Don Elgee, a retired teacher of mathematics and computer science from Ottawa, sends the following inquiry:

In hockey, when a team is down by a goal with about one minute to go, the goalie is pulled in favor of another offensive player. This illustrates a key point in the strategy of most games.
The object is not […]

Saturday’s New York Times had a story by Sam Roberts about a newly released Census Bureau study of the frequency of surnames in the U.S. The Times story was mainly about the names at the top of the list, and especially the increasing prominence of Hispanic names (Garcia and Rodriguez have made it into the […]

I have a few questions for the complexity theorists among us.
Have you ever tried to explain to your grandmother why NP is named NP? Does she get it when you say that problems labeled NP-complete are the hardest problems in NP, but NP-hard problems might be harder, and not in NP?
My concern here is not […]

Barry Cipra, my friend and former neighbor, and a frequent bit-player commentator, is the Talk of the Town this week. A story in The New Yorker by Lizzie Widdicombe highlights Barry’s work on the mathematics of the following calendrical problem.
Doing all arithmetic modulo 100, if you were born in the year X, you reach age […]

Above: A throbbing, wheeling mob of several thousand restless starlings, near a strip mall in Clayton, North Carolina, 27 October 2007. Below: Snow geese on maneuvers near Ashburn, Missouri, 12 November 2004.

In the 1930s, Edmund Selous argued that flocking behavior could be explained only through some form of animal ESP: “thought transference” was the only […]