"Richard Casady" wrote in message
...
On Wed, 17 Oct 2007 07:54:02 -0600, "Bill" wrote:

http://www.youtube.com/watch?v=3aPQq...elated&search=

I missed the part where this has something to do with Nordhaven, or
even boats.

Casady

I'm getting to that part. Be patient please.

"Richard Casady" wrote in message
...


.. This has **** all to do with the earths magnetic field, which
rotates with the earth.

Casady

The source of the field rotates with the earth. The field itself is
decoupled from the source once it leaves the source. An single flux line, as
it expands into space, does not rotate with the earth. (How would it know
the motion of its source after it left it? This would require some type of
messenger wave capable of superluminal velocities). Think of a brief flash
of light toward the heavens given off by a flashlight aimed skyward on the
surface of the earth. Is the light's path a straight or curved?(To the
observer on earth it appears curved opposite to the rotation of the earth).
But is it straight or curved in space? Does the light pulse continue to
rotate with the earth? Now think of a series of pulses, do any of them
rotate with the earth? If the earth were suddenly to reverse rotation would
all the pulses emitted before the rotation change suddenly change their
curvature?

So the earths magnetic field does not rotate with the earth. It expands out
into space at the speed of light based upon the location/orientation of its
magnetic source at the instant it was created. Once it moves out of the
source, the source has no influence upon it. Likewise with charge. A slowly
spinning charged sphere does not have curved lines of force.

So how are you going to get 200 V/m from a wire? You can't. The wire shorts
the field, the voltage at the ends and all over it are equal because it is a
conductor. That 200 V/m figure is a high impedance electrostatic field. One
way to develop voltage across a conductor is to cut magnetic lines of force,
which my method does.

Bill

On Wed, 17 Oct 2007 07:54:09 -0700, Ian
wrote:

The linear velocity of the earth at
the equator is 40,000km / 24 hrs = 462 m/s. The absolute best you can
therefore hope to achieve with a homopolar generator is 462 m/s * 0.07
mT = 0.03 V/m.

A 20m mast will therefore give you a whopping 0.6V (maximum) to play

Unfortunately your calculation is more or less meaningless, and I can
only hope you had a good calculator and didn't waste a lot of time on
it. Since the earth and its magnetic field rotate together, the
maximum velocity relative to the magnetic field, is precisely zero. So
zero voltage is what you get that way.

Of course you actually would get about 12 000 volts, but another way.
Static electricity. A big tower will hold a lot, and it has been known
to kill. Scientific American had an article detailing how to make a
5000 volt motor a pinwheel that uses corona discharge from the tips of
the blades, and spins pretty fast for a little chunk of aluminum foil.
Powered by a vertical wire.

Incidently, orbiting objects do move fast with respect to the field,
and a long wire will stretch out vertically due to tides. This will
creat drag, and lower the orbit if you extract any juice this way. On
the other hand, if you feed in juice from solar cells you get a
current in a magnetic field and have a weak motor, which could,
gradually raise the altitude of the orbit. You would use no reaction
mass, the attraction of the idea. I have seen calculations, probably
in Analog.

This is perhaps a place to use your nice calculation.

Casady

http://tinyurl.com/23669n

On 17 Oct, 16:04, (Richard Casady) wrote:
On Wed, 17 Oct 2007 07:54:02 -0600, "Bill" wrote:
http://www.youtube.com/watch?v=3aPQq...elated&search=

I missed the part where this has something to do with Nordhaven, or
even boats.

Galvanic corrosion down masts?

Ian

On 17 Oct, 17:12, (Richard Casady) wrote:
On Wed, 17 Oct 2007 07:54:09 -0700, Ian
wrote:

Let's have a little think, shall we? The earth's magnetic flux density
has a maximum of around 0.07 mT. The linear velocity of the earth at
the equator is 40,000km / 24 hrs = 462 m/s. The absolute best you can
therefore hope to achieve with a homopolar generator is 462 m/s * 0.07
mT = 0.03 V/m.

