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Historic planetary instability and catastrophe. Evidence for electrical scarring on planets and moons. Electrical events in today's solar system. Electric Earth.

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Re: how can you measure local electromagnetic properties?

Unread postby MrAmsterdam » Mon Aug 09, 2010 4:24 am

Hello Matt,

http://www.trifield.com/

These are several professional field meters. Depending on the strenghth of the field or current, you'll be able to measure it or not.

The earth's magnetic field for example is 0.3 gaus or 30 microtesla. Our bodies have arround 200 microvolt. I would expect it is going to be difficult to measure.

Other question thats related. How would you measure an electric current in the ocean?

BTW This is a proton magnetometer ; http://en.wikipedia.org/wiki/Proton_magnetometer and http://en.wikipedia.org/wiki/Magnetomet ... gnetometer
Today's scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality. -Nikola Tesla -1934
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Re: how can you measure local electromagnetic properties?

Unread postby MrAmsterdam » Mon Aug 09, 2010 7:41 am

Talk to your local telcom provider about electric sea currents....

http://news.discovery.com/earth/tsunami ... rrent.html


" - harkens back to the 19th century scientist Michael Faraday, who showed that water flowing through a magnetic field can induce a flow of electrons -- a.k.a. an electrical current. Ocean water is particularly good at this because it is very salty, making it a better conductor of electricity as it flows through the Earth's magnetic field, Nair explained."

According to their theory a tsunami would induce a electric current of 0.5 Volt. It makes you wonder what kind of current all these 'little' shore waves create...
Today's scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality. -Nikola Tesla -1934
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Re: how can you measure local electromagnetic properties?

Unread postby Osmosis » Mon Aug 09, 2010 8:09 am

Shore waves or swells in mid-water generate currents, which can be measured with a sensitve magnetometer. The swells generate fields in the .1nT to 5 or 10nT range.

These sources are due to the generator interaction between the conductive sea water and the earth's field.

During a magnetic search, such as wreck finding, this "wave noise" can interfere with measurements, if the sensor is too close to the surface.

The deeper waters will not show this noise.

Sea floor magnetometers, in an array could be used to indicate currents, if one has LOTS of money, to deploy such a system.

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Re: how can you measure local electromagnetic properties?

Unread postby MrAmsterdam » Mon Aug 09, 2010 10:08 am

Osmosis wrote:Shore waves or swells in mid-water generate currents, which can be measured with a sensitve magnetometer. The swells generate fields in the .1nT to 5 or 10nT range.

These sources are due to the generator interaction between the conductive sea water and the earth's field.

During a magnetic search, such as wreck finding, this "wave noise" can interfere with measurements, if the sensor is too close to the surface.

The deeper waters will not show this noise.


In another forum post we discussed limestone and biorock briefly.

viewtopic.php?f=10&t=2949#p31750

Corals grow close to the sea surface. Wave action creates micro or nanocurrents. Biorock creation needs 1 volt in seawater which maybe mimics the natural creation of coral. Would this be a correct correlation?

Mr Osmosis, what would be your perspective on this?
Today's scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality. -Nikola Tesla -1934
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Re: how can you measure local electromagnetic properties?

Unread postby Osmosis » Mon Aug 09, 2010 5:48 pm

Is there a Marine-EU Biologist in the crowd?
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Question about the "Right Hand Rule"

Unread postby Shelgeyr » Tue Oct 12, 2010 10:29 am

This question is mainly for the electrical engineers out there - which I'm not - but as always everyone should feel free to opine...

I've seen a lot of graphics representing the "Right Hand Rule" which look like this:

Right_hand_rule.png


This graphic actually says a lot, but focusing exclusively on the blue arcs representing the (man-made) magnetic field lines, since the arcs are merely circling and not spiraling in or out, I would interpret them to represent a field with a fairly even and consistent fall-off. The field is also rotating, which makes me have to ask: what is rotating? Is the gradient strength of the field rotating? Is "rotating" actually a misnomer, and instead the arrows show the direction of the motive force the field imparts to whatever is within (and able to be acted upon by) the field?

This is no small matter to me. I realize that it is about as basic as it gets, but since "magnetic field lines" are drawn representations of field strength and vector, I really want to make certain I understand this correctly, and thus the request for help.

The way I see it, *IF* the magnetic field itself was rotating, variable-force-wise, i.e. that a stationary object positioned a set distance away from the conductive medium would not only experience a motive force wanting to push it in the direction of the arrows, but that this field strength was also a variable gradient as it rotated, then I would think the field should be represented as an "actual spiral" rather than concentric rings.

Like this:
Spiral_Right_hand_rule.png


Now obviously I'm not claiming that this is the case (quite the contrary). And I'm certainly not claiming to have discovered anything. I'm simply wondering - given the shortcuts scientists and the media take, and the incomplete explanations I keep running into, if the top picture - the "normal" one - is strictly accurate, or if the bottom one better represents what's going on.

