Pitahaya
Pitahaya. So hot right now. Finally, the New York Times recognizes it. I’ve seen this day coming for almost ten years, amid continued searches on this website for the pitahaya PLU code, which information (4030) has long been gone. After a years-long personal quest, I finally obtained some a year or two back, and it was nothing to write home about. However, it is beautiful to look at.
GPS mowing
Mowing the lawn with a GPS is an easy way to make a big messy blob of a map!
Turkey Trot 2010
In advance repentance for a delicious Thanksgiving dinner prepared by Grandma, we spent the morning participating in Austin’s annual Turkey Trot. Thanks to the generosity of Grandma and Papa’s neighbors, we were able to borrow a jogging stroller so David could come on the 1-mile walk after his Kids’ K.
David had been talking up how he was looking forward to his race, so I was also looking forward to running along by his side. Not too much of a surprise, however, he decided part-way through after starting to drag his feet a bit that he’d rather ride on my shoulders. We passed under a train, which he found quite impressive. We turned around at the half-way point, and I warned him that he would soon be his turn again. He ran the last third flat-out, and I had trouble keeping up with him at times. When he decides that he is into it, there is no stopping him. So much so, in fact, that I had some difficulty getting his attention so that he would cross the finish line on the right half of the barricade in order to get his finisher’s wrist band! Papa was toward the side near the finish, and I did not even see him while trying to keep David aimed at the finish line amid all the fun and chaos.
The grownups’ race started shortly afterward. This year featured a new course, presumably to accommodate the record 15,000 participant turnout. The previous course, starting at Waterloo Park and winding around the UT campus area was pretty nice, but I think the new course nicely features some different areas of town. Using the Long Center for the start and finish area offered a lot more room. Due to some sort of last-minute mix-up, the course was a half-mile shorter than the advertised five. I’m not complaining, since I found it to be quite hot and humid compared to Indy’s recent weather. Later that day, keeping the shortened course in mind made resisting that fourth slice of pie a little less difficult!
Indianapolis Half Marathon 2010
The Indianapolis Marathon deserves its reputation as a well-respected race. We found it to be well organized, and several nice touches showed attention to detail on the part of those who ran it.
We had a minor hitch getting to the expo and packet pickup due to construction confusion at the YMCA, but it was smooth after that. We arrived just in time too, since we observed that the parking lot seemed completely full when we left a short time later. The entry area to the expo was lined with mums and heaters, a nice but unnecessary touch, as the weather was mild that day. The expo itself was on the small side. We had no trouble walking right up and getting our packets and t-shirts from the friendly and helpful volunteers. The relatively small number of other vendors was no problem for us — less to traffic to dodge on the way out!
We owe a big thank you to the Zembrodts for watching David on race morning. We could not have both participated had it not been for their help. I’m glad that David got to play with his friends Jake and Toby on a Saturday morning, too.
After dropping off David on race morning, we were prepared for heavy traffic on 56th Street. By the time we crossed I-465, traffic was flowing smoothly. The kids directing traffic in the VA parking lots could have coordinated better and filled more spaces, but we didn’t have a problem. People arriving later might have had some difficulty finding parking spots, however. We stayed in the warm car, and Emily did some grading while we passed some time before braving the cold morning. Perhaps we should have left the car a few minutes sooner so that we could have made one last pit stop before the start. The lines were very long!
As the race started, the temperature was quite cool. No complaints though, as the sun felt glorious between the trees. The quiet environment while running in the state park was enjoyable, just the sound of footsteps and concentration. After a while, the park became more challenging for me. First, the hills were more than I am accustomed to, particularly the one at mile 10.5. Second, the design of the course led to some doubling-back even on the half-marathon course, which tends to sap my motivation. Still, the scenery was undeniably beautiful.
The food in the finishing area was a pleasant surprise. Both Emily and I thought that we had to have bought an additional ticket to enter, but we were wrong. All participants were allowed to have a hamburger or bratwurst lunch. Cool, how nice! And a well-earned brat it was. That’s why we run.
Prius nomogram
After finding a nomogram of how the Prius’s continuously variable transmission (or Power Split Device, in Toyota-speak) works, I thought it would be a fun exercise to use PyNomo to create my own Prius PSD nomogram.
The PSD is a planetary gearset, with the sun gear attached to Motor-Generator 1 (MG1), the planet carrier attached to the Internal Combustion Engine (ICE), and the ring gear attached to Motor-Generator 2 (MG2). MG2 drives the front wheels directly.
In the nomogram, the car is travelling 65 mph. Because this is a continuously variable transmission, there are infinite ways of achieving this road speed. MG2 must turn at about 3850 RPM because it drives the front wheels directly. However, the engine can be running at anywhere between idle speed and flat-out. MG1 will then turn at a corresponding speed according to the relationship shown in the nomogram.
The nomogram also illustrates how the Prius can run in “EV mode,” where the car drives under electric power alone. With the ICE off, MG1 rotates backwards and MG2 rotates forward. As the car speeds up and slows down in EV mode, the isopleth line see-saws up and down the MG1 and MG2 scales, anchored at the ICE’s 0 RPM point.
Part of the elegance of the PSD is that there is no reverse gear. MG2 simply rotates backwards with the engine off. Cool!
There is an interactive Flash-based version on eahart.com.
