Lightning connected with the magnetism of Earth core?

[Grek.en]

Thunder in relation to Earth's core.

Is there a relation to how the Earth's core revolves and circulates regarding thunder? What if one would track the amount of energy beeing surged and what direction it might seem to be heading, if has a direction? Is there a inderect link between lightning and Earth's magnetism beeing surged from the Earth's core?

Any thoughts?

 

[Evo]

Here is how lightning is formed.

http://www.wrh.noaa.gov/fgz/science/lightnin.php?wfo=fgz

 

[Grek.en]

"

Here is how lightning is formed.

http://www.wrh.noaa.gov/fgz/science/lightnin.php?wfo=fgz

"
Simple enough, however it does not explain why the larger materia forms the negative charge below the lighter forming the positive. It suggests that lightning has a direction, something like the Earth's core is guiding it.

Why wouldn't lightning be discharged out into outer space rather than towards the ground? it woud actualy make more sense if lightning sought itself towards outer space rather than back unto the ground. Ofcoarse this is all speculation, but it would seem the Earth cores revolvement in speed and direction guides lightning in both direction and intensity. If one would calculate some kindoff pattern between these two, then it would be possible to calculate what speed and direction the eartch core is currently revolving.

it seems Earth's core generates the magnetism causing the discharge motion to be downwards rather than upwards, this would also suggest there is a intimate coaperation between the two.

 

[russ_watters]

Did you miss this part of the explanation?:

In a thunderstorm, lightning is created as a discharge of built up energy due to the separation of positive and negative charges which are generated inside the thunderstorm.

Charges get separated, then discharge to come back to equilibrium. Nothing about the Earth's core or discharge to space in there.

 

[Evo]

Why wouldn't lightning be discharged out into outer space rather than towards the ground?

It does, they are referred to as red sprites and blue jets.

Recently two new types of lightning have been verified: red sprites and blue jets. These atmospheric discharges occur very high in the Earth's atmosphere - much higher than the familiar form of lightning. Red sprites appear red in color and go from the tops of clouds to as high as the ionosphere - an ionized layer 90 kilometers above the Earth's surface. They last only a small fraction of a second. The existence of red sprites has been suggested previously, but only in 1994 were aircraft flown above massive thunderstorms with the high speed video equipment necessary to verify these spectacular events. Scientists are unsure of the cause and nature of red sprites.

http://apod.nasa.gov/apod/ap951111.html

 

[billiards]

I know this is not directly related, but while I'm here I may as well clear up another apparent misunderstanding for the OP.

The Earth's core is not magnetized. The Earth's magnetic field is generated by the swirling around of liquid in the outer core (driven by thermal and, more importantly, compositional convection) in what is known as the geodynamo.

In 1819 Hans Christian Oersted observed that a wire carrying a current could deflect a compass needle, this implied that a current in a wire produces a magnetic field. It was later realized that the magnetism in a material could be explained by considering moving electrical charges on an atomic level.

Ferromagnetism: This is a special case whereby the atomic neighbourhood allows for spontaneous magnetization. In this case, the atomic moments are aligned parallel; few materials are ferromagnetic at temperatures above 0°C, some of which include: iron, nickel, cobalt, gadolinium, and chromium dioxide. In a material such as a rock, small groups of perfectly aligned atoms may exist in a spatial configuration; one of these zones is called a magnetic domain, and has a typical diameter of a few μm, these contribute to the magnetism of a material at a macroscopic scale.


In a ferromagnetic substance the alignment of atoms depends on a balance between thermal and chemical bonding energy. The chemical bonding energy acts to align the magnetic moments of the atoms, whereas the thermal energy causes the atoms to vibrate out of line. At temperatures below the Curie temperature the bonding energy prevails and the atoms are locked into a formation which enables spontaneous magnetization. At temperatures above the Curie temperature thermal agitation destroys existing magnetic domains such that the material loses its magnetization.

As pressure is increased the Curie temperature lowers; thus at the core where temperature and pressure are very high relative to the conditions at the surface, we would expect a material to be below its Curie point such that it is not magnetic.

 

[Evo]

I know this is not directly related, but while I'm here I may as well clear up another apparent misunderstanding for the OP.

The Earth's core is not magnetized. The Earth's magnetic field is generated by the swirling around of liquid in the outer core (driven by thermal and, more importantly, compositional convection) in what is known as the geodynamo.

Good point, thanks for adding that.

 

[DEMcMillan]

Grek.en, I think you may be onto something with the magnetic field idea and thunderstorms. It forms a useful mechanism for charge separation. Electrostatic field generation requires development of positive and negative charge realms separated by non-conducting space and the development of large voltages with later breakdown by lightning formation. Most of the motion of thunderheads is upward, but they clearly are directed across the Earth’s surface as well. The Earth’s magnetic field would favor separation of positively from negatively charged droplets in clouds. Each droplet consists of roughly a trillion water molecules. The charged elements would be about a million hydronium cations and bicarbonate anions and a substantially fewer carbonate divalent anions. Their distribution varies from droplet to droplet and the most charged droplets would migrate in the magnetic field, moving away from oppositely charged water droplets as the cloud rises and moves laterally. The rate of rise and lateral direction could play a role in the magnitude of the electrostatic charge development from the separation. You might see if the direction and speed of clouds plays a role in the magnitude of thunderstorms.

