An overview of backpropagation, the algorithm behind how neural networks learn.

Trees need water to grow, so how do Redwood trees get so big, despite the fact that it gets so dry?



First Grade Next Generation Science

Standards

Cr

osscutting Concept:...

Can we, as adults, grow new neurons? Neuroscientist Sandrine Thuret says that we can, and she offers research and practical advice on how we can help our brains better perform neurogenesis—improving mood, increasing memory formation and...

We finally have some results from the InSight lander’s measurements on Mars, and the Japanese Space Agency is moving forward with a probe that will explore Mars’s moons.

Meet AIVA, an artificial intelligence that has been trained in the art of music composition by reading more than 30,000 of history's greatest scores. In a mesmerizing talk and demo, Pierre Barreau plays compositions created by AIVA and...

Are parrots just good at imitating sounds or is there something else that separates them from other birds?

Today we’re going to go a little meta and talk about how computer science can support learning with educational technology. We here at Crash Course are big fans of interactive in-class learning and hands-on experiences, but we also...

Machines that can think, learn and adapt are coming -- and that could mean that we humans will end up with significant unemployment. What should we do about it? In a straightforward talk about a controversial idea, futurist Martin Ford...

Why are mosquito bites so itchy? Stop scratching while Jessi explains!

We already live among robots: tools and machines like dishwashers and thermostats so integrated into our lives that we'd never think to call them that. What will a future with even more robots look like? Social scientist Leila Takayama...

Today, in our final episode of Crash Course AI, we're going to look towards the future. We've spent much of this series explaining how and why we don't have the Artificial General Intelligence (or AGI) that we see in the movies like...

We've all dreamed of flying -- but for Richard Browning, flight is an obsession. He's built an Iron Man-like suit that leans on an elegant collaboration of mind, body and technology, bringing science fiction dreams a little closer to...

In which John Green teaches you about World War 2, as it was lived on the home front. You'll learn about how the war changed the country as a whole, and changed how Americans thought about their country. John talks about the government...

Rita Pierson, a teacher for 40 years, once heard a colleague say, "They don't pay me to like the kids." Her response: "Kids don't learn from people they don't like.'" A rousing call to educators to believe in their students and actually...

Going to school in a refugee camp can be complicated: students encounter crowded classrooms, rigid curricula and limited access to teachers. Joel Baraka, who grew up in the Kyangwali refugee camp in Uganda, is determined to change that...

The leaves are falling from the trees and the air is getting chilly where Jessi and Squeaks live, which can only mean one thing: it's fall! And to celebrate the season, they've put together a bunch of videos about all the fun things you...

Mister Brown gets a video message from his friend, Ariel Waldman, a real scientist who went all the way to Antarctica to study life that lives under the ice!

Hank gives you a sneak peek into SciShow - a new YouTube program that just might change the way you look at your planet, your universe, and even yourself.

Jessi's in her lab mixing up something scary cool: potions! Join her to learn about different kinds of mixtures and how you can mix up your own potions using things you have at home!

Who says change needs to be hard? Organizational change expert Jim Hemerling thinks adapting your business in today's constantly-evolving world can be invigorating instead of exhausting. He outlines five imperatives, centered around...

Jessi and Squeaks are having pancakes, but first they have to make a key ingredient: butter!

After leading a well-established life as a pastor, father and husband, Paula Stone Williams could no longer deny her truth and transitioned. In this conversational and at times humorous reflection, Williams offers her perspective on the...

Road trips can be fun, but have you ever gotten sick from riding in a car? That's called motion sickness, and it turns out that it's a really common problem!

Army ants move around a lot, which means they can't build a nest like other ants do. So, to build their shelters, they came up with another, way weirder solution...