The Latest on Amalgams and Thermoelectrics



An excellent idea, Keith. Do it. Get back to us with the results.
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Peter Bowditch aa #2243
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Keith P Walsh wrote:

That's the definition of "Seebeck Coefficient." The actual effects are nonlinear.

So do the labwork. However, the physics (potential differences) is extremely well-established. As in, your computer wouldn't work if it weren't so.

If I get into a scientific correspondence, I will. For a Kindergarden class in basic electromechanics, I'm not bothering.

Clue for you, Bucky: I'm citing stuff about as well-established as Ohm's Law. Which I don't cite sources for either.

Well, dip me in shit and call me a Tootsie Roll! Look up "thermocouple."

Well, if you want to highball by a couple of orders of magnitude, you can take the maximum grain size, the maximum temperature gradient (degrees per mm), thus the maximum temperature difference across the grain, and multiply by the Seebeck difference for the materials.
Doing it that way you should be able to come up with as much as several millivolts in the presence of ice cream.

I ballpark much more complex stuff for a living, with millions of dollars at stake. I'm still employed.
Is my guess accurate? Hell, no. It is, as I note, high by several orders of magnitude. If you want precision you're going to have to do a PEEC analysis that will take a while to set up.
Whether that's worth doing depends largely on whether the highball is too low to bother with.
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Wow, that's fantastic.
But I for one would be more interested to know if you have any amalgam fillings in your teeth.
Because if you have then this might have an effect on your ability to be objective when making any guesses on the particular subject of their thermoelectric behavior.
After all, it wouldn't look so good on anyone's resume if it turned out that the real cause of any frustrations, anxieties or lack of contentment that they might feel was the low-level but perpetual dissipation of electrical energy generated by the thermoelectric batteries literally under their very nose, and they never even realised it.
Would it?
Did you know that the widespread adoption of mercury amalgams for use in restorative dentistry was quickly followed by the rise to prominence of psychiatric "medicine" in our societies. Anyway I've explained that already. My real point here is that the reason why experimental evidence from scientifically conducted investigations is essential in establishing an accurate understanding of any physical phenomenon is because guesswork on its own is often (and probably usually) influenced by the emotional priorites of the guesser.
And, as the Nobel prize-winning US physicist Richard P Feynman put it:
" ... we compare the consequences of the guess to see what would be implied if this law that we guessed is right. Then we compare the result of the computation to nature, with experiment or experience, compare it directly with observation, to see if it works. If it disagrees with experiment it is wrong. In that simple statement is the key to science. It does not make any difference how beautiful your guess is. It does not make any difference how smart you are, who made the guess, or what his name is - if it disagrees with experiment it is wrong."
That reminds me, in one of your earlier posts in this thread you asserted that, ".. the resistivity of dental amalgam is known, ..". Well I'm not so sure that this is true. The ONLY scientific paper that I've ever found which purports to present the results of experimentally derived electrical resistivities for dental amalgam is "Resistivity of Silver-Tin Amalgams", by Richard J Schnell and Ralph W Phillips of the Indiana University School of Dentistry, which was published in the Journal of Dental Research in 1964.
See:
http://jdr.iadrjournals.org/cgi/reprint/43/4/501.pdf
I've already pointed out that this paper quotes its results for the resistivities of amalgams in units which are not valid for this property (i.e, micro-ohms per cubic centimeter), but there are some other points also worthy of discussion.
Firstly, of course the authors of this paper did not measure "resistivities" as such. What they measured were the electrical resistances of test pieces of amalgam and then they calculated their resistivity values taking into account the dimensions of the test pieces:
"From the cross-section area and length of the specimens the resistivity was calculated and corrected for room temperature."
- but they have not defined this calculation anywhere in the report. And since they have not included any sample values of the measured resistances either it is impossible to determine that they carried out the correct calculation.
However, of perhaps even greater interest are some numbers which appear in Fig. 5 of the report. A table of values described as "RESISTIVITY OF ORIGINAL COMPONENTS" gives the number 96.256 for mercury (Hg). This corresponds fairly accurately to the resistivity of elemental mercury in units of micro-ohm centimeters. At this scale the resistivities of silver and tin are 1.6 and 11.5 respectively - yet the value given for an 84%/16% split of silver and tin alloy appears to be 55, much higher than both.
If these values are correct then they would imply that the resistivity of an alloy of metals is not necessarily "somewhere between" the resistivities of the individual component metals.
Is it possible that there is an alternative interpretaion of these figures?
And is it not possible that we might find a better source for this information?
Keith P Walsh
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Keith P Walsh wrote: <snip>