The separation of droplets on the basis of net charge would cause repulsion of droplets from each other on an electrostatic basis and allow the 4% water content of thunder clouds to persist until intra-cloud lightning reduces some of that charge to allow raindrop formation and descent.

You have no way to eliminate the earth’s magnetic field to test the mechanisms proposed, but indirect evidence by direction of separation should help. The magnitude of motion in the stable magnetic field should supply the energy necessary for electrostatic voltage development. Net droplet charge development could easily be seen as mediated at least in part by motion and photon activation of electrons, freeing them to migrate to another droplet or to the Earth. Electrons moved to the ground would set up an electrostatic charge causing lightning strikes to the Earth, less common than intra-cloud lightning but of more concern to our lives.

 

[gdp]

Is there a relation to how the Earth's core revolves and circulates regarding thunder?

No. Atmospheric electricity has no known relationship to the geomagnetic field; it is believed to be entirely the product of electrostatic processes within thunderstorms, and is basically confined to the troposphere.

The geomagnetic field only has a significant influence on process in the ionosphere and magnetosphere. While the ionosphere serves as a conducting "roof" that terminates the electric fields and currents driven by individual thunderstorms, and it also contains a set of "ionospheric dynamo" MHD currents that are driven by the component of high-altitude winds that is perpendicular to the geomagnetic field, the ionospheric dynamo currents are not believed to contribute any energy to thunderstorm processes.

 

[DEMcMillan]

gdp has claimed that charge is not meaningfully influenced by a steady magnetic field because it results in a dot product quantity https://www.physicsforums.com/showthread.php?t=252994 in which charge’s (oxygen ions) sign is lost, but the conventional treatment is that of Lorentz in which the result of motion is a cross product in which charge magnitude and sign affect direction http://en.wikibooks.org/wiki/Physics_Study_Guide/Vectors_and_scalars ,
http://en.wikipedia.org/wiki/Lorentz_force .
The resulting vector is influenced by the magnitude and direction of the magnetic field. The same concept may be applied to uncharged electromagnetic waves but the motion is more complex, adding rotation to photon direction. Sunspot radiation shows such behavior from the torus of magnetism that generates sunspot pairs, as shown by G E Hale at Mount Wilson and known as Hale’s laws of polarity http://web.hao.ucar.edu/public/slides/slide19.html ,
http://www.space.gc.ca/asc/eng/sciences/sunspots2.asp .

gdp, I agree with baywax that your discussion of the chemistry and physics of the earth’s core in https://www.physicsforums.com/showthread.php?t=249773 was brilliant. I had been thinking of introducing the concept of critical temperature to this area but have noted the use of absolute boiling point (abp) by geology sources and the incomplete understanding of chemical compound abp and compound temperature stability that limits the addition of these avenues to your model.

Grec.en, keep looking for an effect of the Earth’s magnetic field on thunderstorms.

 

[gdp]

gdp has claimed that charge is not meaningfully influenced by a steady magnetic field because it results in a dot product quantity https://www.physicsforums.com/showthread.php?t=252994 in which charge’s (oxygen ions) sign is lost,

False. I stated that a magnetic field does not in and of itself do WORK on a charged particle, because the magnetic force is identically perpendicular to a charged particle's velocity. Thus, a magnetic field can only change the direction of a charged particle's motion, not its speed --- and since kinetic energy does not depend on direction, but only on speed, the magnetic force does no WORK on a charged particle. A magnetic can only influence the energy of a charged particle indirectly, in that, when a magnetic field changes in time, by "[URL Law[/url] a changing magnetic field induces an ELECTRIC field --- and electric fields, unlike magnetic fields, can do work on charged particle.

but the conventional treatment is that of Lorentz

...Which is, BTW, supported by over a century of experimental data and engineering practice, so it's pretty likely to be right...

in which the result of motion is a cross product in which charge magnitude and sign affect direction http://en.wikibooks.org/wiki/Physics_Study_Guide/Vectors_and_scalars ,
http://en.wikipedia.org/wiki/Lorentz_force .
The resulting vector is influenced by the magnitude and direction of the magnetic field.

Again I did NOT state that magnetic fields do not "meaningfully influence" charged particles. I stated that magnetic fields do no WORK on charged particles, which is a very different statement from your misrepresentation of what I claimed.

The same concept may be applied to uncharged electromagnetic waves but the motion is more complex, adding rotation to photon direction.

Sorry, wrong. Magnetic fields do not change the direction of photons in any way, because Maxwell's equations are linear. Superposing an external magnetic field on an electromagentic wave does absolutely nothing to said wave.

