In this video Paul Andersen explains how the change in angular momentum is equal to the torque applied over a given time. A sample problem and inquiry activity are included.

Who invented microphones, PCs, and video game consoles? In honor of Black History Month, Hank talks about some African Americans scientist/inventors who've helped make all our lives more awesome.

Ocean explorer Robert Ballard takes us on a mindbending trip to hidden worlds underwater, where he and other researchers are finding unexpected life, resources, even new mountains. He makes a case for serious exploration and mapping....

This week Craig Benzine clears up the role of committees in Congress. We’ll talk about standing committees, joint committees, conference committees, and caucuses (and not the candidate-choosing kinds) as well as the staff agencies that...

The classical physics that we encounter in our everyday, macroscopic world is very different from the quantum physics that governs systems on a much smaller scale (like atoms). One great example of quantum physics' weirdness can be shown...

There's a region of Earth's atmosphere known as the South Atlantic Anomaly, and it’s one of the most dangerous near-Earth areas of space, both for satellites and humans.

What's your sign? In Western astrology, it's a constellation determined by when your birthday falls in the calendar. But according to the Chinese zodiac (__), it's your shuxiang, meaning the animal assigned to your birth year. And of the...

In this video Paul Andersen explains how the work is a product of the external force applied to an object or system and the distance it moves. Power is a measure of the amount of work done per unit time. The work can be calculated as...

We've talked about food chains and how energy moves through an ecosystem, but let's take a step back and see how everything starts... and ends. Decomposers! This first series is based on 5th grade science. We're super excited and hope...

You may not realize it, but your body is like a fortress, designed to defend you from tiny foreign invaders known as pathogens. This seemingly small world is actually super diverse, and sometimes super dangerous too. That’s why in this...

While we might consider elections to be the cornerstone of democracy, the Athenians who coined the term actually employed a lottery system to choose most of their politicians. Melissa Schwartzberg describes the ins and outs of the...

In which John Green examines the French Revolution, and gets into how and why it differed from the American Revolution. Was it the serial authoritarian regimes? The guillotine? The Reign of Terror? All of this and more contributed to the...

A SciShow Kids viewer wants to know: How Do Our Bodies Move? Jessi explains, while Squeaks works out!

Consider the following sentence: "This statement is false." Is that true? If so, that would make the statement false. But if it's false, then the statement is true. This sentence creates an unsolvable paradox; if it's not true and it's...

History's first empire rose out of a hot, dry landscape, without rainfall to nourish crops, without trees or stones for building. In spite of all this, its inhabitants built the world's first cities, with monumental architecture and...

How do coral reef conservationists balance the environmental needs of the reefs with locals who need the reefs to survive? Joshua Drew draws on the islands of Fiji and their exemplary system of protection, called "connectivity", which...

How do different societies establish a social hierarchy? Today we’re starting our unit on social stratification, starting with four basic principles of a sociological understanding of stratification. We’ll explain open and closed systems...

Fomalhaut is a massive young star surrounded by a ring of dust debris that can tell us a great deal about the formation of our own solar system.

Everything in our universe has mass - from the smallest atom to the largest star. But the amount of mass has remained constant throughout existence even during the birth and death of stars, planets and you. How can the universe grow...

The best way to make sure you're making the most of the time you have is to start off well organized. This week we're talking about planning and organizational systems and how to set yourself up for success.

Pick up a book, magazine or screen, and more than likely you'll come across some typography designed by Matthew Carter. In this charming talk, the man behind typefaces such as Verdana, Georgia and Bell Centennial (designed just for phone...

When humanity first landed on the moon in 1969, the typeface Futura was right there with them. In this fascinating history of typography, designer Douglas Thomas shares Futura's role in launching the Apollo 11 spacecraft -- and how it...

Historically speaking, there is no one scientific method. There's more than one way to make knowledge. In this episode we're going to look at a few of those ways and how they became more of the "norm."

Most history books will tell you that the Roman Empire fell in the fifth century CE, but this would've come as a surprise to the millions who lived in the Roman Empire through the Middle Ages. This Medieval Roman Empire, today called the...