<snip>
I can't help but find it ironic that Mr Walsh will quote Feynman stating how a hypothesis can only be validated through experiment, and yet Mr Walsh has never made any attempt to validate his own hypothesis by running experiments himself...
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Paul D Oosterhout
I work for SAIC (but I don't speak for SAIC)
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"It's OK fellas. Mr Walsh is just as ignorant as we are!"
Is that what you're saying?
(And I expect you think you're a scientist.)
In recent years technologists have developed extremely sensitive instruments which are able to measure neurological activity in the human body.
However, as far as I know the results of experimental investigations to determine whether any difference can be detected between neurological activity in the vicinity of teeth with amalgam fillings and neurological activity in the vicinity of teeth without are not available.
I do not have access to the instruments required to carry out these investigations myself.
However I feel sure that I should have access to those results.
Keith P Walsh
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Keith P Walsh wrote:

Mr Walsh, Before we go investigating the neurological activity in the vicinity of teeth with amalgam fillings, why don't you just find out just how good a thermoelectric battery a tooth with an amalgam filling really is. Until you know much how much voltage and current can be produced by the filling, then all this talk about neurological activity is just hand waving.
Buy (or rent) some equipment, purchase some dental amalgam material, fabricate a test fixture, and take some measurements. What the heck are you waiting for?
--

Paul D Oosterhout
I work for SAIC (but I don't speak for SAIC)
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I'm afraid I disagree with you Paul.
The fact is that if an instrument designed to measure neurological impulses was able to detect a greater degree of neurological activity in the vicinity of teeth with amalgam fillings than in the vicinity of teeth without them, then it wouldn't really matter in what proportion the electrical potentials in the fillings were generated by electrolytic, thermoelectric or faradaic phenomena, the more important questions would be concerned with establishing the degree to which the increase in neurological activity might be causing so called "psychological" effects in the patients.
For example, is there any evidence to suggest that people with large quantities of amalgam in their teeth are more likely to commit suicide than people with fewer or none? You'd have to record numbers of amalgams for a significant number of suicides and compare the average with that of the general public in order to tell.
Or do the inmates of psychiatric institutions and perhaps prisons have, on average, greater quantities of amalgam in their teeth than the general average? You'd have to do similar studies to find out.
Of course, members of the dental profession might argue that these people simply lack intelligence, and any correlation is explained by the fact that it was the same lack of intelligence which led them to neglect the proper care of their teeth in the first place when they were young.
On the other hand however, if that experimental investigation had given an indication that the electrical potentials generated by amalgam fillings in people's teeth really do dissipate electrical energy through the nerves in their heads, then this might provide a direct causal link between amalgam fillings and a myriad of so called "behavioral disorders".
The former sci.med.dentistry guru and amalgam apologist Joel M Eichen once wrote "If metal were harmful as Jan Drew posits, the epidemiology would jump out at you!".
Well maybe the epidemiology did jump out at us (not actually us, but our forefathers), but in an age of ignorance when the real problem was undetectable, what happened was that a lot of best-guesses amounting to nothing more than clever excuses were concocted, and people had little choice but to believe them. And then over time the equally unscientific argument that, "we've been using amalgam for so long that there can't possibly be anything wrong with it!" became blindly accepted.
Epidemiological studies don't do themselves. They have to be properly planned and executed in order to yield useful information, just like any other scientific experiment.
We've all grown up in societies where large numbers of people with amalgam fillings in their teeth is the norm. And a wide variety of socially problematical behaviors is also the norm. What if the former is a significant, if not major, cause of the latter. How would we know that it is? It isn't necessarily true that it would be obvious.
I expect that you might be able to convince yourself that you "just know" that what I am suggesting cannot possibly be correct. But I put it to you that you don't "know" any such thing. I'd say that it has been demonstrated that too many of the investigations necessary for you to be in that position of knowledge appear not to have been carried out.
And in the absence of the results of those investigations you're just guessing.
(And you know what Richard P Feynman said about that.)
You may also protest that the scientific community could not possibly have made such an enormous and ridiculous error for such a long time without even realising it - and for the simple reason that if it had made such an error then it would make all of its members, including perhaps yourself, significantly ignorant. And this cannot be true because you've managed to establish, at least in your own mind, that you're not ignorant.
But that isn't scientific reasoning. You're simply choosing the belief which is most emotionally gratifying to you without having established the required scientific basis.
Like I said, large numbers of people have amalgam fillings in their teeth. What would our society be like if amalgam fillings made people unhappy without them realising it? Well I suppose one thing it would mean is that there'd be a lot of unhappy people about.
Take a look around you.
Keith P Walsh
PS, if you really are interested in whether or not the thermoelectric effect on its own is enough to stimulate neurological synapses in animal tissue then you might want to read professor L I Anatychuk's paper "Seebeck or Volta?", published in the Journal of Thermoelectricity, No.1, 1994. (He thinks it is.)
Or are you the Greggie Gibson type of "scientist" who doesn't need to?
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On Dec 25, 5:29am, Greggie Gibson >

