It’s all about the constants you start with, but if you think any aliens out there are exploring the galaxy at 10 percent of the speed of light, as physicist Rasmus Bjork proposes, then it’s not surprising that we haven’t met any yet (and aren’t likely to for a very long time).

Security cameras in the United Kingdom are getting an “upgrade:” now they sport speakers so the bored camera jockey can yell at you when you deviate from his definition of social norms. [slashdot]

David software lets you scan an object in 3D using a webcam, the corner of your room, and a laser pointer. Best of all, it’s free software. [engadget]

…the explosive kind. A researcher at MIT has developed a device that energizes a minefield with ultrasonic sound, then finds the buried mines by watching the sympathetic vibration with lasers. It burns out after only a few uses now, but if they can overcome that drawback it could be a more accurate and safer means of clearing mines.

The Mag-Wind vertical magnetically levitating turbine is almost pretty. Almost. But I could forgive a minor offense against aesthetics if their almost-too-good-to-be-true statistics are right: 1100kWh per month in a 13 mph average wind, at 3.5 cents per kW. [treehugger]