This is a beautiful and interesting video that explores the construction of a hyperdodecahedron.
http://www.youtube.com/watch?v=MFXRRW9goTs
A hyperdodecahedron is like a four-dimensional version of the dodecahedron. It is also known as a 120-cell, as it is composed of 120 dodecahedrons. It has 720 pentagonal faces, 1200 edges, and 600 vertices.
The folks at EvilMadScientist.com bring you a giant working replica of the Digi-Comp II, a 60s-era build-it-yourself computer kit:
http://www.evilmadscientist.com/article.php/dciivid
After the switches are initialized to choose the operation, the machine channels a stream of pool balls through various binary gates to effect addition, multiplication, and other basic mathematical and computational procedures. For more information, check out www.digi-compii.com.
As a pure math person, I never fully appreciated these mechanical computers. But after seeing things like the Digi-Comp, cam-based mathematics, and various mechanical calculators, I’m developing a genuine respect for them
Well, they got me again.
I’ve become something of a coffee snob. A few years ago I never drank the stuff, but now I buy good coffee and enjoy it. To me, it’s worth paying a little extra per pound to get high quality coffee. I just didn’t realize how much I was paying per pound.
Operating under the assumption that the standard unit of coffee beans was one pound, I assumed that I had been paying around $11 per pound for my coffee. But recently I found myself buying coffee a little more frequently than usual. So the next time I bought a bag, I threw it on my scale.
And then I took a closer look.
The fine print says this is 12 ounces of coffee, a full 25% less than the 16 ounces I naively assumed I was buying!
Come to think of it, my coffee shop doesn’t advertise prices by the pound. If they did that, they’d have to admit that my bag of coffee was actually around $15 per pound, not the $11 that common experience might suggest.
I might not have noticed this, had I not recently had a similar realization about my orange juice.
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Through Math for America, I am part of an on-going collaboration with the New York Times Learning Network. My latest contribution, a Test Yourself quiz-question, can be found here:
https://learning.blogs.nytimes.com/2011/06/27/test-yourself-math-june-27-2011/
This problem is based on a recent jobs report and the number of unemployed people in the United States.