Professor L I Anatychuk of the Institute of Thermoelectricity in the Ukraine appears to believe that the thermoelectric behavior of a piece of metal is enough on its own to stimulate neurological synapses in animal tissue. (See: "Seebeck or Volta?", L.I.Anatychuk, Journal of Thermoelectricity, No.1, 1994.)
Can you tell us whether or not the results of your research confirm this?
Or are you keeping them a secret?
Keith P Walsh
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oups.com:

I was more interested in how hard it would be to find out the information than I was in the information.
As I had no trouble after such a short time getting a Dept of the local University to test these theses and provide quantitative answers, my experiment was a success.
So, if you really do want the answers, go to your local University and see if you can interest a professor or two to design a project that can answer your questions.
One Caveat: It's pretty late in the year so you might have to wait until next fall. But then again it's always possible there is some student that needs a neat little project.
Good luck,
Let us know your progress.

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wrote:

I'm sorry D.C. but I don't buy this.
And I will explain why not.
In their book "Restorative Dental Materials", Robert G. Craig and John M. Powers make the following assertion:
"The conductivity of materials used to replace tooth tissue is of concern in restorative dentistry." (from Chapter 3, "Optical, Thermal and Electrical Properties", page 55.)
Oddly this statement is not expanded upon in the book.
However, it clearly contradicts your own assertion with regard to the resistivity of amalgams that, ".. it's trivial and not interesting."
(May I assume that you understand the relationship between electrical conductivity and electrical resistivity?)
First you presumed that the reistivity of amalgams was "known" (a presumption which, by the way, ought to be a reasonable one). Then when you found out that it wasn't known you simply guessed that it's not important.
And the statement by Craig and Powers quoted above contradicts your guesswork so directly that I shall repeat it again with an emphasis of my own added for effect:
"The conductivity of materials used to replace tooth tissue IS of concern in restorative dentistry."
I think it is interesting enough to note that Craig and Powers quote electrical resistivities for the following materials:
Human Enamel: 2.6-6.9x10^6 ohm.cm
- someone thought it was worth the bother to measure that and publish the results.
Human Dentin: 1.1-5.2x10^4 ohm.cm
- someone thought it was worth the bother to measure that too.
Glass Ionomer Dental Cement: 0.8-2.5x10^4 ohm.cm Zinc Oxide-Eugenol Dental Cement: 10^9-10^10 ohm.cm Zinc Polyacrylate Dental Cement: 0.4-4.0x10^5 ohm.cm Zinc Phosphate Dental Cement: 2.0x10^5 ohm.cm
You see, somebody took the bother to measure the electrical resistivities of all of these dental materials, and to publish the results.
And Messrs. Craig and Powers have also bothered to quote the values in their book, presumably because, "The conductivity of materials used to replace tooth tissue IS of concern in restorative dentistry."
(Go on then, I'll say it - electrical conductivity is the reciprocal property of electrical resistivity.)
So tell me D.C., what's so special about dental amalgam such that it should be the ONLY dental material whose electrical resistivity is not worth bothering to know?
Back in 1950s someone agreed that it would be worth a masters degree each to Richard J Schnell and Ralph W Phillips for them to bother publishing the electrical resistivities of a range of dental amalgams. The trouble is, as we have seen, their paper is useless because it quotes all of the electrical resistivities in meaningless units, and it doesn't specify the calculation used to derive the resistivities from the measured resistances, see:
