Driving Me Up a Wall

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

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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.

Ph'amazing

Top 10 physics videos (which constitutes a full rebuttal to the “Top 10 Amazing Chemical Reactions” I had linked to earlier, and had only rebutted with a single physics video, which is #5 on the list.)

You’ll also note that two of the so-called chemical reactions are properly classified as being in the physics videos (Meissner effect and breathing helium/sulphur hexafluoride). Ha! Take that, chemistry. You’re down to a top 8! (Without even arguing that floating a boat of air of the sulphur hexafluoride is a physics effect as well)

(Note the flash photography during the musical tesla coil video. Gee, I wonder if that helps?)

via The Great Beyond, which adds two Feynman drumming videos to the list. Wait, that’s twelve! Twelve videos! (A, ha, ha, ha. I love to count science videos!)

FAIL

The fastest clock in the world, my ass.

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Oooooh. It displays six whole digits past the decimal. Down to the microsecond. (can you sense the sarcasm?) It’s a display. Just because it reads that many digits doesn’t mean the measurement actually has that precision.

I’ve wanted to get a display that went to the picosecond for the lab, but have it flash 12:00:00.000000000000 the whole time. Add it to the list of my unadopted suggestions.

“I see no progress in this industry. These clocks are no faster than the ones they made a hundred years ago.” — Henry Ford

Polarized, Non-politically

I’ve inadvertently (and advertently) been doing some experimentation with polarized light lately. Liquid Crystal Displays (LCD) typically emit linearly polarized light, and most decent sunglasses act as polarizing filters. This can cause some problems, if you happen to have some gadget whose display is inconveniently set to emit light with horizontal polarization — since reflected light tends to become polarized parallel to the surface from which it reflects, sunglasses are made to filter that light. But it also makes it tough to read any LCD that is oriented to emit that polarization.

There are ways around this, though. I’ve noticed that my iPod screen (unlike my GPS receiver and watch) doesn’t go black at any orientation of my sunglasses, though I do get some shifting rainbows on the screen. Here are two orthogonal orientations of a linear polarizer:

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