elizabeth priddy on sat 20 nov 99
eutectics is voodoo and is one of the main
reasons I have as little interest in glaze
chemistry as I do. Also not a pyro...
But the world wouldn't be the same with out
the fire freaks and the witch doctors, so
keep following your own path proudly!
---
Elizabeth Priddy
personal email: epriddy@usa.net
website: http://www.angelfire.com/nc/clayworkshop
On Fri, 19 Nov 1999 11:52:01 Craig Martell wrote:
>----------------------------Original message----------------------------
>
>>Ivor commented:
>>Since a eutectic point is a precise temperature the quotation seems to be a
>>nonsense statement. I do not have the mathematical ability to sort out the
>>Algebra which would enable me to calculate the weights of Wollastonite,
>
>Hello Ivor:
>
>Since I am the one that is guilty of babbling the nonsense about eutectics
>I should make some attempt to clarify my point.
>
>I was speaking about observations regarding fusion line blends of feldspars
>and calcium introduced with whiting and or wollastonite. There is a strong
>"melt" that can be observed at about the 70/30 point with spar being 70 and
>whiting being at 30. Whether or not this is a true eutectic is open to
>endless debate. The term gets tossed around a lot even though the true
>phenomena may only be a myth. It's a way of talking I guess. I will edit
>my nonsensical statement to read "strong melt". Eutectics may or may not
>be attainable and understood. My aim is to make glazes and understand how
>they work and I can do this with or without eutectic precision.
>
>regards, Craig Martell in Oregon
>
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Gavin Stairs on sun 21 nov 99
At 05:05 PM 20/11/99 , you wrote:
>----------------------------Original message----------------------------
>eutectics is voodoo and is one of the main
>reasons I have as little interest in glaze
>chemistry as I do. Also not a pyro...
No, Elizabeth, not Voodoo. Chemistry.
Folks, a lot of people have spent their lifetimes working out how things go
together, and what happens when they do. We call them
scientists. Chemists. What they have left for the rest of us is a
systematic, repeatable description of their findings. The stuff that just
ain't so has been thrown out: what's left is what does work, each time you
do the experiment. This work can be the basis of what we call predictive
science: being able to say before you do something what the outcome will
be. This is not Voodoo, which is a very respectable system in its own
right. It is science. This doesn't cover everything possible, but it does
cover most of the basics of what is called natural material ceramics, or
pottery and glazing. The true scientists are off at the frontiers,
battling for new knowledge, while the rest of us practicing engineers are
trying to apply the old science to the practical problems of traditional
pottery, glazing and kilns.
What is wrong here is the idea that people who have had no training in the
system should be able to jump in at the deep end and not drown (make
sense). It's just not reasonable. Art schools and artists are noticeably
lacking in science training. This is not astonishing, really. The problem
is that understanding glaze chemistry is at the far out edge of predictive
science. What we have here is oil and water.
The science-knowledgeable people on this list are making valiant attempts
to reduce the science to words of few syllables and concepts familiar to
people who have not been introduced to the rudiments of the scientific
arts, like thermodynamics (and the dynamics in thermodynamics means change,
by the way: thermodynamics is by no means limited to statics, or
equilibrium states), and calculus. I have great respect for the geologists
who are attempting to explain what I know to be exceedingly complex
chemical systems. There is no time on this list to cover all the
introductory ground, to explain why differentiation occurs, to explain the
dynamic equilibrium of multiple phase systems, to explain what diffusion
is, and how it works in systems as disparate as flame dynamics and magma
melts. Most working scientists simply don't have the time to make the
attempt. These are people who have attended university for a minimum of 4
years, and many much longer, to attain their credentials and preparatory
knowledge, and who have then practiced their specialties for many more
years, to gain their intimate knowledge of these systems.
Now, the artist potters on this list have studied quite as long in a
different direction. They have learned many things about their art, but
unfortunately in a craft like potting, very little about the science. They
certainly have a practical base, but it is not of a nature which allows
them any predictive confidence. Unfortunately again, in this era we are
all expected to have an understanding of the behaviour of our products, at
least insofar as the safety of the users of our wares is concerned. That
is why some of us are concerned that potters not trained in science should
become at least sensitized to the inherent dangers of glaze and body
chemistry, and perhaps even a bit knowledgeable in the realms of
science. The renaissance man/woman is demanded by these circumstances.
Yes, there is a certain amount of noise on the list, from people who speak
beyond their knowledge. Yes, this is confusing. But do understand that it
is very costly in terms of time and money to mount convincing and
instructive demonstrations of the phenomena we discuss. Especially if you
want to do so with the integrity and rigor of a scientist. The
universities should be funding this and carrying it out, but they have
their own agendas, apparently. So truly knowledgeable people will often
speak of things which they know to be true, but have not demonstrated by
specific experiment. Perhaps one day...
As to the noise: No-one should be an uncritical reader. One of the first
lessons of science is that one must understand what is being taught, and
judge whether it is reliable, based on one's prior knowledge. The best
learning experiments are designed to explode ill founded preconceptions by
confronting them with contradictory reality. Learning is quite as much a
case of removing old, ill conceived "knowledge" as it is providing
new. When you read something that you think is wrong, confront it with an
experiment, or with accurate observation. Similarly, when someone asserts
something which you think is right, see if it agrees with your
experience. In either case, look critically and carefully at what you take
to be real. Seeing scientifically is like proofreading: you can read the
same passage over and over and still miss the error that someone else can
pick up in a momentary glance.
