pdp1@EARTHLINK.NET on mon 2 apr 07
mentions...
Hi Ivor,
It is a long time since I was doing anything with a Microscope, or Slides,
and I had not done much with them anyway 'then'...! - though I not long ago
bought a very sweet one which sits un-touched...sigh...
But, if my recollections are correct...this is only true if you have
squeezed them together...or possibly, mitigated, if the Slides are the thick
kind and hence 'heavier'.
If the Water layer
between the Glass slides has not been attenuated or thinned to the utmost,
( at least I think I remember, that ) it can remain elastic and
'lubricating'...at least untill enough slideing or displacement has occurred
to coax out the difference.
And definitely yes, similar to your observation, Commercial Glass concerns
know only too well, that if sheets of Window Glass are on the Truck to go
out to some job or installation, leaning as they do against one-another in a
not quite vertical way...if they are not seperated by some small spacers,
and if rained on or splashed on or otherwise wetted, the Water can get
between them - can migrate in it's affection for Capillary Attraction - and
effectively adhere them together so firmly that no human effort can slide
( let alone pry ) them apart...and the Glass Sheets must be broken up and
discarded.
This can be done experimentally of course on a Table, where, similarly to
the Microscope Slides, one CAN slide the two sheets of Glass on eachother,
so long as the Water layer is not allowed to become thin to it's
utmost...which of course it will with very little encouragement...
...'thicker' Water ( whatever that may be!...or possibly Deuterium? - and
those of us who have Swamp Cooler, likely have gallons of it by Summer's
end - just kidding...) might not be so easily coaxed to become so
inconveniently 'thin' when between sheets of Glass...and hence might allow
the two sheets of Glass to slide all they like, all day long...
Too, just musing in general...as we know, the Surface Tension of Water will
of course effect things in the scale in which it is operating...so very
'small' things will be confronting what for them may be quite viscous or
tenacious conditions. But then the Elextrical and Molecular interactions at
small scales will likely off-set this or displace it as for their influence
being more profound.
So, I would expect considerable viscosity or tenaciousness in small scales,
but only up to a point , while of course in larger scales the viscosity or
tenaciousness will appear very mild.
Surfactants which effect a diminishment of the surface tension of Water,
will of course do so on whatever scale that Water is confronting, or in
proportion to their degree or concentration to which they are capable...
Which interest underlay my aside a little while back, that 'lots of spit'
might be one of many promising 'Organics' which singly or in concert with
other things, could be investigated for it's possible role in the aging of
Clay...or to be more concise, for adding to those Slurrys, Slips, Slops,
Slakes, or Soups one WILL make of Clay, if one intends to "age" it...by then
letting it evaporate 'down' at liesure...
...that Surfactants ( especially of whatever kinds which ancient or long ago
peoples had handy, ) might influence the 'early' mechanisms or arrangement
of particles, before the Surfactants themselves themselves break down or
change chemically from the general interactions of the 'stew'.
But, as you and others know well, and I do not know at all...at very small
scales, especially if Water is at least approximately saturating...there are
many Electrical and Chemical things going on which will be doing important
Work...and changes which impirically can be associated with some 'gross'
thing or another, turn out to be complex and interactive Electrical and
Molecular negotiation/socializeing/events which are really on a very small
and discrete scale indeed.
Best wishes..!
Phil
Las Vegas
----- Original Message -----
From: "Ivor and Olive Lewis"
Dear Hank Murrow
I wondered about space for the water, but for differing reasons.
You suggest <between them. they slide but do not pull apart.>>.
Well, having played around with microscope slides and cover slips for close
to sixty five years I recalled that your visualisation differed from my
experience. If you have a thin layer of water between the two slides there
is a high degree of friction. It is very difficult to slide one cover slip
past the other. It takes force to make the glass slide past glass unless
there is a lot of water, enough to exude from between the sheets. So I
checked. Just did it with a couple of brand new cover slips. Almost
impossible to make one slide past the other.
I think that this illustrates the proposition that clay water systems would
not have the properties they do have if water was such a good lubricant. The
words of Lawrence and West seem wise to me.
Best regards,
Ivor Lewis.
Redhill,
South Australia.
______________________________________________________________________________
Send postings to clayart@lsv.ceramics.org
You may look at the archives for the list or change your subscription
settings from http://www.ceramics.org/clayart/
Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
| |
|
