What does a magnetic pole shift really mean?
474837
The direction of the north magnetic pole on the earth changes slowly over time. In addition, occasionally, the north and south poles reverse with the pole in the northern hemisphere becoming a south magnetic pole and vice versa. This can be recorded in magnetic rocks and even has utility as a dating method. According to our understanding right now, we are in the middle of such a switch. This is why the strength of the magnetic filed is decreasing. Anyway, a shift is when one of these switches happens.
787791
The magnetic field obey the principle of superposition, so it will point against the magnetic field vector at that point.
1081450
yes, assuming the poles were damn near touching. as for the distance, magnetic force vs distance is an exponential curve so technically the force never diminishes. you have to set a lower threshold to say that the force has diminished once below that threshold, e.g <1lb.
699383
First of we have to understand magnetism. All magnetic objects produce invisible lines of force that extend between the poles of the object. An easy way to visualize this is to spread iron filings on a sheet of paper and place a bar magnet under the paper. The iron filings will arrange themselves around the magnet and along the magnetic field lines.\n\nIn the simplest terms, Earth can be thought of as a dipole (2-pole) magnet. Magnetic field lines radiate between Earth's north and south magnetic poles just as they do between the poles of a bar magnet. Charged particles become trapped on these field lines (just as the iron filings are trapped), forming the magnetosphere.\n\nThe origin of the Earth's magnetic field is not completely understood, but it is generally believed to be associated with electrical currents produced by convective effects and rotation in the spinning liquid metallic outer core of iron and nickel. This mechanism is generally known as the dynamo effect. \n\nBecause of the rotating outer core, this then produces an electric current, which in turn, produces a magnetic field that is also known to interact with the fluid motion to create a secondary magnetic field. Together, the two fields are stronger than the original and lie essentially along the axis of the Earth's rotation.\n\nHope this helps you out a little :)
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.
486884
Magnetism is the property of magnetic materials to exert forces of certain objects, mainly iron and other magnetic materials; this force is known as the magnetic force.\n\nThe origin of this force is the movement of electrons or charged particles (ions) inside the materials.  When an electron spins around the atom's nucleus, according to the Biot-Savart Law it produces what we call a Magnetic Field, which exerts Magnetic Induction on it's surroundings.  Not only that, but also moving electrons in the surroundings of the original one (say, electrons of another object) will "feel" this induction as a force.\n\nSo, everything exerts a magnetic force on everything else, but the thing is that the magnetic induction and hence the direction of the force electrons in the surroundings will feel depend on the direction in which the original electron is moving (more specifically, on the vector Angular Momentum and/or the vector Magnetic Moment), and since there are lots of electrons moving in different directions in every material, the forces will point in every direction, cancelling themselves and producing a net force equal to zero.\n\nBut magnetic materials have the property of "aligning" the Angular Momentum/Magnetic Moments of all its atoms, and the forces produced by all its electrons (in the average) point in the same direction, producing the net force we feel when we put a magnet (magnetic material) near some piece of iron (a material susceptible to magnetism).\n\nHope I helped
915454
The Zeeman effect is the splitting of atomic spectra in the presence of a magnetic field. A certain spectral line without the field will be observed but contains more than one quantum state for the electrons there. The multiple states are indistinguishable (e.g. magnetic quantum number) until a magnetic field is applied. In the field the single spectral line splits to reveal a more complex structure.\n\nHere's more detail;\n\nhttp://en.wikipedia.org/wiki/Zeeman_effect#Strong_Field_.28Paschen-Back_effect.29
484193
You mean 2 P of a M which is 2 poles of a magnet.
