Cogito, Ergo Sumana for 2007 August 1 (entry 0)

# 01 Aug 2007, 12:53PM: Catenary: 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."

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