Social justice belongs in our schools, says educator Sydney Chaffee. In a bold talk, she shows how teaching students to engage in activism helps them build important academic and life skills -- and asks us to rethink how we can use...

What does a disgusting image have to do with how you vote? Equipped with surveys and experiments, psychologist David Pizarro demonstrates a correlation between your sensitivity to disgusting cues -- a photo of feces, an unpleasant odor...

It was the dawn of 1863, and London's not-yet-opened subway system - the first of its kind in the world - had the city in an uproar. Most people thought the project, which cost more than 100 million dollars in today's money, would never...

In ancient Greece, violent internal conflict between border neighbors and war with foreign invaders was a way of life, and Greeks were considered premier warriors. Sparta, specifically, had an army of the most feared warriors in the...

More than half of the world's population already lives in cities, and another 2.5 billion people are projected to move to urban areas by 2050. The way we build new cities will be at the heart of so much that matters, from climate change...

Infinitesimally small quantum dots can turn a window into a see-through solar panel!

Cinematic love stories come in all shapes and sizes. Movies are really good at both capturing and projecting emotions. And one of the best directors at the modern love story is Wong Kar-Wai. In this episode of Crash Course Film...

The 17th Century in Europe was pretty rough in a lot of ways. The Thirty Years War involved a lot of countries, and a lot of battles, and it was terrible for everyone involved, as wars have aa historical tendency to be. At the same time,...

At the end of the Civil War, the United States was still a very divided place. 700,000 people had died in a bitter fight over slavery. Reconstruction was the political process meant to bring the country back together. It was also the...

To move forward in the United States, we must look back and confront the difficult history that has shaped widespread injustice. Revisiting a significant yet overlooked piece of the past, Hasan Kwame Jeffries emphasizes the need to weave...

Asgard, a realm of wonders, was where the Norse Gods made their home. There Odin's great hall of Valhalla towered above the mountains and Bifrost, the rainbow bridge, anchored itself. Though their domain was magnificent, it stood...

On the coast of Northern Ireland, a vast plateau of basalt slabs and columns called the Giant's Causeway stretches into the ocean. The scientific explanation for this is that it's the result of molten lava contracting and fracturing as...

The words we use to describe our emotions affect how we feel, says historian Tiffany Watt Smith, and they've often changed (sometimes very dramatically) in response to new cultural expectations and ideas. Take nostalgia, for instance:...

Digital archaeologist Chance Coughenour is using pictures -- your pictures -- to reclaim antiquities that have been lost to conflict and disaster. After crowdsourcing photographs of destroyed monuments, museums and artifacts, Coughenour...

This is the story of how a young Englishman named William Shakespeare stormed London's theater scene in the late 16th century, and wrote a bunch of plays and poems that have had pretty good staying power. We'll learn about Shakespeare's...

Asteroid strikes get all the coverage, but "Medea Hypothesis" author Peter Ward argues that most of Earth's mass extinctions were caused by lowly bacteria. The culprit, a poison called hydrogen sulfide, may have an interesting...

Hank squares off against Crash Course Astronomy host Phil Plait in our special Valentine’s/Old Timey Medicine edition of SciShow Quiz Show!

Throughout six centuries, the Ghent Altarpiece, also called "The Adoration of the Mystic Lamb," has been burned, forged, and raided in three different wars. It is, in fact, the world's most stolen artwork— and is considered one of the...

Tech enthusiast Kevin Kelly asks "What does technology want?" and discovers that its movement toward ubiquity and complexity is much like the evolution of life.

Two extinct relatives of horses and rhinos are closely related to each other but have strikingly different body plans. How did two of the same kind of animal, living in the same place, end up looking so different?

Do you think you're good at spotting fake videos, where famous people say things they've never said in real life? See how they're made in this astonishing talk and tech demo. Computer scientist Supasorn Suwajanakorn shows how, as a grad...

Every new invention changes the world -- in ways both intentional and unexpected. Historian Edward Tenner tells stories that illustrate the under-appreciated gap between our ability to innovate and our ability to foresee the consequences.

When historians talk about the atrocities of the 20th century, we often think of those that took place during and between the two World Wars. But two months before the Rape of Nanking in China, and a year before Kristallnacht in Germany,...

Parallel Universes - Many Worlds