Date: Tue Mar 17 16:13:56 2009 ** **Back to Contents ** ------------------------------------------------------------------------ **

Author: Zani, Gerald

Subject: Re: Power Lines and cows?


Does the cow B or not B? - J

-----Original Message-----
From: [] On
Behalf Of David Sturm
Sent: Tuesday, March 17, 2009 12:29 PM
Subject: Re: [tap-l] Power Lines and cows?

Doug J. is on to something. If you have the old Welch-style coil & ring
launcher that has the "tabletop" that allows any variety of
side-demonstrations such as the shaded pole motor... park the wire
bundle in the "down" position. Now, put a cow
magnet on top. Turn on the coil. That cow magnet will rattle all over
the place (as will most any magnet, and refrigerator magnets are
particularly peculiar). I've done this for table demo shows for ages.
I think Colorado State's Little Shop has
a few table demo boxes using the same phenomena, and someone I know has
a demo labeled "Temporary Guest Worker Jumping Magnet"

But that's a coil, so strong alternating magnetic fields make sense
there. How could you get a similarly *strong* alternating magnetic
field off a long wire, even with it being driven at 14 kVAC? Are the
bundles of wire that make up the long
transmission line coiled in some fashion that I'm missing?

As the great-grandson of a farmer whose farm featured 30 head, and
having fed a cow magnet to a cow (yuck: insert your hand a ways into
their mouth), I'm thinking that even if I brought the coil up to the
outside of the cow, it mightn't give a flip.
;) I'll look into seeing (being at a cow college land grant) if the
folks over at our Witter Farm might let me try a quick experiment.

I think the previous lister who noted the cows see the towers as "trees"
are on to something too, but my experience is cows don't give a damn
about anything but grazing.

And I've seen them line up in a field in the manner described in the
article but not due to magnetism: I think they've neglected to note
that almost every field in the US midwest is N/S/E/W laid out the same
Jeffersonian grid that the Northwest
Ordinance set forward. Following from that, most fallow fields have
been farmed at some point with corn or other rowed vegetables. The
fallowed field usually isn't level. It has gentle "grooves" (just look
at this mapquest link:

for many subsequent years even after cultivation. The lower right
quadrant is the O. D. Heath farm... notice in the fields S and E of the
farmhouse that you can clearly see lines N/S and E/W resulting from
previous cultivation of corn. The
diagonal lines in the field E of the house seem to be clouds, as the
drainage there is more front to back.

The cows aren't lining up, they're just walking along the path of least
change in potential energy, keeping their altitude constant.

Would you rather walk in a trough of a ruffled potato chip, or
perpendicularly over and over and over like a bumpy road?

David E G Sturm - - 1.207.581.1241
--Physics & Astronomy Instructional Laboratories
--Bennett Hall Lecture Demonstration Facilities
--Mainely Physics Road Show --PIRA President '08-09
Dept of Physics & Astronomy -- University of Maine
5709 Bennett Hall -- Orono ME 04469-5709

From Tue Mar 17 16:13:56 2009