You are perhaps confusing the http://en.wikipedia.org/wiki/Faraday_effect" of a photon's plane of polarization when it passes through a magnetized nonlinear medium with a "rotation of photon direction." However, the Faraday effect has no affect on a photon's direction of travel, --- and even said change in polarization a property of the photon's interaction with the molecules of the magnetized medium, and is not due to any interaction of the photon with the magnetic field itself.

Sunspot radiation shows such behavior from the torus of magnetism that generates sunspot pairs, as shown by G E Hale at Mount Wilson and known as Hale’s laws of polarity http://web.hao.ucar.edu/public/slides/slide19.html ,
http://www.space.gc.ca/asc/eng/sciences/sunspots2.asp .

First, sunspots are not "radiation," they are a magnetohydrodynamic phenomenon in the outer layers of the sun. Second, the fact that sunspots occur in oppositely polarized pairs is a trivial consequence of http://en.wikipedia.org/wiki/Gauss%27_law_for_magnetism" which implies that magnetic field lines cannot begin or end at any point, but must always form topologically closed loops.

Thus, when motions of the plasma in the outer layers of the sun concentrate magnetic flux lines into a "bundle" or "tube" of flux, and a portion of this bundle or tube floats above the notional "surface" of the solar photosphere, the closed topology of every magnetic field-line loop necessarily requires that there must be two "spots" of opposite polarity (i.e., opposite-signed fluxes through the "surface") in the region where the flux tube rises above the photosphere.

(Magnetic flux tubes "float" upward toward the Sun's notional surface because the interaction of a magnetic field with a plasma manifests itself as an effective "pressure" perpendicular to the flux lines, and an effective "tension" along the flux lines. The effective "pressure" perpendicular to the flux lines partially excludes plasma from the interior of the flux tube, reducing its density, and therefore making it more "buoyant" than the surrounding plasma. Once a portion of the flux tube has "floated" above the "surface" of the photosphere, the enhanced transport of particle thermal energy along the field lines and suppressed thermal transport perpendicular to the field lines causes the plasma in the tube to cool off relative to the surrounding plasma, causing it to look "darker" by comparison to the surrounding plasma --- although even sunspot plasma is still hotter and brighter per unit area than the hottest tungsten lightbulb filament!)

 

[DEMcMillan]

I recommend that gdp study the offered citations before responding so quickly. The Wikibooks article develops application of the right hand rule to Lorentz forces. The Wikipedia article clearly shows that movement orthogonal to a magnetic field will act to separate charged particles and generate an electrostatic field. Near longitudinal and vertical motions qualify. The historical Lord Kelvin alternative depends on already present electrostatic charge. http://www.eskimo.com/~billb/emotor/kelvin.html
http://www.eskimo.com/~billb/emotor/ikelv.html

I took my first college physics course from the late Felix Bloch, who later won the Nobel prize for his work on nuclear magnetic behavior. http://nobelprize.org/nobel_prizes/physics/laureates/1952/bloch-lecture.pdf One day after class, I asked him about the potential of bimetallic surfaces to generate electric currents when exposed to light photons, then recently observed. He dismissed the idea as impractical. That idea has led us to all of our solar power discoveries. I learned from this experience to be less dismissive of unexpected ideas.

I will take a few days to add to the Hale discussion. It offers a lesson in funding as well as being historically important to astrophysics.

 

[LURCH]

...False. I stated that a magnetic field does not in and of itself do WORK on a charged particle, because the magnetic force is identically perpendicular to a charged particle's velocity. Thus, a magnetic field can only change the direction of a charged particle's motion, not its speed --- and since kinetic energy does not depend on direction, but only on speed, the magnetic force does no WORK on a charged particle. ...

I'm always a bit wary when someone tries to make a distinction between a change in speed and a change in direction. Either way, if the magnetic field changes the direction of a particle, has it not caused an acceleration? If it has caused an acceleration, has it not done work?

 

[LURCH]

Also;

Here is how lightning is formed.

http://www.wrh.noaa.gov/fgz/science/lightnin.php?wfo=fgz

I have heard this explanation of lightning formation many times, but I have also heard it said that we really don't know exactly how lightning is formed. What especially intrigues me is this process of charge being built up as a result of the collisions of ice crystals. Has anyone ever recreated lightning this way in a laborotory environment? Or, has anyone at least generated a charge this way?

 

[gdp]

I recommend that gdp study the offered citations before responding so quickly. The Wikibooks article develops application of the right hand rule to Lorentz forces. The Wikipedia article clearly shows that movement orthogonal to a magnetic field will act to separate charged particles and generate an electrostatic field.

So what? The energy for your electric field is coming from the kinetic energies of the charged particles, and NOT from the static magnetic field itself. According to over 100 years of experimental evidence, a static magnetic field cannot in, of, and by itself do any net work on charged particles.

