# Monthly Archives: December 2006

## Math baubles

Yesterday’s mail brought the latest issue of Focus, the magazine of the Mathematical Association of America. On the cover is a photograph of a gold icosahedron offered for auction last year at Sotheby’s. One reason for the MAA’s interest in … Continue reading

## Jacobsthal numbers, part 3

Our story so far: Having stumbled upon the Jacobsthal numbers, 1, 3, 5, 11, 21, 43, 85, 171, 341,…, I idly asked, “Who was Jacobsthal?” Keith Matthews promptly responded with a wealth of biographical information, even arranging to have an … Continue reading

## Wantzel’s Theorem

The new issue of American Scientist is on the Web and will soon be in the mail. My “Computing Science” column begins disarmingly enough, “I was a teenage angle trisector,” but shortly descends into the usual boring pedantry. On the … Continue reading

## The arXiv rolls over

The mathematics section of the arXiv archived 989 preprints in October. Why is that fact worth noting? Because arXiv papers are identified by numbers of the format YYMMNNN, with two digits for the year, two digits for the month, and … Continue reading

## Good company

Scott Aaronson, at Shtetl-Optimized, blogs: To those of us who can’t tell a hypotenuse from a rhombus, the phrase “math journalism” sounds like an oxymoron. It brings to mind boring pedants like Martin Gardner, Sara Robinson, and Brian Hayes…. Thanks, … Continue reading

## Nullity

This just in from the BBC…. Maths boffin from Berkshire solves 1200-year-old problem of division by zero. Dr James Anderson, from the University of Reading’s computer science department, says his new theorem solves an extremely important problem – the problem … Continue reading

## Snappy or sappy?

Dear Readers, You may have noticed something weird in these pages over the past few days. When you roll your mouse cursor over a link to an external web page, a thumbnail preview of the page pops up like a … Continue reading

## Back to school

The U.S. Supreme Court heard arguments the other day on programs meant to maintain racial diversity in the public schools of Seattle and Louisville. Listening to accounts of the debate put me in mind of Thomas C. Schelling’s elegant mathematical … Continue reading