What makes dry quicksand so deadly?

Dry quicksand was a mythical substance — normal-looking sand that could swallow you in a flash. That is, until 2004, when scientists made the stuff in a lab. (Mark told you about that development.)

In this video, geologist Matt Kuchta explains how dry quicksand is different from both wet quicksand and stable sand. Hint: Think "Jenga".

Khan Academy explains SOPA/PIPA

The globally praised Khan Academy comes out against SOPA and PIPA in this explainer video, which does a really excellent job of digging into the implications for legitimate sites (like Khan Academy) in a world where SOPA/PIPA become law. This is a great explanation of what SOPA and PIPA means for people trying to communicate with a broader public, but one thing to keep in mind as you watch is that there's another constituency that's missing: all the people who are using the net for other reasons: people who want to post videos of human rights abuses, who want to talk with other sufferers from a rare disease, who want to privately share private family moments with distant relatives. All these constituencies depend on services like YouTube and Twitter as a platform for communications, too.

SOPA and PIPA (via Waxy)

Scary science, national security, and open-source research

I’ve been following the story about the scientists who have been working to figure out how H5N1 bird flu might become transmissible from human to human, the controversial research they used to study that question, and the federal recommendations that are now threatening to keep that research under wraps.

Read the rest

Why would a battery burst into flame?

In several crash tests, the battery on a Chevy Volt began to heat up or burst into flame. The battery problems happened a few days or weeks after the impact and the National Highway Traffic Safety Administration is investigating. (One potential factor: NHTSA testers didn't drain the batteries of juice after the crash, which is recommended. As a comparison, it's standard practice to drain a gas tank after a similar collision. So this could be an issue of new technology learning curve.) If you want to better understand why a battery that's been through a car accident could burst into flame, I'd recommend reading this piece by the Midwest Energy News. It's a nice summary of how lithium-ion batteries work, and how they respond to damage.