Mathematicians use Sudoku to understand a mysterious, powerful algorithm.

Two studies apply social networking ideas to data from health studies of thousands of people, and suggest different interpretations of how contagious happiness or other experiences can be.

Some game theory paradoxes can be resolved by assuming that people adopt multiple personae, and aren’t rational.

Florence Nightingale pioneered the use of applied statistics to develop policy and developed novel ways of displaying them.

Here’s the rule: To assure cards get sufficiently mixed up, shuffle a deck about seven times. Mathematician, magician and card shark Persi Diaconis of Stanford University, along with David Bayer of Columbia University, created shock waves in Las Vegas when he figured that out back in 1992. Most dealers had been shuffling much less. But now Diaconis and his colleagues are issuing an update. When dealing many gambling games, like blackjack, about four shuffles are enough. The reason for the lower number is that many games require randomness for only a few specific aspects of the cards, not al...

New techniques are beginning to unravel the mysteries of knots, revealing a great mathematical superstructure in the process.

In the 1980s, an inkling emerged among some scientists that very disparate phenomena might on some deep level be related. The weather, protein folding, computers, evolution, the stock market, the immune system … each shows complex behavior arising from fairly simple interactions among its parts. For the past 20 years, researchers have labored to understand how these and other “complex systems” work. But there’s still no agreement about even the most basic of questions: What is a complex system? The frustration of this enduring question has led one researcher to a ...

The U.S. News & World Report rankings of colleges and universities are largely arbitrary, according to a new mathematical analysis.