Hank veers away from human anatomy to teach us about the (mostly) single-celled organisms that make up two of the three taxonomic domains of life, and one of the four kingdoms: Archaea, Bacteria, and Protists. They are by far the most abundant organisms on Earth, and are our oldest, oddest relatives.

You're being watched. That sounded more sinister than I intended, but online, it's true. Facebook, Instagram, Amazon, Netflix... the list goes on and on. They're watching what you do, what you shop for, what you watch... all of it. And have you actually read the Terms of Service? In this episode of Crash Course Media Literacy, Jay talks about how Online Advertising works and why companies want to know everything you're looking at.

So as you may have noticed from last episode, computers keep getting faster and faster, and by the start of the 1950s they had gotten so fast that it often took longer to manually load programs via punch cards than to actually run them! The solution was the operating system (or OS), which is just a program with special privileges that allows it to run and manage other programs. So today, we’re going to trace the development of operating systems from the Multics and Atlas Supervisor to Unix and MS-DOS, and take at look at how these systems heavily influenced popular OSes like Linux, Windows, MacOS, and Android that we use today.

Today we're going to talk about p-hacking (also called data dredging or data fishing). P-hacking is when data is analyzed to find patterns that produce statistically significant results, even if there really isn't an underlying effect, and it has become a huge problem in science since many scientific theories rely on p-values as proof of their existence! Today, we're going to talk about a few ways researchers have "hacked" their data, and give you some tips for identifying and avoiding these types of problems when you encounter stats in your own lives.

Last week we introduced p-values as a way to set a predetermined cutoff when testing if something seems unusual enough to reject our null hypothesis - that they are the same. But today we’re going to discuss some problems with the logic of p-values, how they are commonly misinterpreted, how p-values don’t give us exactly what we want to know, and how that cutoff is arbitrary - and arguably not stringent enough in some scenarios.

This week, Stan teaches you about patents. It turns out, they're patently complicated! So, patents have some similarity to copyright, in that they grant a limited monopoly to people who invent things. The key difference in patents and copyright is that patents are for THINGS. Copyright is for an idea. So, if you've come up with a great new invention, like for example, a condiment gun, you should get a patent. We'll also talk about some of the limitations and problems of patents, including patent trolls

This week, we're going to Italy for a Renaissance. The Middle Ages are over, and it's time to talk about the flourishing of art and humanism across Europe. Painting, sculpture, music, architecture, and plays with fart jokes were all thriving between from 1300 - 1500, and we're going to teach you about the theatrical aspects of that flourishing, as it happened in Italy.

In which John compares and contrasts Greek civilization and the Persian Empire. Of course we're glad that Greek civilization spawned modern western civilization, right? Maybe not. From Socrates and Plato to Darius and Xerxes, John explains two of the great powers of the ancient world, all WITHOUT the use of footage from 300.

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 introduction of the Altair 8800 in 1975. In the years that follow, we'll see the founding of Microsoft and Apple and the creation of the 1977 Trinity: The Apple II, Tandy TRS-80, and Commodore PET 2001. These new consumer oriented computers would become a huge hit, but arguably the biggest success of the era came with the release of the IBM PC in 1981. IBM completely changed the industry as its "IBM compatible" open architecture consolidated most of the industry except for, notably, Apple. Apple chose a closed architecture forming the basis of the Mac Vs PC debate that rages today. But in 1984, when Apple was losing marketshare fast it looked for a way to offer a new user experience like none other - which we'll discuss next week.

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.

Hank describes why plants are so freaking amazing - discussing their evolution, and how their cells are both similar to & different from animal cells.

Hank gets into the dirty details about vascular plant reproduction: they use the basic alternation of generations developed by nonvascular plants 470 million years ago, but they've tricked it out so that it works a whole lot differently compared to the way it did back in the Ordovician swamps where it got its start. Here's how the vascular plants (ferns, gymnosperms and angiosperms) do it.

We're going to finish up our discussion of p-values by taking a closer look at how they can get it wrong, and what we can do to minimize those errors. We'll discuss Type 1 (when we think we've detected an effect, but there actually isn't one) and Type 2 (when there was an effect we didn't see) errors and introduce statistical power - which tells us the chance of detecting an effect if there is one.

Today we’re going to finish up our unit on data visualization by taking a closer look at how dot plots, box plots, and stem and leaf plots represent data. We’ll also talk about the rules we can use to identify outliers and apply our new data viz skills by taking a closer look at how Justin Timberlake’s song lyrics have changed since he went solo.

While politics is generally seen as the domain of a civics class (and Craig did a great job of teaching US Government & Politics elsewhere on this channel!) it’s something that sociology is interested in too. Today we’re looking at the sociological approach to politics, different types of authority and political systems, and different sociological theories of power.

Hank talks about the last major way humans are impacting the environment in this penultimate episode of Crash Course Ecology. Pollution takes many forms - from the simplest piece of litter to the more complex endocrine distruptors - and ultimately, humans are responsible for it all.

We’re continuing our look at engineering materials with third main type of material that you’ll encounter as an engineer: polymers. They’re made of long, repeating chains of smaller molecules known as monomers and today we’ll explore their strange history of polymers and the things that contributed to how we use them today.

Population ecology is the study of groups within a species that interact mostly with each other, and it examines how they live together in one geographic area to understand why these populations are different in one time and place than they are in another. How is that in any way useful to anyone ever? Hank uses the example a of West Nile virus outbreak in Texas to show you in this episode of Crash Course: Ecology.

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.

We’re continuing our unit on health with a discussion of some of the indicators that help us measure health for different populations. We’ll also explore three contributors to health disparities: individual factors like genetics, physical factors like pollution, and social factors like stress.