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Natural Science Forum / Physics / Electromagnetism / July 2008Error in Wikipedia article: Faraday's law of induction
It seems there is an error in this Wikipedia article: http://en.wikipedia.org/wiki/Faraday%27s_law_of_induction Faraday's law says the induced EMF is in proportion to the rate of CHANGE (my emphasis) of the magnetic flux. The article describes this much OK. Later on, the article then says: In the case of motional EMF, the idea is to move all or part of the circuit through the magnetic field, for example, as in a homopolar generator. But this last case is a situation where the magnetic flux does not change. Isn't this the aspect that Faraday saw as a paradox because it did not obey his law of induction? Apparently he realized that no flux change happened when he rotated the magnets with the rotating disk in his unipolar generator. As I understand all this, there are TWO ways to induce electricity from a magnetic field: 1. A conductor at a right angle to the magnetic field alignment experiencing a change in the magnetic field flux density (strength). [Faraday's law of induction] 2. Motion of a conductor at right angle to the magnetic field alignment and simultaneously at right angle to the line of the conductor. [Fleming's right hand rule, Lorentz force law] The article seems to be trying to convert everything into one. |WARNING: Due to extreme spam, googlegroups.com is blocked. Due to ignorance | | by the abuse department, bellsouth.net is blocked. If you post to | | Usenet from these places, find another Usenet provider ASAP. | | Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) | On Jul 12, 7:19 am, phil-news-nos...@ipal.net wrote: > As I understand all this, there are TWO ways to induce electricity from a > magnetic field: [quoted text clipped - 8 lines] > > The article seems to be trying to convert everything into one. Not really. Yes there are two ways and electric field can be produced in a conductor (wire). One would be the relative motion between a magnetic field and the conductor. That is related to the Lorentz force law on charges. A simple example would be the moving of a magnet in and out of a coil of wire. Also generators work on this principle and the calculation of operation this way is usually called "flux cutting" methods. The wires pass through the flux "cutting" it and producing Lorentz EMF inside the wires. The other way of producing electric fields inside wires is known as "flux changing". IF we have two coils of wire and we put a current through one of them, a pulse of voltage appears in the other. Note that NOTHING is moving so there is no "flux cutting". Only the flux through the second coil is changing because the current in the first coil is changing. So now there are TWO ways to produce an "emf" in a wire by means of magnetic flux. But flux methods of BOTH types are limited. Sometimes they fail altogether! A Faraday generator is a perfect example. The magnetic field is not changing so there is no flux changing. And since the disk is solid and continuous it really isn't "cutting" the flux either. There are other examples of geometry that show the failure of flux methods. Feynman notes that in such cases you go back to first principles (Maxwell's equations) no matter how handy flux methods are in calculating answers in many practical cases. In the case of mutual induction the Vector Magnetic Potential can be seen to play a vital role. There have been many attempts to convert these two things into one. For example people have argued that as a current increases in a wire the magnetic field expands from the wire and thus produces Lorentz forces in neighboring wires. These theories to date have all failed. Flux theories have all pretty much failed to be fundamental. In fact the whole concept of "lines of flux" is rather bogus to begin with! Not that they are not useful, mind you. So yes, there is no combining these things. You are allowed to go "fix" the Wikipedia article you know! | On Jul 12, 7:19 am, phil-news-nos...@ipal.net wrote: | [quoted text clipped - 38 lines] | induction the Vector Magnetic Potential can be seen to play a vital | role. I don't see an issue with considering the Faraday generator solid disk as not fitting the Lorentz force law. "Cutting" was an erroneous convenience that explained some things prior to understanding this in terms of particles. Certainly there are cases where you have to consider both laws to figure out what is happening. But how does a transformer need the Lorentz law? How does the Faraday disk need Maxwell's upgrade of Faraday's law? | There have been many attempts to convert these two things into one. | For example people have argued that as a current increases in a wire [quoted text clipped - 3 lines] | the whole concept of "lines of flux" is rather bogus to begin with! | Not that they are not useful, mind you. If you want to convert both laws into one, you will have to consider space and time as a single entity, and use a vector product that works between them. | So yes, there is no combining these things. You are allowed to go | "fix" the Wikipedia article you know! This is an area I still have a lot to learn about. Unfortunately, many of the puzzles I am pondering are not addressed in the multitudes of examples I have found both in Wikipedia and elsewhere. Google has helped, but it doesn't seen to have a way to do a search like "take the example described on this page and find a page that describes a scenario which transposes the field and the motion and flips the EMF". For example, instead of using a solid disk in the Faraday generator, use a spoked wheel. I did see one such example somewhere online with the claim that it works the same as the solid disk, but only described a scenario of stationary magnets creating a uniform field over the entire wheel. Now change this to rotate the magnets with the wheel. I don't see why it would be any different than the disk with rotating magnets, but I cannot be 100% sure since apparently no one tested it (so I might have to). However, I am more interested in additional modification of this wheel with a non-uniform magnetic field, using magnets rotating with the wheel. So it still should be a case of no flux change for any particle of the wheel mass itself. What would be different is that some spokes have the field in one direction and other spokes have the field in the other direction. So I would expect the latter spokes to be producing an EMF in the opposite direction, continuously. If I need to do a test of this, it would seem the best way to measure current between alternating spokes would be to have some kind of low voltage light on the wheel itself. That way, there are no external wire leads that could be influenced by the flux changing going on in the extraneous field that reaches beyond the wheel. I would expect this extraneous field to be much less since the field lines would be between the opposing magnets instead of being limited to being between the opposite sides of the wheel assembly. I expect this to better confine the field to the wheel. Still, what remains of the extraneous field could disturb the experiment. I also suggest that instead of having what amounts to a group of loops making up the wheel (a loop exists between each spoke pair with opposite fields), the alternating spokes could be "wired in series" by breaking the loop near the edge for loops in one direction, and near the axis for loops in the other direction. This would end up being a zig-zag around the wheel, where even spokes doing the zig have a field in one direction, and odd spokes doing the zag have a field on the other direction. Shouldn't this series circuit have an increased voltage with less current? |WARNING: Due to extreme spam, googlegroups.com is blocked. Due to ignorance | | by the abuse department, bellsouth.net is blocked. If you post to | | Usenet from these places, find another Usenet provider ASAP. | | Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) | On Jul 12, 12:22 pm, phil-news-nos...@ipal.net wrote: I'll say this much. I'm also very much interested in this subject and would like to try to find a way to combine Lorentz and Faraday laws into one thing. I DO believe that as you put a current down a wire the magnetic field expands aways from a wire causing an apparent Lorentz force at a distance. After all, we know that as we put current down a wire energy is stored in the magnetic field. Causality means that energy is traveling away from the wire at the speed of light or slower. Therefore, the "expanding field" theory could make sense. But I've never found a calculation that would work to prove this. You try and nothing ends up making sense. Also as for Faraday Disks including the One Piece Faraday Homopolar Device (OPFHD) which means magnets rotate with disk. You CAN split the disk into radials or as Tesla proposed into a spiral which actually enhances the magnetic field as it produces current. It works the same. Yes then in the case of non-rotating magnets one actually can then say that the wires DO "cut" the flux. But in the one piece case, the problem is that you are using a loop to measure emf. One scenario is this: The magnet and the disk turn together. Therefore, there is NO emf induced into the disk no matter WHAT it's configuration! There is NO relative motion between them. The emf you are measuring is coming ALL from the wire loops hooked between the disk and meter. A similar argument ensues if you assume the magnetic field does not rotate with the magnet. These kind of experiments are easy to do. I've done quite a few. Just find some old dead large loudspeakers and remove the large ceramic disk magnets from them (they are usually glued in so it can take some work). Then set up your ideas. The voltages and currents from a Faraday disk should easily light most LEDs. But dig. They DON'T! All your various ideas somehow almost always seem to forget about the "complete" loop thing. The laws of line integrals in a conservative magnetic field are totally unforgiving! Nope, the LEDs do NOT light! Just gets you scratching your head. Evenually I had to join everyone else in the idea that the measurement cannot be made with a loop. It has to be made electrostatically. I don't like it, but it's just how it is. | I'll say this much. I'm also very much interested in this subject and | would like to try to find a way to combine Lorentz and Faraday