Category Archives: Cool stuff

Cool in a geeky way, at least.

Phenomenal Flickr Fun

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The Shape of Alpha

Using Where-On-Earth geotagged photos uploaded to Flickr, one is often able to reverse-engineer maps, sometimes even at the neighborhood level.

Over time this got us wondering: If we plotted all the geotagged photos associated with a particular WOE ID, would we have enough data to generate a mostly accurate contour of that place? Not a perfect representation, perhaps, but something more fine-grained than a bounding box. It turns out we can.

via Kottke

Frozen Waterfalls

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10 Most Incredible Waterfalls of Ice

BP (before physics) I used to wonder how waterfalls could freeze. But if one looks at the physics, it’s apparent that the motion of water moving in a stream, river or waterfall is small compared to the thermal motion, so this motion really has little effect.

Take a peek at picture #5, showing the frozen outer cylinder, with water still falling inside of it.

Driving Me Up a Wall

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Air Hog Zero G micro car. Think “reverse hovercraft” — a fan inside makes it hug the wall or ceiling.

You need to a flashplayer enabled browser to view this YouTube video

The car is 6″ long and perhaps 3″ wide, and the shipping weight of the whole thing is 2 lbs, so let’s say that 1 lb is for the car. (sorry, no SI units for this. Imperial units given, and this is just a quick ‘n dirty analysis) So you need somewhere around 0.1 psi of pressure differential generated by the fan to have it “stick” to the ceiling.