I traveled back to LA from DC today, and did a whole bunch of work. So I am tired. I wish you all a safe and happy Labor Day, and leave you with a link to NPR’s series on High Speed Rail, featuring David Levinson, of the Transportationist blog (oh, and he’s a chaired professor of civil engineering and the director of a well-respected research institute at the University of Minnesota with a cv longer than the wait for the Sears Tower elevator, but his blog has much less math than most of his papers, so I’m going with it…*)

*If my dean is reading this and is tempted to draw any specious comparisons between David and me, I should note that the weather is a lot nicer in LA than it is in Minnesota, and David has more reason to stay inside and work than I do. Just saying.