June 13, 2007  

    Some more wildflowers that grow in our lawn: common buttercup, Canadian dwarf cinquefoil, and hawkweed.  There's an unusual pink-and-yellow columbine blooming in the garden.
    Saturday was the Greenfield Historical Fair in Oak Park. There were craft vendors, a blacksmith, a fiddler, Civil War reenactments, and refreshments.  Here's a page of pictures. 
    Monday we went to grandson Alex's first performance His nursery school has a year-end party, and the kids sang and danced to a recording.  At one point the teacher tells Alex to face forward; she hasn't seen the boy behind him fooling with Alex's head.
    I've been volunteering at Jaffrey Elementary School once a week to help some fourth-graders on a science project.  It's a Rube Goldberg invention to put a Graham cracker on a s'more sandwich.  Tuesday we demonstrated it to the school.  In the video, you can see a boy rising from a chair, releasing a "rocket" down a string that knocks over some blocks that start a couple balls rolling that knock a stick that knocks a marble down a track to trigger a mouse trap that pulls a string that starts some dominos falling up a ramp that knock over a water bottle that fills a cup that tips the cracker onto the sandwich (lower right).  

Feature - In 1983 Bill Roadstrum and I wrote an electrical engineering textbook.  The approach was to describe the big picture first and go to ever-finer detail. We published a paper describing this approach, comparing the teaching of electrical engineering to drawing a horse or following a dinner recipe.

Quote for the Day -
   "There are three kinds of men: the ones that learn by reading,  the few who learn by observation, and the rest of them have to pee on the electric fence and find out for themselves." - Will Rogers