In a message dated 97-12-02 15:37:00 EST, ckotting@iwaynet.net writes:
> Hokay folks, I can't resist. I have to weigh in here. Somebody earlier in
> this thread suggested an experiment where you cut a ring out of a cylinder
> wall, cut the ring, straighten it, freeze it and rejoin the ends. The
ring
> is smaller, so of course the cylinder gets smaller when it's colder,
right?
> Wrong.
Chris:
That somebody was me, and while I can't take credit for the analogy - I read
it in a magazine - a hole in a piece of material does indeed get smaller as
it gets colder. If you don't believe it, bore a hole in a piece of metal,
freeze it, and measure the hole diameter before and after freezing. I did,
and the hole was smaller when frozen. Several other folks on the list have
also reported experimental data to support this position.
If the hypothetical ring gets smaller, as you seem to agree, how can it also
get larger? It gets smaller when it's only "representing" the cylinder wall,
but gets larger when it is actually part of the wall? Hmmmm? How odd?
> because the "pull" created by the walls of the cylinder getting thinner is
> going on all around the cylinder, to one extent or another, so the cylinder
> still gets larger in diameter, while the outside dimension of the whole
> block decreases.
Maybe I've been out in the cold too long, and my brain cells have shrunk, but
it seem to me if the molecules are "pulling," the circumference is
decreasing. To increase the circumference, the molecules would have to be
"pushing," which implies expansion, which results from heat, not cold.
Molecules don't expand when they get cold, they contract, as you said.
I'll be the first to admit I don't know enough about this to carry on an
intelligent discussion, but it's hard to argue with factual data. Till I
actually made the measurments, I wasn't sure, even though I thought the
analogy made sense. Having made the measurements, I feel relatively certain
of my position. I say relatively, because I have learned a long time ago
never to say absolutely, as someone is bound to come along and show the flaw
in the data.
Dan Masters,
Alcoa, TN
'71 TR6---------3000mile/year driver, fully restored
'71 TR6---------undergoing full restoration and Ford 5.0 V8 insertion - see:
http://www.sky.net/~boballen/mg/Masters/
'74 MGBGT---3000mile/year driver, original condition
'68 MGBGT---organ donor for the '74
|