and explains why it's all about surface area.

While the focus has been on Western Europe so far, there has also been a lot going on in Eastern Europe, which we'll be looking at today. The Commonwealth of Poland-Lithuania, The Ottoman Empire, and Russia were all competing at the...

This week, we're back in Europe to learn about Realism and Naturalism. In the 19th Century, playwrights like Eugene Scribe, Alexandre de Dumas Fils, and Emile Zola remade the French theater, first with Realism, and later with Naturalism....

In business, growth basically means making a company more successful in some way: finding a new revenue stream, revamping the cost structure to minimize expenses and increase profit, or adding new people and knowledge to the team. Our...

Let's talk about Wikipedia. Wikipedia is often maligned by teachers and twitter trolls alike as an unreliable source. And yes, it does sometimes have major errors and omissions, but Wikipedia is also the Internet's largest general...

Today, we’re going to visit Siberia and take a closer look at how temperatures there (and around the globe) impact the way cultures, communities, and landscapes form. Air temperature plays a much bigger role than just helping us decide...