Archive for December, 2006

Math baubles

Friday, December 15th, 2006

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 this artifact is that the association’s emblem is an icosahedron. But there’s also a mathematical […]

Jacobsthal numbers, part 3

Monday, December 11th, 2006

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 obituary translated from the Norwegian. So I asked, “Where did Jacobsthal mention these numbers?” and […]

Wantzel’s Theorem

Friday, December 8th, 2006

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 other hand, I do answer the question that has been on every lip these past […]

The arXiv rolls over

Friday, December 8th, 2006

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 a three-digit sequence number. Ten more papers and all the world’s mathematicians would have been […]

Good company

Friday, December 8th, 2006

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, Scott! Can I get that on a teeshirt?

Nullity

Thursday, December 7th, 2006

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 of nothing….
The theory of nullity is set to make all kinds of sums possible that, […]

Snappy or sappy?

Wednesday, December 6th, 2006

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 thought balloon. For example, try it with This Link. If any of you have strong opinions […]

Back to school

Wednesday, December 6th, 2006

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 model of race relations. The model suggests that extreme segregation can arise spontaneously even when […]