Chronicle: For the past four years, Salman Khan has been posting brief video lessons to what he calls the Khan Academy on YouTube, the video-sharing site. The lessons are popular. Hundreds of thousands of people have viewed them. A former financial analyst, Khan focused first on math and other topics he knows best. Now, he teaches about topics he’s had to learn about himself, such as entropy. A news story by the Chronicle‘s Jeffrey Young examines the Khan Academy and its implications for online education.
The finding that the Saturnian moon may host layers of icy slush instead of a global ocean could change how planetary scientists think about other icy moons as well.
Modeling the shapes of tree branches, neurons, and blood vessels is a thorny problem, but researchers have just discovered that much of the math has already been done.
January 29, 2026 12:52 PM
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