A 20m mast will therefore give you a whopping 0.6V (maximum) to play
with.

More like 12 000 volts.

The earth has an electrical field of, average, 200 volts per vertical
foot. You can be well zapped by the charge on tower that is insulated
from the ground. The object sucks electrons from the air, and although
you don't get much current, the juice accumulates, like static charges
do. This has **** all to do with the earths magnetic field, which
rotates with the earth.

When did we shift into bizarre kook science?

Ian

"Richard Casady" wrote in message
...


Unfortunately your calculation is more or less meaningless, and I can
only hope you had a good calculator and didn't waste a lot of time on
it. Since the earth and its magnetic field rotate together, the
maximum velocity relative to the magnetic field, is precisely zero. So
zero voltage is what you get that way.


Casady


So you never heard of Faraday's Paradox?

http://en.wikipedia.org/wiki/Faraday_paradox

"The experiment proceeds in three steps. First, the magnet is held to
prevent it from rotating, while the disc is spun on its axis. The result is
that the galvanometer registers a direct current. The apparatus therefore
acts as a generator, variously called the Faraday generator, the Faraday
disc, or the homopolar (or unipolar) generator.

In the second step, the disc is held stationary while the magnet is spun on
its axis. The result is that the galvanometer registers no current.

In the third step, the disc and magnet are spun together. The galvanometer
registers a current, as it did in step 1."



Another reference:

http://www.physics.brown.edu/physics...emo/5k1080.htm

a.. "Rotating disc; rotating magnet
As stated above, the motion of the magnetic disc is immaterial. Therefore,
as long as the conducting disc is rotating, the galvanometer will indicate a
current as in the first case. "

On Wed, 17 Oct 2007 11:34:16 -0600, "Bill" wrote:

The source of the field rotates with the earth. The field itself is
decoupled from the source once it leaves the source.

Sorry, but you are the only one who thinks that the earths magnetic
field doesn;t rotate with it.

Mason Peck of Cornell University in Ithaca, New York, US, has received
a grant to study the idea, which is based on the fact that magnetic
fields exert forces on electrically charged objects.
He says a satellite could charge itself up in one of two ways – either
by firing a beam of charged particles into space, or simply by
allowing a radioactive isotope to emit charged particles. The charged
satellite would then be gently pushed by Earth's rotating magnetic
field, enabling it to change orbit and even escape to interplanetary
space

Took all of two minutes with a search engine and 'earths rotating
magnetic field'. Got quite a few hits for something that doesn't
exist.

Casady

"Richard Casady" wrote in message
...
On Wed, 17 Oct 2007 11:34:16 -0600, "Bill" wrote:

The source of the field rotates with the earth. The field itself is
decoupled from the source once it leaves the source.

Sorry, but you are the only one who thinks that the earths magnetic
field doesn;t rotate with it.

Mason Peck of Cornell University in Ithaca, New York, US, has received
a grant to study the idea, which is based on the fact that magnetic
fields exert forces on electrically charged objects.
He says a satellite could charge itself up in one of two ways - either
by firing a beam of charged particles into space, or simply by
allowing a radioactive isotope to emit charged particles. The charged
satellite would then be gently pushed by Earth's rotating magnetic
field, enabling it to change orbit and even escape to interplanetary
space

Took all of two minutes with a search engine and 'earths rotating
magnetic field'. Got quite a few hits for something that doesn't
exist.

Casady

http://en.wikipedia.org/wiki/Faraday_paradox

"The experiment proceeds in three steps. First, the magnet is held to
prevent it from rotating, while the disc is spun on its axis. The result is
that the galvanometer registers a direct current. The apparatus therefore
acts as a generator, variously called the Faraday generator, the Faraday
disc, or the homopolar (or unipolar) generator.

In the second step, the disc is held stationary while the magnet is spun on
its axis. The result is that the galvanometer registers no current.

In the third step, the disc and magnet are spun together. The galvanometer
registers a current, as it did in step 1."



