For particular personal reasons (not terribly unfathomable), I am particularly grateful to coffee this week. Not for coffee, but to coffee (and yes, to my coffee supplier, who has spoiled me such that I dread coffee shops, and can’t wait for my own home brew). I’ve written a few coffee verses over the years, and have long wanted an excuse to re-post the following verse, on the physics of the coffee ring. The full explanation is at the original posting. [Read more…]