Date: Wed, 29 May 2002 11:52:29 -0400

Author: Machele Cable

Subject: Re: Weird mercury tube

Post:

Oooo...hey, what a good distinction! While demonstrations are the best,
sometimes we just must make do with a simulation.

Chele

"Jason St. John" wrote:

> Hello.
>
> These descriptions match two tubes that I remembered seeing in deepest
> storage here, so I dug them up an tried it. Looks to me like the violent
> movements of the little glass bits isn't due to the invisible collisions
> that I think of as Brownian motion; the Hg is BOILING, and the roiling
> surface of the dense liquid is what kicks around the little glass bits.
> My evidence is that the Hg is also recondensing, in the form of small
> beads that sit temporarily atop the larger puddle of liquid before joining
> it.
>
> More a simulation than a demonstration?
> -St.John
> Boston University Physics Demos
>
> On 2002-05-28.10:41 owner-tap-l@listproc.appstate.edu sent:
>
> My understanding of it was that it's designed to show Brownian motion of
> particules...the mercury heats up and moves the crystals. I had one around
> the lab....I disposed of it as a safety hazard.
>
> John Mocko
>
> On Tue, 28 May 2002, Duane Pontius wrote:
>
> > Greetings,
> >
> > We're moving into a new building, which entails plowing through piles
> > of weird objects in the demo room that haven't been disturbed for
> > decades. One item in particular has everyone puzzled. It's a sealed
> > glass tube with a few cc's of mercury and some bluish-purple
> > crystals. The tube is supported in a heat-resistant clamp, so I
> > presume it was once heated. Anybody have any ideas about what it
> > might be good for, or should I consign it for hazardous waste
> > disposal? Thanks.
> >
> > dp
> >
> >
>
> ______________________________________________________________________
>
> John Mocko
> Senior Teaching Laboratory Specialist (Lecture Demonstrations)
> Department of Physics
> University of Florida
> Gainesville, Fl.

--
Machele Cable-----Lab Manager-----Wake Forest University

-----"Nothing shocks me. I'm a scientist." - Indiana Jones-----

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