The historical Lord Kelvin alternative depends on already present electrostatic charge. http://www.eskimo.com/~billb/emotor/kelvin.html
http://www.eskimo.com/~billb/emotor/ikelv.html

...And since almost no body will ever be perfectly electrically neutral, and since the Kelvin process leads to an initially exponentially growing charge-separation as long as there is any initial imbalance at all, it is entirely capable of explaining the observed thunderstorm electrification, without resort to any speculative new physics involving non-lorentzian static magnetic forces that somehow do work, in violation of the experimental evidence to the contrary.

I took my first college physics course from the late Felix Bloch, who later won the Nobel prize for his work on nuclear magnetic behavior. http://nobelprize.org/nobel_prizes/physics/laureates/1952/bloch-lecture.pdf One day after class, I asked him about the potential of bimetallic surfaces to generate electric currents when exposed to light photons, then recently observed. He dismissed the idea as impractical. That idea has led us to all of our solar power discoveries. I learned from this experience to be less dismissive of unexpected ideas.

Irrelevant red-herring argument. And please note that there is such a thing as being so "open-minded" that your brains fall out.

If you have experimentally reproducible evidence that the lorentz force has been experimentally falsified, and that a static magnetic field can indeed do net work on a charged particle, the post it or a reference to it. However, "you should be more open-minded --- who knows, the lorentz force just might be wrong, despite 100 years of experimental evidence to the contrary" is NOT a scientifically or logically valid argument.

 

[gdp]

I'm always a bit wary when someone tries to make a distinction between a change in speed and a change in direction.

Why? speed is a directionless non-negative scalar, while velocity is a is a three-dimensional, directed vector. Speed and velocity are physically distinct quantities.

Either way, if the magnetic field changes the direction of a particle, has it not caused an acceleration? If it has caused an acceleration, has it not done work?

No, it has not. Since the kinetic energy --- a scalar quantity! --- is the same after a pure change in direction with no change in speed, no net work has been done by the external force.

If a force had done net work while changing the direction of the particle without changing its speed, it would violate the Law of Conservation of Energy: It's not in the particle, and its been lost by the force-producing agent, so where would the work have gone? Has it vanished into the Aether?

If forces could do work by changing a particle's direction without changing its speed, then nearly all of physics as we know it would have had to have been wrong; we would have to scrap everything all the way back to Newton, and start over from scratch. Does it really seem plausible to you that over 300 years worth of physical experiments are wrong, and that nearly all the conclusions drawn from those experiments and the theory developed from those conclusions are falsified?

[Part of your conceptual problem may be that you may emotionally feel as if your muscles are "doing work" even when exerting a static force, or perhaps you cannot imagine that a chair can hold you off the floor without somehow "doing work." However, in the first case, the "work" is actually being wasted as heat dissipated inside your muscles due to their internal inefficiency --- the molecular motors inside your muscle fibers are constantly grabbing and pulling, then releasing and sliding back, and then grabbing and pulling again, wasting energy during every cycle --- while the "work" done by a chair is a conservative force: Any work done by the chair when you compress its physical structure by sitting on it will be released again when you get off of it --- and no work at all is done while you are sitting on it.]

 

[gdp]

Also;

I have heard this explanation of lightning formation many times, but I have also heard it said that we really don't know exactly how lightning is formed. What especially intrigues me is this process of charge being built up as a result of the collisions of ice crystals. Has anyone ever recreated lightning this way in a laborotory environment? Or, has anyone at least generated a charge this way?

Sure. To find out about generation of charge separation by friction or impact, google on http://www.google.com/search?q=triboelectricity" You separate charges by this process every time you scuff your feet across a carpet.

And you can easily build a device that generates electric sparks of quite respectable voltages using the splitting-off of falling water droplets called a http://www.google.com/search?q=kelvin generator" out of two tin cans, two lengths of stiff wire, two short lengths of metal tubing, after just a bit of soldering.

 

[LURCH]

Why? speed is a directionless non-negative scalar, while velocity is a is a three-dimensional, directed vector. Speed and velocity are physically distinct quantities.

But speed and direction are not. The difference between them is frame-dependent. What one observer calls a "change in speed," another can call a "change in direction." But regardless of one's frame, a change in speed or a change in direction is a change in velocity. And a change in velocity is an acceleration, which is work.

 

[gdp]

But speed and direction are not. The difference between them is frame-dependent. What one observer calls a "change in speed," another can call a "change in direction." But regardless of one's frame, a change in speed or a change in direction is a change in velocity. And a change in velocity is an acceleration, which is work.

I'm sorry, but you are confusing a passive change of inertial frame of reference with an active change in some particle's velocity when it is acted upon by some external force; however, these two concepts are again physically quite distinct. The former is just a passive relabeling of spacetime points, and it does nothing "physical;" in particular, no new "forces" act on any particle if one arbitrarily selects a new inertial frame of reference, and no "work" is done on anything by arbitrarily selecting a new inertial frame of reference.