laws [quoted text clipped - 6 lines] | I've never found a calculation that would work to prove this. You try | and nothing ends up making sense. I'm not currently interested in trying to combine Lorentz and Faraday laws. My interest right now is playing around with the Lorentz law and seeing just what its boundaries are, especially with respect to the relativity of motion. In other words, how far can I go with this concept of having the magnets attached to the disk, and then modify the configuration beyond the solid disk. | Also as for Faraday Disks including the One Piece Faraday Homopolar | Device (OPFHD) which means magnets rotate with disk. You CAN split the | disk into radials or as Tesla proposed into a spiral which actually | enhances the magnetic field as it produces current. It works the same. That's an interesting one I had not seen. I looked at one patent Tesla got that involved two disks edge to edge connected by some kind of belt to make it easier to extract power. Back to Google. | Yes then in the case of non-rotating magnets one actually can then say | that the wires DO "cut" the flux. But in the one piece case, the [quoted text clipped - 5 lines] | argument ensues if you assume the magnetic field does not rotate with | the magnet. Are you saying this in terms of an argument one may face and have to ponder or are you saying that the OPFHD really produces no EMF at all? There is the counter argument that if the magnets rotate, and the disk does not (wires are attached to measure), then this should induce some voltage in the attached wires as well. Yet this configuration nets no EMF. But then, there is the counter argument to the counter argument that with the magnets rotating, the disk is relatively going backwards with respect to the magnets, and has an EMF in opposite polarity (compared to the disk rotating and the magnets not) and this EMF bucks the EMF in the sensing wires, resulting in nothing measured. So which is it? If the OPFHD really produces no EMF at all, then there was no paradox? | These kind of experiments are easy to do. I've done quite a few. Just | find some old dead large loudspeakers and remove the large ceramic [quoted text clipped - 8 lines] | has to be made electrostatically. I don't like it, but it's just how | it is. I plan to buy some strong neodymium magnets to try things with when I do pick an experiment to try. I don't know what you mean by "measurement cannot be made with a loop". I am not suggesting some kind of loop coupling to sense the EMF in the disk/wheel. The loop is to generate a larger EMF potential. Putting the light on the wheel itself is a means to directly measure without using brushes on the disk. I'm also considering the drum configuration. The conductors would run along the drum parallel to the axis. The field would be radial to/from the axis. And of course the motion would be circular around the drum. |WARNING: Due to extreme spam, googlegroups.com is blocked. Due to ignorance | | by the abuse department, bellsouth.net is blocked. If you post to | | Usenet from these places, find another Usenet provider ASAP. | | Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) | On Jul 12, 9:18 pm, phil-news-nos...@ipal.net wrote: > That's an interesting one I had not seen. I looked at one patent Tesla > got that involved two disks edge to edge connected by some kind of belt > to make it easier to extract power. Back to Google. Yes, the dual Faraday generator used flanged disks with a copper mesh belt around them. This places (if you choose magnetic polarity correctly) the two generators in series which doubles the voltage (I think Tesla had the idea of a series of these to get voltages to useful ranges) and also lets the brushes be on the disk shafts rather than sliding on the disks (which has lots of friction and losses at the low voltages and high currents). The spiral one was interesting too in that he was trying build a "self- excited" Faraday generator. The idea was that the high currents in the spiral rotor automatically generate a stator field without a field supply or permanent magnets. > Are you saying this in terms of an argument one may face and have to ponder > or are you saying that the OPFHD really produces no EMF at all? The OPFHG actually produces voltage (which seems rather amazing at first) But if you use Lorentz arguments you have to say that since there is no relative motion between the magnet and disk there can be no Lorentz voltage. Thus EITHER the field rotates with the magnet and ALL the output voltage comes from the non-disk part of the circuit OR the field does NOT rotate with magnet in which case the voltage comes from the disk [no relative motion then between magnetic field and external wiring]. > There is the counter argument that if the magnets rotate, and the disk > does not (wires are attached to measure), then this should induce some > voltage in the attached wires as well. Yet this configuration nets no > EMF. The actual counter argument actually involves the case with the disk stationary and the brushes and meter are moving around the disk. And that DOES produce a voltage. > If the OPFHD really produces no EMF at all, then there was no paradox? But is does produce voltage. In fact the SAME voltage as if the magnets didn't move. > I plan to buy some strong neodymium magnets to try things with when I do pick > an experiment to try. Me too! But right now I"m using Speaker magnets. One experiment is to encase the whole thing in an iron magnetic circuit (as Tesla did) Iron elements complicate the picture but I'm wondering what the effect of such flux concentration would be on output voltage and current. Especially if you spin the disk, magnets AND iron circuit! The thing I'm building needs a bit more machining before I try it. > I don't know what you mean by "measurement cannot be made with a loop". I am > not suggesting some kind of loop coupling to sense the EMF in the disk/wheel. It means that if you are measuring output using a meter and a "circuit" there is a loop of wire there and you MUST consider the ENTIRE loop for Lorentz forces. Consider the following: A spinning magnet. a "Loop" consisting of a wire down the axis of the disk shaft. A wire vertically up the face of the magnet. A wire away from the magnet following a "line of flux" and finally a vertical wire back down to the shaft where it is twisted with the other wire and goes to the meter. The standard thought is that if you make the flux line wires long enough, the downward wire will be in such a weak field that you can ignore any induction there. That is totally wrong! Dig. The wire down the shaft follows a fluxline and has no induction. The upper wire following a flux line has no induction. The twisted wire pair has no induced voltages. The wire up the magnet face will have the Lorentz force you expect due to the relative motion of the magnetic field and the wire. So far the experiment has everyone fat and happy. But wait. If you look closely, you'll find that the SAME flux lines that cut the wire on the magnet face ALSO cut the DOWNWARD connecting wire and do it in the OPPOSITE sense. You can show the induced voltages are equal and opposite! Hence you can experiment until you are blue in the face and you get NOTHING! And that also includes no conclusions! So long as there is a loop in the field you simply can't get around this cancellation! It turns out the loop shape makes no difference. This is why people suggest using electrostatic measurements which do NOT use a closed circuit to measure emf. > The loop is to generate a larger EMF potential. Putting the light on the > wheel itself is a means to directly measure without using brushes on the > disk. Tried it. But if you think about it, you see that wires going to the light are the part of the light-loop! No light is seen. > I'm also considering the drum configuration. The conductors would run along > the drum parallel to the axis. The field would be radial to/from the axis. > And of course the motion would be circular around the drum. Yes the drum configuration is good, See the old EM books by E.G. Cullwick who derives a lot on the drum and notes the "meter and brushes" relative motion thing. Good luck! WARNING: Due to extreme spam, googlegroups.com is blocked. Hey, I'm posting in GoogleGroups.com! How am I getting through? Is this evidence of superluminal transmission? | Yes, the dual Faraday generator used flanged disks with a copper mesh | belt around them. This places (if you choose magnetic polarity [quoted text clipped - 3 lines] | than sliding on the disks (which has lots of friction and losses at | the low voltages and high currents). The original I idea I had was to have 2 parallel disks. Each disk would have a magnet (same size as the disk) on each side. Looking down the axis one disk would have both of its magnets with N-pole facing at you. The other would have S-pole facing at you. These 2 disks would be spaced a bit apart due to the S-poles facing each other. There would be field lines reaching around each disk as well as going through each disk. Wires would cross connect the two disks at their edges. The axis between disks would be non-conductive. This design is flawed because both disks would have the "extraneous" field intersecting the cross-connect wires. | The spiral one was interesting too in that he was trying build a "self- | excited" Faraday generator. The idea was that the high currents in the | spiral rotor automatically generate a stator field without a field | supply or permanent magnets. I'd have to see the geometry of this to know where the field lines would be causing problems for this. | The OPFHG actually produces voltage (which seems rather amazing at | first) But if you use Lorentz arguments you have to say that since [quoted text clipped - 4 lines] | from the disk [no relative motion then between magnetic field and | external wiring]. One or the other it seems. |> There is the counter argument that if the magnets rotate, and the disk |> does not (wires are attached to measure), then this should induce some [quoted text clipped - 4 lines] | stationary and the brushes and meter are moving around the disk. And | that DOES produce a voltage. Another thing I have been wondering about is treating the Earth as a OPFHG. While there are not conductors as we think of them extending outward from the Earth, there actually are some, as well as a stream of particles. So I wonder how much of this is charge from