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 agricultural systems into three scales: subsistence, small-scale, and industrial agriculture. And we’ll take a look at how a place's history plays a huge role in the system we see today as we follow the story of agriculture in the Philippines.

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 what we’re going to wear everyday, it dictates the kind of foods we can grow, how we build our cities and roads, and the kinds of industries that can even exist in a location. And in a region like Siberia, where it can get cold, like REALLY COLD, the air temperature has had an incredible impact on life. But before we end this episode we’ll warm up with a visit to Phoenix, Arizona to talk about how they too have to make a lot of decisions due to the extreme heat of a city in the middle of the desert.

From cave paintings to public murals, humans have told stories with art for thousands of years. In this episode of Crash Course Art History, we discover that visual storytelling is elementally human — and so is competing over whose story is told.
Chapters:
Introduction: Narrative Art
History as Story
Contradictory Stories
Official & Unofficial Stories
Review & Credits
Credits

From outbreaks of measles in the United States and cholera in Haiti to patterns of lead poisoning near gold mines in Nigeria, medical geographers play an important role in tracking disease in the landscape. Today, we're going to look at strategies medical geographers use to help as many people as possible achieve the highest level of health possible.

While we can’t explore every cultural trait in the world, language is an important system of spoken, signed, or written symbols humans use to express themselves. It’s a major marker of identity that often unites members of the same nation, or people with similar cultural identity.
And it’s a cultural trait that has enormous power because language helps other cultural traits move through the spoken, visual, tactile, and musical word. So today, we’re going to explore how words move, because the activities that prompt that movement can tell us a lot about how ideas as well move around the world.

Public health activities are all the ways society coordinates to deliver better health to people. That may sound super broad, and it is, so in this episode of Crash Course Outbreak Science, we'll take a look at public health works to prevent outbreaks. We'll learn what public health is and what public health agencies do, look at the three tiers of public health responses, and revisit one of our favorite fictional cities to see these responses in action.

Cliffs and canyons, beaches and dunes, floodplains and river valleys, plateaus and mountains — these are all products of a restless Earth. In today’s episode we’re going to take a closer look at how landforms greatly influence how people live and derive meaning and a sense of place. From the hills and ponds we see everyday to impressive landscapes like Uluru in Australia or the Kamchatka Peninsula in Russia they all have stories to tell.

Today, we're going to talk about how the Earth moves, but to do that, we're going to have to go way back to the early days of the galaxy! Processes that happened before the Earth even formed have led us to the geographic patterns and processes that create Earth's environments and support all living things. We'll talk about how the Earth rotates, the effects of it being slightly tilted, how events like sea ice melting impact how the Earth wobbles, and of course talk about how our elliptical orbit gives us seasons. So many of our life decisions are influenced by the motion of Earth. It guides where we decide to live, what food we eat, or even what weather we experience - which we'll talk about more next time.

Day to day, hospitals provide all kinds of services to help us get better and stay healthy, but during an outbreak, hospitals are the front line of the emergency. In this episode of Crash Course Outbreak Science, we'll look at how hospitals and other healthcare facilities adapt in the face of an outbreak, from resources needs, the roles of healthcare workers, and costs.

In this episode we looked at robots and the engineering principles of robots. We learned how robots use sensors to interpret their environment, how actuators and effectors allow a robot to manipulate the objects around it to accomplish a task, and how computers coordinate the efforts of the two.

If nearly all your cells have the same DNA, why are muscle cells so different from skin cells? In this episode, we’ll learn how gene expression is regulated in eukaryotes, and how methylating DNA, modifying histones, and messing with translation not only leads to different types of cells, but allows cells to adapt to the world around them.
Chapters:
Introduction: A Cellular Cookbook
Gene Regulation
Differential Gene Expression
Gene Regulation Strategies
Epigenetic Mechanisms
Review & Credits
Credits

In our last episode, Dr. Katie Mack and John Green discuss what the ultimate fate of the universe might look like.

If you’ve been paying attention to the news since, oh, say, 2020, then you’ll no doubt be aware that public health policy can often create tension. Having policies that affect public health can, and does, save lives, but not all policies affecting our health are “health policies.” Don’t worry, we’re going to break it all down in this episode of Crash Course Public Health, where we will discuss how an orthopedic surgeon’s love of racing helped create seatbelt policies in the US, and why sometimes laws governing what can be built where affect our health.

Chapters:
Seat Belts & Your Health
Understanding Health & Policy
Vaccination Policies
How Policies Save Lives
Who Makes Health Policy?
Review & Credits
Credits

Here on Earth, life is dizzyingly diverse—but it’s also surprisingly organized. A sense of order structures life and its processes, from the tiniest cell to the total sum of every living thing. In this episode of Crash Course Biology, we’ll uncover the levels of biological organization, discover soil’s superpowers, and find out why the biosphere is kind of like a really, really long train.

Chapters:
Life's Layers
Themes of Life
Form Fits Function
Regulation
Levels of Organization
Life's Flows
Review & Credits
Credits

When we think of world religions, we often think of the Big Five: Judaism, Christianity, Islam, Hinduism, and Buddhism. But why do we think of those? In this episode of Crash Course Religions, we’ll learn why “world religions” is a category constructed by human choices—and why that matters for the communities that are left out.
Chapters:
Introduction: "Coexist"
The "Big Five"
Colonialism & Religion
"World Religions"
Family Resemblance
Essentialism & Nationalism
The Limits of "Major Religions"
Review & Credits
Credits

Today we’re going to explain how exchangers...exchange heat. We’ll look at concentric tubes, finned tubes, plate heat exchangers, and shell-and-tube heat exchangers. And we’ll look at some equations to help us sort through heat transfer and decide what heat exchangers are best suited for our designs.

Today we're going to begin our three-part unit on p-values. In this episode we'll talk about Null Hypothesis Significance Testing (or NHST) which is a framework for comparing two sets of information. In NHST we assume that there is no difference between the two things we are observing and and use our p-value as a predetermined cutoff for if something seems sufficiently rare or not to allow us to reject that these two observations are the same. This p-value tells us if something is statistically significant, but as you'll see that doesn't necessarily mean the information is significant or meaningful to you.

Is the world overpopulated or underpopulated? While we worry about there being too many people for the planet to support, we can also worry about how fewer people in a given place may affect the economy, what may happen when there are more elderly people who need care than there are healthcare workers, or even be concerned about how many people are necessary to carry on other aspects of culture. Today, we'll discuss Malthusian and Boserup predictions on the planet's carrying capacity and take a close look at a popular demography tool geographers use to predict population change: the Demographic Transition Model or DTM.

In this episode of Crash Course Physics, Shini talks to us about how power gets to our homes. It's kind of amazing when you think about it and much more complicated than it may seem!

This week Craig Benzine talks about how the President gets things done. Filling the role of the Executive Branch is a pretty big job - much too big for just one person. It's so big that the President employs an entire federal bureaucracy! Today, we’re just going to focus on those closest to the President, like the Vice President, the Cabinet, and the Executive Office of the President. We’ll figure out which strategy is most useful in helping the President make things happen and we’ll discuss the controversy around the President’s gradual increase in power. Oh, and as many of you noticed - last episode eagle got off too easy. Let’s see if we can make it up to you.

Chapters:
Introduction: Governing
Who makes up the Executive Branch?
Who makes up the Executive Office of the President?
Independent agencies & government corporations
How the President can use party leadership to govern
How the President can use the media to shift public opinion
How the President can use administrative strategy to govern
Why Presidents rely on administrative strategies
Credits