http://jdr.iadrjournals.org/cgi/reprint/43/4/501
And this paper is STILL the only document that anyone can find anywhere in the world which purports to give electrical resistivities (or electrical conductivities) of dental amalgams.
If I were the guessing kind I might guess that there's something untoward about the electrical behavior of dental amalgam which is indicated by the honest findings of experimental procedures to measure it's electrical properties.
But then of course I would never presume that my guesswork was correct until such findings had been verified scientifically.
Is that the main difference between my position and yours I wonder? If it is then I should remind you that guesswork on its own never constitutes science, not even your guesswork.
(And don't be misled by whoever it is who keeps following your postings around giving them five-star ratings - the liklihood is that, when it comes to the electrical properties of dental amalgams, they're just as ignorant as you are.)
Keith P Walsh
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ups.com:

And you believe this fairy tale?
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wrote in

My reaction is that science is dynamic, that the scientific method requires results that are repeatable, that every day new scientific methods become available...but that really isn't the point, is it?

My reaction is that there are literally millions of structures throughout the world with metal supports and they aren't collapsing from thermoelectric eddy currents (possibly rust though). That in fact the thermoelectric effects of metal have been researched continuosly for decades. We drive in metal cars, we eat with metal utensils, we use metal tools, we use metal of every kind on a continuos basis and no harm (think of that as deterioration due to eddy currents...and yes they would be subject to your thermal gradients) has ever, I repeat, EVER, been associated with it.

No there isn't. You cannot demonstrate that amalgams in situ are subject to thermoelectric effects because teeth are not good conductors and you can't have a large temperature gradient in your mouth.
However, should such an effect exist, amalgam fillings that are removed would show signs of pitting and the tooth cavity would show metallic coating. Can you document one single case of either?

I respond with a question: What exactly have you done about this? Have you done anything except support your electric utility by posting? Have you gone to your local university and sought the help of a professor in Mechanical Engineering, Chemical Engineering, Electrical Engineering or Medical Research and asked them if they thought it might be an interesting project either for a class or a PhD candidate?
I have done this and gotten the research done. All free.

Actually I doubt you want to.

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Keith P Walsh wrote:

Look up "Faraday cage."
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You could make a more honest contribution than simply dropping hints.
Who do you think you are? "Mr Big"?
My worry is that such is the mentality of some of the correspondents who frequent this newsgroup they might automatically assume that advising me to "Look up "Faraday cage."" represents some kind of refutation of an aspect of my argument, without even knowing or bothering to find out what a Faraday cage is.
So if you think that the function of the Faraday cage has some relevance in this debate you should at least have the integrity to explain what you think it is.
Keith P Walsh
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<snip>

Mr. Walsh
Why haven't you done any experiments?
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