Another reference:

http://www.physics.brown.edu/physics...emo/5k1080.htm

a.. "Rotating disc; rotating magnet
As stated above, the motion of the magnetic disc is immaterial. Therefore,
as long as the conducting disc is rotating, the galvanometer will indicate a
current as in the first case. "


Case 1: The conductor rotates but not the magnet and voltage is measured.

Case 2: The magnet rotates but the conductor remains stationary. No voltage
measured.

Case 3: The magnet and conductor rotate together and voltage is measured.

Premise: A conductor must have relative motion through a magnetic field to
produce voltage.

Conclusions:

Case 1: Relative motion between conductor and magnetic field.

Case 2: No relative motion between conductor and magnetic field, yet
relative motion between magnet and conductor. Voltage is not measured.
Simplest explanation: Magnetic field does not rotate with magnet.

Case 3: No relative motion between magnet and conductor, yet voltage is
measured. There must be relative motion between magnetic field and
conductor. Simplest explanation (also consistent with #2): magnetic field
remains fixed in space regardless of rotation of magnet.

If you can offer a better explanation of Farady's Paradox let's hear it.

A better way to say it is that the earths magnetic field is decoupled from
its source as it rotates.

Also I'm not the only one who thinks so:

http://www.geocities.com/terella1/

And our very own NASA:

http://www-spof.gsfc.nasa.gov/Education/magnQ&A3.htm

1.. Can we tell if a symmetric magnetic field rotates around its axis?
a.. (shortened)
Question that puzzles me for a long time is basically very simple. Does
earth's magnetic field rotate around it's magnetic poles axis Well, looking
at the rotation of magnetic anomalies, and rotation of magnetic poles, this
is true. But that cannot be, and should not be considered as rotation of
magnetic field on it's magnetic axis. The experiments can show us that the
rotation of any magnetic field on it's magnetic axis is impossible and
contrary to the very laws of nature. That should be viable even for complex
magnetic structures as earth's magnetic field is. Yet, it is obvious that
majority of scientific community is even unaware of Faraday's experiments
with rotating magnets.. REPLY


Your question brings up something which has confused many people (even me,
when I was younger).


Basically, the rotation of axially symmetric magnetic fields in a vacuum
around their axis of symmetry is NOT observable. If you have a bar magnet
and attach it to a shaft which rotates it around its symmetry axis (the line
connecting its poles) you will not find any difference whether it rotates or
not. The outside magnetic field--and the electric field, too--is not changed
by the rotation, and the equations which determine these fields do not
reflect rotation of the source.



However, that is in a vacuum (and to all practical purposes, also in
air). When matter is present--especially, electrically conducting
matter--rotation may make a difference. Take for instance Faraday's disk
dynamo, where a conducting disk rotates in a magnetic field (see
illustration in http://www.phy6.org/earthmag/dynamos.htm ). The magnetic
field may be axially symmetric, and the disk and its motion have the same
symmetry, but it makes a difference, because a moving CONDUCTOR in a
magnetic field B, at a point moving with velocity V, experiences an electric
field E = VB in a direction perpendicular to both B and V (mathematically
you need use here a "vector product", but let me not go into that detail).

If instead the magnet rotates around its axis and the disk is at rest,
nothing happens to the disk, which shows that it is the motion of the
CONDUCTOR that matters, not that of the magnetic source. Except of course in
non-symmetric sources, where the motion causes observable changes in
B--these do matter, and such irregular components clearly rotate with the
Earth.
If the disk is not connected, the only effect of this E is to move
electric charges across the disk, until they create an opposite field which
cancels E, and nothing more happens. However, if electrical contacts from
the outside touch the disk as in the drawing, connecting it to a circuit
which does NOT rotate, then the electrical charges which try to neutralize E
are carried away to the outer circuit, and the device works as an electric
generator.
Just for your interest: at one time it was suggested that any spinning
matter, conducting or not, produced a magnetic field, but experiments showed
that was untrue. See 2nd paragraph in section 14 on web page
http://www.phy6.org/earthmag/ /mill_5.htm.