I can think of at least one reason why my bottom graphic might be totally wrong, but again - I'm not sure. If the magnetic field strength and vectors were best represented by a rotating outward-pointing spiral, wouldn't that negate the concept of "fall-off"? If so, then the second picture is nonsense, and I probably wasted my time creating it. However, I keep seeing this type of spiral (helical current sheath - solar wind - some planetary EDM scars, etc.) and am seriously trying to understand its formation... which I think would be either difficult or impossible if the motive force were imparted in a strictly declining strength gradient, as represented in the "normal" standard picture.

Can someone please help me understand this mess?

Thanks!
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Re: Question about the "Right Hand Rule"

Unread postby Jarvamundo » Tue Oct 12, 2010 5:40 pm

I don't think you're far off...

Blue rings and arrows, always indicated polarity "direction" to me. Like topographical lines and height, blue rings indicate field strength, can't cut em or cross em, they always come back to meet.... arrows indicate "direction".

then I would think the field should be represented as an "actual spiral" rather than concentric rings.


The in the top example, field and indicators (lines) are circular, concentric, at this point we are only describing the established field. Nothing is in it, nothing is getting affected by it.

However, in what i take as picture 2, the motion of the object (be it say a charged particle) may form a spiral in it's motion through the field.

I think you might be mixing up the vector of the field itself, with the vector of the 'something' being effected by the field.

However, I keep seeing this type of spiral (helical current sheath - solar wind - some planetary EDM scars, etc.)

Yep, these are the 'somethings' being affected by the field. You're seeing the spiral "effect" of the polarity "cause".

The above of-course is with perfect theoretical controls ie a confining wire. But with plasma, as each particle moves, they establish fields and are acted upon by surrounding fields, it then becomes very complex to model (PIC). An easy and handy averaging technique to make it all a bit simpler is to stop the fields from moving around... ie 'freeze them into the body' (Ideal MHD). This ofcourse ignores the complex reality of how the plasma and all it's contributing particle motions behave. And so we may have the vectors of the heliosphere current sheet m-fields not being themselves perfectly circular.

hope this helps, kinda how i read it all.
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Re: Question about the "Right Hand Rule"

Unread postby jjohnson » Thu Oct 14, 2010 7:30 am

Forget the spiral idea and picture 2, which is just incomplete circles, which themselves are sections of imaginary cylinders of "sheets" of equal force. A spiral is a form that starts at one radial distance and ends at another, like galactic arms, and this is not a representation of that.

The sImple-case diagram shows just two things: [1] If you have a current I whose direction (i.e., which way the positively charged particles move) is "up" as shown, then your right hand's thumb should be aligned in that same direction (thumbnail up). [2] This current I generates or is accompanied by (not sure how to say this; they are like Siamese twins) a magnetic field all around it.

This magnetic field B is strongest right at the current or conductor and it weakens with distance. The circles are sections cut across cylinders of equal magnetic strength. There are infinitely many "equipotential cylinders" nested coaxially around the current, like the layers in a long scallion or young green onion. Each cylinder outward is a little weaker than the one just inside it. The circles shown in blue are selected values of equal magnetic field intensity, each one being centered on the "wire" or current filament running up the axis.

The blue arrows show the direction of the magnetic force field as it would be applied to a positively charged "test particle" at a given point - i.e., tangent to the circle (cylinder) at the particle's position anywhere in the magnetic field around the current. Your curled fingers point around in the direction of the magnetic field due to the current. If the test charge is simply "let go" at a point with no initial velocity , it would be accelerated into a circular orbit perpendicular to the axis of the current. If it had a moving velocity vector when it entered the influence of the magnetic field, its resultant velocity would be a vector addition of its own vector plus that exerted by the mag field B. The radius of the circular or helical path (not a spiral path in this geometry) that a charged particle follows is proportional to the velocity and the mass of the charge, and inversely proportional to the "amount" of charge carried by the particle and the strength of the field. Strong field, low mass particle = tight orbit. Weak field, large mass particle = wider orbit.

The convention is that the force exerted by an electric or a magnetic field is in the direction which a positively charged particle would be accelerated by the field. Negative charges such as electrons are accelerated in the opposite direction. In the electric field, a positive charge is accelerated toward the surplus negative side of the capacitor or voltage differential, because different charges attract, while like charges repel. In a magnetic field, it's similar. The field exerts a force on a positive charge in one direction, while a negative charge would have the force exerted in precisely the opposite direction. If you see arrow heads in a diagram of an electric or a magnetic field, read it as showing the "direction" that that field exerts upon a positive charge.

