Election References

A display of the frequency of references to the candidates.

Interactive Bar Chart

Here is an interactive bar chart in a museum where people take tokens depending on how they answer a question. The frequencies of their responses can be seen as the columns get diminished with each selection.

Pentagon 9-11 Memorial

Today the Pentagon 9-11 Memorial is dedicated. Benches dedicated to each victim are arranged by the victim's age. Age lines start at 1930 for the oldest (71 years) and continue to 1998 for the youngest (three years old). An age wall runs along one edge from a height of 71 inches down to a height of 3 inches. Here is an interactive virtual tour of the memorial from the Washington Post.

Also Today, an unsettling normal distribution

According to an old article in the NY Times (April 2, 1946, p12) this is a copy of an official captured German map found by Allied intelligence officers sometime after WWII. It shows a bulls-eye target in the middle part of lower Manhattan. The concentric circles show concentrations of destruction from multiple V-2 type rockets or special orbital bombers. Elsewhere the map is topped with the normal curve modeling the east-west error distribution of these multiple attacks.

A Model of a Characteristic Function

I was looking at a CD holder and noticed that it could represent the unit circle and provide a model of a characteristic function. It reminded me of a paper by Epps, available here, whose abstract begins: "The value of a characteristic function of a random variable X at some real number t is the center of mass of the distribution of tX wrapped around the unit circle in the complex plane." I have cut the sides of the CD holder to leave a normal distribution wrapped around a circle. The balance point of this model is the center of mass mentioned by Epps. As t gets smaller, approaching zero, the wrapped distribution gets more concentrated around a modal point. Also, the balance point moves toward the edge of the unit circle, directly under the mode of the wrapped distribution. The rate at which this balance point moves, at the edge of the unit circle, is the mean of the the random variable X.

Markov's Inequality Without Words

A very clever derivation by Pat Touhey of Markov's Inequality from The College Mathematics Journal, September 2008 published by the Mathematical Association of America.

Olympic Medal Plots

Very cool interactive graphic from the New York Times.