the Earth rotating in its own magnetic field. There are some strange things like "lightning sprites" emerging from the tops of storm clouds, suggesting electrical fields extending much higher. |> If the OPFHD really produces no EMF at all, then there was no paradox? | | But is does produce voltage. In fact the SAME voltage as if the | magnets didn't move. But is it really the OPFHD producing the voltage? Or is it there is a voltage in the whole system consisting of the OPFHD and the wires that are stationary, attached to brushes to extract current? If those wires were constructed in a way that they were very loose so that small forces could move them some distance to one side or the other, would the rotation of the OPFHD mechanically deflect the wires? If the voltage is being induced on these wires, shouldn't there be at least some mechanical force, as well? Of course one problem with this is, since these wires are carrying current, and there is a magnetic field (we claim is stationary even if the magnets are rotating), then I'd expect the wires to deflect even if they are not where the EMF is induced. They would have their own magnetic field, and that would interact with the rotor field. |> I plan to buy some strong neodymium magnets to try things with when I do pick |> an experiment to try. [quoted text clipped - 19 lines] | wires long enough, the downward wire will be in such a weak field that | you can ignore any induction there. That is totally wrong! There is an "extraneous" field going around a magnet between poles. There is a field inside the magnet between them as well. If you have 2 flat magnets, with poles on their flat faces, and they are placed with the N-pole face of one close to the S-pole face of another, you have a strong field between them. But there is also that "extraneous" field going around the outward face of one to the outward face of the other. Both of these fields have to be the same strength in much the same ways as an electric circuit has the same current at two points. | Dig. The wire down the shaft follows a fluxline and has no induction. | The upper wire following a flux line has no induction. The twisted [quoted text clipped - 10 lines] | makes no difference. This is why people suggest using electrostatic | measurements which do NOT use a closed circuit to measure emf. This is why I want to explore a modification of the field. Consider a disk with 12 radials (so clock hour positions are easy ways to identify specific radials). The magnets I would use are half-donut shaped, with poles at the ends, somewhat like a stubby horse-shoe magnet. These would be placed so that the N-pole faces the disk from the top at radial 1, and S-pole faces the disk from the top at radial 2, of the same magnet. Below the disk is another magnet with its S-pole facing radial 1, and N-pole facing radial 2. Several of these "facing pairs" would be placed along the radial, from 3/4 of the way away from the axis to the edge (so this is all in the outermost 1/4 of the disk, measured radially). Repeat for radials 3 and 4. Again for 5 and 6. Then 7 and 8. Then 9 and 10. Then 11 and 12. The conductor runs outward along radial 1, then jumps over to radial 2 at the edge, then runs inward along radial 2, then jumps over to radial 3 at the 3/4 distance. It repeats this back and forth until it reaches back to radial 1 where it began. This is where we can insert the small light. The disk itself is not a conductor. It would be a plastic frame holding the conductor and the magnets. The fields of these magnets are closely confined. The space between the magnets above and below is kept close relative to the space between the radials. The orientation of the conductor is reversed where the magnetic field is reversed. So any induced EMF should add up in each radial. There are no "off the disk" stationary conductors (yet). If this does induce EMF in the parts of the conductor directly between the magnets, and if this EMF is going to be "bucked to zero" by other parts of the conductor not directly between the magnets, then it will have to be in the part where the conductor runs in the direction of disk rotation between the radials. Even if there is magnetic field there, it's not changing (since it is all rotating as one piece) so changing flux will not be an influence. And the conductor direction is the same as the motion direction, so that leaves insufficient conditions for any field to induce an EMF by Lorentz law. This configuration could also be done on a drum by having the radials run parallel to the axis, with half the magnets outside and half inside of the tubular surface of the drum. |> The loop is to generate a larger EMF potential. ?Putting the light on the |> wheel itself is a means to directly measure without using brushes on the |> disk. | | Tried it. But if you think about it, you see that wires going to the | light are the part of the light-loop! No light is seen. So how can the configuration I describe above have this issue, where there is enough "extraneous" induced EMF to fully buck the expected inducted EMF? I hope my description of the configuration is clear enough. I'm very bad at drawing, and even worse at 2D drawing of 3D depictions. I can imagine my own ideas in 3D rather readily. I suppose what I need to do is learn to use the POVRAY program to make my 3D ideas at least show up visually. |> I'm also considering the drum configuration. ?The conductors would run along |> the drum parallel to the axis. ?The field would be radial to/from the axis. [quoted text clipped - 3 lines] | Cullwick who derives a lot on the drum and notes the "meter and | brushes" relative motion thing. I want to avoid the brushes as much as I can, at least until I can raise the voltage and lower the current enough to make it not so much of an issue. In the big design I gave above, if it really does induce an EMF, then I guess I could take off power by having one end connected to one axis, and the other end connected to the other axis (the axis in the middle being non-conductive). | Good luck! | | WARNING: Due to extreme spam, googlegroups.com is blocked. | | Hey, I'm posting in GoogleGroups.com! How am I getting through? Is | this evidence of superluminal transmission? It seems you get through because you did followup on either a non-blocked post or maybe my post, or a thread I posted in. |WARNING: Due to extreme spam, googlegroups.com is blocked. Due to ignorance | | by the abuse department, bellsouth.net is blocked. If you post to | | Usenet from these places, find another Usenet provider ASAP. | | Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) | > Another thing I have been wondering about is treating the Earth as a > OPFHG. While there are not conductors as we think of them extending [quoted text clipped - 3 lines] > "lightning sprites" emerging from the tops of storm clouds, suggesting > electrical fields extending much higher. Storm clouds are high voltage generators (Armstrong and Kelvin). As such they must send electrons in ALL directions. S* |> Another thing I have been wondering about is treating the Earth as a |> OPFHG. While there are not conductors as we think of them extending [quoted text clipped - 6 lines] | Storm clouds are high voltage generators (Armstrong and Kelvin). As such | they must send electrons in ALL directions. How can a storm cloud generator a charge if it would send electrons in all directions? Do these new charges emerge from some kind of singularity in the middle of the cloud? |WARNING: Due to extreme spam, googlegroups.com is blocked. Due to ignorance | | by the abuse department, bellsouth.net is blocked. If you post to | | Usenet from these places, find another Usenet provider ASAP. | | Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) | > On Mon, 14 Jul 2008 16:42:08 +0200 "Szczepan Bia?ek" <sz.bialek@wp.pl> > wrote: [quoted text clipped - 5 lines] > directions? Do these new charges emerge from some kind of singularity in > the middle of the cloud? A storm cloud generate the high VOLTAGE not a charge. The Earth has the excess of electrons so the atmosphere too. But currents and lightnings take place only if the difference of voltage exist. Water droplets work like the capacitor. Small drops in cloud small voltage, large drops large voltage (see Kelvins high voltage generator). In a storm cloud are stored heat and electrons. The both must be dissipated when the cloud disappear. S* |> On Mon, 14 Jul 2008 16:42:08 +0200 "Szczepan Bia?ek" <sz.bialek@wp.pl> |> wrote: [quoted text clipped - 12 lines] | (see Kelvins high voltage generator). In a storm cloud are stored heat and | electrons. The both must be dissipated when the cloud disappear. If there is a voltage and no current, there is a charge. That's the initial state of the clouds. A capacitor charged up has voltage and charge. Voltage is just the density of a change (the same charge spread over more capacitors has less voltage). Also, for a charge to have been established, there had to be some current at some point. Either there was current between the + and - ends of the charge to pull things apart, or there was current from externally feeding in more electrons. |WARNING: Due to extreme spam, googlegroups.com is blocked. Due to ignorance | | by the abuse department, bellsouth.net is blocked. If you post to | | Usenet from these places, find another Usenet provider ASAP. | | Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) | > On Tue, 15 Jul 2008 10:25:45 +0200 "Szczepan Bia?ek" <sz.bialek@wp.pl> > wrote: [quoted text clipped - 30 lines] > of a change (the same charge spread over more capacitors has less > voltage). If small drops join together the charge is the same but the voltage rise. The volume is proportional to r^3 and capacitance to radius. S* |> On Tue, 15 Jul 2008 10:25:45 +0200 "Szczepan Bia?ek" <sz.bialek@wp.pl> |> wrote: [quoted text clipped - 33 lines] | If small drops join together the charge is the same but the voltage rise. | The volume is proportional to r^3 and capacitance to radius. There's also the change in capacitance as lifting (thermal) takes place. So the voltage rises. The distance rises along with that. Fluctuations in the distance (turbulence) and many other things expose opportunities for a discharge. |WARNING: Due to extreme spam, googlegroups.com is blocked. Due to ignorance | | by the abuse department, bellsouth.net is blocked. If you post to | | Usenet from these places, find another Usenet provider