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Sha31
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Would Magnetic Monopoles Violate Conservation of Energy?
Sha31 replied to Mr Skeptic's topic in Physics
Ok. You say ball lost energy that it previously gained from being carried up. So' date=' isn't that just the same as when you start with two permanent magnets that are already stuck together and you have to do some work and invest energy to move them apart? Consider this. Piece of asteroid, or something, is on it way towards Earth and its velocity vector points 1,000km north above. However, as it closes by it gets attracted and its trajectory curves, so it ends up colliding with the planet. Where does this energy come from? I didn't say that, did I? Those were my questions. My only statement was that two questions, about gravity and magnetic dipole forces, are the same as for magnetic monopole, or maybe even any other force. Anyway, I think current theory explains this situation so that magnets, as they move closer together, gain kinetic energy and lose potential energy, hence energy gets conserved, similar to what you said about bowling ball and gravity. This can be understood as that energy comes from the differences in field potentials. Merged post follows: Consecutive posts merged Ignorance will not help you to learn. Since you can not articulate your argument you should at least let other people think for themselves. I told you facts. What part do you not believe? Do you want some more reference or more explanations? What part do you not understand? -
Would Magnetic Monopoles Violate Conservation of Energy?
Sha31 replied to Mr Skeptic's topic in Physics
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Would Magnetic Monopoles Violate Conservation of Energy?
Sha31 replied to Mr Skeptic's topic in Physics
Magnetic monopoles would not be some new particles, but just like magnetic dipoles they would be an effect of motion of electric charges, also known as electron and positron. Charge spin produces magnetic dipole moment, but those two poles are not two new "magnetic particles", just two additional fields, and only one particle, one charge, is "producing" all these fields. There is another kind of motion next to spin, that is spatial displacement, be it along a straight line or circular, it again produces magnetic field. However, as it happens, different kinds of motion produce different kinds of magnetic fields. You say this magnetic field of moving charge has no poles, I say it has one pole, the place where the field is strongest, the charge itself, again. Whatever the case, if magnetic monopoles exist they would not be some new type of particles, because magnetic fields are just an effect of motion of electric charges. Particles to look at for magnetic fields are always electron and positron. -
Where did you get that definition from? - Pole is the place where the field magnitude is strongest. This is the definition used in all the equations. Is there something wrong with this definition' date=' can we agree? The field magnitude is determined by force, and the direction of the force can be different to the direction of the field. How many places does magnetic field of moving charge have where this magnetic force is strongest? Filed lines or topology has nothing to do with number of poles or what pole actually is. Consider a solid box with cone shape cut out on the top pointing down the bottom. It's a kind of sink and its topological lines would be in the direction of attraction. But, consider this box is liquid or gas and instead of rigid sink you have a whirlpool or tornado. Topology of this "field" would show concentric circular direction, but the force would still act directly inwards, right? -- So, we obviously need to distinguish between field lines and force lines. Force lines always point towards a pole, but filed lines do not need to. Do you agree? [mp']Consecutive posts merged[/mp] What kind of reference is that? No one sane, in the whole world, will ever agree with you, nor has anyone ever said anything like that, anywhere, ever. So, you should really try to find some reference as to finally wake up from your hallucination. But, you do agree "pole" is defined with the point where field is strongest, then why is not this moving charge a 'pole' since that's where its magnetic field is strongest? Vectors need initial position, direction and magnitude. How else do you imagine we can use Biot-Savart law without knowing where the fields are? How do you calculate distance and magnitude of magnetic field of moving charge? Where from does magnitude in "your equations" start to drop off? It looks like a duck, walks like a duck, quacks like a duck... and you call it owl.
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Ok' date=' maybe I got it wrong, but that's why you're here, so please tell us: - Does magnetic field of a current carrying wire attract or repel north pole or south pole of a permanent magnet, both or neither? But force is perpendicular to that field so the force vector actually does point toward the charge, hence two parallel current carrying wires attract. REFERENCE: http://en.wikipedia.org/wiki/Lorentz_force http://en.wikipedia.org/wiki/Amp%C3%A8re%27s_force_law http://en.wikipedia.org/wiki/Z-pinch "The Z-pinch is an application of the Lorentz force, in which a current-carrying conductor in a magnetic field experiences a force. One example of the Lorentz force is that, if two parallel wires are carrying current in the same direction, the wires will be pulled toward each other. The Z-pinch uses this effect: the entire plasma can be thought of as many current-carrying wires, all carrying current in the same direction, and they are all pulled toward each other by the Lorentz force, thus the plasma contracts." No, that's maybe valid for electric monopoles, but that is not the definition of what "pole" is. Can you provide some reference to support what you said? Pole is defined as the origin of some field, the point where the field is strongest and from where it's magnitude drops with 1/r^2 if it is monopole. Field lines are not part of the definition of what 'pole' is, they only describe topology or direction of the field. Can you provide some reference to support the claim how magnetic, or any other fields, can exist without poles? By the way, fields "need" poles as to define where the field magnitude is strongest and where from the magnitude will drop off, so to put some coordinates into those equations and calculate vectors and trajectories. How exactly do you calculate distance vector "r" in Biot-Savart law and Lorentz force equations, how do you model forces in coordinate system if you don't know where are, and how many, magnetic poles you have? Without poles (field origins) those equations would simply not work, but they do work exactly as equations for monopoles should.