In a conventional wire, the voltage differential that is created by a chemical battery or by a generator is the electrical (E) field that accelerates charges and it is largely constrained within the conductor. In space, we do not yet know what conditions provide the electric field / voltage differential that drives huge electric currents between stars and galaxies. But even at the low charge density in the interstellar medium, a Birkeland current with a 1 light year diameter, for example, can have a very large current conveying energy among very widely separated locations.
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Re: Question about the "Right Hand Rule"

Unread postby Shelgeyr » Fri Oct 15, 2010 3:10 pm

Jarvamundo, jjohnson,
Thank you both!

Jarvamundo: I was indeed mixing up the vector of the field with the vector of “something” being effected by the field.

jjohnson: You clarified several things for me, not the least of which was that all my mental pictures had the current and the effected particles running the wrong way.

I really appreciate the time and effort you both took to respond!

My second picture is indeed nonsense after all - hope I haven't misled anyone with it!
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Re: Question about the "Right Hand Rule"

Unread postby jjohnson » Fri Oct 15, 2010 9:20 pm

No problem. I'm still learning this stuff, too. A good, cheap and comprehensive review book that I use is Schaum's Outlines Electromagnetics, Second Edition, a paperback from McGraw-Hill, ISBN 0-07-021234-1. Brush up on vector math a little and try the worked examples. Knowing the basic stuff almost by rote lets you get into harder stuff more easily. They lied if they told you in school that memorization is an overrated and unnecessary skill.

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Re: Question about the "Right Hand Rule"

Unread postby Biggins » Mon Oct 18, 2010 2:52 am

One thing to remember...
The magnetic field is only part of the sequence. you have to use Lorentz's equation to find the force on a particle in the field:
F=q(vXB)
i.e. the force is the cross product of the particle velocity and the B field multiplied by the charge of the particle.

For a current in a wire it is:
F=ILXB
Force is current in the wire times the corss product of the length of the wire and the B field.

The fore is NOT the B field, not is it in the direction of the B field. In the case of the wire, a particle is either attracted towards or repulsed from the wire.

I hope that this helps.
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Re: Question about the "Right Hand Rule"

Unread postby mharratsc » Mon Oct 18, 2010 8:17 am

You guys are all much more savvy than I regarding EM dynamics, but I think I have a good visual analogy for explaining magnetic fields.

A magnetic field around a spherical object or cylinder is much akin to looking at a light bulb of similar shape on a foggy night- brighest near the bulb, dimmest farther away. You can go on to explain particle motions in the field by using the analogy of dust motes moving in the field as well.

A bit oversimplified, granted- but it goes a long way with the people who literally are trying to imagine 'magnetic field lines' and getting all messed up because of it. :)
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Re: Question about the "Right Hand Rule"

Unread postby Jarvamundo » Mon Oct 18, 2010 3:13 pm

Biggins wrote:One thing to remember...
F=q(vXB)
I hope that this helps.

Quite correct Biggins, my interpretation of the spiral shape diagram2 was incorrect
F = VxB

So. (considering a static time-invariant magnetic field established by a constant dc current traveling through the wire)
1) If a particle is inserted with no velocity. It is not accelerated, it doesn't move. V=0
2) If a particle is inserted with velocity, it is accelerated along the cross product.

(1) is of course hypothetical, since you must either establish the m-field at which point it's time-variant (V>0), or, put the particle in there at which point V>0.

Thanks Biggins JJ and all. MikeH has the tag line.
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Hydrogen Spectra

Unread postby kiwi » Thu Oct 21, 2010 3:02 am

apparently the measurements combined (red-shift and Hydrogen spectral imaging) are said to affirm the age of this object.I have seen the work of H Arp and others concerning the red-shift but are curious as to how the Hydrogen measurements are found to fit

The article has a few puzzling statements ... to their credit they acknowledge there is an "ageing" controversy ..I assume its referring to red-shift .... who are the skeptics I wonder?

While Ellis finds the basis for the study "pretty good," there have been other claims about the age of distant space objects that have not held up to scrutiny. And some experts have questions about this one. But even the skeptics praised the study as important and interesting.


Then this...

In the new study, researchers focused on a single galaxy in their analysis of hydrogen's light signature, further pinpointing the age. Garth Illingworth of the University of California, Santa Cruz, who was the scientist behind the Hubble image, said it provides confirmation for the age using a different method, something he called amazing "for such faint objects."


and then back again

The new galaxy doesn't have a name — just a series of letters and numbers. So Lehnert said he and colleagues have called it "the high red-shift blob.


http://news.yahoo.com/s/ap/20101020/ap_ ... est_galaxy

http://www.youtube.com/watch?v=7eBAPhldg78
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Re: Faint Early Sun Paradox Resolved

Unread postby nick c » Tue Mar 29, 2011 4:39 pm

This thread is composed of the following threads:

Faint Early Sun Paradox Resolved

Question about the "Right Hand Rule"

Hydrogen Spectra

how can you measure local electromagnetic properties?
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