ASAP. | | Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) | ---------------------------- >> On Mon, 14 Jul 2008 16:42:08 +0200 "Szczepan Bia?ek" <sz.bialek@wp.pl> >> wrote: [quoted text clipped - 15 lines] > heat and electrons. The both must be dissipated when the cloud disappear. > S* It's a bit more than this simplistic and superficial approach. To get a high voltage between two points, it is NECESSARY that there is a charge separation. This separation of charge is the cause of the voltage difference- look at the definition of potential difference. Updrafts, wide temperature ranges, and charge separation due to changes in temperature followed by freezing are some of the factors. Suffice it to say that there are parts of a cloud that are negative with respect to earth and parts which are positive due to charge buildup. The electric fields are related to these charges and lightning, between earth or cloud to cloud consists of high field breakdown (in steps) providing an ionized path for a rebalance of charge. As for heat stored in a storm cloud- note that the temperature of the known charge storage regions of thunderheads is generally in the -30 to -40C range. Thermal energy is involved- it is the driving force behind the charge separation, but somehow, heat storage is rather questionable at least. As for storage of electrons (and actually in some regions, storage of positive ions) -isn't that a storage of charge? You are contradicting yourself. Do we know the actual mechanisms involved? To some extent we do but we certainly cannot say "this is what happens" rather than "this may be the main mechanism" Do we know all the mechanisms and what part each of the known mechanisms play?- definitely not. There is a great deal of literature with respect to lightning- read it! Don Kelly dhky@shawcross.ca remove the X to answer > It's a bit more than this simplistic and superficial approach. > To get a high voltage between two points, it is NECESSARY that there is a > charge separation. No. Assume that you have very small cloud composed of 10 small charged drops. Between the cloud and the Earth is some voltage. If the drops join together the voltagr rise. >This separation of charge In contemporary science the separation of charge is used in place of build/lowering of voltage. Current flow from high voltage to lower. Not from more charge to less. > is the cause of the voltage difference- look at the definition of > potential difference. Updrafts, wide temperature ranges, and charge > separation due to changes in temperature followed by freezing are some of > the factors. > Suffice it to say that there are parts of a cloud that are negative with > respect to earth and parts which are positive due to charge buildup. Are you talking about voltage? All parts of clouds have excess of electrons. >The > electric fields are related to these charges and lightning, between earth > or cloud to cloud consists of high field breakdown (in steps) providing an > ionized path for a rebalance of charge Charge or voltage? > As for heat stored in a storm cloud- note that the temperature of the > known charge storage regions of thunderheads is generally in the -30 [quoted text clipped - 3 lines] > of positive ions) -isn't that a storage of charge? You are contradicting > yourself. During condensation of steam the heat is expeled. > Do we know the actual mechanisms involved? To some extent we do but we > certainly cannot say "this is what happens" rather than "this may be the > main mechanism" Do we know all the mechanisms and what part each of the > known mechanisms play?- definitely not. > > There is a great deal of literature with respect to lightning- read it! Meteorology is a new science. Physics is older. Lightnings folows the physics laws. Meteorologist should read physics. S* |> It's a bit more than this simplistic and superficial approach. |> To get a high voltage between two points, it is NECESSARY that there is a [quoted text clipped - 3 lines] | drops. Between the cloud and the Earth is some voltage. If the drops join | together the voltagr rise. Same total charge in Coulombs. Same distance in meters. Same potentin in Volts. What is it that you are changing to raise the voltage? |>This separation of charge | | In contemporary science the separation of charge is used in place of | build/lowering of voltage. Current flow from high voltage to lower. Not from | more charge to less. The voltage is a difference between two points. |> is the cause of the voltage difference- look at the definition of |> potential difference. Updrafts, wide temperature ranges, and charge [quoted text clipped - 5 lines] | Are you talking about voltage? | All parts of clouds have excess of electrons. Maybe the whole planet has an excess. Or the whole solar system. Or ... | Meteorology is a new science. Physics is older. Lightnings folows the | physics laws. Meteorologist should read physics. They do. |WARNING: Due to extreme spam, googlegroups.com is blocked. Due to ignorance | | by the abuse department, bellsouth.net is blocked. If you post to | | Usenet from these places, find another Usenet provider ASAP. | | Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) | > On Wed, 16 Jul 2008 09:51:51 +0200 "Szczepan Bia?ek" <sz.bialek@wp.pl> > wrote: [quoted text clipped - 15 lines] > Volts. > What is it that you are changing to raise the voltage? The ratio Q/C In physics is the equation: C = Q/V. So we have: 1. For 10 drops: Let assume that the voltage on each is 1 V and Q is 1 electron and C is 1, 2. For one large drop: V = Q/C but now Q is 10 electrons and C is proportional to the new radius of large drop. The new radius is 10^-3 bigger so the C also. In rsult we have: V = !0/10^-3 = 100V. I have used the theoretical equations. In reality is 10V. > |>This separation of charge > | [quoted text clipped - 4 lines] > > The voltage is a difference between two points. The second is the Earth. But you can have many charged particles in the air with the same voltage. If the voltage is diferent current or sparks start between them. > |> is the cause of the voltage difference- look at the definition of > |> potential difference. Updrafts, wide temperature ranges, and charge [quoted text clipped - 4 lines] > with > |> respect to earth and parts which are positive due to charge buildup. It is impossible. All parts are negative but the voltage may be diffrent. > | Are you talking about voltage? > | All parts of clouds have excess of electrons. > > Maybe the whole planet has an excess. Without any doubts. Or the whole solar system. Or ... > | Meteorology is a new science. Physics is older. Lightnings folows the > | physics laws. Meteorologist should read physics. > > They do. But they use their own terminology. In physics negatively charged means excess of electrons. Positively deficit. In a cloud no drops with deficit of electrons. S* ---------------------------- >> On Wed, 16 Jul 2008 09:51:51 +0200 "Szczepan Bia?ek" <sz.bialek@wp.pl> >> wrote: [quoted text clipped - 24 lines] > bigger so the C also. In rsult we have: V = !0/10^-3 = 100V. I have used > the theoretical equations. In reality is 10V. ------------- Consider the 10 original drops having a radius of 1mm and spaced equally around a sphere of 10cm radius. Modifying an expression for bundled conductors of power lines, the equivalent radius of the whole becomes about 6 cm That is, a virtual conductor of 6cm cm radius carrying ten electrons. At distances over a few m from the charge center, it is almost impossible to tell the difference between the virtual sphere and the actual charge distribution. For purposes of calculation of capacitance to ground there is no measurable difference. Now doing your math correctly the radius cubed should be the cube root of 10 times as large as the original droplet for the same total volume. The single droplet (of the same total volume) that you propose is not 10^-3 (as stated) or even 10^3 times as large but will have a radius that is 2.15 mm . So, the group of droplets has a greater capacitance to ground than your single large drop. The original total capacitance of the separated drops depends on their positions- with respect to each other and with respect to ground or whatever is being used as a reference- this is something that you have entirely ignored. You are trying to compare a single large drop with 10 electrons to a single small drop of 1 electron. and haven't even got the math right. Meaningless! -------------- >> |>This separation of charge >> | [quoted text clipped - 8 lines] > air with the same voltage. If the voltage is diferent current or sparks > start between them. ----------- No kidding. Then each of these charges contribute to the field and if you have a lot of similar charges- then one must consider the total effect. The multiple individual charges in a cloud are individually negligable but the total can amount to many Coulombs and can be treated as a charged ball. What becomes important in breakdown (, is not the total voltage to ground but the high fields in the vicinity of this large charge. --------- >> |> is the cause of the voltage difference- look at the definition of >> |> potential difference. Updrafts, wide temperature ranges, and charge [quoted text clipped - 6 lines] > > It is impossible. All parts are negative but the voltage may be diffrent. --------- You say it is not possible but it has been found by measurements that there are regions of positive charge not just different amounts of negative charges. There is theory backed by experiment that gives at least one mechanism for this. In addition, there is solid data that some lightning strokes originate in regions of positive charge. I'll stick with what is known rather than what you say is not possible. --------- >> | Are you talking about voltage? >> | All parts of clouds have excess of electrons. [quoted text clipped - 12 lines] > of electrons. > S* ------------- The references that I have given are physics and engineering references- not meteorologists ' terminology. Consider a droplet that is being swept up and cooled - there is a difference in mobility between the H+ ions and the OH- ions in the drop. Suffice it to say that a supercooled droplet may suddenly freeze (same as water in a supercooled stream can suddenly freeze from the bottom) and the outer and lighter shards are + and are swept upward faster and further than the heavier -ve core. Whether this is the actual mechanism or some other mechanism occurs - there do exist regions of positive charge (not less negative charge) - as you would know if you sat down and read some of the technical literature with regard to lightning. A review of electrostatics might also help. In other words take time to learn more about the subject before making patently incorrect statements.  