of course not. you have again grasped at straws and missed. the 250mhz will induce currents in any conductor within range. and since fillings are conductors they will have currents induced in them and these will of course produce potential differences.
Do you think that it should be possible to determine whether or not the electrical potentials thus generated in amalgam fillings are able to dissipate electrical energy through the nerves in people's heads?
Keith P Walsh
it should be possible to determine that. i have had tests that measure the normal nerve pulses and stimulated signals when testing for carpal tunnel syndrome. there is probably no reason the same type of test couldn't be used to test for nerve impulses in the head... there would be two problems though, getting access to the nerves with the probes, and preventing interference from the electromagnetic field you are testing with. there would be a big problem with the probes actually injecting signals from the emf instead of measuring the effect on the nerves themselves, some tricky shielding or processing to cancel out the rf effects on the probes would be needed to see the actual nerve impulses.
Are you also concerned about the electrical potentials generated in the nerves in people's heads (they are conductive material, after all) dissipating energy in their fillings?
Do you think it's possible to pose these questions to the experts at your local college/university?
Do you think it's possible to specifically identify which nerves YOU are talking about?
As I've mentioned previously, I have done just that. You could do it or you could arrange to pay me for my time and effort. The price keeps going up.
Keith, aren't you saying that the MRI process itself cannot be taken as a negative on other types of EM radiation? It seems Dave has suddenly focused in on the EM radiaiton in an MRI which is probably a very small amount of energy. The point is what the Magnetic field does during an MRI, not the tiny dose of RF radiation they give you. Let's also not forget that this (magnetic) field probably isn't switching at a very high rate at all, even if it is large, (because, remember a constantly CHANGING field is need to induce voltage,).
Good grief... An MRI will suck up a floor buffer; forget about it rattling your fillings. Patients are constantly exposed to huge amounts of EMR during an MRI. -- See:
Sigh...Bill your understanding of physics seems to be a little, well off. A magnet will fly into a refrigerator, that doesn't mean that the magnet is generating any substantial emf in the refrigerator or itself. of course if you spun the magnet around real fast so it generated a changing magnetic field...
Magnets create attraction with magnetic materials because the little tiny weeny magnetic domains align to become one great big, huge magnetic domain when exposed to a magnetc field, no changing flux requred!
Patients are constantly exposed to huge amounts
That is apparently caused by the magnetic field, not electromagnetic radiation. If so you cold point an attenna at a nail and watch it fly across the room. Do you see cars lifting up into the air when they drive by a radiostation anntena, or a microwave dish. That's EMR! My understanding is that MRI's do not use substantial electromagnetic radiation but only a little in the RF range. If they do, a lot of people would like to know because on of the big selling points of MRI's is that they are safer than x-rays because of the small-low energy EMR exposure.
It's the change in the flux that matters, not the total strength of the field, for the purpose of induced voltage. You would think that for a while, while it powers up some voltage would be generated, but I don't even know how long it takes the machine to reach full strength. I could sit in a magnetic field 1,000,000 times the earth strength and still not generate a voltage in a wire
A magnetic field attracts objects because they have miniature currents loops inside them, aligned with exposure to the magnetic field and force equals B(H)x(current). this is not the same mechanism by which a magneic field induces a voltage. A changing magnetic field will induce an electric field in AIR, but it won't exert a force on the air molecules, otherwise we would have tornado's near power generators!
In message , Keith P Walsh writes
Wrong, or at least sloppily worded. The frequency of the electromagnetic field is matched to the frequency of precession of nuclei with magnetic moments in the _static_ magnetic field.
[snip irrelevant information about nuclear precession]And even if they did, it wouldn't be relevant. Nuclear magnetic resonance has nothing to do with whether the radio-frequency part of the scanning technology induces electric currents in conductive materials. That's down to Maxwell's equations and Ohm's law.
