[Today’s run: 5 miles]
First run since last week… went well.
Yesterday I went to Batesville, Mississippi to cheer on my wife at a 10 mile run.
While I was there I sat at the finish line and watched people come in. I was on a walkway in front of stores, above the road level. A kid spent some time kicking the pipe railing at a place where it had been cut. He was enjoying it. The thing would really vibrate. It was possibly moving half an inch in amplitude. What he didn’t notice was that another loose end of similar size at the other end of the railing would respond in a resonant manner.
My pictures don’t fit together, unfortunately. Pretend that the last picture is up on the right end of the other two. The vertical, ornamented pillar in picture #2 is the same one as in picture #3.
Anyway, the really interesting part is that the lower-rail pipe piece that he was kicking actually was cut, with a big air gap around that post, between the place where he was kicking and the place where the resonant shaking happened. The smaller hanging-ended pieces did not appear to shake; must not have been resonant.