Tuesday, March 27, 2012

Back To The Old Nose And Grindstone

Morning weigh-in: 184#
The second rest week is behind me -- last night was an hour of towpath E2 on the Turner, and tonight will be this new period's first new training ride: M2 or "cruise intervals." I'll be doing three 10-minute intervals in Zones 4 and 5a, two minutes easy spin between each one, and will probably follow it up with another hour of Zone 1/Zone2 spinning. Each new period ups the intensity a little...
Luckily for me, this is the first week of the new period, thus a low-volume week, since I will be out of town for work starting tomorrow morning -- the trip is to somewhere in Arizona, north of the Apache National Forest, for a plant inspection. I'll be home Friday night though, and should be able to do a longish tempo/endurance ride on Saturday, and a real MTB ride Sunday, maybe American Standard. If all goes well, I should break 100 miles for the week despite the trip, and break 300 for the month of March.
I'm blowing off a few things this week to make room for the trip, and a few others to make room for the rides that I don't want to blow off because of the trip; one thing that must go overboard is the VMB board meeting tonight. I feel a little guilty, but I really don't have time to do everything I need to and still make the meeting, so I have to skip the meeting, ride or no ride, and I might as well get my ride in. However, I was at two officer meetings last week when I should have been doing other things, including trip preparation I'll be doing tonight, and I made one of two trail maintenance days over the weekend, so I don't feel too bad. I played catch-up a bit with my club secretary duties last night too, posting preliminary copies of the minutes for the February general and board meetings.
(It was kind of cute, Anne and I typing away on our laptops at the dinner table last night, me on the minutes and she on her latest project, which involved her taking notes from the handwritten transcripts of the Molly Maguire Trials.)
Meanwhile, on the computer: Over the weekend I became a bit obsessed with the question of how much a tee (tee as in piping) weighs, based on a weight take-off for work, which I did with a quick and dirty estimation of the weight of two intersecting hollow cylinders. I got to wondering how accurate my estimate was, and what the actual, exact volume of intersecting cylinders would be. I could have found the volume by integrating, but thought that someone must have worked this out before... Googling took me first to a whole lot of nothing, then to pages and pages about Steinmetz solids (close but no cigar), and finally to a general formula for the volume of two intersecting cylinders.
The formula is straightforward enough, but unfortunately it involves elliptic integrals, and I could find no elliptic integral functions in any spreadsheet program I owned. This looked like a job for octave, but my version didn't have the functions either -- they were available through a package, one I hadn't installed, that accessed the GNU Scientific Library. OK, install the package, a "learning experience" in its own right, figure out how to use the elliptical functions, and... the actual computation I was trying to do, once I got this far, was a piece of cake. The final result: weights based on my quick-and-dirty estimation method were about 1% off from the exact solution. Which is probably why no one ever bothers to use, or even talk about, the pain-in-the-ass exact solution.
See you in a few days.