sci.physics.electromag

"Benj" wrote in message
news:9a395157-13fb-475c-8249-28eb779a3abc@i7g2000prf.googlegroups.com...
> On Mar 1, 12:26 pm, Uncle Al wrote:
>>
>> http://www.mazepath.com/uncleal/lilies.htm
>> http://www.mazepath.com/uncleal/field.htm
>
> So I'm reading Unc's stories about "brain-sucking" NMR magnets and
> that brought to mind some previous musings of mine.
>
> Most of you here are into physical sciences but if for some reason you
> would go to medical school, one of the classes you'd take would be
> physiology and one of the experiments you'd do would be to cut open
> some dogs and play with their hearts.
>
> What you'd discover is that with voltages in the millivolt level a
> wire touched to the outside of a beating heart (depending on the
> electrical signal) can send it in to sudden arrhythmia (Known as
> fibrillation...so called because it was originally believed that each
> heart fiber was beating independently) or with a quick DC pulse send
> it back into normal rhythm. Remember I said millivolts!
>
> Now as you probably know from TV when the heart goes into such
> arrhythmia emergency people use a device called a "defibrillator" It
> is essentially a huge capacitor with a couple paddle electrodes
> designed to send JOULES of energy through a patient's chest. Now the
> reason for all this voltage and energy is that the heart is more or
> less isolated from the rest of the body and is electrically isolated
> even more by being covered with the pericardium sack. So much energy
> and voltage is needed to defibrillate the heart that the machine often
> burns the patient's tissue.
>
> Well, crap, I've thought from time to time, I've seen with my own eyes
> that all you need is MILLIVOLTS to do the job, so why in hell can't
> one simply use a pulsed magnetic field as a defibrillator? One
> additional piece of data came to me when I had an MRI scan. I thought,
> hey, there is a really nice intense field there pulsing away, that
> should surely induce some hum or noise in the nerves in my head or
> ears! If it did, that surely would be evidence that one could build
> an inductive defibrillator! Well, no soap. Lots of noise alright,
> but as Uncle Al notes it was from the vibrations of the heavy current
> coils and not my insensitive brain!
>
> So how about it? Why won't a pulsed magnetic field induce nervous
> firings? Why won't a pulsed magnetic field make your hand twitch? I've
> heard that the Gummint has secret devices that can create voices in a
> persons head (probably lots of victims here on usenet!) but that they
> use microwaves rather than magnetic fields to do the job.
>
> So why is it that one cannot build a magnetic defibrillator? Why won't
> pulsed magnetic fields that SHOULD be creating voltages high enough to
> do the job have any effect? What am I missing here?
>
Hi Benj...

Re-read Jefimenko. Then repeat after me:

An electric field cannot cause a magnetic field.
and
A magnetic field cannot cause an electric field.

Neat demonstration of the above, isn't it?

Bill