Energy in a permanent magnet question

The model I use to think of a PM magnet is a shorted inductor i.e. electromagnet made with superconducting wire and a DC current flowing in the wire. Some work was done to start the current flow and that energy is stored in the current flow and of course creates a magnetic field. If the wire resistance is ==0, that can sit in steady state forever like a PM..

If you move a hunk of metal near the (electro) magnet, it changes the current flow because there is a change in the stored energy. Depending on which way the mechanical force is going you can add or remove current/energy. If you remove enough energy, the current will be zero.

While that model makes sense to me, I'm not sure however if it is correct :-)

Mark

photons.

--
?? 100% natural

--- Posted via news://freenews.netfront.net/ - Complaints to news@netfront.net

Only way it "dies" is via hawking radiation AFAIK,

So that is where the energy goes.

--

John Devereux

.highlandtechnology.com=A0 jlarkin at highlandtechnology dot com

Round off, down to almost nothing.

.highlandtechnology.com=A0 jlarkin at highlandtechnology dot com

One quenched at my friend's development lab. He lost $3,000 worth of helium in a few seconds!

to

t.net ---

uh, vanishes, as in fades away, does not supply a lot of photons. Oh, right, it's a black hole so the photons can't escape.

can you bury magnetism in a shallow grave to make hundred year old magnetism.

i am REAAALLLLLY worried

producing

quantum

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One AA in the LED display would be more than enough.

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For the LED's but not for the motor though I expect it is slowing down anyway.

Hardy

When a black hole dies it's by hawking radiation: photons.

--
?? 100% natural

r

=A0Oh,

If the dieing flash represents ALL the energy inside the black hole, then that must be SOME flash, eh?

It doesn't come out all at once - the effective temperature is inversely proportional to the mass. And it can take a long time, a solar mass black hole lasts 2E67 years...

But yes there is a big flash at the end.

--

John Devereux

Hawking radiation isn't all photons. But it is (per current theory at least) how a black hole dies.

No one's gotten close enough to a black hole to prove out Hawking radiation one way or another, although if it doesn't exist it would require some rearrangement of quantum mechanics, relativistic physics, or both.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

t

"A Globe in Every Home"

ct

New Zealand, but does that make any real difference?

,

I pictured a little hawker's stall: Photons for Sale: 5 Cents

It must go down. The magnet did work pulling the object in. The energy stored in the magnet goes back up [1] when you pull the object off.

[1] some magnets will partially demagnetize if a keeper is not in place all the time.

--

John Larkin         Highland Technology, Inc

jlarkin at highlandtechnology dot com
http://www.highlandtechnology.com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom laser controllers
Photonics and fiberoptic TTL data links
VME thermocouple, LVDT, synchro   acquisition and simulation

LOL!

How about a sideshow barker calling out "see black hole photons in person"?

?-)