SignatureDon Kelly dhky@shawcross.ca remove the X to answer > So, the group of droplets has a greater capacitance to ground than your > single large drop. It is the full knowledge about atmospheric electricity. > The original total capacitance of the separated drops depends on their > positions- with respect to each other and with respect to ground or > whatever is being used as a reference- this is something that you have > entirely ignored. They are details. >You are trying to compare a single large drop with 10 electrons to > a single small drop of 1 electron. and haven't even got the math right. > Meaningless! I was in a hurry. The 100V is for 1000 drops. But I do not know if the capacitance of drop is proportional to the surface or to the radius. In painting is assumed that to surface. But it is also detail. >. What becomes important in breakdown (, is not the total voltage to >ground but the high fields in the vicinity of this large charge. Field are math. > --------- > --------- [quoted text clipped - 4 lines] > lightning strokes originate in regions of positive charge. I'll stick > with what is known rather than what you say is not possible. Could you explain the term "regions of positive charge". There are the two possibilities: 1. On the drops (or ice) is deficit of electrons, 2. The voltage is lower than in adjacent region > --------- > ------------- [quoted text clipped - 11 lines] > take time to learn more about the subject before making patently incorrect > statements. I have had resently a glance at: http://www.springerlink.com/content/w54350750g275214/ It is obvious that many terms my be incorect understand by readers. The most important are: 1. Electrification 2. Negative/positive charging 3. Charge separation 4. Charge generation. Almost all references are in full agreement with my point of view. It is time to prepare definitions for the above terms ( "A review of electrostatics might also help") Could you start with your proposals? S* ---------------------------- >> So, the group of droplets has a greater capacitance to ground than your >> single large drop. [quoted text clipped - 14 lines] > capacitance of drop is proportional to the surface or to the radius. In > painting is assumed that to surface. But it is also detail. ------------- So with 1000 drops, we jump from 1000 1mm droplets with 1 electron charge to a 10mm drop with 1000 electrons and you are still wrong. Now consider the non trivial problem of the capacitance of a sphere to a ground plane. It seems that details are only of interest if they support your contention. When considering these details, your contentions are shown to be garbage, then they are unimportant. ------------- ------------ >>. What becomes important in breakdown (, is not the total voltage to >>ground but the high fields in the vicinity of this large charge. > > Field are math. ---------- Again you are wrong. A field is a region of influence-no more, no less. If you stand in front of a thermal source, you are influences - thermal field. If you step off a cliff, you may be terminally influenced by gravity. This influence is real, not a mathematical abstraction. Mathematics is the simply the most appropriate language for quantitative and qualitative description of a given reality. --------- >> --------- >> You say it is not possible but it has been found by measurements that [quoted text clipped - 8 lines] > 1. On the drops (or ice) is deficit of electrons, > 2. The voltage is lower than in adjacent region ---- 1. is valid .See below >> ------------- >> The references that I have given are physics and engineering references- [quoted text clipped - 24 lines] > electrostatics might also help") > Could you start with your proposals? ------- I only see the content listed and not the details so I can't comment in detail. However, it appears that it is quite in line with the references that I cited. Note that it does mention the various charging mechanisms which you have completely ignored. It is also interesting to note that you simply have ignored the positive side of negative/positive charging, changed your mind on charge separation and suddenly recognise charge generation. Are you changing your views to fit the references? Good because the views that you have presented here certainly are not valid. My proposal is that you read the available literature, including anything that you can get that is written by Umans and, as a precurser for this , start with a good text dealing with electrostatics. Take note of the actual recorded information and data that is available. This is all that I ask of you. It is a lot as some of the factors are not trivial. When you have done this - and actually know what you are talking about, come back. Bye Don Kelly dhky@shawcross.ca remove the X to answer > ------------- >>> [quoted text clipped - 10 lines] > appropriate language for quantitative and qualitative description of a > given reality. So we have the two kind of field. Electric field (math one) and the field of electric charge. Up to now we have many theories (Faraday, Ampere, Gauss, Weber, Maxwell, Lorentz, Jefimienko and so on). But we do not know the reality. We do not know how high is absolute Earth voltage and if in air is excess of electrons or lack Do you know it? > --------- >>> --------- [quoted text clipped - 4 lines] >>> lightning strokes originate in regions of positive charge. I'll stick >>> with what is known rather than what you say is not possible. As I have mentioned early now is a mess in terminology. My proposal is to use on clouds sketches colors instead of +/-. The same method as in mountains map. The higher the stronger color. Now we have only the two "colors" plus and minus. A huge storm cloud has many levels of voltage. Description with many colors would be easy to understand for all. > My proposal is that you read the available literature, including anything > that you can get that is written by Umans and, as a precurser for this , [quoted text clipped - 4 lines] > When you have done this - and actually know what you are talking about, > come back. Try understand the nuance of the terminology and next come back. It will be easy to you. Start from Clive Saunders statement: "Wordwide thunderstorm activity is responsible for maintaining a weak negative charge on the Earth's surface and a corresponding positive charge in the atmosphere." At a fair weather is current of about 2x10-12 amperes/meter2. Electron migrate up day after day. What is the result - excess or lack? You must find the ansfer what exactly means the term "positive charge" in very sophisticated references. S* >> ------------- >>>> [quoted text clipped - 13 lines] > So we have the two kind of field. Electric field (math one) and the field > of electric charge. ----------- No. Charges produce an influence. We name this region of influence as an electric field. It is not a mathematical concept. We can take measurements in a region and note that there are potential differences and equipotential surfaces - essentially map the field. We can also apply mathematics to produce models of the field but we don't confuse the model with the reality. ----------- > Up to now we have many theories (Faraday, Ampere, Gauss, Weber, Maxwell, > Lorentz, Jefimienko and so on). But we do not know the reality. We do not > know how high is absolute Earth voltage and if in air is excess of > electrons > or lack > Do you know it? --------- No- the absolute earth voltage is a chimera. The earth voltage is a potential difference between the earth and some reference point. We don't have an absolute reference point and if we take one such as a point at infinity, we still don't know the voltage. Do we need to know? No. Do we know that air has an excess of electrons? We don't. Hence any of your statements about air (or earth) having an excess of electrons or with respect to the voltage of earth with respect to some unknown reference are meaningless. Doe that change the reality of the earth-ionosphere relationships or earth- cloud relationships- where the earth is then taken as the reference. Do I know the potential of the earth with respect to the ionosphere- there are numbers tossed out but these numbers are based on other data and a lot of estimation. >> --------- >>>> --------- [quoted text clipped - 10 lines] > "colors" plus and minus. A huge storm cloud has many levels of voltage. > Description with many colors would be easy to understand for all. ------ And the levels of voltage must be referenced to something. For us, earth is a reasonable reference and the clouds can be + or - with respect to this reference. The colour scheme is nice and is often used now in displaying fields. In a mountain map, the use of contours of equal height are far more useful than colours- the equivalent is equipotential lines in the electric field. Both are visualisations. >> My proposal is that you read the available literature, including anything >> that you can get that is written by Umans and, as a precurser for this , [quoted text clipped - 14 lines] > You must find the ansfer what exactly means the term "positive charge" in > very sophisticated references. ---- I have no problem with either of the above information that I saw a long time ago. I do have a problem with your interpretations and extrapolations that defy the actual data. SignatureDon Kelly dhky@shawcross.ca remove the X to answer ---------------------------- "Don Kelly" >> Do you know it? > --------- > No- the absolute earth voltage is a chimera. The earth voltage is a > potential difference between the earth and some reference point. We don't > have an absolute reference point and if we take one such as a point at > infinity, You are victim of math. Zero voltage is on the body where no free electrons. The Earths is a body and a drop also. >> Try understand the nuance of the terminology and next come back. It will >> be easy to you. Start from Clive Saunders statement: [quoted text clipped - 9 lines] > time ago. I do have a problem with your interpretations and > extrapolations that defy the actual data. The fundamental data are always the same. Electrons migrate up and without