As an aside, I have read about people receiving radio broadcasts within the vicinity of high power AM transmitters. Supposedly the corrosion, of whatever chemical means, had created rectifiers. The resultant DC and I suppose a loose part of a filling resulted in audio being generated and conducted via bone to the inner ear. I have not experienced this.
If this is true, might not people who have this defect in their fillings also experience some kind of sound. Or is the noise of the damn machine so loud and synchronized with the "tooth generated" audio that it is not detected by the patient.
The only effect I remember from the procedure is that I saw pink clouds floating in a light blue background when I closed my eyes.
I might add that they found nothing wrong. But my left ear still rings.
Al
Would you presume that the medical profession has enough scientific evidence to conclude that the ringing in your ear is not the result of a neurological injury caused by the discharge of elecrical energy through the nerves in your head resulting from the generation of electrical potentials by the metal fillings in your teeth?
Keith P Walsh
PS, remember that it has been demonstrated experimentally that metal amalgam dental fillings generate electrical potentials with magnitudes of up to 350 millivolts. See:
By the way "Dave", a few weeks ago our fellow newsgroup contributor billkatz wrote this:
"Amalgam is a metallic compound but because of the high resistance of amalgam, it cannot truly be classified as a conductor. "
This appears to directly contradict what you are saying with regard to amalgam fillings being conductors.
It looks as if one of you must be mistaken.
Is it you or is it him?
Keith P Walsh
PS, I'd guess that it's him.
But your inability to state categorically that this is true shows how little faith or knowledge you have in the subject.
I've read what you have to say. Keep rationalizing. You'll finish digging your own grave, soon enough.
Bye!
I don't like threating language like that. By the way telling someone to dig their own grave can be construed as a direct threat according to google laws, say "bye bye" to your account.
google laws? LOL
google has become the largest haven for spammers, what makes you think they care about newsgroup postings
No it doesn't.
It simply allows (deliberately) for the fact that after a long time looking and asking the right questions I have not been able to find an experimentally determined value for the electrical conductivity (or resistivity) of a typical dental amalgam.
And I think it shows that my own scientific thought process is perhaps more rigorous than yours.
Would you yourself describe amalgam dental fillings as "conductors"?
And, if so, would you be able to quote an experimentally determined value for the material's electrical conductivity - measured in siemens per metre - (or its electrical resistivity - measured in ohm-metres) in support of it?
Keith P Walsh
Robert's not good at answering questions.
He can't answer the below ones either.
What is*your* position on the safety of amalgams, Robert?
What is *your* position on the electromagnetic properties of typical dental amalgams, Robert?
Okay, lets simplify a bit. TAke two magnets near each other and hold them in place with say a wooden clamp. Now you would agree that the voltage one induces in the other is zero?
In fact it's obvious that since everything is static no energy is being put into the system so it would be hard to see how a voltage could be induced, if say one of the magnets was connected in a loop with a wire and was doing work!
Now imagine the clamps were suddenly removed from the magnets. Note that no voltage is induced, the instantaneous velocity is zero, no change in flux going through the magnet etc, yet there WILL be a strong force on the magnet. The generation of force on the magnet is not the same thing as the induction of voltage and current. Thus the fact that an MRI can exert a large force on an object does not imply that it induces a large voltage, although, when the object moves and depending on changes in the field strength some production of voltage is likely to occur. (I have no idea how much becaue I don't know that field strengths and changes of the magnetic field in an MRI)
This concludes kindergarten physics 101.
Asking the right questions? Who have you been asking? Certainly not the Physicists at your local college/university. Inquiring minds want to know.
Please describe the experiments that you have performed or asked to have performed by legitimate scientists. Please explain your refusal to ask the physicists at your local college/university for their help in determining these values.
What scientific thought process is that? What experiments have you conducted and what were the results? How can you say your "thought experiments" are more rigourous than mine when yours are just theories and I have had the actual experiments performed?
I am not about to provide you with any useful info prior to proper payment for my research.
Yes.
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