Sunday, December 26, 2004

Wedding Ring Stiction

Maribeth bought me a replacement wedding ring. The original ring was slightly loose and I would sometimes slip it off and on. I had a near-miss experience where I lost it for a few days, but it turned up in my jacket pocket. And then I lost it again presumably-for-good somewhere in Santa Barbara.

The new one is tighter-- it leaves a mark on my finger. I wasn't sure whether this would turn out to be a good thing (harder to take the ring off, or for it to fall off) or a bad thing (because it would bother me and make me want to take the ring off). But a few days in, I think it will be a good thing. I think the ring is wearing itself a little groove in my finger and I will forget about it. Hopefully my finger won't get any fatter.

By the way, it's interesting that you can slip a ring off a finger more easily by twisting it. I guess this is because the stiction and/or the coefficient of static friction is greater than the coefficient of sliding friction, so if you can get up some sliding velocity in the azimuthal direction around your finger, it's easier to slide up the finger also.

Re-write: Perhaps that was not the best use of the word "because." Because the stiction is greater than the friction? Isn't that just a description of the phenomenon rather than an explanation? Why is static friction greater than sliding friction anyway?

Also, perhaps losing a wedding ring "for good" was not the most fortuitous phrasing.


Post a Comment

<< Home