The latter, an active acceleration of a particle by an external force does involve a force by definition, and may do work if said active force vector has a component parallel to said particle's velocity vector.

You can't make a measurement of velocity in one inertial reference frame A, change reference frames to another inertial frame Z, then make a second measurement of velocity, and claim that an "acceleration" has occurred between the two measurements, because by doing so you are trying to compare apples to zucchini (velocity relative to inertial frame A with velocity relative to inertial frame Z). Measurements may only be physically compared when all of the measurements have been taken IN THE SAME INERTIAL FRAME, notwithstanding whether you are working from Newton's Principia or Einstein's Special Relativity.

Furthermore, to return to the original contrafactual claim that a static magnetic field can somehow "do work," by dragging in a second inertial reference frame, you're no longer talking about just a "pure" magnetic field, because a magnetic field will appear as a magnetic field plus an electric field if you boost crosswise to the original "pure" magnetic field's direction. And electric fields do do work.

Finally, don't muddy the water further by trying to drag General Relativity into it, because things will only get worse: Inertial frames don't even exist in General Relativity, except in the limit of "local tangent frames" which are infinitesimal in spacetime extent --- so in GR you can't even compare two velocities at all any more, unless two particle's worldlines' just happen to both pass through the same spacetime event (i.e., you can't compare the relative velocities of anything in GR, except when they collide with each other!).

 

[LURCH]

I'm sorry, but you are confusing a passive change of inertial frame of reference with an active change in some particle's velocity when it is acted upon by some external force...

Absolutely not. I'm saying that a change in speed or direction is a change in velocity, and therefore an acceleration.

...however, these two concepts are again physically quite distinct. The former is just a passive relabeling of spacetime points, and it does nothing "physical;" in particular, no new "forces" act on any particle if one arbitrarily selects a new inertial frame of reference, and no "work" is done on anything by arbitrarily selecting a new inertial frame of reference.

The latter, an active acceleration of a particle by an external force does involve a force by definition, and may do work if said active force vector has a component parallel to said particle's velocity vector.

You can't make a measurement of velocity in one inertial reference frame A, change reference frames to another inertial frame Z, then make a second measurement of velocity, and claim that an "acceleration" has occurred between the two measurements, because by doing so you are trying to compare apples to zucchini (velocity relative to inertial frame A with velocity relative to inertial frame Z). Measurements may only be physically compared when all of the measurements have been taken IN THE SAME INERTIAL FRAME, notwithstanding whether you are working from Newton's Principia or Einstein's Special Relativity.

Furthermore, to return to the original contrafactual claim that a static magnetic field can somehow "do work," by dragging in a second inertial reference frame, you're no longer talking about just a "pure" magnetic field, because a magnetic field will appear as a magnetic field plus an electric field if you boost crosswise to the original "pure" magnetic field's direction. And electric fields do do work.

Finally, don't muddy the water further by trying to drag General Relativity into it, because things will only get worse: Inertial frames don't even exist in General Relativity, except in the limit of "local tangent frames" which are infinitesimal in spacetime extent --- so in GR you can't even compare two velocities at all any more, unless two particle's worldlines' just happen to both pass through the same spacetime event (i.e., you can't compare the relative velocities of anything in GR, except when they collide with each other!).

But your final conclusion is that particle with mass can change direction without any acceleration, is this true or false?

 

[gdp]

Absolutely not. I'm saying that a change in speed or direction is a change in velocity, and therefore an acceleration.

Please go back and read what I actually wrote more carefully. Nowhere have I claimed that a change in direction without a change in speed did not require an acceleration.

I claimed that a change in a particle's direction of motion that does not change its speed --- i.e., an acceleration that does not change the magnitude of its velocity, but only its direction --- does not require a net expenditure of WORK, because its kinetic energy would remain unchanged by such an acceleration. "Work" and "acceleration" are physically distinct concepts.

But your final conclusion is that particle with mass can change direction without any acceleration, is this true or false?

False, and I never said any such thing. Please do try to read what I actually wrote.

I said that to change a particle's direction of motion without changing its speed does not require the expenditure of WORK. "Work" and "acceleration" are physically distinct concepts.

 

[LURCH]

So then, you're saying the acceleration takes place without work being done, right?

 

[gdp]

So then, you're saying the acceleration takes place without work being done, right?

No. Please go back and read what I actually wrote. (You should also learn the difference between a logically necessary condition and a logically sufficient condition.)

"Force," "Work," "Velocity," and "Acceleration" are all physically distinct concepts, as should be obvious from the mere fact that they each have different physical units.

It is possible to accelerate an object and do work, if the object's speed changes. It is also possible to accelerate an object without doing work, by changing the direction of its motion without changing its speed. And it is also possible to do work without changing the speed of any macroscopic body, e.g., by exerting force on a dashpot piston. However, none of these conditions are necessary conditions; they are merely possible conditions --- because Force, Work, Velocity, and Acceleration are all physically distinct concepts.

