Barack Obama speaks to the 146th Annual Meeting of the National Academy of Sciences

*Calculus Made Easy: Being A Very Simplest Introduction To Those Beautiful Methods Of Reckoning Which Are Generally Called By The Terrifying Names Of The Differential Calculus And The Integral Calculus* (2nd Ed., 1914), by Silvanus P. Thompson ~ What one fool can do, another can (ancient Simian proverb)

An ‘Accordion’ of Wood and Glass ~ You can earn a lot of money from derivatives (not these derivatives, *these* derivatives)

Ed Burger does Calculus in 20 minutes (part 1), (part 2)

Tricki: a repository of mathematical know-how ~ now live

Two coffee drinks I would like to make ~ 1 and 2

Periodic tables… Periodic table of mathematicians ~ Periodic table of videos ~ Tait’s first seven orders of knottiness

Deep Down Inside, We All Love Math ~ T-shirt for sale

Position cues from a moving shadow ~ who doesn’t love a good optical illusion?

Pie-cosahedron and fractal pecan pie ~ Math is yummy

Martin Gardner puzzle from the most recent *College Mathematics Journal*. Add one line segment to make the following statement true: 5+5+5=550 (there are two correct answers)