Archive for August 10th, 2009

Driving Cognitive Costs Down

Realizations of Rounded Rectangles

Time for an expert: I asked Professor Jürg Nänni, author of the exemplary Visual Perception, a book detailing our best-to-date scientific understanding of the processes involved in visual cognition. “Could rounded rectangles actually take less effort to see?”

Nänni confirmed my theory: “You are absolutely right. A rectangle with sharp edges takes indeed a little bit more cognitive visible effort than for example an ellipse of the same size. Our “fovea-eye” is even faster in recording a circle. Edges involve additional neuronal image tools. The process is therefore slowed down.”

IT’S PROBABLY ONE REASON WHY ALLCAPS is so frikkin’ annoying, too.

Getting All Charged Up

I bought another toy recently. A “fun fly stick,” which is a static electricity generator. Here are two of my colleagues playing with it. The levitating object is some aluminized mylar, i.e. tinsel.

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The low ceiling in my office makes it difficult to truly appreciate it, but does show some physics. You can see the tinsel collapse when it touches the ceiling and discharges, and then pop open again when it’s free. The charges on the aluminum repel each other, and spread out as much as they can in order to minimize their energy. That’s what we are taught in E&M, and it’s easy to see this with a deformable object rather than the canonical rigid sphere.

The tinsel does actually get charged (rather than having some induced charge distribution), which you can feel on the occasions where you get too close and it attacks your face. Not too much of a shock, though. I tried aluminum foil, but it’s too heavy. (foil = fail) Packing peanuts didn’t repel like I expected, but that may work better in drier weather. The tinsel targets are a bit delicate and I have empirical evidence that they do not stand up to the treatment of two/three year-olds.

This is an ad from ThinkGeek (not where I got this particular toy) that uses a little more free space.

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