The Calkin-Wilf tree on Wikipedia ~ I’m very excited to teach this countability argument

Long-Exposure Shot of a Roomba’s Path Shows Beautifully Organized Chaos ~ Polygonal billiards in action

Clay Klein bottle ~ “It’s a bad idea to put sealed items in a kiln because they will burst as they heat. It took some time to convince the staff that our Klein bottle was actually unsealed.”

The Pattern Does Not Hold

Restore the Integral to the Fundamental Theorem of Calculus

Exploring Euclid’s Elements ~ proposition dependency tree for Book I of Elements

Just some good books about math, for those who like math ~ Summer reading suggestions in the article and the comments

Odd day ~ 5/7/09: how did I miss this one?

Brouwer’s Fixed Point Theorem is Unstable

Even the Science Magazines Can Blow It Sometimes ~ When a coffee cup and a donut are not the same

Humor

Enter the mathematician ~ For my colleague, the black belt mathematician

For every action, there is an equal and oposite reaction ~ same advice I got from my physics teacher 20 years ago; I remember it to this day

Integral limericks ~ there once was a integrand from Nantucket…