On Mon, 17 May 2004 15:33:17 GMT, alexy
posted:

Sandy wrote:

Disagree. One can observe a cause and effect repeatedly and draw valid
conclusions without understanding the mechanism.

Disagree. If you don't understand the mechanism, or the rationale, you
are very likely to cock it up when things don't go exactly as
expected. Especially with complex procedures.

LOL! Do you really think that the inorganic chemistry involved in the
derusting process is more complex than the operation of the
gravitational force and the organic chemistry and electrical processes
involved in the sensing, transmittal, and interpretation of the pain
signal?

Nope, and I don't think I said it was.
What I said was the steps involved and decisions needed to implement
the procedures are more complex in the derusting example.
Dropping a rock on your foot is rather simple, but derusting an object
requires many step decisions and step understandings.

Understanding theory does help immensely, when deviating from
experience, but empirical evidence can be adequate for some instances,
such as derusting some particular steel.

Which particular steel? How do you tell what kind of steel? So many
decisions
With the rock example, you don't even have to decide what kind of
rock, or which foot to drop it on

Where I see theoretical
knowledge of the mechanism helping is knowing how it might work on a
different alloy, how different solutions might work if the known one
is not available, predicting long-term effects if evidence is not
available, etc.

Exactly, so the bottom line is, are you siding with my desire to
thrash out the chemistry involved so we can make rational process
decisions, or do you side with Charlie in objecting to the presence of
this discussion here because he does not want to understand anything
other than a simple recipe that allows for no rational deviation?

Folks knew that
dropping a stone on their foot would hurt long before Newton and an
understanding of the nervous system (and do we yet fully understand
the mechanism of gravity, or just have more sophisticated observations
about it?) Charlie's point is valid; all we NEED to know is whether it
works.

And does it?

I'd like to know.

So would I. That's why I asked the question, and enjoy reading and
absorbing the various learned responses I have gotten.
Charlie objects to this. God knows why he hasn't got the willpower or
tolerance to ignore what does not interest him, but feels the need to
stick his nose in and have a whinge.

Charlie will likely never be quite sure.
Someone has to figure out how it works to be able to do it
competently.

No, I can quite competently grill a steak without understanding the
physical and chemical changes taking place in the steak when it is
heated.

And if your steak turns out tough, or not to the liking of some
consumers? I'm very interested in the biology of steak vis-a-vis the
cooking process. Our scientific/agricultural institutions are too, and
are studying the subject intensively.

And a steak is, I would suggest, a far more complex object
than a piece of rusted steel, and the processes involved are also more
complex.

Not really, depends how deep you go into it.
The variation in treating a rusted article are far more diverse than
the heating of a steak, but even there, as I explained above there is
much process choice even with this simple (apparently) heating
process. I've cooked steak according to the "recipe" I knew, only to
have it turn out tough sometimes and perfect at other times.
I really need to research why this is.

Not much is likely to go wrong with your strange hobby of
dropping rocks on your foot, I would have thought. Now chemical
procedures...

I'm sure you think they are more complex than the elemental forces of
physics or biological systems. We might just have to agree to disagree
on that! g

We are talking about two things. The complexity of the phenomenon, and
the complexity of the process that a human must undertake.
Dropping a rock on your foot is a simple process, whereas derusting a
rusty article is a complex process with many decisions to make.
Both have underlying phenomena that are equally complex, I would
argue. It's the decisions involved in the required steps of the
processes that differentiate these two.

I'm with you in fascination with understanding why it works,
but that understanding is a want more than a need.

Again I disagree. So many things can go wrong with things chemical. So
many things waiting to bite you on the ass. DAMHIKT.

Yep. Sometimes I overcook a steak, and wonder if a more thorough
knowledge of the chemical changes going on in it might have kept me
from getting a medium-well steak when I wanted it medium.

But as I said above, there is apparently much more to cooking steaks.
Starting from choosing the piece of meat from the butcher's display
case, apparently. I would like to learn more, and listen with interest
when I hear the CSIRO discussing their latest research.

I, like most woodwrkers,
am not a chemist.

Are woodworkers prevented from being chemists?

Reread the sentence you quoted.

Yes, and what point is it trying to make? Charlie is not a chemist, so
woodworkers don't need to know any chemistry?

No. That he is not a chemist, and that most woodworkers are not
chemists, and are probably more interested in whether it works than
how it works.

Do you disagree?

Yep. Close, but not my reading. His context was a complaint that this
discussion was irrelevant to this forum, and because he was not a
chemist, and couldn't follow it, it should not be discussed here.

Do you really think that most woodworkers ARE
chemists?

Of course not, and that was not the point that Charlie conveyed to me.
He was complaining about the presence of the discussion, remember.

If they were mine, and I valued them, I would not use salt and vinegar
on them. This comes from my understanding of chemistry.

Why? What are the bad effects predicted by your understanding of
chemistry, and do they prove out in practice?

Yep. Salt will enter the fine pits and interstices of the corroded
surface and perpetuate future corrosion. Very difficult to clean
thoroughly.

That's good for part 1 of my question. And I believe I saw in another
post that you were going to do an experiment to find out part 2? I'll
be interested in hearing your results.

I did not mention an experiment regarding this. I have read much on
salt inclusions in rust pits, and the resident expert here mentioned
such in a girder for a bridge. I would not like to put all my weight
behind a rusty spanner that had been soaking in salt in a previous
life.

There was a guy once who ignored chemistry and
shot-blasted his aluminium boat with copper shot. It lasted but a few
weeks. Chemistry is VERY important!

Absolutely! And this is an excellent example where theory is important
to predicting the result of an untried process.

Exactly my point.

That's why I'm interested, and like you, think it is on topic and
worthwhile.

I'm rather ****ed off at Charlie for butting in with his selfish
objections, and then ****ing off, so to speak.