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From: Vic Fraenckel (no email)
Date: Sat Jul 12 2003 - 08:51:38 EDT
In James Gleick's 2003 biography of Isaac Newton, he alludes to the
possibility that Newton was poisoned by mercury during a period when he was
engaged in some alchemy experiments and this caused the "madness" that
overcame hime for a period. Gleick alludes to the detection of mecury in a
recent spectrographic analysis of a lock of Newton's hair as possible
evidence of this.
Vic
________________________________________________________
Victor Fraenckel - The Windman
KC2GUI www.windsway.com
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----- Original Message -----
From: "Dr. Geoffrey Kolbe" <>
To: <>
Sent: Saturday, July 12, 2003 3:41 AM
Subject: Re: Artificial Horizons and Tea
| George Huxtable wrote,
|
| >Later, at university, we found a similar environment. We would use
mercury
| >in pint quantities for diffusion-pumps in high-vacuum systems.
| >
| >I suspect many physics students from my generation, the world over, could
| >tell a similar story.
|
| Quite so. When they pulled down the old Royal College of Science in the
| early '60's (to build what is now Imperial College, London), the mercury
| vapour in the Spectroscopy lab had reached the level where absorption
lines
| of mercury were always present in any spectra taken in the lab. A lake of
| mercury was found under the floor boards when they pulled them up! My ten
| years in the Spectroscopy group was spent when it had moved to the new
| physics department of Imperial College, but the researchers who worked in
| old Spectroscopy lab were still alive and working when I was there - and
it
| goes without saying that they were hale and hearty and lived to a ripe old
| age...
|
| >I'm not convinced about the virtues of floating a solid mirror on a
| >disc-raft on liquid. The liquid and the solid would need to have a
| >repulsive surface tension between them to ensure blobs wouldn't gather up
| >the sides of the raft. That surface tension would require to be exactly
| >even around the edges of the disc or the raft would be unbalanced. How
| >would one prevent the raft from nearing the edges of the container, which
| >would unbalance the surface-tension forces or give rise to friction which
| >would constrain the self-levelling? There are serious problems here which
| >would need resolving.
|
| I am not so sure that this is as much of a problem as you paint it George.
| It is quite easy to work a glass disc so that it is flat and the two sides
| parallel to a micron or so, and with a sharp uniform edge. In my
| experience, the main problem was making sure the surface of the mercury
was
| absolutely clean, or the glass would sit on top of a spec of dust and the
| glass would not be level.
|
| The surface tension forces between mercury and glass are repulsive, so the
| problems of blobs of mercury adhering to or sitting on the glass raft
| disappear.
|
| Geoffrey Kolbe.
|
|
|
|