1005522
The earth's magnetic poles move constantly, and on some days the North magnetic pole moves by as much as 80 km (50 miles). To see a map of this go here:\nhttp://gsc.nrcan.gc.ca/geomag/nmp/daily_mvt_nmp_e.php\n\nThe short term wandering of the magnetic poles is caused by the Sun, which emits charged particles that disturb the Earth's magnetic field. Long term movement of the magnetic poles is due to changes within the Earth's molten core, which is thought to generate an electric field that in turn forms the magnetic field. At present the North Magnetic Pole is moving more than 40 km per year towards Siberia. To see the map:\nhttp://gsc.nrcan.gc.ca/geomag/nmp/long_mvt_nmp_e.php\n\nThe magnetic field of the Earth has undergone many complete reversals. The most recent reversal was about 730,000 years before present. Here is a timescale:\nhttp://gsc.nrcan.gc.ca/geomag/nmp/reversals_e.php\n\nIn addition to the reversals, the Earth's magnetic field has what are called excursions. These are wide variations in the strength of the field and in the direction of the magnetic force. On average, these excursions are less than 50,000 years in duration. \n\nThere have been many recorded episodes of climate change, both warming and cooling, over geologic time, and so far there has been no observed correlation between changes in the Earth's magnetic polarity or 'pole shift'  with any sort of climate change. There are some scientists that proposed that changes in the Sun's magnetic field might be causing an increase in Solar wind, which in turn would affect the Earth's atmosphere and might alter the cloud formation level. If this effect reduced lower level stratus clouds, it would cause global warming, but if it reduced high level cirrus clouds the effect would be cooling. However this possible climate effect caused by the Sun's magnetic field has nothing to do with Earth's magnetic field.
502394
No(yes). It is not real(it is).\n\nhttp://www.poleshift.org/sublim/
674108
The poles of any magnetized item will be at the extreme opposite points...in other words the positive will be as far as it can get from the negative.  In the case of a sphere this would be "top" and "bottom" not core and perimeter.  (Think of the Earth's magnetic poles!).
148700
Typically this refers to magetic fields.  If you align a large magnet (like a NMR - nuclear magnetic resonance instrument) protons or electrons (ESR - electron spin resonance) are aligned to a certain angle and the like.  Once the magnet is removed, the electrons and protons can start "precessing" and this is recorded via the sound it emits and it is then Fourier transformed into a typical spectra that can be interpreted. \n\nAtoms in degenerate orbitals will align under a big enough magnetic field.
219376
The earth has two magnetic poles, a north pole and a south pole.\n\nThe effect of both poles can be detected by a good compass from anywhere on earth.
135567
well there are two answers.  The pole is actually shifting as we speak albeit to such a minor degree that we would never notice during our lifetimes.  The present 'north star' polaris was not always the 'north star' and in the future a new 'north star' will take it's place.  There have been drastic pole shifts possibly resulting from the passage of an enormous comet or asteroid within or close to the orbit of the moon.  When this occurs, drastic changes take place in a short span of time.  It is theorized that the break-up of pangaea into the continents was caused by a sudden pole shift.  From Straight Dope :Geologist Jean Andrews of Columbia University has found evidence to suggest that 180 million years ago the poles were displaced about 22 degrees from their present alignment, with the North Pole located on the northern coast of what is now the Soviet Union.
511616
First: Gravity is due to mass, while magnetism is due to the movement of an electric charge.  For earth, this is believed to be caused by the movement of ions within the earth, the magma near the core.\n\nSecond: The poles of a magnet were misnamed.  They named the poles of a magnet because of the direction they pointed.  However, once the properties of magnetism were truly understood, it was too late.  So, appropriately, it could be said that near the north pole is the south magnetic pole, but I'm sure most teachers would frown upon that assertion.\n\nOther notes about magnetism on earth: The earth is imperfect.  The magnetic field is not uniform, so there are variations.  Magnetic north is not geographic north in all situations.  The earth is tilted, and we don't really know the flow of the magma that causes the magnetic field all that well.  Not to mention, there is speculation that magnetic north and south may flip at some point in time, but the mechanism of this is lost on me.  It has happened a very long time ago, and is expected to happen again sometime in the future.
1074720
none of the answers is correct , actually magnetic lines of force will be acting in anticlockwise direction.
85373
Magnetic force........