# [ExI] Thermal expansion - Ball and ring experiment

Emlyn emlynoregan at gmail.com
Wed Jun 13 01:53:57 UTC 2007

```Yep, that's my contention also. My problem is, how to prove this to
someone who doesn't believe me, short of actually doing the
experiment?

Emlyn

On 13/06/07, spike <spike66 at comcast.net> wrote:
> The gap gets larger.  Imagine the arc piece that is missing from the ring to
> form a C.  That piece of nothing expands the same way the piece of something
> would have expanded were it present.  So the gap gets larger as the C is
> heated.
>
> spike
>
>
>
> > -----Original Message-----
> > From: extropy-chat-bounces at lists.extropy.org [mailto:extropy-chat-
> > bounces at lists.extropy.org] On Behalf Of Emlyn
> > Sent: Tuesday, June 12, 2007 5:42 AM
> > To: ExI chat list
> > Subject: [ExI] Thermal expansion - Ball and ring experiment
> >
> > I was just in a "heated" discussion with a friend about a twist on the
> > classic ball and ring experiment:
> >
> > http://www.physics.usyd.edu.au/super/therm/tpteacher/demos/ballring.html
> >
> > When the ring is heated, it expands, and so the hole gets larger, and
> > you can pass the ball through the ring, even though the ball doesn't
> > fit through the ring when the ring is at room temperature.
> >
> > The point of contention was this: What if there was a gap in the ring
> > (so it is now a letter "C" shape). Will the gap in the "C" close or
> > open further on heating?
> >
> > My contention is that the gap will get larger, only in that the entire
> > C shape scales up as it is heated.
> >
> > My friend's contention is that the gap will become smaller, (because
> > the metal expands into the gap).
> >
> > I can't find anything online even close to settling this score. We
> > tried some experiments with wire rings and the gas stove top playing
> > the role of bunsen burner (amazingly no one ended up branded for
> > life), but it was inconclusive.
> >
> > Any pointers to anything that can settle this argument?
> >
> > Emlyn
> > _______________________________________________
> > extropy-chat mailing list
> > extropy-chat at lists.extropy.org
> > http://lists.extropy.org/mailman/listinfo.cgi/extropy-chat
>
>
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```