activity of clouds all would be above your head (as the excess) in a short time. They come back in areas under clouds. The details are investigated by meteorologist. S* ---------------------------- > "Don Kelly" >> [quoted text clipped - 7 lines] > You are victim of math. Zero voltage is on the body where no free > electrons. The Earths is a body and a drop also. ------------ Bull: Use the world wide definition of voltage or potential difference. Voltage is always measured with respect to some other point. -------- >>> Try understand the nuance of the terminology and next come back. It will >>> be easy to you. Start from Clive Saunders statement: [quoted text clipped - 14 lines] > time. They come back in areas under clouds. The details are investigated > by meteorologist. Yes =and if you look at the "global circuit" it is a voltage source connected to the ionosphere through a low resistance and to earth through a high resistance along with high resistances between the ionosphere and earth. The earth is negative (on the whole) with respect to the ionosphere by about 500KV more or less but it is positive with respect to the lower part of the cloud. Basic circuits 101. The thunderstorm is the source and external energy is needed to cause the charge separation in this "source. Without this source, the global circuit doesn't exist. However, when considering what goes on in the storm cell- tthe local conditions in the thunderstorm as well as in the earth underneath it are what matters- not what current flows back to earth many km away. By the way, there are also positive ions involved, not just electrons. So far, all that I have heard from you is a distortion of some facts and the ignoring of other facts and the ability to weave and bobble around and change direction (and, it appears, definitions) at will. Anything you can't handle appears to be "details". The whole subject is, apparently, details. I would be happy to argue (win or lose -as it is a learning experience) with somebody competent and knowledgable . That is not the case here. I can't waste any more time on this thread, SignatureDon Kelly dhky@shawcross.ca remove the X to answer "Don Kelly" > ------------ > Bull: Use the world wide definition of voltage or potential difference. > Voltage is always measured with respect to some other point. We need absolute potential. A technical one. A neutral body is such. See Rowland effect: http://www.edumedia-sciences.com/a190_l2-rowland-s-disk.html > So far, all that I have heard from you is a distortion of some facts and > the ignoring of other facts and the ability to weave and bobble around and > change direction (and, it appears, definitions) at will. Anything you > can't handle appears to be "details". The whole subject is, apparently, > details. Phil wrote: "Another thing I have been wondering about is treating the Earth as a OPFHG." Many people try to analyse winds and ocean currents. But they often assume that the air is positivelly charged in electrostatic sense. They should know that on the surface of the Earth and in the air is an excess of electrons. The "details" are for meteorogists. > I would be happy to argue (win or lose -as it is a learning experience) > with somebody competent and knowledgable . That is not the case here. Yes. I am not a meteorologist. In textbooks on Electrostatics I have only on page about "Global circuit" and there is wrote that clouds are the "high voltage generators". Of course there is all about the Earth electric field > I can't waste any more time on this thread, My answer was to Phil. Your statement: "The problem is that the droplets are essentially neutral so the net charge is 0. In a storm, there are mechanisms that cause charge separation." makes that not easy to me to argue with you on "details". It will be possible if you understand that all suspensions in the air have en excess of electrons. S*. > "Don Kelly" > > Bull: Use the world wide definition of voltage or potential difference. > > Voltage is always measured with respect to some other point. > > We need absolute potential. A technical one. A neutral body is such. See > Rowland effect:http://www.edumedia-sciences.com/a190_l2-rowland-s-disk.html A neutral body still has a Debye span ("length"). ---------------------------- > "Don Kelly" >> ------------ [quoted text clipped - 4 lines] > Rowland effect: > http://www.edumedia-sciences.com/a190_l2-rowland-s-disk.html Is this the best reference that you can find ? Pathetic! As for Rowland's experiment "The compass is deflected and the faster the spin the greater the deflection. It appears that a magnetic field is not only set up by a current moving through a wire but by a moving electrostatic field as well. " It has nothing to do with the subject under consideration. "We need absolute potential. A technical one. A neutral body is such." consists of 3 meaningless statements for which the sum is even more meaningless. The term "absolute potential" is meaningless unless you have a specific reference point. If you consider a point charge then you can calculate the field that it produces in free space assuming that the reference or 0 point is at infinity and from this calculate the potential at any point in space due to that point charge and some may call it the absolute potential -that is the potential with respect to a point at infinity. You still have a reference point but you can't get at it. So for a number of point charges providing you know their location and magnitude, it is possible to find an "absolute" potential. however, in the real world we have a problem with taking a measurement with respect to a point at infinity so we have to deal with potential differences between points. --- Oh, what's the use- it is physics, not hand waving and you have trouble with that. ---------- >> So far, all that I have heard from you is a distortion of some facts and >> the ignoring of other facts and the ability to weave and bobble around [quoted text clipped - 18 lines] > "high voltage generators". Of course there is all about the Earth electric > field -------- You are also not a physicist or an engineer. The clouds themselves are not the generator- it is what goes on in the clouds that produces the conditions for charge separation just as, through different mechanisms, there is charge separation in a battery. Now when you consider the "global circuit" then globally, at any point in the circuit the total current in is 0. This includes the earth. The earth is negative with respect to the ionosphere or some other point (and positive with respect to some other reference)- but that doesn't mean that it has an excess of electrons. It is simply (particularly as your reference indicates it is slightly negative- with respect to the ionosphere or the ionosphere is slightly positive with respect to the earth- the usual way it is expressed) the location of earth in the total circuit. Unfortunately the global circuit is a concept that is not proven but is likely. It may well have very little to do with thunderstorms. http://books.google.ca/books?id=MNPPh7B3WTIC&pg=PA257&lpg=PA257&dq=global+circui t&source=web&ots=PwjIpaIjSx&sig=NLYClY6x_qwgEQ-KCYBOhBhkE4E&hl=en&sa=X&oi=book_r esult&resnum=7&ct=result#PPP1,M1 Is a water drop charged? Since, inherently it has as many H+ as OH- ions, it is neutral. Can it pick up or lose electrons- certainly. Put the drop in an electric field and it will be polarized without any change in the number of electrons or positive ions. Provide some means to extract or add electrons and it is no longer neutral. A cat and a glass rod are both neutral but stroke the cat with the rod and one will gain electrons from the other- no longer neutral. Of course, the stroking involves mechanical work as producing a potential difference involves work- just as work is done to separate charge in a storm. I have learned something, but not from you but in checking some references so I have gained. Bye and don't bother with a reply. SignatureDon Kelly dhky@shawcross.ca remove the X to answer "Don Kelly" > Is a water drop charged? Since, inherently it has as many H+ as OH- ions, > it is neutral. Can it pick up or lose electrons- certainly. Put the drop > in an electric field and it will be polarized without any change in the > number of electrons or positive ions. You forget about one more mechanism. The Earth is the charged body and as such attract neutral body. When neutral body tauch the charged body it gains electrons and is repelled. Water also gains electrons - dry air not. In the result all bodies in the air have an excess of electrons. >Provide some means to extract or add electrons and it is no longer neutral. A cat and a glass rod are both > neutral but stroke the cat with the rod and one will gain electrons from > the other- no longer neutral. > Of course, the stroking involves mechanical work as producing a potential > difference involves work- just as work is done to separate charge in a > storm. A cat and a glass are at the same end of the triboelectric series (positive). So the charge separation means also more and less (not +/- only). The same is in a storm. It is a problem of terminology. Maybe that "fluctuations" and/or distribution would be better than separation. > I have learned something, but not from you but in checking some references > so I have gained. Me too.You have admitted that the Kelvin's generator needs a initial charge. The fact that the wet air gains electricity was discovered by Coulomb. The both are still in power. So your problem is the terminology. Please take into account that the terminology is from times where were the two electric fluids. Now is time of electrons and all must be "translated" correctly. > Bye and don't bother with a reply. Here is more readers (I hope). S* Certainly every material has free or valence electrons. That doesn't make them negative. I know what you are saying and I disagree with your terminology. As for the Kelvin generator- I didn't realise that I was admitting anything. I simply said that it is the externally applied field (which can be due to stray ions ) which causes the ionization of the water- take this away and there will be no more charging. In order to keep this going, it is necessary to have positive feedback and this device has that - it wouldn't work if you had more or less negative ions only. It is an ingeneous device. A few details: - absolute potential is a mathematical concept and, in itself , is meaningless