Ulam's Spiral: In 1963 mathematician Stanislaw Ulam found that if you count around a grid of squares in a spiral starting from the center and fill in all the squares that are prime numbers a pattern will emerge. This is called Ulam's Spiral, or sometimes a prime spiral. These 3 spirals were made in Matlab with the following code: (This version requires the image processing toolbox)
Surprising result: What is the volume remaining in a sphere with a 6" hole drilled through it?
Are you impressed by savants who can recall the day of the week on any given date in history? Well don't be, anyone can do it. Here's how
A step-by-step method for the 4x4x4 Rubik's Cube.
This page is a kind of catch-all for things I find interesting. Some may be only indirectly related to mathematics....