Consider the following explicit example of the second case. The rate of work on an object is given by dW/dt = F.v, where work W is a scalar, the force F and the velocity v are vectors, and `.' denotes the "dot product" between vectors. From Newton's 2nd Law, F = ma; therefore, dW/dt = ma.v. Expanding the dot product in a cartesian coordinate system, dW/dt = m(a_x * v_x + a_y * v_y + a_z * v_z). Consider the case where a unit force parallel to the Z-axis is applied to a unit mass. The velocity vector and the acceleration vector are physically distinct quantities. Consider the case where the velocity is instantaneously along the X-axis. Then v_x = 1 m/s, v_y = 0 m/s, v_z = 0 m/s, while a_x = 0 m/s^2, a_y = 0 m/s^2, a_z = 1 m/s^2. The velocity is not zero. The acceleration is not zero. The acceleration is perpendicular to the velocity. Thus, the dot product of velocity and acceleration is zero:

F.v = m*[(1 m/s)*(0 m/s^2) + (0 m/s)*(0 m/s^2) + (0 m/s)*(1 m/s^2)] == 0 kg*m^2/sec^3.

Therefore, the rate of work is zero in this specific case, even though neither the force, nor the velocity, nor the acceleration vanish.

Contrawise, consider a force exerted on a linear dashpot piston oriented along the X-axis. In this case, F_x = k * v_x, where `k' is the viscous friction coefficient of the dashpot. If the piston is moving at a constant speed equal to the terminal velocity for the applied force, the acceleration is zero. The constant rate of work, however is dW/dt = k * (v_x)^2, which is not in general zero.

Thus, one has seen an explicit case where acceleration occurs without work, and an explicit case where work occurs without acceleration.

Again, Work, Force, Velocity, and Acceleration are all physically distinct concepts, as evidenced by the fact that they each have different physical units. It is possible (but not necessary!) to have acceleration without doing work, and it is possible (but not necessary!) to do work without having an acceleration, because Work and Acceleration are physically distinct concepts; neither one necessitates the other, as has been explicitly shown through two physical examples.

 

[DEMcMillan]

I suggested to Grec.en that the Earth’s magnetic field could play a role in generating electrostatic charge in clouds by separating positively from negatively charged water droplets, interfering with their coalescence by electrostatic means. I claimed that the idea was testable because magnetic influence was sensitive to cloud movement direction. I did not initially mention Lorentz force and its cross product nature. gdp then posted a paragraph dismissing the possibility that the Earth’s magnetic field could play a role in thunderstorms. His reasoning appears to be that he would have heard about it if it were true. I then introduced the Lorentz force and cross product concepts. He seems to believe in Lorentz force and its cross product character but not to accept either concept fully. The cross product means that the force is orthogonal at all times to both the motion of each droplet and the applied magnetic field. Neither dot product can do any work even in a magnetic field that must always be changing because of charged particle motion. Separation of charges by their affected motion generates an electrostatic field, further complicating the analysis. Fluctuation of the applied magnetic field is not a factor in its inability to do work. It applies at all altitudes. I offered Grec.en a testable and plausible model and gdp’s dismissal needs to be reinforced by a more careful and physically plausible critique or withdrawn.

gdp appears to be attracted by the Kelvin model I cited as an explanation for thunderstorms, but not by its need to be initiated by an electrostatic device. If all liquid flows generated large electrostatic voltages, this could be offered as the best explanation for the crash of TWA 800 in 1996. Avoidance of electrostatic induction remains important to avoid such problems.

Laurentz’s 1902 Nobel lecture included Zeeman’s observation of the rotation of light by magnetic fields because Zeeman, who shared the prize, was too ill to go to Stockholm. http://nobelprize.org/nobel_prizes/physics/laureates/1902/lorentz-lecture.html . His own work was on electrons and light. Later he was reported to reject the concept of electron spin but its suspected existence was reported anyway http://books.google.com/books?id=xn...hl=en&sa=X&oi=book_result&resnum=10&ct=result This is another example of premature rejection of new ideas. Felix Bloch won his prize for work on nuclear magnetic behavior mediated by particle spin.

I still plan to add to the Hale discussion later. Zeeman’s work was seminal to Hale’s.

 

[DEMcMillan]

George Ellery Hale was born in Chicago in 1868. http://books.nap.edu/html/biomems/ghale.pdf His father’s business success combined with his boyhood interest in astronomy led to his baccalaureate in physics at MIT in 1890. He then helped raise the money and built the University of Chicago Yerkes Observatory in Wisconsin in 1897. His move to Mount Wilson began in December 1903. The first telescope he installed there was designed to look at the Sun. Sunspot studies became a major early target with investigations of their temperature and spectral emission lines. By 1908 he published evidence of Zeeland rotational magnetic effects on light coming from the sunspots. During the December 1912 sunspot nadir he noted that the polarity of the new high (~26o) latitude sunspots was opposite to the polarity of the last remaining prior cycle low (5-10o) latitude sunspots. He would wait until 1925, after another 11 year cycle to report the 22 year magnetic rhythm that underlies the 11 year quantitative sunspot cycles. The latitudinal migration pattern and the slower at the poles differential rotation rate of the supercritical fluid gas surface of the Sun suggest a fluid mechanical explanation for the development of sunspots http://solarscience.msfc.nasa.gov/presentations/20040428_UTA_Seminar.ppt#278 and stabilization of their rotating surfaces by the toroidal magnetic fields that are anchored in them. But a consensus mechanism for the magnetic behavior and that of the entire Sun still eludes us, in part because of confusion about the time of polarity reversal (Seminar slide 9).

