Date: Tue Oct 7 15:22:59 2008

Author: Paul Nord

Subject: Re: Another pacemaker question...

Post:

BC,

A little more doubting would be healthy for you.

There's no clear evidence of dental radio reception. It's an urban
legend.

Paul


On Oct 7, 2008, at 1:12 PM, Bernard Cleyet wrote:

> But you never tested her, did you? Minimum single blind -- double
> blind before I'd be convinced.
>
> bc still doubting.
>
> p.s. If "sensitive", numbers would be interesting. Note some people
> receive radio stations from rectification in their metallic teeth
> restorations. Conceivably? one could detect low freq. mag. fields
> this way, and the reaction would be psychosomatic, i.e. detection
> results in fear of pace maker disruption.
>
>
>
> On 2008, Oct 07, , at 08:24, Adam Beehler wrote:
>
>> Stan Dodds wrote:
>>> ...The rest of the story may be true, but what she "feels" is more
>>> likely caused by expectations rather than magnetic fields.
>> Oh yes, I thought of that. So we checked. Let's just say that her
>> doctor was convincing.
>>
>>> Refrigerator magnets are made from stripe-domain materials, like
>>> lots of tiny horseshoe magnets, so the fields extend only a
>>> millimeter or two beyond the magnet surface. Once stuck to a
>>> ferromagnetic refrigerator casing, the field will be even more
>>> effectively confined to the high-permeability material.
>> Granted. This is one I did not check the effect of on her.
>> However, a lot of refrigerators have more than just "refrigerator"
>> magnets on them. Generally, those "refrigerator" magnets are lame
>> at holding anything much onto the fridge, so stronger ones are used.
>>
>>> The magnetic fields produced by power supplies, presumably leakage
>>> from the transformers, would also decrease rapidly with distance,
>>> and would be at AC line frequency. If a few lab supplies really
>>> had an effect, there would be essentially no place in a modern
>>> building that the person could go that would not cause the same
>>> feelings. It also seems unlikely that a company could sell a
>>> device so vulnerable to the ordinary environment.
>> All I know is that I could physically see a difference in her face
>> when she walked out of the lab. She had to sit down to recoup.
>> Granted, maybe she was psychosomatic, but I was certainly
>> convinced. She was honestly not trying to just get out of physics
>> either. Any labs she missed were made up in other ways. She was
>> more than willing.
>>
>>> My best guess is that the student has been told, possibly
>>> correctly, to avoid strong DC fields, and has generalized that
>>> beyond its applicability. The advice from Medtronic, a major
>>> manufacturer, seems fairly sensible: www.medtronic.com/wcm/groups/mdtcom_sg/@mdt/@crdm/documents/documents/electromagnetic-compatibility.pdf
>>> , and suggests that most activities are quite safe.
>> I agree with you and this advice; however, I was just bringing up
>> the point that each case is different and some people really do
>> have to be that careful. She was great in that she was aware and
>> took precaution. Maybe she took more precaution than was totally
>> necessary, but wouldn't you in that situation?
>>
>> Adam Beehler
>>
>


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