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Thank you. Merged post follows: Consecutive posts merged I define pole as the strongest point of a field. I found magnetic strength diverges toward only one point, where polarity is dependent of the electron velocity vector i.e. current direction. Therefore, I concluded magnetic field of a moving charge(s) is monopole. My turn. a.) Magnetic filed of a single moving charge drops off as 1/r^2, yes? b.) How do you define filed 'pole'? c.) How do you explain magnetic field of moving charge has "no poles"? d.) Can you provide some reference for the claims you're going to make?
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Show me your calculus or reference, you're imagining things. I'm talking about MONOPOLE, single charge, not infinite wire, ok? Magnetic filed of a single moving charge drops off as 1/r^2. YES/NO?
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Ok, I used car battery this time and I confirmed only one pole. Now, can you do it yourself and tell us: - does magnetic field of a current carrying wire attract or repel north pole or south pole of a permanent magnet, both or neither? Can you support your claim about "magnetic NO POLE"? How do you define 'pole'?
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You got it wrong then. Biot–Savart law http://en.wikipedia.org/wiki/Biot-savart The Biot–Savart law is used to compute the magnetic field generated by a steady current, i.e. a continual flow of charges, for example through a wire, which is constant in time and in which charge is neither building up nor depleting at any point. The equation is as follows: If the current has some thickness, the proper formulation of the Biot–Savart law (again in SI units) is: In the special case of a constant, uniform current I, the magnetic field B is: These equations are called the "Biot–Savart law for a point charge":
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It has no poles. Hmm? Magnetic nopole?! Is that from some text-book' date=' or just your 'gut feeling', perhaps experimental observation? Let me show you something... http://my.execpc.com/~rhoadley/field01.htm TWO WIRES This shows the field around two wires, side by side, that are carrying current in opposite directions. DISK MAGNET This shows the field lines around a disk magnet where the North pole is at the top. This shows the magnetic field strength around the disk magnet. It is strongest in the corners, not in the center of the poles!
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You're right about assumptions, I agree, but it turns out it's all very similar whether you have two free electrons or bunch electrons together with protons and neutrons in some wire. You can model either case with the difference that free electrons experience more electrostatic repulsion, while when modeling wire protons would mostly neutralize this electric repulsion, but then you would have extra mass from these protons and neutrons. In any case Lorentz force equation would give you correct prediction of trajectories for free charges, electron beams, electrons inside a wire and even plasma. Merged post follows: Consecutive posts merged Do you not see two set of circles? What are you doing? Are you blind' date=' hypnotized... what? Depends, of course, how you define a pole. Can you tell me where is the south and north pole fields strongest? Can you locate these two points and let me know where they are, approximately? That's where poles should be. Let's see' date=' magnetic moment of a moving charge... a.) has only one pole b.) magnitude of the field drops with the distance by 1/r^2 c.) direction of the force is directed towards this one pole Yet, you say it's a... what? What do you say? Is it a dipole or what? Right now I have only a DC transformer giving 5V, 4.5A and small permanent magnet, but I can not make wire move. You say it's easy, so tell us please: - Does magnetic field of a current carrying wire attract or repel north pole or south pole of a magnet, both or neither?
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Where did you get that from? What equation is that? If you take equation for point charges, either for magnetic or electric potential, you will see it drops with 1/r^2, so forget the wire for whatever efect that might have on compound field strength, consider just one electron, i.e. just one electric and one magnetic field. Merged post follows: Consecutive posts merged No. This magnetic force is perpendicular to magnetic field. It actually acts directly toward the monopole origin i.e. electron. http://en.wikipedia.org/wiki/Lorentz_force Can we finally agree and can I get some prize for this discovery now?
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Very close to where the field magnitude is the strongest, of course. What did you think? This works for gravity monopoles, electric monopole, for magnetic dipoles, and is therefore the definition of how to find a pole... then you can count them.
