How does ultrasound work?
Lesson duration 05:16
In a dark cave, bats can’t see much. But even with their eyes shut, they can navigate rocky...
Lesson duration 05:16
In a dark cave, bats can’t see much. But even with their eyes shut, they can navigate rocky...
Lesson duration 05:07
Satan, the beast crunching sinners’ bones. Lucifer, the fallen angel. Mephistopheles, the...
Lesson duration 04:58
Fourteen Greenlands could fit in Africa— but you wouldn’t guess it from most maps of the world....
Lesson duration 06:17
In this quick, fun talk, astronaut Cady Coleman welcomes us aboard the International Space...
Lesson duration 05:43
After much debate, the realm has decided dragon jousting may not be the best way to choose its...
Lesson duration 05:42
In 1478, Pope Sixtus IV issued a decree authorizing the Catholic monarchs, Ferdinand and...
Lesson duration 04:16
If you look at the wake behind a duck, or a kayak, or a ship, you might notice two things: first,...
Lesson duration 04:41
Historically, most cars have run on gasoline, but that doesn’t have to be the case in the future:...
Lesson duration 12:23
In 2017, Priya Vulchi and Winona Guo traveled to all 50 US states, collecting personal stories...
Lesson duration 04:51
In the 1950s, the discovery of two new drugs sparked what would become a multi-billion dollar...
Lesson duration 04:48
No matter how we make electricity, it takes up space. Coal requires mines, and plants to convert...
Lesson duration 05:10
As a breeze blows through the savannah, a snake-shaped tube stretches into the air and scans the...
Lesson duration 04:57
Today, artificial intelligence helps doctors diagnose patients, pilots fly commercial aircraft,...
Lesson duration 05:02
All around the world, millions of people are flipping a switch, plugging in, and pressing an ‘on’...
Lesson duration 06:10
For over 30 years, thousands of people were imprisoned, tortured, and murdered under Rafael...
Lesson duration 11:43
In this revelatory talk, gynecologist and author Jen Gunter explains how menstrual shame silences...
Lesson duration 01:30
Sir Ken Robinson believed that humans have an inexhaustible power: our imaginations. We don't...
Lesson duration 05:10
After a concert, you find it difficult to hear your friend rave about the show. It sounds like...
Lesson duration 05:27
Today roads, sidewalks, bridges, and skyscrapers are made of a material called concrete (aka...
Lesson duration 04:43
In the 1860’s, 11 southern states withdrew from the United States and formed the Confederacy....
Lesson duration 12:02
When one of Liz Kleinrock's fourth-grade students said the unthinkable at the start of a class on...
Lesson duration 05:06
Once a year, thousands of logicians descend into the desert for Learning Man. At the center of...
Lesson duration 15:37
Since the start of the coronavirus COVID-19 pandemic, the term “herd immunity” has been all over...
Lesson duration 05:16
As of 2020, the world’s biggest lithium-ion battery is hooked up to the Southern California power...