In order to understand how we study the universe, we need to talk a little bit about light. Light is a form of energy. Its wavelength tells us its energy and color. Spectroscopy allows us to analyze those colors and determine an object’s...

In the second video of our two-part series on HIV and AIDS, we look at the challenges that have kept scientists from developing a cure, and the treatments that have still managed to improve the outlook for those infected. Chapters View...

For years, astronomers have been unable to find up to half of the baryonic matter in the universe. We may just have solved this problem.

In this video Paul Andersen introduces electric charge. Electric charge has been studies by humans and was generalized by scientists such as Benjamin Franklin. The amount of charge in a system is conserved but individual charges can move...

Welcome to Crash Course Kids. In this first episode, Sabrina takes a look at why all living things need to eat. Plus, she shows you a way to investigate why all living things need to eat. This first series is based on 5th grade science....

In which Hank shows you that, while it may seem like the Universe is messing with us, equilibrium isn't a cosmic trick. Here, he shows you how to calculate equilibrium constant & conditions of reactions and use RICE tables all with...

Hank explains the power of solar energy and describes how it may fit into our diversified energy future.

The days of oil may be numbered, but there's another natural resource that's never been touched, Asteroids.

In this video Paul Andersen explains how energy can enter and leave a system. The amount of energy a substance can receive through heating or lose through cooling is measured using the specific heat capacity. Phase changing energy from...

Honeybees are some of nature's finest mathematicians. Not only can they calculate angles and comprehend the roundness of the earth, these smart insects build and live in one of the most mathematically efficient architectural designs...

In order to have a meaningful conversation about the dangers of radiation exposure, it’s important to be clear about just how much radiation we are dealing with. Unfortunately, the units we use are kind of a mess… but SciShow is here...

In this video Paul Andersen discriminates between spontaneous (or thermodynamically favored) processes and those that are not spontaneous. A spontaneous process requires no external energy source. If the enthalpy change in a reaction...

In this video Paul Andersen explains how the activation energy is a measure of the amount of energy required for a chemical reaction to occur. Due to the collision theory the activation energy requires proper energy and orientation of...

Upside Down Mountains in Real Life

Mr. Andersen contrasts nuclear reactions to chemical reactions. He explains the four main forces of nature; including gravity, electromagnetism, strong, and weak nuclear forces. He also explains how fusion differs from fission.

In this video Paul Andersen explains how the conservation of charge applies to objects in a system. When a charged object induces charge or conducts charge to a neutral object the net total of charge will not change. Grounding allows...

Ever wonder why something as heavy as a cruise ship could float above the water? Learn about displacement with Jessi and The Giant Squid, Squidstravaganza!

We’ve introduced the 0th and 1st laws of thermodynamics, so now it’s time to move on to the second law and how we came to understand it. We’ll explain the differences between the first and second law, and we’ll talk about the Carnot...

When ultraviolet sunlight hits our skin, it affects each of us differently. Depending on skin color, it'll take only minutes of exposure to turn one person beetroot-pink, while another requires hours to experience the slightest change....

No matter how full you are, it seems you can find room for dessert. It’s not your imagination, and once you understand why, you’ll see how you can use this weird quirk of your appetite to your advantage!

People have been using silkworm silk to make stuff for thousands of years, but spider silk could potentially be even more useful. It's stronger than steel, super stretchy, and could be made into anything from bridge cables to...

In this video Paul Andersen explains how air pollution is any chemicals in the atmosphere that negatively affect human health. Primary pollutants (like CO, VOCs, NOx, SO2, PM, and Lead) as well as secondary pollutants (like Ozone,...

As the cargo director on the maiden voyage of the S.S. Buoyant, you've agreed to transport several tanks containing the last specimens of an endangered fish species to their new aquarium. Unfortunately, the boat is battered by a fierce...

There's a game of Tetris happening on a global scale: The playing space is planet Earth, and all those pesky, stacking blocks represent carbon dioxide -- a greenhouse gas that is piling up ever more rapidly as we burn the fossil fuels...