Tag «Hank Green»

Crash Course European History Preview

Crash Course European History Preview

Hello and welcome to Crash Course History. I’m John Green; you may know me because I once hosted a series of Crash Course videos on world history, which depending on your perspective was either far too Eurocentric or not nearly Eurocentric enough. Well, we’re about to get rather Eurocentric, because over th… Mr. Green Mr. …

The Cosmic Lasers That Form in Outer Space

The Cosmic Lasers That Form in Outer Space

This episode is sponsored by The Ridge. Go to ridge.com/SciShow and use promo code “scishow” to get 10% off your next order. [♪ INTRO] Lasers are an incredible human invention. They’re basically a way to hack light and turn it into this narrow beam that can do things like cut through metal and also perform …

The Risky Paleo Diets of Our Ancestors

In 1973, a fossil hunter discovered the partial skeleton of a female Homo erectus in the Koobi Fora formation of northern Kenya. The specimen dated to 1.6 million years ago; today she’s known as KNM-ER 1808. Her skeleton was pretty complete, given its age, including parts of her skull, limbs, and pelvis. And the anthropologists …

Roman Engineering: Crash Course History of Science #6

Roman Engineering: Crash Course History of Science #6

The Romans invented concrete over two thousands years ago and built roads which are still around today. They used arches and domes to create monumental buildings with big airy interiors that looked truly Olympian—also still around. And they moved thousands of tons of water using aqueducts to keep a bustling population un-thirsty. These old buildings? …

When a Billion Years Disappeared

When a Billion Years Disappeared

When geologist Clarence Dutton first saw the Grand Canyon in 1880, he was spellbound by its colorful walls. The Grand Canyon’s walls are made up of rock layers, each representing a distinct period of Earth’s history. And some of the lower rock beds–deep down in the canyon–look kind of tilted. Dutton knew these layers were …

How Two Microbes Changed History

How Two Microbes Changed History

What if I told you that, more than two billion years ago, some tiny living thing started to live inside another living thing … and never left? And now, the descendants of both of those things are in you? Well, brace yourselves, because I gotta tell you about one of the biggest breakthroughs in the …