why does the magnetic field lines move only from south to north and not from north to south?
827354
The magnetic field of Earth is caused by molten iron rotating around in the core.  The lines of magnetic flux follow the right-hand rule (RHR).  Curve the fingers of your right hand into a loose fist and extend your thumb upward.\n\nAs the molten iron swirls around in the direction of your curled fingers, the flux is emitted in the direction of your extended thumb.  The flux is created because the swirling molten iron creates an electrical current that follows the swirl.  That current, like a current going through a coil, creates the magnetic flux.\n\nA flux is simply a line of force and that force, like all forces, has direction.  In this case, the force points outward in the direction of your thumb.  That's called the magnetic north pole, by convention.  \n\nHowever, because the magnetic flux exits the Earth at this pole it really is the south pole.  This can be verified because the north pole of a compass needle will point north and, as you well know, north is attracted to south.  Thus, the magnetic north pole is really the south pole...argh...physics is so complicated.\n\nAs to why like poles repel and dissimilar poles attract, blame in on the direction of the forces...the flux of that magnetic current.  (Magnetism does not really flow, but the forces act as though it does.)  Two similar poles either push each other away (e.g., two south poles) or pull away from each other (e.g., two north poles) because the forces are toward or away from the two magnets respectively.  Two dissimilar poles attract each other because the alligned forces pull one toward the other when they are all in the same direction.  [See source.]
523133
Earth's magnetic field, among other things.
778516
as far as i know of, yes.\n\nthink, the man made magnets create their own magnetic field and have always been exposed to the earths magnetic field. Reguardless of the man made one's position, they still emit the same pull towards each other based on their own magnetic fields. Just like magnets work in outer space, they should work at the north and south poles. (also, the man made magnets pull isn't effected when you connect multiple ones together so off of this example, they should work at the north and south poles also.)
126028
Currently, the earth's north magnetic pole moves about 40 kilometers per year.  The rate has varied considerably; it was only 10 km per year a century ago.
944389
I researched this as a geology student 20 years ago and has interested me since then.  By researching cores of basalt, they have a pretty good idea what the magnetic field does when it starts to shift but it is somewhat random and slow.  I remember that typically, before the switch in polarization, the poles starts to migrate in a spiral as it is doing now.  It has been an extra long time since the last switch so it is due.  I suspect that it is about to switch (within the next thousand years or so) but no one can say for certain in my opinion.  Apparently there is a period of time (100 years or so) when the field is next to zero in strength.  I saw a show on it recently that demonstrated they have learned a lot since I studied it in school.
566155
it's to do with the magnetic field of the water and or the geology. I did gold exploration for several years and on weekends we'd help the local farmers source underground water. And we used both a magnetometer to chec k for magnetic anonamalies amd then walked exactly the same path with a diving rod, a piece of fence wire and the rod would move at exactly the same places we found magnetic kicks with the magnetometer.
30487
Well even though humans have known about magnets for thousands of years, the real reason they work is still somewhat mysterious. Depending on how deep you want to investigate, it can be a very complicated phenomenon. \n\nA magnet is, at its foundation, caused by the movement of electrical charge (yes this is the Biot-Savart Law). When charges (like electrons for example) move, they produce magnetic fields. If a charge moves in a loop, it creates a magnetic field. The magnetic field can be basically represented by an invisible set of arrows in space, that point in a direction. In the case of the loop, the arrows of the magnetic field will point out of the loop for a positive charge moving counter clockwise (this is the so-called "right hand rule"), and into the loop for a charge moving clockwise (some pictures are in the reference attached). \n\nThe magnetic field has a "north" end and a "south end". The little arrows from our moving charge are pointing in the "north" magnetic direction, and away from the "south" magnetic direction. It is a mysterious and interesting property of electromagnetism that two objects with fields that oppose each other, i.e., the little arrows of the field do not line up, so either the north end of one field is facing the north end of the other field, or the two south ends are facing each other, repel, or resist movement of the two objects towards each other with some force. \n\nOn the other hand, if the little arrows line up, the two objects attract each other with some force. \n\nThe little arrows are aligned along the so-called "magnetic lines of force". \n\nThe forces that result from magnetic fields (and for that matter, electric fields) are fundamental forces, and part of the four fundamental forces of the universe (strong, weak, electromagnetic and gravity). It is believed that these forces are caused, at their base, by particles passing "messenger particles" back and forth. In the case of electromagnetism, the messenger particle is a photon. How this actually works is still somewhat poorly understood, and is involved with the world of quantum mechanics, which is very counterintuitive but interesting. \n\nHowever, what is important is that we understand it well enough to make models of magnetism, and to make predictions based on those models which we can verify and use. All of electricity and electric motors are based on our ability to design systems with magnets and to be able to build and use them.