Dear Elizabeth, if you are still with me, the "Voodoo" is not in eutectics,
which are precisely defined chemical states which define the boundaries
between chemical regimes in polyphase systems. It is in the imprecise
understanding of the terms and the underlying systems. If one wants to
understand, one must make the effort to get it right. And it is in trying
to ignore reality while pursuing ill-founded recipes and old saws. Science
isn't everything, but it is a great deal more than nothing.
Gavin
Ron Roy on tue 23 nov 99
Hi Gav, I sure like the way you talk - and good on ya! - R
>----------------------------Original message----------------------------
>At 05:05 PM 20/11/99 , you wrote:
>>----------------------------Original message----------------------------
>>eutectics is voodoo and is one of the main
>>reasons I have as little interest in glaze
>>chemistry as I do. Also not a pyro...
>
>No, Elizabeth, not Voodoo. Chemistry.
>
>Folks, a lot of people have spent their lifetimes working out how things go
>together, and what happens when they do. We call them
>scientists. Chemists. What they have left for the rest of us is a
>systematic, repeatable description of their findings. The stuff that just
>ain't so has been thrown out: what's left is what does work, each time you
>do the experiment. This work can be the basis of what we call predictive
>science: being able to say before you do something what the outcome will
>be. This is not Voodoo, which is a very respectable system in its own
>right. It is science. This doesn't cover everything possible, but it does
>cover most of the basics of what is called natural material ceramics, or
>pottery and glazing. The true scientists are off at the frontiers,
>battling for new knowledge, while the rest of us practicing engineers are
>trying to apply the old science to the practical problems of traditional
>pottery, glazing and kilns.
>
>What is wrong here is the idea that people who have had no training in the
>system should be able to jump in at the deep end and not drown (make
>sense). It's just not reasonable. Art schools and artists are noticeably
>lacking in science training. This is not astonishing, really. The problem
>is that understanding glaze chemistry is at the far out edge of predictive
>science. What we have here is oil and water.
>
>The science-knowledgeable people on this list are making valiant attempts
>to reduce the science to words of few syllables and concepts familiar to
>people who have not been introduced to the rudiments of the scientific
>arts, like thermodynamics (and the dynamics in thermodynamics means change,
>by the way: thermodynamics is by no means limited to statics, or
>equilibrium states), and calculus. I have great respect for the geologists
>who are attempting to explain what I know to be exceedingly complex
>chemical systems. There is no time on this list to cover all the
>introductory ground, to explain why differentiation occurs, to explain the
>dynamic equilibrium of multiple phase systems, to explain what diffusion
>is, and how it works in systems as disparate as flame dynamics and magma
>melts. Most working scientists simply don't have the time to make the
>attempt. These are people who have attended university for a minimum of 4
>years, and many much longer, to attain their credentials and preparatory
>knowledge, and who have then practiced their specialties for many more
>years, to gain their intimate knowledge of these systems.
>
>Now, the artist potters on this list have studied quite as long in a
>different direction. They have learned many things about their art, but
>unfortunately in a craft like potting, very little about the science. They
>certainly have a practical base, but it is not of a nature which allows
>them any predictive confidence. Unfortunately again, in this era we are
>all expected to have an understanding of the behaviour of our products, at
>least insofar as the safety of the users of our wares is concerned. That
>is why some of us are concerned that potters not trained in science should
>become at least sensitized to the inherent dangers of glaze and body
>chemistry, and perhaps even a bit knowledgeable in the realms of
>science. The renaissance man/woman is demanded by these circumstances.
>
>Yes, there is a certain amount of noise on the list, from people who speak
>beyond their knowledge. Yes, this is confusing. But do understand that it
>is very costly in terms of time and money to mount convincing and
>instructive demonstrations of the phenomena we discuss. Especially if you
>want to do so with the integrity and rigor of a scientist. The
>universities should be funding this and carrying it out, but they have
>their own agendas, apparently. So truly knowledgeable people will often
>speak of things which they know to be true, but have not demonstrated by
>specific experiment. Perhaps one day...
>
>As to the noise: No-one should be an uncritical reader. One of the first
>lessons of science is that one must understand what is being taught, and
>judge whether it is reliable, based on one's prior knowledge. The best
>learning experiments are designed to explode ill founded preconceptions by
>confronting them with contradictory reality. Learning is quite as much a
>case of removing old, ill conceived "knowledge" as it is providing
>new. When you read something that you think is wrong, confront it with an
>experiment, or with accurate observation. Similarly, when someone asserts
>something which you think is right, see if it agrees with your
>experience. In either case, look critically and carefully at what you take
>to be real. Seeing scientifically is like proofreading: you can read the
>same passage over and over and still miss the error that someone else can
>pick up in a momentary glance.
>
>Dear Elizabeth, if you are still with me, the "Voodoo" is not in eutectics,
>which are precisely defined chemical states which define the boundaries
>between chemical regimes in polyphase systems. It is in the imprecise
>understanding of the terms and the underlying systems. If one wants to
>understand, one must make the effort to get it right. And it is in trying
>to ignore reality while pursuing ill-founded recipes and old saws. Science
>isn't everything, but it is a great deal more than nothing.
>
>Gavin
Ron Roy
93 Pegasus Trail
Scarborough
Ontario, Canada
M1G 3N8
Evenings 416-439-2621
Fax 416-438-7849
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