I used Stella 4d to make this. This program’s name, in the last sentence, is a link; if you follow it, you’ll be taken to a site where you can give it a try for free.
Monthly Archives: February 2015
5, 10, and 15 (from 2012)
Nine (2015) / Nine (2013)
A True Story from My Childhood: Roman Numeral Dollar Signs
When I was a child, I learned Roman numerals before I learned about the dollar sign. When I first encountered a dollar sign, I interpreted it as an “S” with a Roman numeral one superimposed over it. It then followed (I thought at the time) that the symbols for $2 through $10 would look like those shown above.
Fortunately, it didn’t take long before I figured out this would be impractical. I certainly would not want to have to write the symbol for $3,978, after all.
Euclid’s Spiders
The image of two black spiders above is created by interference, and is an example of an interference pattern. The figures which are interfering are four points (and the rays which go with them), two close together on the right, and two close together on the left, but with the two pairs in different orientations. Each point has 240 rays emanating from it, and the rays are equidistant (in terms of angle measure), making each of these rays one euclid (1.5º) apart from its nearest neighbors.
Star and Protostar
First, Protostar:
In nature, protostars collapse under their own gravity until enough heat is generated to ignite nuclear fusion, at which point they become stars. The image above is my interpretation of a protostar, just before the moment it becomes a star. As for Star, my post-ignition interpretation, here it is:
While I did just make these images, they are simply inverted-color versions of images I made back in 2012, using Geometer’s Sketchpad. Here are the original-color versions (which I don’t like as much, myself), presented in a smaller size. You may enlarge either or both with clicks, if you wish.
Bumper Sticker Design for Arkansas Ice Storms
I need two of these for my car — one for the rear bumper, and one for the front. I drive, on icy roads, about as well as the average Arkansan. This means I am proficient at sliding into ditches. It also means that, if our current weather forecast proves to be accurate, I’ll be staying home for at least the next 42 hours.
Hex
Five Mandalas from 2012 and 2013
A Non-Convex Polyhedron with Cuboctahedral Symmetry
I used Stella 4d to make the polyhedron above, and you can try this software for yourself here.

















