## Wild About Math bloggers 2/11/11

[ The 2/18 edition of Wild About Math bloggers! is at Equalis. ]

Welcome to Wild About Math Bloggers!

Carnival of Mathematics # 74 - The Tungsten Edition - has been published at Walking Randomly. One link of particular interest was A cute result relating to sums of cubes. This article shows a great generalization of the formula: 1^3 + 2^3 + 3^3 + ... + n^3 = (1 + 2 + 3 + ... + n)^2. Be sure to read the comments to make the connection between the well-known result and the generalization.

March 1 is World Maths Day. What is World Maths Day? How does it work? When is the registration deadline? Denise at Let's Play Math tells all.

Irrational Cube has some nice visual illustrations of sums of geometric series. Here's one. Can you figure out what it demonstrates? [ Hat tip to Pat Ballew. ]

God Plays Dice has a nice article, Pixar Mathematics.

Pixar's use of harmonic functions (by David Austin) describes mathematical techniques used by Pixar. Incidentally, apparently there exists something called Pixar University, which I learned when I went to the excellent Pixar exhibit at the Oakland Museum of California. As far as I can tell they are not hiring, they're really an internal training program, and anyway I don't know anything about animation. (The exhibit's next stop is in Hong Kong.

Here's a video that illustrates the use of harmonic functions:

## Wild About Math bloggers! 2/4/11

[ The latest Wild About Math bloggers! is at Equalis. Here is last week's edition. ]

Welcome to February!

Speaking of February, Alex Bellos has a fun article about February, leap years, different calendar systems, the golden ratio and the golden string.

Science News explores the science of bike-sharing.

While the idea [bike-sharing] is gaining speed and subscribers at the 400 locations around the world where it has been implemented, there have been growing pains -- partly because the projects have been so successful. About seven percent of the time, users aren't able to return a bike because the station at their journey's destination is full. And sometimes stations experience bike shortages, causing frustration with the system.

James Tanton has a great new YouTube video exploration: A Leap-Frog Puzzle using Vectors (Tanton: Mathematics):

Choose any three points A, B and C in the plane. Starting anywhere you like on the page, "leapfrog" over the point A to land on the other side of A the same distance from it as you started. Now leapfrog over B, and then C, and then A again, and then B again and finally C again. Something astounding happens!

## Wild About Math bloggers 1/28/11

[ The current edition is at Equalis. ]

Here's the end-of-January edition of Wild About Math Bloggers! Enjoy.

Math Teachers at Play Carnival #34 is up at Math4allages.

One post in the Carnival that particularly got my attention was by John Cook telling us about an amazing lightning computing calendar produced by Ron D and available at the Dead Reckonings blog. It's free as a PDF download or you can buy a printed copy at Lulu.

Jon McLoone has a really fun article on using Mathematica for cracking ciphers using frequency analysis techniques.

NPR has an interview with Keith Devlin, the Math Guy, about a fun new book for kids on factoring integers into primes.

The book is based on this great poster.