Today, we’re going to take a look at how computers use a stream of 1s and 0s to represent all of our data - from our text messages and photos to music and webpages. We’re going to focus on how these binary values are used to represent numbers and letters, and discuss how our need to perform operations on larger and more complex values brought us from our 8-bit video games to beautiful Instagram photos, and from unreadable garbled text in our emails to a universal language encoding scheme.

Hank lets us in on the meaning of life, at least from a biological perspective - it's reproduction, which answers the essential question of all organisms: how do I make more of myself? So, sex, how does it work?

In which John Green returns to teaching World History! This week, we'll be talking about the idea of civilization, some of the traditional hallmarks of so-called civilization, and why some people would choose to live outside the civilization model. It turns out, not everyone who lives outside of what we traditionally think of as a "civilized" social order is necessarily a barbarian! To defuse any tension you may be feeling, I'll just tell you now, the Mongols are back. You'll learn about Zomia, swidden agriculture, and even a little about anarchy!

How do we design the most efficient machines and processes? Today we’ll try to figure that out as we discuss heat & work, reversibility & irreversibility, and how to use efficiency to measure a system.

At the turn of the 18th century, audience were ready to go over the top, and get some really, really dramatic theater in their lives. Like, a dog dueling a man type of dramatic. In London, only two theaters were licensed, but entertainment entrepreneurs figured out that musical entertainments weren't subject to the same restrictions. So, incidental music was invented, and the melodrama was born. And then switched with another infant. And later tied to train tracks, but rescued at the last minute. And so forth.

In which John Green talks about the methods of writing history by looking at some of the ways that history has been written about the rise of the West. But first he has to tell you what the West is. And then he has to explain the Rise of the West. And then he gets down to talking about the different ways that historians and other academics have explained how the West became dominant in the world. He'll look at explanations from Acemoglu and Robinson's "Why Nations Fail," Francis Fukuyama's "The Origins of Political Order," and Ian Morris's "Why the West Rules, for Now."

Today we're going to talk about robots! Robots are often thought as a technology of the future, but they're already here by the millions in the workplace, our homes, and pretty soon on the roads. We'll discuss the origins of robotics to its proliferation, and even look at some common control designs that were implemented to make them more useful in the workplace. Robots are often thought of as a menace or danger to society, and although there definitely is the propensity for malicious uses, robots also have the potential to drastically improve the world.

The Romans developed a lot of infrastructure like roads and aqueducts to both help their cities flourish and to... you know... be better at war. But the interesting thing about Roman Engineering is how it was almost all focused on Techne and not Episteme. In this episode of Crash Course History of Science, Hank takes us down the road of road building, domes, and some really cool cement.

In which Mike delves into the theater of ancient Rome. It wasn't all gladiators and Christian-killing, you know. There was theater, too. Roman drama drew heavily on Greek drama. So heavily, in fact, that many of the stories and characters were lifted directly from Greek plays. This time around, you'll learn about Plautus, Terence, and Seneca, and just what they owe to Menander.

Today we’re going to talk about good and bad surveys. From user feedback surveys, telephone polls, and those questionnaires at your doctors office, surveys are everywhere, but with their ease to create and distribute, they're also susceptible to bias and error. So today we’re going to talk about how to identify good and bad survey questions, and how groups (or samples) are selected to represent the entire population since it's often just not feasible to ask everyone.

In which John Green teaches you about Nationalism. Nationalism was everywhere in the 19th century, as people all over the world carved new nation-states out of old empires. Nationalist leaders changed the way people thought of themselves and the places they lived by reinventing education, military service, and the relationship between government and governed. In Japan, the traditional feudal society underwent a long transformation over the course of about 300 years to become a modern nation-state. John follows the course of Japanese history from the emergence of the Tokugawa Shogunate to the Meiji Restoration, and covers Nationalism in many other countries along the way. All this, plus a special guest appearance, plus the return of an old friend on a extra-special episode of Crash Course.

In the second half of our education unit, we’re using conflict theory to explore a few social inequalities in the US education system. We’ll look at variation in school funding and quality, the role of cultural capital, and some of the ways in which the American school system disadvantages minority students.

We’ve talked a lot in this series about how often you see data and statistics in the news and on social media - which is ALL THE TIME! But how do you know who and what you can trust? Today, we’re going to talk about how we, as consumers, can spot flawed studies, sensationalized articles, and just plain poor reporting. And this isn’t to say that all science articles you read on facebook or in magazines are wrong, but that it's valuable to read those catchy headlines with some skepticism.

Historically speaking, there is no one scientific method. There’s more than one way to make knowledge. In this episode we're going to look at a few of those ways and how they became more of the "norm."

So, what exactly is a scientific revolution? And are they more than just moments in time Historians use to mark the beginning and ending of things through time? In this episode we'll look into some ideas and people named Nick and how they fit into science and the search to understand ourselves and our place in the universe.

Hank introduces us to nonvascular plants - liverworts, hornworts & mosses - which have bizarre features, kooky habits, and strange sex lives. Nonvascular plants inherited their reproductive cycle from algae, but have perfected it to the point where it is now used by all plants in one way or another, and has even left traces in our own reproductive systems.

While sociology is a social science, we can use it to explore some intensely personal, private things. Today we’ll explore what sociology can tell us about sex and sexuality. We’ll also see what the three sociological paradigms have to say about sexuality and sexual orientations.

Shakespeare's tragedies...were tragic. But they had some jokes. They also changed the way tragedies were written. Characters like Hamlet, Macbeth, and King Lear had tragic outcomes, but they were sympathetic characters in a lot of ways. This was a big change from the way Seneca and the Greeks wrote tragedies, and it caught on.

When collecting data to make observations about the world it usually just isn't possible to collect ALL THE DATA. So instead of asking every single person about student loan debt for instance we take a sample of the population, and then use the shape of our samples to make inferences about the true underlying distribution our data. It turns out we can learn a lot about how something occurs, even if we don't know the underlying process that causes it. Today, we’ll also introduce the normal (or bell) curve and talk about how we can learn some really useful things from a sample's shape - like if an exam was particularly difficult, how often old faithful erupts, or if there are two types of runners that participate in marathons!

Today we’re looking at silicon, and how introducing small amounts of other elements allow silicon layers to conduct currents, turning them into semiconductors. We’ll explore how putting two different types – N and P semiconductors – together gives us electrical components like diodes, transistors, and solar cells.