and cannot be measured. I have looked through some references and dredged my memory and if I had heard the term it would have been about 1950. Modern texts don't use the term, although they do give an expression for it, without naming it, based on the field due to point charges (also mathematically expressed). It is useful for the evaluation of a potential difference in simple configurations where you can consider a collection of known charges at known positions and want to find the potential difference between two points in that space. In other words it can be used to find something meaningful but, in itself, is meaningless as it is the potential with respect to a point at infinity which is literally out of this universe- a non-physical idealism. -I note that an H+ion has no free electrons. Other positive ions exist which can have no free electrons. Are they still negative? or neutral? -In gasses, positive ions can be charge carriers. Their behavour in such factors as breakdown and corona differ from the behaviour of electrons. This is not going back to some long obsolete "two fluid" approach. -charge separation is not just a fluctuation and the distribution is such that, with respect to a neutral reference some areas are positive and some are negative. That is the terminology used and you simply are using your own terminology which doesn't help. -With regard to this- fire a positive ion through a magnetic field and its turns in the opposite direction to that which a negative particle turns (observed). If it were simply "less negative" this wouldn't be the case. There are other problems with your contention such as the direction of force between two charges. (again the observed behavior is not consistent with the "all negative" concept.). So, while I know enough to know limits on my knowledge, it appears that you haven't reached that stage as yet. My previous advice still holds. Bye, have a good day Don Kelly dhky@shawcross.ca remove the X to answer ---------------------------- > "Don Kelly" >> [quoted text clipped - 36 lines] > Here is more readers (I hope). > S* "Don Kelly" > As for the Kelvin generator- I didn't realise that I was admitting > anything. I simply said that it is the externally applied field (which can > be due to stray ions ) which causes the ionization of the water- take this > away and there will be no more charging. In order to keep this going, it > is necessary to have positive feedback and this device has that In our schools is a version without the feedback. Droplets falls down to a ONE container and the voltage rises. You can use a ionometer above a pan with water and observe the readings with and without conection to earth. Coulomb discovered that air gains electricity from a charged body. The Earth is the charged body. - it wouldn't work if you > had more or less negative ions only. It is an ingeneous device. > > A few details: > - absolute potential is a mathematical concept and, in itself , is > meaningless and cannot be measured. Exist patent descriptions. So many people do not know that it cannot be measured. > I have looked through some references and dredged my memory and if I had > heard the term it would have been about 1950. Modern texts don't use the [quoted text clipped - 7 lines] > respect to a point at infinity which is literally out of this universe- a > non-physical idealism. I am interested in the technical reality. Now is is the technical zero. The absolute zero is when, for example, no Rowland effect. > -I note that an H+ion has no free electrons. Other positive ions exist > which can have no free electrons. Are they still negative? or neutral? [quoted text clipped - 11 lines] > of force between two charges. (again the observed behavior is not > consistent with the "all negative" concept.). You are writing about ions and charges. I see only charged bodies. > So, while I know enough to know limits on my knowledge, it appears that > you haven't reached that stage as yet. My previous advice still holds. You go into details. XIX century knowledge is enough for atmospheric electricity. Kelvins generator (verion with one container) and the Coulomb discovery that air gains electricity. Do you neglected them? S* > "Don Kelly" >> [quoted text clipped - 6 lines] > In our schools is a version without the feedback. Droplets falls down to a > ONE container and the voltage rises. ----------- Yes and there is a one container version which you can find on the net. However, it simply puts the positive and negative sides in series mechanically and still has the feedback. Otherwise it would be necessary to have some external charging source continually present. However, I would like to see the device that you indicate because I wan't to see the details of its construction and how it works- not just a statement that your school had one. Did you bother with these details or simply ignore them? By the way I have one book that does mention the term "absolute potential" in part of a sentence leading up to the expression for voltage with respect to a reference at infinity - it simply notes the name and goes on to further development. I rewrote much of the remainder of this particular text but not the introductory chapters. > You can use a ionometer above a pan with water and observe the readings > with and without conection to earth. > Coulomb discovered that air gains electricity from a charged body. The > Earth is the charged body. ------ Is it now? - and how do you know? References? Does it matter when it comes to lightning storms?- not really- because the earth is not charging the cloud centres- it takes work to do that. > - it wouldn't work if you >> had more or less negative ions only. It is an ingeneous device. [quoted text clipped - 5 lines] > Exist patent descriptions. So many people do not know that it cannot be > measured. ---- Sure and I have seen a patent for a perpetual motion (pardon me -overunity)--SO?? --------------- > I am interested in the technical reality. Now is is the technical zero. > The absolute zero is when, for example, no Rowland effect. ---------- No sense in that statement. ---- >> -I note that an H+ion has no free electrons. Other positive ions exist >> which can have no free electrons. Are they still negative? or neutral? [quoted text clipped - 13 lines] > > You are writing about ions and charges. I see only charged bodies. -- So take a larger charged "body" than an ion and do the same thing. >> So, while I know enough to know limits on my knowledge, it appears that >> you haven't reached that stage as yet. My previous advice still holds. > > You go into details. XIX century knowledge is enough for atmospheric > electricity. ---- Then why are we still spending a great deal of effort in trying to understand atmospheric electricity? -maybe it is because so far, we still don't have the required knowledge. Yes- we do need to know the details rather than hand wave and refer to XIX century knowledge. We also need to come up with models that reflect known facts and observations. I have said this repeatedly and you have repeatedly ignored these facts. Why? Bye SignatureDon Kelly dhky@shawcross.ca remove the X to answer ---------------------------- "Don Kelly" >> Earth is the charged body. > ------ > Is it now? - and how do you know? References? In each references is: ""Wordwide thunderstorm activity is responsible for maintaining a weak negative charge on the Earth's surface and a corresponding positive charge in the atmosphere." We are discussing about the "positive charge in the atmosphere." Do you neglect "a weak negative charge on the Earth's surface". > ---- > Then why are we still spending a great deal of effort in trying to [quoted text clipped - 3 lines] > come up with models that reflect known facts and observations. I have said > this repeatedly and you have repeatedly ignored these facts. Why? Here is sci.physics.electromag. Here is enough: "Wordwide thunderstorm activity is responsible for maintaining a weak negative charge on the Earth's surface and a corresponding positive charge in the atmosphere." That sentence is from meteorologist area. My intention is to inform physicists that the "positive charge in the atmosphere" in the above sentence means that electrons migrate up at fair weather and in the result in the air is an excess of electrons. It is important at determining the force direction for winds in the Earh magnetic field. S* ---------------------------- > "Don Kelly" >> [quoted text clipped - 28 lines] > magnetic field. > S* --------------- I do know that the ionosphere is + with respect to the earth and there is a relatively weak field. Now if it is due to thunderstorms as thought, then there is a net 0 change of charge between the earth and ionosphere -for every electron going up there is one coming down- i.e. a current. So, what goes on is dependent on where you are. As for the "force direction of winds" there are other factors which are far larger- hurricanes aren't produced or initiated by Lorentz forces on electrons in the earth's field. Hot air rises, coriolis forces exist and the combination has a lot more to do with winds than Lorentz forces on electrons in the earth's field. I also know that there is information that indicates that perhaps the driving cause of the ionosphere- earth charge separation may only be partly due to thunderstorms. We still don't know enough. It's been interesting, but you haven't been convincing- for reasons that I have given (i.e details and facts that differ from your position). It may be a problem of language but it does seem to go beyond that. A little bit of poor math doesn't help. SignatureDon Kelly dhky@shawcross.ca remove the X to answer "Don Kelly" < > As for the "force direction of winds" there are other factors which are > far larger- hurricanes aren't produced or initiated by Lorentz forces on > electrons in the earth's field. Hot air rises, coriolis forces exist and > the combination has a lot more to do with winds than Lorentz forces on > electrons in the earth's field. Let assume that somebody wants to calculate the Lorentz forces for winds ( to be sure that they may be neglected). Such must know the sign of a charge. What he should do. An excess of electrons, deficit or zero? S* ---------------------------- >> It's a bit more than this simplistic and superficial approach. >> To get a high voltage between two points, it is NECESSARY that there is a [quoted text clipped - 3 lines] > drops. Between the cloud