Hi, My new essay is called "Roasting a Dodo and Biking on Mars: The Magic of Dimensional Analysis" and as usual I plan to publish it on the 17th. If you have comments, please sign them, so that I can ask followup questions. Thanks, Jim Propp Title: Roasting a Dodo and Biking on Mars: The Magic of Dimensional Analysis Beginning: The first time I encountered dimensional analysis, I didn't recognize it for the magic wand it is; it seemed to be just a form of mathematical hygiene --- useful for avoiding mistakes, but not much else. To get a sense of what I mean by hygiene, consider a question that came up in my own household ... Read more: https://mathenchant.wordpress.com?p=2141&shareadraft=5a7dd23703363