In which John Green teaches you about the rise of the conservative movement in United States politics. So, the sixties are often remembered for the liberal changes that the decade brought to America, but lest you forget, Richard Nixon...

Over the millennia, every region on Earth has developed its own successful agricultural ecosystem from flat fields of grain and mountainside rice terraces to coastal fish farms and goat herding. Today, we’re going to break down...

In which John Green teaches you about the United States Constitution. During and after the American Revolutionary War, the government of the new country operated under the Articles of Confederation. While these Articles got the young...

We’ve already learned a lot about electrophilic aromatic substitution (EAS) and benzene, but guess what? There’s even more to learn! In this episode of Crash Course Organic Chemistry we’ll revisit our old friends the Friedel-Crafts...

Today we're going to talk about Chi-Square Tests - which allow us to measure differences in strictly categorical data like hair color, dog breed, or academic degree. We'll cover the three main Chi-Square tests: goodness of fit test, test...

Today we are investigating our moral obligations to our parents and our families. Do we owe our parents anything as adults? Would it be a good idea to license parents? We’ll explore these questions as well as the ethics of care, and some...

Last week we talked about language and meaning. Today, Hank explores some of the things that complicate meaning and how we get around that. We’ll explain conversational implicature, the cooperative principle, and the four main maxims of...

Nearly 200 years ago, Alexis St. Martin was shot in the stomach. He was saved by local army doctor William Beaumont, but had to live out his remaining years with a gaping hole in the stomach -- allowing Beaumont to learn a lot about how...

It is now time to meet the system that helps your crazy brain stay in touch with the outside world. We follow up last week's tour of the central nervous system with a look at your peripheral nervous system, its afferent and efferent...

In which Adriene Hill and Jacob Clifford teach you about specialization and trade, and how countries decide whether they're going to make stuff or trade for stuff. You'll learn about things like comparative advantage, the production...

So far in this series we’ve focused on molecules with tens of atoms in them, but in organic chemistry molecules can get way bigger! Polymers are molecules that contain hundreds, thousands, or even millions of identical subunits. In this...

Hank talks about population genetics, which helps to explain the evolution of populations over time by combing the principles of Mendel and Darwin, and by means of the Hardy-Weinberg equation.

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...

Death is what fungi are all about. By feasting on the deceased remains of almost all organisms on the planet, converting the organic matter back into soil from which new life will spring, they perform perhaps the most vital function in...

Phil takes us for a closer (eye safe!) look at the two-octillion ton star that rules our solar system. We look at the sun's core, plasma, magnetic fields, sunspots, solar flares, coronal mass ejections, and what all of that means for our...

As we learn more about electricity, we have to talk about fields. Electric fields may seem complicated, but they're really fascinating and a crucial part of physics. In this episode of Crash Course Physics, Shini chats about capacitors,...

Language is complicated, especially in organic chemistry. This episode of Crash Course Organic Chemistry is all about nomenclature. We'll dive into IUPAC systematic naming of organic molecules, and get to practice with the help of three...

Hank explains the extremely complex series of reactions whereby plants feed themselves on sunlight, carbon dioxide and water, and also create some by products we're pretty fond of as well.

Today we're going to talk about how and why floods happen both in spite of, and because of, us. Specifically, we'll take a closer look at the island of Java, and its largest city, Jakarta, and explain the factors that lead to serious...

What comes to mind when you think of alcohol? Probably alcoholic drinks like beer or wine. But in organic chemistry alcohols are an important and versatile family of compounds. In this episode of Crash Course Organic Chemistry, we’ll use...

We get it, learning so many different organic reactions is probably giving you a headache, but hopefully this episode can help! We’re getting even deeper into carboxylic acid derivatives, some of which are used in common headache...

Hank takes you on a tour of your two-part autonomic nervous system. This episode explains how your sympathetic nervous system and parasympathetic nervous system work together as foils, balancing each other out. Their key anatomical...

In which John Green teaches you how to assess the sources of information you find on the internet. The growing suspicion of expertise is a growing problem on the internet, and it can be very difficult to figure out which sources are...

In which John Green teaches you about what is often called the Reagan Era. Mainly, it covers the eight years during which a former actor who had also been governor of the state of California was president of the United States. John will...