I find it easy to postulate that the Sun goes through alternative eleven year periods of positive and negative total charge, concentrated on the Sun’s surface by electrostatic dissociation and that this charge generates sunspot magnetic fields by its rotation. The magnetic fields become intense and stabilize the shape of the sunspot pairs for weeks to months or even longer.

The basic lesson that Hale teaches us is that personal commitment, family money, and willingness to seek funds from many sources (see first site above) allow discoveries that take decades.

 

[gdp]

I find it easy to postulate that the Sun goes through alternative eleven year periods of positive and negative total charge, concentrated on the Sun’s surface by electrostatic dissociation and that this charge generates sunspot magnetic fields by its rotation. The magnetic fields become intense and stabilize the shape of the sunspot pairs for weeks to months or even longer.

You may "postulate" anything you want, but your "postulate" is useless if it fails to explain the data --- which your "postulate" in fact does not.

Sunspots in each solar hemisphere http://adsabs.harvard.edu/abs/1976IzKry..54..184K"

Moreover, the rotational velocities of gases in the sunspot can be measured, and they aren't all that fast --- http://adsabs.harvard.edu/abs/1976IzKry..54..184K" The observed small flow velocities would require ENORMOUS charge separations to generate the observed sunspot magnetic fields --- which are on the order of several thousand gauss --- whereas the Sun can easily be shown to necessarily be bulk quasineutral, with negligible internal charge separations. There is simply no force known in nature that can maintain a large charge separation in a highly conductive plasma --- which is only one of the many, many, many reasons why the so-called "Electric Sun" model fails utterly.

Furthermore, your "postulate" falsely predicts enormous electric fields on the Sun, which would generate a large http://en.wikipedia.org/wiki/Stark_effect" Therefore, the fields near the "surface" of the Sun are predominantly magnetic, not electric.

Since your "postulated" sunspot model falsely predicts that all sunspots in each solar hemisphere have the same magnetic polarity, rather than occurring in opposite polarity pairs as observed, your "postulate" immediately fails --- whereas http://solarscience.msfc.nasa.gov/dynamo.shtml" of the sunspot pair. Moreover, your "postulate" also falsely predicts enormous electric fields that are not observed, so your "postulate" immediately fails twice.

 

[DEMcMillan]

I used the verb postulate in my cited sentence without looking up its meaning. My Webster’s second unabridged dictionary indicates three choices. The second, to assume without proof to be true was closest to my intention. I had already indicated that there is no current consensus on the basis for sunspot magnetism before exposing my postulation as a mnemonic for the young physicist to avoid the mistake in slide 9. A reading of Hale’s 1915 paper
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1090830 will make the basis for the mistake clearer.

I have been forming a clarifying response, but have been delayed by a need to assure myself about a point before proceeding. I now have preliminary information that the Sun’s overall polarity changes every 11 years, a required feature of the solar charge model I offered http://helios.gsfc.nasa.gov/solarmag.html If anyone has strong negative information about this point, I hope they will furnish it.

Absent negative information about solar overall polarity change, in two or three days I will flesh out the model to make it testable. In the meantime, I ask gdp to offer any alternative that you find attractive

 

[gdp]

I used the verb postulate in my cited sentence without looking up its meaning. My Webster’s second unabridged dictionary indicates three choices. The second, to assume without proof to be true was closest to my intention.

You do not merely "assume without proof" --- you `assume' in direct contradiction to a large body of observed data.

I had already indicated that there is no current consensus on the basis for sunspot magnetism

On the contrary, there is a VERY strong scientific consensus on sunspot magnetism (see, e.g., http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/14171/1/00-0576.pdf" --- and directly falsify your "postulate" on at least two distinct grounds.

A reading of Hale’s 1915 paper http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1090830 will make the basis for the mistake clearer.

Please note that in the above paper Hale did not measure the orientations of sunspot rotations --- he merely speculated on the orientations of sunspot rotations. What he actually measured was merely the orientations of sunspot magnetic fluxes. Hale freely admits on p.382 that direct measurement of sunspot rotation was "remote" given the equipment he had available in his day --- which was far less precise than the equipment that we have available now, and which, unlike Hale's equipment, is now precise enough that we can now make http://adsabs.harvard.edu/abs/1976IzKry..54..184K" These measurements directly falsify Hale's speculation that a sunspot's magnetic flux orientation was determined by said sunspot's circulation direction.

