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# Date Archive: 2008 March

Products

## Decorating Eggs with Mathematica

A week or so ago I made an Easter egg in Mathematica and emailed around a bit to see if I could get other people to try it, too. I consulted with my family, dared readers of my blog to send me Mathematica eggs and mentioned my egg to my friend science-fiction writer Cory Doctorow, who blogged it on BoingBoing. I also spread the idea around Wolfram Research. As someone with a small collection of ornamental eggs in a glass case in my living room, I am quite pleased with the results. Here’s how it came about: My kids are enthusiastic celebrators of holidays. They want to start decorating for Halloween in August, and decorating for Christmas as soon as the pumpkins and spider webs come down. Last week, I had bought a carton of eggs and a package of egg dye, and kept finding my kindergartner getting out the eggs or the dye without permission. So I’d promised that Thursday, absolutely, we would begin work on eggs. I have a copy of Michael Trott’s The Mathematica GuideBook for Graphics, and on Thursday afternoon, my fifth-grader was flipping through it, looking at the pretty pictures. He saw a picture in it and asked if I could scan in and print out a picture like that on a sticker for him to put on an Easter egg. I decided he had a point there: that one could and should decorate eggs with Mathematica. The example he’d chosen was more elaborate than I was willing to take on in 3D, but I decided to see what I could do while we boiled the eggs. I looked for something to work from and found the Ellipsoid Demonstration on the Wolfram Demonstrations Site. I adapted from that, using the mathematical description of an egg shape from Jürgen Köller’s website as my guide to egginess.
Computation & Analysis

## Friends, Earthlings, ETs—Lend Me Your Sensory Organs!

Yesterday, I put together a Demonstration about the Clarke Belt---the ring of satellites 22,300 miles above the equator. Sir Arthur C. Clarke wrote in 1945 about the future usefulness of geosynchronous orbits, and I wanted to see a picture of them. Coverage of the Pacific seemed spotty. A few hours later, I saw the first news reports about his passing.

## Pi Day

Pi (π, the ratio of the circumference of a circle to its diameter), its older brother the golden ratio phi (φ) and the much younger e and i are the most famous numbers in mathematics. Pi is everywhere: not only in circles and spheres, but also in the results of all kinds of integrals, sums and products, as well as in number theory and physics. The personality of π is largely unknown: irrational, transcendental, possibly and probably normal. Because of π’s importance, its digits (3.14159265...) have an almost cult following. The first few digits, 3.14, correspond to notation for March 14, which was first celebrated as Pi Day in 1988, in the San Francisco Exploratorium. Wolfram Research has the most π presence on the web, with material at the Wolfram Functions Site (pi page, pi visualizations), MathWorld (pi, circle, sphere) and the Wolfram Demonstrations Project (pi, circle, sphere, disk, wheel), not to mention several built-in Mathematica symbols (Pi, EllipticPi, PrimePi). For NUMB3RS episode 314 (“Takeout”), we helped to fold many hidden π references into the script review and math notes. The writers, director, cast and crew added many more. The opening Black Box, for example: a 3-course meal, 1 restaurant, 4 robberies, 1592 death squad murders. Charlie mentions a circle-circle tangency joke not working, right before a James Bond reference (007---circle, circle, tangent). Below are a few of our π-related Demonstrations. Click any of them to reach an interactive math demonstration. Enjoy!
Announcements & Events

## Get Coordinates: New in 6.0.2

Many new features in Mathematica are manifested in new functions with definite names, but some are not so prominent. You might miss one of the new features that I implemented for Mathematica 6.0.2---but it’s really useful, and so I thought I’d write about it here. Let’s say you have a plot, or some other kind of graphic. You see something in the graphic---some special point---and you want to know where that is, what its (x, y) coordinates are. In earlier versions of Mathematica, there were primitive ways to find this out. Now in Mathematica 6.0.2 there’s a nice, clean, general way to do it. Open the Drawing Tools palette (from the Graphics menu, or by typing CTRL-d or CTRL-t). Choose the “Get Coordinates” tool at the upper right.
Products

## Adventures in the Wolfram Demonstrations Project

As the project coordinator of the Wolfram Demonstrations Project, I have an inbox that is overflowing with fantastic ideas from Mathematica users and coworkers for how to make the Demonstrations site even more user-friendly and easy to navigate. One of the most exciting new features we’ve implemented recently is the new topics page. In a few easy clicks, users can fine-tune their searches to browse topics ranging from Middle School Mathematics to the Solar System to Natural Forms and everything in between.