In this video Paul Andersen explains how waves interact with objects and with other waves. When a wave hits a fixed object it will be reflected and inverted. When a wave hits a free object it will be reflected without being inverted. ...

In which John Green continues discussing George Orwell's 1984. Today we're talking about what the novel 1984 has to say about what some have called today's surveillance society. We'll also look at the idea that language can be used as a...

Paul Andersen explains how natural selection is a major mechanism in evolution. The video begins with a discussion of Charles Darwin and the details of natural selection. The data of the peppered moth during the industrial revolution...

Is our universe a definitive single reality or is it merely one within an infinitely branching multiverse?

In this video Paul Andersen explains how covalent network solids form elementally (like graphite) or by combining multiple nonmetals (like quartz). Covalent network solids contain elements from the carbon group because they have four...

In 2006, Tarana Burke was consumed by a desire to do something about the sexual violence she saw in her community. She took out a piece of paper, wrote "Me Too" across the top and laid out an action plan for a movement centered on the...

In which John Green returns for a dystopian new season of Crash Course Literature! We're starting with George Orwell's classic look at the totalitarian state that could be in post-war England. Winston Smith is under the eye of Big...

Scientists often use the phrase “anatomically modern humans” to describe the point when our ancient ancestors looked like us. But when did humans become behaviorally modern?

There are aspects of computer code that look like language and some that seem more like algebra, and since we may be headed for a future where many people will need to learn to code, researchers are interested in figuring out how exactly...

In this video Paul Andersen explains how scientific theories are created and modified over time. He starts by discussing the theory of natural selection as a model for the creation and modification of theories. He gives examples of...

Modifiers are words, phrases, and clauses that add information about other parts of a sentence-which is usually helpful. But when modifiers aren't linked clearly enough to the words they're actually referring to, they can create...

Paul Andersen explains how mathematics and computational thinking can be used by scientists to represent variables and by engineers to improve design. He starts by explaining how mathematics is at the root of all sciences. He then...

In this video Paul Andersen explains how chemical reactions progress as bonds are broken and reformed reformed. He explains the difference between changes in state and changes in molecules. He discussed collision theory and explains...

Mr. Andersen walks you through the cellular respiration lab.

Neuroscientist uri Hasson researches the basis of human communication, and experiments from his lab reveal that even across different languages, our brains show similar activity, or become "aligned," when we hear the same idea or story....

You need social skills to have a conversation in real life -- but they're quite different from the skills you need to write good dialogue. Educator Nadia Kalman suggests a few "anti-social skills," like eavesdropping and muttering to...

Mr. Andersen shows you how to draw Lewis Dot Diagrams for atoms and simple molecules.

In this video Paul Andersen explains how the resources required for survival come from the Earth. The resources are not evenly distributed on the planet and neither are the humans. According to the NGSS we need to limit the use of...

The Zika Virus is spreading at an alarming rate. SciShow News will explain what we know and what we don't know thus far.

With enough passion and practice, becoming a slam poet is within your reach. Explore a distant memory on paper, then read it out loud. Edit. Try reading it out loud again, and add your finishing touches. Gayle Danley offers five steps to...

In this video Paul Andersen explains how biodiversity can be measured through genetic, species, or ecosystem variety on the planet. Species diversity is increased through speciation and decrease through extinction. The mechanism for...

Paul Andersen explains how eukaryotic cells were formed through a process of endosymbiosis. He describes how aerobic bacteria became mitochondria and cyanobacteria became chloroplasts. He mentions an example of symbiosis that occurs...

With candor and cunning, sex historian Kate Lister chronicles the curious journey of an ancient, honest word with innocent origins and a now-scandalous connotation in this uproarious love letter to etymology, queens, cows and all...

Infectious disease has affected the human species for as long as we’ve existed, but in that time we’ve come a long way in understanding what they are and how they spread. In this episode of Crash Course Outbreak Science, we’ll introduce...