Why don't you try reading a few papers a little more recent than the "ancient history" of 1915 --- like http://journals.royalsociety.org/index/U164400254564003.pdf" You might learn a few new facts about sunspots that Hale didn't know --- because Hale died in 1938, long before they were discovered.

Solar Astronomy didn't stop when Hale died. Your preference for citing ancient papers containing lower quality or ambiguous data while obdurately ignoring more recent papers with higher quality data that directly falsify your "postulate" loses you credibility points each time you do it.

I have been forming a clarifying response, but have been delayed by a need to assure myself about a point before proceeding. I now have preliminary information that the Sun’s overall polarity changes every 11 years, a required feature of the solar charge model I offered http://helios.gsfc.nasa.gov/solarmag.html If anyone has strong negative information about this point, I hope they will furnish it.

Quite frankly, I do not think you fully understand the difference between "electrical polarity" (i.e., sign of the electrical charge density), and "magnetic polarity" (i.e., the relative orientation of the magnetic flux through a specified oriented surface). Electric charge is a scalar. Magnetic "polarity" is the relative orientation of the http://info.ee.surrey.ac.uk/Teaching/Courses/EFT/dynamics/html/magnetic_flux.html" when projected along some specified reference vector; neither of these magnetic "polarities" are the least bit "charge-like."

Absent negative information about solar overall polarity change, in two or three days I will flesh out the model to make it testable. In the meantime, I ask gdp to offer any alternative that you find attractive

I have already pointed you to the http://helios.gsfc.nasa.gov/dynamo..html" containing measurements of sunspot magnetic structure and gas-flow structure that directly falsify your "postulate" --- and which you again clearly either did not bother to read or failed to understand.

I have pointed out that your "postulate" is immediately falsified because, given the fact that all sunspots have the same gas-flow circulation, http://adsabs.harvard.edu/abs/1976IzKry..54..184K" your "postulate" falsely predicts that all sunspots in a given hemisphere must have the same magnetic polarity, rather than occurring in opposite polarity pairs as observed --- a "prediction" which is clearly directly contradicted by the very observations by Hale that you so like to cite.

I have pointed out that your "postulate" falsely predicts that sunspots will have an electric field that dominates their magnetic field, so that sunspots should show a http://en.wikipedia.org/wiki/Stark_effect" who was very unhappy about it because it falsified his sunspot model), a sunspot's magnetic field must necessarily be very much stronger than its electric field, directly falsifying your "postulate," which falsely predicts that a sunspot's electric field must be very much stronger than its magnetic field.

I suggest that rather than "postulating" from your armchair, you behave like a Physicist, and go to the blackboard to use the observed typical sunspot size (~1e4 km) and magnetic fields strength (~1e3 Gauss) to estimate the order of magnitude of a typical sunspot's magnetic moment --- which will allow you to estimate the magnitude of electric current required to produce the field, which together with the http://adsabs.harvard.edu/abs/1976IzKry..54..184K" (~ 1 km/sec) will allow you to estimate the order of magnitude of the required surface-charge density, which will tell you the order of magnitude of the electric fields that your "postulate" would predict. You will find that the required charge densities and electric field strengths are totally implausible.

Until you bother to take the time to perform the above calculation and see how badly it disagrees with the observed data, your continued armchair "postulating" in contradiction to the observed data will merely continue to rack up points on your http://math.ucr.edu/home/baez/crackpot.html"

 

[DEMcMillan]

gdp has generated an abrupt, prolonged and incredibly vituperative response to my description of Hale’s contribution to astrophysics and a theme from it. I can sense from his diatribe that he has no interest in entertaining any alternative to his opinions about solar magnetic behavior. I withdraw my offer to develop an alternative to the theory that he favors. He does not grasp the dialogue concept that is basic to this or any other forum. Ad hominem attacks are improper and deserving of an apology before proceeding further. Anyone surviving the reading up to now and interested in my solar magnetism thesis is welcome to contact me by e-mail.

 

[misgfool]

Consider the following explicit example of the second case. The rate of work on an object is given by dW/dt = F.v,

I don't think that equation holds. W = Cinteg(F.ds) and it is path-dependent and cannot be differentiated to get F.ds.

Then v_x = 1 m/s, v_y = 0 m/s, v_z = 0 m/s, while a_x = 0 m/s^2, a_y = 0 m/s^2, a_z = 1 m/s^2. The velocity is not zero. The acceleration is not zero. The acceleration is perpendicular to the velocity. Thus, the dot product of velocity and acceleration is zero:

F.v = m*[(1 m/s)*(0 m/s^2) + (0 m/s)*(0 m/s^2) + (0 m/s)*(1 m/s^2)] == 0 kg*m^2/sec^3.

This would also mean that even if velocity is zero (=stationary object) all acceleration in any direction requires no work.