On 7/5/10 7:08 AM, rw wrote:
On 7/5/10 5:12 AM, riverman wrote:

I'm not convinced that heat expands the radius of the hole, as in a
photographic enlargement. Objects expand around their physical mass.
There is a classic physics demonstration with a steel ring and a steel
ball where you heat the ring and find that the ball will not fit
through the ring. So, just as the hole in a rising donut (or bagel is
more like it) gets smaller, I would expect the hole to get smaller if
you heated the female section. But countereffecting that would be that
the circumference of the torus would also increase. Maybe there is
some sort of ratio of circumference to torus thickness where the hole
actually does not change....I don't know. But the action of the female
end of a ferrule is a very thought-provoking thing.

http://physics.bu.edu/~duffy/py105/Temperature.html


BTW, I think you're misremembering the ring and ball experiment. It
actually demonstrates just what I (and others) have been saying about
thermal expansion of a hole.

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