Faradaic Activity in Dental Amalgams

Particularily when one train leaves Chicago at 65 mph and one leaves Denver at 55 mph.........

The answer in this years SAT is

c. 350 mV

carabelli

It is stupid posts like this, that show the dentists think the dangers of amalgams are all a joke.

I find the following suggestion pretty funny myself. I suppose this is why nobody takes any personal responsibilty anymore.

"The batteries in my teeth made me do it!"

"I am being controlled by aliens..."

"Low frequency radio waves are controlling my brain..."

Dear

The enclosed sheet shows how when a crude electric battery, such as a metal amalgam filling, is inserted into the tooth of a live human being, then the innervation of the head (through the upper and lower mandibles, tongue, sinuses, eyes, bridge of nose, ears and all the way back to the pons) provides a network of circuitry capable of dissipating the potential of the battery in the form of an electric current.

It must be recognised that each individual in society has their own unique array of tooth batteries and these vary from person to person with regard to size, number and time of life when each battery was fitted/removed.

It is my firm belief that it is the presence of these batteries in peoples mouths which is causing many to feel that they have inadequate control of their own lives.

Could you please supply me with any evidence you have which contradicts this belief.

Kindest regards,

snipped-for-privacy@comcast.net wrote: (snip)

Sorry, it is not my job to contradict your beliefs (and I can't imagine any evidence for the absence of such a hypothetical effect that would change your mind).

You are welcome to any beliefs that suit you, as long as you don't try to force me to believe.

It is your job to support your beliefs with evidence and logic, if you expect to persuade any reasonable person that your beliefs are valid.

You are also free to skip this part and blame the world for not being inspired by your unfounded presuppositions.

That would put you in large company.

Good question.

Can you suggest how anyone might find the answer?

Keith P Walsh

PS, further enquiries regarding the electrical properties of dental amalgams can be found at:

The relevance of this link is that it provides experimental evidence that it may be inaccurate to describe an electrical potential measured in a dental amalgam as a "transient maximum", something which you had implied was the case in your previous message.

Can you explain the relevance of your pointing out that this paper was written in Polish? (I wonder if I detect a distinct whiff of arrogance here.)

Keith P Walsh

One way is to construct a shield which would absorb EM radition, near the amalgam being tested. Ever notice how the radio goes off under a bridge. Go to a remote location where he EM fields are weak and even cell phones and pagers don't work.

Also you've got to realize that energy moving in an electic field is in the form of propagating waves. therefore induced voltages will be sinsusoidal. In fact, if you look at the output from say an antenna, you can even separate out the EM energy received by frequency. Voltages from galvanism would probably be DC.

You could ask the electical engineering department to look at the voltages being generated with a frequency spectrum meter. Even if the EM radiation was somehow modulating the galvanic voltage you could still match the frequency with that of the closest radio station and compare the output before and after using and EM shield.

or Keith could go to the physics department of his local college/university and ask them this question.

The real question is: Keith, why aren't you doing this?

The real question is: Keith, why aren't you going to the physics department of your local college/university and asking them this?

"Robert Morien" wrote

The real questions are Robert: What is*your* position on the safety of amalgams?

What is *your* position on the electromagnetic properties of typical dental amalgams?

The truth is that if you went to a physics department and asked them to write an equation for changes in hg vapor release as a function of Electromagnetic fields they wouldn't be able to answer.

but if you asked them to determine the amount of EM radiation absorbed and dissipated they could probably come up with a pretty good answer.

the information you posted in the other thread was very interesting but keep in mind that galvanism and changes in chemical behavior in general (including Hg vapor pressure) as a function of EM fields is a separate phenomena from absorbtion and dissipation of Electromagnetic energy by amalgams.

Too many millivolts to be safe ........

This is true. Few people realize that most Physics Departments have loads of staff sitting around, just waiting for visitors to come in with requests like this ........

Wait a minute, sorry, ,,,,,,, I got that mixed up with the internet.

Joel

Good point. I just got scared and went downstairs and removed all the magnets from the front of my refrigerator and tossed them in the trash. Does anyone know whether they are considered hazardous waste?

Joel

Here is a thought experiment. take a square conducting loop. Inside a fluctating magnetic field is applied as found in a power generator capable of producting 2000V or more and transmitting a large amount of power through the loop, to say a power line.

Now replace the square conductor with a plastic one, and in addition rotate the plastic conductor at a high rate of speed in and out of the magnetic field.

Theoretically a fluctating magnetic field will induce an electric field and thus a "voltage" in space or any moving loop. Why doesn't the plastic conductor burn up with all the electric energy generated by the magnetic field, which normally would have been transmitted by the "conducting loop".

What do you mean "thought experiment?" A number of posters conduct this kind of inquiry three, maybe four times a day right in their bedrooms .......

Joel

Joel M. Eichen wrote:

Thus, Faraday's law implies that the line integral of the electric field around circuit (in the positive direction) is equal to minus the time rate of change of the magnetic flux linking this circuit. Does this law just apply to conducting circuits, or can we apply it to an arbitrary closed loop in space? Well, the difference between a conducting circuit and an arbitrary closed loop is that electric current can flow around a circuit, whereas current cannot, in general, flow around an arbitrary loop. In fact, the emf induced around a conducting circuit drives a current around that circuit, where is the resistance of the circuit. However, we can make this resistance arbitrarily large without invalidating Eq. (7.13). In the limit in which tends to infinity, no current flows around the circuit, so the circuit becomes indistinguishable from an arbitrary loop. Since we can place such a circuit anywhere in space, and Eq. (7.13) still holds, we are forced to the conclusion that Eq. (7.13) is valid for any closed loop in space, and not just for conducting circuits. Equation (7.13) describes how a time varying magnetic field generates an electric field which fills space. The strength of the electric field is directly proportional to the rate of change of the magnetic field. The field lines associated with this electric field form loops in the plane perpendicular to the magnetic field. If the magnetic field is increasing then the electric field lines circulate in the opposite sense to the fingers of my right-hand, when the thumb of my right-hand points in the direction of the field. If the magnetic field is decreasing then the electric field lines circulate in the same sense as the fingers of my right-hand, when the thumb of my right-hand points in the direction of the field. This is illustrated in the diagram below.

We can now appreciate that when a conducting circuit is placed in a time varying magnetic field, it is the electric field induced by the changing magnetic field which gives rise to the emf around the circuit. If the loop has a finite resistance then this electric field also drives a current around the circuit. Note, however, that the electric field is generated irrespective of the presence of a conducting circuit.

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So if I took a loop of say plastic and rotated it in a strong magnetic field, like is done with conducting loops in power stations to generate current why wouldn't the plastic loop heat up from the induced voltage. Or would it?

In such a case you should avoid spinning near magnetic fields, because you might spontaneosuly combust!

Well you know what a dramatic effect magnetic fields can have on the sense of direction of even a pigeon. Many people, including some dentists therefore should avoid driving near power lines!

Plastic will not conduct because of its molecular valance. That's why they use some plastics as insulators.