In article , Steve wrote:

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what does it do??

They are magic, aren't they? Have you tried the drop a magnet down a
copper pipe trick?

The magnet moving down the pipe induces eddy currents. These eddy
currents produce an electromagnetic force that resists the movement of the
magnet (with respect to the pipe) and does so to an extent varying
directly with the speed at which the magnet is moving. This slows down
the magnet.

At least this is what I have heard.

And aluminum tubes do this also, just not quite as much as copper ones
do. And I have seen aluminum tube stock.

Most other metals do this less, but I imagine that iron and lead pipes
may slow the fall of a close-fitting "rare earth magnet" a little in
comparison to nonconductive pipes.

- Don Klipstein )

"Steve Nosko" wrote in message
...

"Steve J. Noll" wrote in message
...
On Tue, 22 Jun 2004 08:21:58 GMT, "Greysky"
wrote:

ever since I was a child, magnets have held a fascination for me. ...


They are magic, aren't they? Have you tried the drop a magnet down a
copper pipe trick?

Now how come I never thought of that one. Know what i'll be doing this
evening...

Chuckle chuckle...anyone have a silver pipe?


Steve N, K,9;d, c. i My email has no u's.

On Tue, 22 Jun 2004 13:06:08 GMT (Steve J.
Noll) wrote in Message id: :

Have you tried the drop a magnet down a
copper pipe trick?

I'll bite. What happens?

"JW" wrote in message
...
On Tue, 22 Jun 2004 13:06:08 GMT (Steve J.
Noll) wrote in Message id: :

Have you tried the drop a magnet down a
copper pipe trick?

I'll bite. What happens?

I'm guessing some EMF is induced.

"PM"

"Paul_Morphy" wrote in message
...

"JW" wrote in message
...
On Tue, 22 Jun 2004 13:06:08 GMT (Steve J.
Noll) wrote in Message id: :

Have you tried the drop a magnet down a
copper pipe trick?

I'll bite. What happens?

I'm guessing some EMF is induced.


....and... continue with the line of reasoning...

What does that EMF produce and where?...

--
Steve N, K,9;d, c. i My email has no u's.

In article , Steve Nosko wrote:

"Paul_Morphy" wrote in message
...

"JW" wrote in message
...
On Tue, 22 Jun 2004 13:06:08 GMT (Steve J.
Noll) wrote in Message id: :

Have you tried the drop a magnet down a
copper pipe trick?

I'll bite. What happens?

I'm guessing some EMF is induced.


...and... continue with the line of reasoning...

What does that EMF produce and where?...

Current in a closed loop or two in the pipe, and heat in the pipe.

- Don Klipstein )

Steve Nosko wrote:
"Paul_Morphy" wrote in message
...

"JW" wrote in message
. ..

On Tue, 22 Jun 2004 13:06:08 GMT (Steve J.
Noll) wrote in Message id: :


Have you tried the drop a magnet down a
copper pipe trick?

I'll bite. What happens?

I'm guessing some EMF is induced.



...and... continue with the line of reasoning...

What does that EMF produce and where?...

Hmmm, sorta like a rail gun in reverse?

JW wrote:

On Tue, 22 Jun 2004 13:06:08 GMT (Steve J.
Noll) wrote in Message id: :

Have you tried the drop a magnet down a
copper pipe trick?

I'll bite. What happens?

http://my.execpc.com/~rhoadley/magpipes.htm

They are magic, aren't they? Have you tried the drop a magnet down a
copper pipe trick?

Hi, see some more experiments at
http://www.scitoys.com/scitoys/scito...html#magnetism

BR from Ivan OK1SIP

Greysky wrote:

ever since I was a child, magnets have held a fascination for me. I've been
collecting them ever since. It used to be that you could always scrounge
loudspeakers for Alnico magnets. Then when the newer ceramic magnets began
to be incorporated into loudspeakers, it became a challenge to remove them
from their enclosures without breaking them. Now, I have to admit, I am
having a ball collecting the new 'super magnets' - like the ones inside hard
drives. There are also cool cylindrical magnets that you can get from inside
the heads of VHS machines. My question is does anyone know of other sources
either for Neodymium 'duper magnets', or strong ceramic magnets that I may
be missing out on? Magnets like these come closest to being perpetual motion
machines we have yet to make, and I'd hate to have some just wind up into
the trash because I didn't know they were there :-)

Thanks.!

For purchase:

http://www.gaussboys.com

has a small assortment.

As you are probably aware, the older the drive, typically the bigger the
magnets. The largest that I've found were from an old full-height 5 1/4"
internal 300 MB SCSI drive. Newer drives are a bit disappointing, their
magnets are getting pretty thin and break easily...