36195
Actually our geographic north is south pole of our big earths magnet and similarly with south....\n\nActualy it is just a convention we can consider anything as north or south,..... similar to positive and negative chages.\n\nRecently scientists have found that the earth's polarity is changing, while this process is going on there will be a break down in our earth's protective magnetic field.\n\nSo cosmic radiations can through earth's atmos.....\n\nFor this stage to sttain there is around a 1000 years to go.
42983
It doesn't matter if you are in the East or West. If you can, try to get your bed's head & foot pointing from North to South. This way the lines of your personal magnetic field (the aura) run parralel with that of the Earth.Using this method, there won't be much 'cross-grain' interference. I know it works for me!!
167430
We do not really understand what causes the earth's magnetic field, but presumably it is caused by electric currents flowing in the earth, possibly as charged pieces of molten metal move around in the outer core. \n\nSo in this way, the earth's field is due to something more like an electromagnet, which is not destroyed by heat, instead of a permanent magnet, which is destroyed by heat.
57388
There is no west line.  East and west are relative terms.  North and south are obsolute terms, because they relate to absolute locations (the North and South poles, respectively).  East and west don't work like that.  They are like right and left--you could turn right infinitely and never reach a maximum state of rightness.
699104
Compass needles align themselves with the magnetic field directions. On earth, the magnetic field direction is always from the north pole to the south pole (approximately), hence the compass shows north and south directions.\n\nThus, if in a particular location in space there is a magnetic field, the compass will align itself with it, otherwise, if there is no magnetic field around (most likely in your assumption of space) the needle will not try to show any direction, as you turn the compass, the neddle will freely turn with it.
108576
It has to do with horizontal and vertical lines of magnetic propogation, and it also deals with the way that EMI fields of energy will dissipate from an antanae when a volatage is applied through it.\n\nBasically you will use different shaped antenna to get better RF coverage to certain areas.
33674
Whe teaching basic navigation we cover the difference between magnetci and grid north.  Previous answer here is good.  But I would like to add the ditty we use to remind people to apply the variation figure when moving from the map to compass and vice versa.\n\nwhen taking bearing from the map and putting onto the compass add the variation (From grid to mag ADD)\n\nWhen applying a compass bearing to the map then take the variation off. (From mag to grid get rid).\n\nAlso the amounbt of variation and its direction will vary depending on where you are on the earth.. In the UK the magnetic variation is about 6 degrees West.\n\nWe use the ditty "Variation East Compass Least (ie take the figure off the magnetic reading)- Variation West Compass Best." (ie add it to the magnetic reading.)
1170767
Magnetism arises from the movement of electric charge. It is a manifestation of the electrosatic force (there is per se no magentic force). \n\nA moving charge always creates and polarised magnetic field - ie it has a north and south. Monopoles do not exist.\n\nHowever, it would be equally possible to describe the situation with magnetic monpoles leading to polarised electric charge. \n\nNo magenticm monopoles have been found to exist.
60283
This question has been adequately answered, but it is a trick question in that every direction at the north pole is south (you can't walk east, west, or north of the north pole), and every direction at the south pole is north. You could, however take one step south, turn and walk east, but you would have to walk in a little circle to maintain your easterly direction. Weird, huh?
31611
Well even though humans have known about magnets for thousands of years, the real reason they work is still somewhat mysterious. Depending on how deep you want to investigate, it can be a very complicated phenomenon. \n\nA magnet is, at its foundation, caused by the movement of electrical charge (yes this is the Biot-Savart Law). When charges (like electrons for example) move, they produce magnetic fields. If a charge moves in a loop, it creates a magnetic field. The magnetic field can be basically represented by an invisible set of arrows in space, that point in a direction. In the case of the loop, the arrows of the magnetic field will point out of the loop for a positive charge moving counter clockwise (this is the so-called "right hand rule"), and into the loop for a charge moving clockwise (some pictures are in the reference attached). \n\nThe magnetic field has a "north" end and a "south end". The little arrows from our moving charge are pointing in the "north" magnetic direction, and away from the "south" magnetic direction. It is a mysterious and interesting property of electromagnetism that two objects with fields that oppose each other, i.e., the little arrows of the field do not line up, so either the north end of one field is facing the north end of the other field, or the two south ends are facing each other, repel, or resist movement of the two objects towards each other with some force. \n\nOn the other hand, if the little arrows line up, the two objects attract each other with some force. \n\nThe forces that result from magnetic fields (and for that matter, electric fields) are fundamental forces, and part of the four fundamental forces of the universe (strong, weak, electromagnetic and gravity).  It is believed that these forces are caused, at their base, by particles passing "messenger particles" back and forth. In the case of electromagnetism, the messenger particle is a photon. How this actually works is still somewhat poorly understood, and is involved with the world of quantum mechanics, which is very counterintuitive but interesting. \n\nHowever, what is important is that we understand it well enough to make models of magnetism, and to make predictions based on those models which we can verify and use. All of electricity and electric motors are based on our ability to design systems with magnets and to be able to build and use them.