watching it rise

Bedspread mathematics

So, whether or not she knew it, the quilter had infused her blanket with tidbits of considerable mathematical interest. It turns out that this is actually not uncommon in quilts: from the color patterns of the quilt blocks to the intricate curves in the top-stitching, quilts can communicate a great deal of mathematical insight… and keep you warm, as well! I spent the rest of that day making interesting mental notes about the lovely intersection between the art of quilting and the art of mathematics. That carried over to today, and I figured it’d be neat to show you, valued reader, some of the gems I found over the past two years. Let’s go.

Leland McInnes at The Narrow Road gives us a lesson on the varieties of the infinite:

Problems that involve infinity have a tendency to read a little like Zen koans. Take, for example, this problem: Suppose we have three bins (labelled “bin A”, “bin B” and “bin C”) and an infinite number of tennis balls. We start by numbering the tennis balls 1,2,3,… and so on, and put them all in bin C. Then we take the two lowest numbered balls in bin C (that’s ball 1, and ball 2 to start) and put them in bin A, and then move the lowest numbered ball in bin A from bin A to bin B (that would be ball 1 in the first round). We repeat this process, moving two balls from bin C to bin A, and one ball from bin A to bin B, an infinite number of times. The question is, how many balls are in bin A and how many balls are in bin B when we’re done? Think carefully!