Buckle up for a trip to the asteroid belt -- though it's not nearly as dangerous out there as you might think. But there's a LOT waiting to be discovered, including some crucial clues about the formation of the solar system itself.

You may know it as a miracle powder or an ice cream flavor, but activated charcoal can do some pretty cool stuff.

The perfect balance of radioactive elements inside planets like ours might make it habitable, and researchers are challenging some ideas about how Mars is losing its water.

In this video Paul Andersen explains how light that is perfectly reflected creates specular reflection. The angle of the incident ray is equal to the angle of the reflected ray. Specular reflection is also known as mirror-like...

The hair on your scalp can get really long, but your leg hair doesn't sweep the floor. Why not?

In this video Paul Andersen explains how light can be refracted, or bent, as it moves from one medium to another. The amount of refraction is determined by the angle of incidence and the index of refraction. Snell's Law can be used to...

We have a lot of water on Earth, but we also can't actually drink much of it... or use it for farming. That's because most of the water on Earth is saltwater. We humans, like a lot of living things, need freshwater to survive. In this...

In February of 1942, Mexican farmer Dionisio Pulido thought he heard thunder coming from his cornfield. However, the sound wasn't coming from the sky. The source was a large, smoking crack emitting gas and ejecting rocks, and would come...

The Arab-Israeli Conflict, which is the ongoing political tensions and military conflicts between Arab nations and Israel, is one of the longest and most complex disputes in the world. Today, we're going to focus on more recent events,...

In this video Paul Andersen explains how the gravitational field strength is directly related to the mass of the object and indirectly related to the square of the distance from the center of mass. The equation for gravitational field...

In this video Paul Andersen compares and contrasts the properties of solids and liquids. Solids have a more organized structure which can either be amorphous or crystalline. In liquids the intermolecular forces are lower and so the...

Did you know we can actually make diamonds in a lab? It's true! We can! And this is both really good and really cool. In this episode of Crash Course Kids, Sabrina shows us how materials scientists have done just that and why it's so...

Writing a great English paper can be tough because literature doesn't always reveal its deeper meanings immediately. You might not know Mr. Darcy's true feelings for Elizabeth Bennett in Jane Austen's Pride and Prejudice or grasp the...

Deep in the ocean, fluffy bits of organic matter fall like snow. But this marine snow isn’t just pretty; it’s an essential part of our ocean food webs and our global climate!

The welding process usually involves pretty extreme levels of heat. But it turns out that in the cold vacuum of space, metals can weld together... automatically.

Mountains are some of the biggest things in the world, but today, we're going to teach you how to make some of your own, right on your kitchen table!

Remember Sol, the closest star to Earth? We like to call it The Sun and we haven't talked about it in a little while. One interesting thing about the energy we get from the sun is that it's not absorbed the same way by different...

When you look at a picture of Mars next to a picture of Earth, you might notice one big difference: Earth is covered in blue oceans and Mars doesn't seem to have any water at all! But scientists have discovered all kinds of...

What is the maximum height for a mountain on Earth!? And why?

In the Zagros Mountains of Iran lie some strange, multi-colored glaciers that don’t melt, even in the heat of summer. But, in a rainstorm, these glaciers will start to dissolve away.

These days, it seems like we're finding water all over the solar system. Still, it takes a lot more than a little H2O to support life.

Glaciers might look like just lifeless frozen wastelands, but they are not! There are unique ecosystems hidden inside of them.

Paul Andersen explains the importance of blood types in blood transfusions. He starts with a brief discussion of blood antigens and antibodies. He describes how the ABO differs from the Rh blood type. He shows you how to solve simple...

Today we’re going to take a closer look at these beautiful but dangerous landforms as we explore the different types of volcanoes and trace the patterns of volcanic activity around the world. From the explosive power of a stratovolcano...