and the Earth is some voltage. If the drops join > together the voltagr rise. -------- Voltage between what and what? You are hand waving. Certainly there will be a larger electric field in the vicinity of the larger charge. However the field at some distance from this charge may be lower than in the original situation and the total voltage to ground may be larger, smaller or unchanged, depending on the geometry of the situation. The charge separation between two points is the cause of the voltage between the two points. There are lots of ways to get charge separation and a resultant potential difference. --------------- >>This separation of charge > > In contemporary science the separation of charge is used in place of > build/lowering of voltage. Current flow from high voltage to lower. Not > from more charge to less. ------------ And the reason that one point is at a higher voltage is that there has been a charge separation. Look up the definition of potential difference (or voltage between two points). Last time I looked, voltage was defined as the work per unit charge to move it from one point to another. Put a path between the two points and there is a redistribution of charge ------------- - >> is the cause of the voltage difference- look at the definition of >> potential difference. Updrafts, wide temperature ranges, and charge [quoted text clipped - 5 lines] > Are you talking about voltage? > All parts of clouds have excess of electrons. ------ This was proven wrong well over 50 years ago. Where have you been. There can be and are regions of positive charge. > >The >> electric fields are related to these charges and lightning, between >> earth or cloud to cloud consists of high field breakdown (in steps) >> providing an ionized path for a rebalance of charge > > Charge or voltage? --------- Electric fields- volts/meter are due to charge distributions. These fields (and their integrals- voltages between points) are due to charges. Charges aren't due to voltages. >> As for heat stored in a storm cloud- note that the temperature of the >> known charge storage regions of thunderheads is generally in the -30 [quoted text clipped - 5 lines] > > During condensation of steam the heat is expeled. ------- And where is the steam in a thunderstorm? Not the clouds. >> >> Do we know the actual mechanisms involved? To some extent we do but we >> certainly cannot say "this is what happens" rather than "this may be the [quoted text clipped - 5 lines] > Meteorology is a new science. Physics is older. Lightnings folows the > physics laws. Meteorologist should read physics. ----------------- And so should you and you might then stop putting the cart before the horse. The literature that I refer to is related to the physics involved, known data, and practical engineering. It is not meteorology. Quote: "During thunderstorms a charge separation takes place in a cloud by a process which is the subject of several theories but is still not fully understood....Usually positive charges drift to the upper layer of a cloud and the bulk of the cloud becomes negatively charged" [Gallagher & Pearman "High Voltage, Measurement, Testing and Design" Wiley 1983. ] Included is a sketch based on actual measured charge distributions in a cloud- and also shown in the sketch is a small region near the base of the cloud that is also often positively charged. This particular book is a bit dated but there are references dated later than 2000 in the Wikipedia article on lightning (which is fairly good). The article indicates that only about 5% of strokes are due to positive cloud charges but these are generally much higher currents than average. However, data based on actual measurements of over 4000 strokes in Alberta, Canada indicate about 25% are positive, corresponding with Swedish data. Worldwide, Wiki is correct. You may be interested in a newer book (2007) Rakov & Uman (Dept. of Electrical and Computer Engineering, University of Florida) "Lightning, Physics and Efffects" Martin Uman is considered a leading, if not the foremost, authority on lightning. Also a very abbreviated non-technical summary of lightning indicated in the following http://thunder.msfc.nasa.gov/primer/primer2.html. This doesn't deal with the "positive" top of cloud to ground strokes of more northerly latitudes. There's lots of information out there if you care to look. -- Don Kelly dhky@shawcross.ca remove the X to answer > S* Quote: > "During thunderstorms a charge separation takes place in a cloud by a > process which is the subject of several theories but is still not fully > understood....Usually positive charges drift to the upper layer of a cloud > and the bulk of the cloud becomes negatively charged" What means "positive charges"? > Also a very abbreviated non-technical summary of lightning indicated in > the following http://thunder.msfc.nasa.gov/primer/primer2.html. Look than in page 3: http://thunder.msfc.nasa.gov/primer/primer3.html There is the sketch in "The global electric circuit" You can see that at fair weather electrons migrate up (small arrows represets currents - electrons move in opposite direction). They are atached to H2O. The voltage is low because the aggregates of H2O molecules are small. After condensation the voltage arises and the slectrons are send to places where the voltage is lower. The sentence: "Present measurements indicate that an average of almost 1 ampere of current flows into the stratosphere during the active phase of a typical thunderstorm" cannot be true. Storm cloud send electrons in all directions.e Global Electric Circuit > the "positive" top of cloud to ground strokes Positive strokes are inter-clouds where the Earth is the intermediary. I am not interesting in details. "The global electric circuit" is enough for me. S* ---------------------------- > Quote: >> "During thunderstorms a charge separation takes place in a cloud by a [quoted text clipped - 16 lines] > After condensation the voltage arises and the slectrons are send to places > where the voltage is lower. -------- There is nothing in this simple diagram or the text that gives the conclusions about the voltages, condensation etc. ----------------------- > The sentence: "Present measurements indicate that an average of almost 1 > ampere of current flows into the stratosphere during the active phase of a > typical thunderstorm" cannot be true. Storm cloud send electrons in all > directions.e Global Electric Circuit. ---------- Again, the facts are there and if your conceptions ignore the facts, then it is quite possible that you are wrong. --------------- >> the "positive" top of cloud to ground strokes > > Positive strokes are inter-clouds where the Earth is the intermediary. ---------- Horsefeathers! However you are now admitting that positive strokes exist. ------------ > I am not interesting in details. "The global electric circuit" is enough > for me. ---------- You claim a flaw in the global circuit model but then it is good enough for you. In other words, you are happier being ignorant. Why? SignatureDon Kelly dhky@shawcross.ca remove the X to answer "Don Kelly" < > ---------- > Horsefeathers! > However you are now admitting that positive strokes exist. No.It is negative stroke cloud-ground-next cloud. Japanese dicoverd it. > ------------ >> [quoted text clipped - 3 lines] > You claim a flaw in the global circuit model but then it is good enough > for you. In other words, you are happier being ignorant. Why? I am not an meteorologist. For me is enough to know: 1. Earth has excess of electrons 2. Electrons migrate up with H2O at fair weather (wet air "destroy" the charge of a charged body - dry not) 3. Voltage is raising when drops rise (Armstrong and Kelvin made such high voltage generators in XIX century) 4. Electrons come back to Earth when a cloud disappear Meteorologist must know more to be able make forecast. S* | I am not an meteorologist. For me is enough to know: | 1. Earth has excess of electrons [quoted text clipped - 3 lines] | voltage generators in XIX century) | 4. Electrons come back to Earth when a cloud disappear That's a new one. I hadn't heard that one before. I'll have to add it to my list of other ones. If the Earth has an excess of electrons and some of them move away to some distance, what is it that causes a voltage difference to appear? FYI, I've been in a location with a clear sky that had more "charge" than other areas. After noticing my 2m ham antenna on the car was giving me 1/4 inch arcs to the frame of the car, I decided it was best to leave the area. The sky was clear. By the time I was 4 miles away, the spot I was at had big cloud starting to billow up from it. So why that one spot and not another spot in the same clear sky? |WARNING: Due to extreme spam, googlegroups.com is blocked. Due to ignorance | | by the abuse department, bellsouth.net is blocked. If you post to | | Usenet from these places, find another Usenet provider ASAP. | | Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) | > On Fri, 18 Jul 2008 10:40:32 +0200 "Szczepan Bia?ek" <sz.bialek@wp.pl> > wrote: [quoted text clipped - 13 lines] > If the Earth has an excess of electrons and some of them move away to some > distance, what is it that causes a voltage difference to appear? Electrons migrate very high. Storm clouds are to 18 km high. But electron migrate higher. In sunny day the electrons are emitted intensely by thermo- and photo- emission. In such time H2O aggregates contain more electrons (than in night) and migrate higher. We do not know how high is absolute Earth voltage but in clear air is lower. > FYI, I've been in a location with a clear sky that had more "charge" than > other areas. After noticing my 2m ham antenna on the car was giving me > 1/4 inch arcs to the frame of the car, I decided it was best to leave the > area. The sky was clear. By the time I was 4 miles away, the spot I was > at had big cloud starting to billow up from it. In sticky air is plenty of electrons but the voltage is relatively low. So you have only 1/4 inch SPARKS (In sparks electrons oscillate - in arc no). After condensation the voltage rises. > So why that one spot and not another spot in the same clear sky? Thats are details. Your topic is about the Faraday paradox. At analysing such phenomenon you must take into account that on all elements and in the air is an excess of electrons. S* ---------------------------- > "Don Kelly" < & |
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