On earth a sound echo lets you hear something again. Over great distances, a light echo can let you see something again, specifically an exploding star.

Talk Show: Henry Reich, Fluorescence, and a Half-moon Conure

A clever mechanical proof of Snell's law.

Paul Andersen explains how biogeochemical cycling is used to move nutrients from the environment into living material and back again. He explains the water cycle, the carbon cycle, the nitrogen cycle and the phosphorus cycle. He also...

Sam the Bat noticed that some stars are different colors, so Mister Brown teaches him about what colors stars can be, and what all the colors mean!



Next Generation Science
Standards
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Patterns:...

In this video Paul Andersen explains how classical waves (like light) can have particle properties. Albert Einsetein used the photoelectric effect to show how photons have particle properties.

While not used much any more as a primary source of light, candles are still everywhere, from an aroma in a bathroom to a mood during dinner. That is, until they’re gone.

We know more about some other planets than we do about the deepest corners of Earth's oceans, and the species we've found there are almost alien. Here's some of the most unbelievable oddities ever observed! Special thanks to the Monterey...

Statistically, the least reliable part of the car is ... the driver. In 2015, Chris Urmson was head of Google's driverless car program, one of several efforts to remove humans from the driver's seat. He shares fascinating footage that...

If you’ve been brave enough to open your eyes underwater, you might have noticed that everything is blurry. But fish have no trouble finding their way beneath the waves. So why can’t we see as clearly below as we do above?

Did Thomas Edison invent the lightbulb? I mean... kind of... but also... no. Every great, world-changing invention is the culmination of efforts by dozens or hundreds of people, spanning decades or centuries.

You might have wondered why bumblebees stop for a moment to stare at the flower they were just interacted with. Are they cherishing all the good times they had together, or is this behavior serving a biological purpose?

Did you play with glow in the dark toys as a kid? They’re super cool, but kind of mysterious. How do they glow after all? Hank explains the phenomenon in this quick question.

Researchers found water in the atmosphere of an exoplanet about 110 light-years away, and there's another rock from interstellar space flying through our solar system!

This week, John is talking about Toni Morrison's novel of friendship, betrayal, and loss, Sula. Sula tells the story of two African American girls, the town where they grew up, the tragic even that was central to their youth, and the...

Is there life on Venus? Quantum astrochemist Clara Sousa-Silva makes the case for a new way to seek and possibly discover habitable planets -- and shares her research into a poisonous, smelly molecule that might signal life beyond Earth.