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That is electric polarity, indicating direction of electrons in the wire. You see how magnetic dipole looks like, right? So, where is the second MAGNETIC pole in that other picture? Merged post follows: Consecutive posts merged What are you talking about? It is the same thing with dipole lines, even if you consider the field lines of only one pole you will get DIRECTION at any point i.e. magnetic field line entering and leaving each point. Why are you surprised magnetic monopoles would behave exactly as on of the magnetic dipole poles? Why does that magnetic field looks like only half of dipole, why does it not look like normal dipole? How do you know dipole field lines do not circle around these two poles? Why do you think magnetic dipole field lines go through the poles exactly? Merged post follows: Consecutive posts merged Where did you get that? It drops of as 1/r^2. http://en.wikipedia.org/wiki/Biot-savart Just like Newton's gravity and Coulomb's law. This should finally confirm how magnetic moment of a moving charge is actually monopole.
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Yes' date=' that's what you still think even if I keep showing you one, like this: [img']http://upload.wikimedia.org/wikipedia/commons/thumb/9/91/Electromagnetism.svg/180px-Electromagnetism.svg.png[/img] I would define monopole normally' date=' like they are defined: a.) monopole has only one pole, only one center of origin b.) strength of monopole decreases with distance by inverse-square law c.) finally, to avoid confusion, strength of dipole decreases with distance by inverse-cube law Simply said, monopole is what you get when you split dipole in half, like this: [img']http://upload.wikimedia.org/wikipedia/commons/thumb/3/3f/Magnetic_ring_dipole_field_lines.svg/180px-Magnetic_ring_dipole_field_lines.svg.png[/img]
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For some reason, all of you expect field-lines of magnetic monopole to be like the field-lines of electric monopole, even though it's very well known, from what we do certainly know, how these fields differ and produce very different field-lines. -- All you have to do is take a battery, wire and some magnet, then pass the current and move magnet around, see how many poles can you find.
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What field lines? Magnetic' date=' electric, dipole, monopole? [img']http://upload.wikimedia.org/wikipedia/commons/thumb/9/91/Electromagnetism.svg/180px-Electromagnetism.svg.png[/img] What are you trying to say and how does that tell you this is not a monopole? How do you imagine magnetic monopole looks like when you are so sure this magnetic moment of a moving charge, as shown above, is not one? How does that tell you that's not a monopole? According to whom? Why are you talking about field lines when all we have to do is count the poles? Field lines are just 2D topological visualization of 3D fields. Magnetic fields are obviously different to electric fields, so they have different topology, which has nothing to do with the number of poles. Why do you expect magnetic monopole should look like electric monopole?
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According to whom? Can you show some reference?
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"No monopoles."? What in the world? Is it a dipole then? Please count how many poles do you see on that image above?
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Why are you talking about "field lines"? What does that have to do with the number of poles? Field lines are only 2D topological representation of 3D fields' date=' it is only a two-dimensional plane intersection of field magnitude-gradient aka "slope". This is more like horizontally equidistant contour lines describing elevation gradient on topographic maps, where the direction of the slope and magnitude has to do with the spacing of the lines, not the direction. [img']http://upload.wikimedia.org/wikipedia/commons/thumb/d/d1/Courbe_niveau.svg/180px-Courbe_niveau.svg.png[/img]
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None?! ...infinite??!! Both of those answers are awful, especially since you actually gave two oppositely contradicting answers... that's just terrible. Nonsense. To distinguish between monopole and dipole you only have to know how to count up to two. Monopole fields have one pole' date=' dipole fields have two. How did you come up with that? Where did you get an idea to dismiss experimental facts with your imaginary assumptions? "Monopole" means "one pole", "dipole" means "two poles", ok?
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No. What is shown there is a magnetic field (potential) of a single electron (moving charge) in a single point in time. Therefore, monopole electric charge is in the same time monopole magnetic charge. The field of a single charge does look like that. How do you think it looks like? Can you provide some image, some reference? How many poles do you see there, one or two? Real wires do not need to have circular circuit, all you need is lack of electrons on one end, be it circular or straight line that has nothing to do with this. For simplicity you can imagine electron beam - no circuit, just the beam and magnetic field still has only one pole, which you ought to call "monopole", yes? Merged post follows: Consecutive posts merged That's right. And yes Wikipedia also says: "there is no direct evidence of magnetic monopoles in nature." But now, I'm asking _you, to tell me, based on your reason, logic and deduction - how many poles does magnetic field of a moving charge have, one or two? Is then magnetic field of a moving charge monopole or dipole, why?
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http://en.wikipedia.org/wiki/Magnetic_charge - "monopole detection is an open problem in experimental physics" - "magnetic monopole particle has never been conclusively observed" - "has never been evidence for the existence of magnetic monopoles" How come magnetic monopoles supposedly do not exist, and why would it be hard to find evidence and conclusively observe magnetic monopole fields if all we need is a battery, wire, permanent magnet and know about Ampere's law? http://en.wikipedia.org/wiki/Ampere%27s_law So, obviously magnetic field of a moving charge has only one pole, right? Magnetic dipoles look like this: http://en.wikipedia.org/wiki/Magnetic_dipole