A wiki about blogs

I just added my blog to the Mathematics/Statistics page of the Academic Blog Portal. As the name implies, this is a resource for gathering together links to academic blogs. The FAQ gives the purpose of the blog: This is a portal that is intended to provide resources for (a) academic bloggers, and (b) people who want…

The 56th Carnival of Mathematics is now online

Head over to Reasonable Deviations to see the 56th Carnival of Mathematics. I’d also like to point out a post by Terrence Tao on mathematical research and the internet. He has a link there to an interesting talk (5mb pdf file) that he is going to give on this subject.

More on twin primes and Pythagorean triples

Pat B. wrote a response to my last post on the number 867-5309. In that post I pointed out that: 8675309 is a prime. 8675309 is a twin prime (8675311 is also prime). 8675309 is the hypotenuse of a (primitive) Pythagorean triple: 86753092 = 24602602+83191412. Pat asked: What is the smallest number that would meet…

867-5309; more than Jenny’s phone number

A few days ago I posted a video about the twin prime conjecture, which states that there are infinitely many primes that are two integers apart: 3 and 5, 5 and 7, 11 and 13, 101 and 103, 1607 and 1609… Well, check this out. Type 8675309 into WolframAlpha and it says: “Jenny’s phone number.”…

Applets for multivariable calculus

When I was in Portland a few weeks ago for MathFest 2009 I attended the minicourse Creating Demonstrations and Guided Explorations for Multivariable Calculus using CalcPlot3D by Paul Seeburger. Paul has created some applets to be used in calculus classes (mostly, but not exclusively, multivariable calculus). They can be found on his Exploring Multivariable Calculus…

What is a howicide?

I’m a huge fan of HBO’s series The Wire. Today, while I was watching the 4th episode of season 4, I saw a curious word on the strap hanging around Sgt. Landsman’s neck: HOWICIDE. At first I thought this was a mistake or an easter egg. Why would they misspell homicide? But then I quickly…

Photos of Family Matters panel

A week ago I mentioned that I was going to sit on a panel called Family Matters at MathFest sponsored by the Association for Women in Mathematics. It was to focus on balancing work and family. I was nervous about it, but it turned out to be a great experience. My fellow panelists and the…

Delicious pie chart

An accurate pie chart: [Image by Laszlo Thoth under a Creative Commons license]

Calculating miles per gallon for electric cars

“GM says new Volt could get 230 mpg in city driving.” This was a headline yesterday about GM’s new electric car. Wow, pretty impressive! But wait,… what?!? This car (which seems quite promising, actually) has batteries that can propel the car for approximately 40 miles. Only after the batteries are empty does a gas-powered generator…

Infinite hat problems (solutions)

Yesterday I stated four hat problems. Today’s post contains the solutions to those problems. 1. Alice and Bob are wearing hats. The hats are either red or blue. They can see each other’s hats, but not their own hat. They are tasked with guessing their own hat color. If either person gets the color right, then they…

Infinite hat problems

I got back from MathFest yesterday after a long 3-leg red-eye trip across the country. It was a great meeting. It is always fun to hear some good talks, visit a new city, and see old friends (and meet another math blogger). The first talk that I attended was given by Alan Taylor: “Predicting Values of…