How to validate a credit card number (click for full pic)
[via:Viralliset Linkit]
Math Overflow, a Questions and Answers site for math problems
Implemented using the platform of Stack Overflow, a Q&A board for programming topics. Beats any old-type forums or wiki sites, they have among other things, an addicting reputation and badge system inspired by Xbox Live.
[via:Spolsky]
In “Infectious Disease Modelling Research Progress,” eds. J.M. Tchuenche and C. Chiyaka, Nova Science Publishers, Inc. pp. 133-150, 2009.
Wired provides a summary.
[via:Slashdot]
The magic word is PolarPlot[(1 + 0.9 Cos[8 t]) (1 + 0.1 Cos[24 t]) (0.9 + 0.05 Cos[200 t]) (1 + Sin[t]), {t, -Pi, Pi}.
[via:saasta.fi]
Mathematicians create videos that help in visualizing four-dimensional objects
The article has a broken link to dimensions-math.org.
[via:Slashdot]