Blog by Sumana Harihareswara, Changeset founder
Catenary
Hi, reader. I wrote this in 2007 and it's now more than five years old. So it may be very out of date; the world, and I, have changed a lot since I wrote it! I'm keeping this up for historical archive purposes, but the me of today may 100% disagree with what I said then. I rarely edit posts after publishing them, but if I do, I usually leave a note in italics to mark the edit and the reason. If this post is particularly offensive or breaches someone's privacy, please contact me.
While reading Leonard's retrospective of the future, I had reason to ask, "what's a catenary?"
Leonard went into the bedroom and emerged, holding one end of a cell phone charger cord high in each hand, like a mad scientist about to show them, show them all. "This is a catenary," he explained -- the shape a hanging cord or cable describes when its ends are held up but gravity pulls down the weight of the cord itself.
"So it's a parabola, right?" I asked. He said no, and I looked it up.
Galileo claimed that the curve of a chain hanging under gravity would be a parabola, but this was disproved by Jungius in a work published in 1669."I am so wrong," I said. "I was proved wrong in 1669!"
"On the other hand," Leonard pointed out, "you're as good as Galileo."
