Poles Apart

USA Politics are more polarized than usual these days. What does polarized actually mean? The pole is a fundamental concept that gives rise to a vast swath of physical science. Poles are discussed early in the study of electromagnetism—essentially the second half of classical physics.

Earth spins on an axis—an imaginary line that passes through the north and south poles.

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Actually, the axis doesn’t pass through the magnetic poles.

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Earth has a magnetic field. Magnetism arises from charges in motion. Molten iron churns in Earth’s core.

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Metals, like iron, often have an abundance of delocalized electrons. Electrons have negative charges. It’s the motion of these charges that most likely creates Earth’s magnetic field.

The north magnetic pole is a bit off from the axis.

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The same is true for the south magnetic pole.

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Here’s the confusing part: Earth’s geographic north pole is actually a magnetic south pole, and the geographic south pole is a magnetic north pole.

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Why do we call Earth’s magnetic south pole, the north pole? Because an independent magnet’s north pole, points north on Earth. (A compass is just a magnet that rotates about a central point–an axis–with minimal friction.) The north pole of a magnet is attracted to the south pole of other magnets. The arrow of a compass points at Earth’s south pole. That arrow is on the north pole of the independent magnet; hence, we call that direction north.

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I guess we could say the south pole is on the tail of the arrow, but there is a better, simpler way to describe whats happening. It doesn’t matter what point you specify on a magnet. The field passing through the magnet points in one direction.

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Notice that the arrows leave the north pole and enter the south pole. This is what’s called a convention. Conventions are arbitrary things. We could just as easily assume field lines leave south pole and enter north poles. It doesn’t matter. We do need to agree on one or the other so we can communicate about magnetic fields without needless confusion.

Magnetic fields exist inside of magnets too. Remember: magnetic fields come from charges in motion. Most magnets are made of metals. Metals have more mobile charges than other types of materials. The magnetic fields arise from small regions called domains that sometimes align. When the domains point in the same direction, the material is magnetized.

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North and south poles are a false binary reference systems to help us explain magnetic fields. The only crucial characteristic of a magnetic field is direction. (Actually, magnetic field strength is important too, but not necessary in this post.)

USA has a two-party system. Each party serves as a pole of sorts: the Republicans are at one, and the Democrats occupy the other. Partisans at each extreme believe they have philosophies that clearly distinguish themselves from the opposition. We could say the Republicans stand over the south pole while Democrats reside at the northern extreme. It could be the other way, too. Political poles suffer from some of the similar confusing conventions that we see with magnetic poles.

Political poles are similar to magnetic poles in that they don’t really exist other than a means to explain–and complicate in some ways–a more simple phenomenon. For magnetism, poles help us understand magnetic fields. Political poles help us understand historical progress in the distribution and dispensation of power–this is commonly known as governance.

Republicans are typically classified as conservative, while Democrat are pegged as liberals. Conservatives are leery of change while liberals are more eager to make progress–liberals are sometimes called progressive too. Political progress is similar to a magnetic field line in that  it points in one direction. Conservatives and liberals both advocate progress; truly, they differ only in the preferred rate of change. Conservatives like the way things have been done in the past: they know what works and they think it’s best to stick to the tried and true as we move forward in history. Liberals advocate for a quicker pace and they are keen to experiment with new ideas on how to govern.

If you liked this post, you might like A republic if you can keep it and/or Hunter Gatherers in the Quantum Age.

 

10 thoughts on “Poles Apart

  1. kaptonok

    These small domains you mention are they only found in magnetic metals such as iron cobalt and nickel?
    I well remember winding a coil onto a six inch nail and connecting to a battery to make an electro magnet.
    It was long ago and far away I’m 74 now and still steeped in ignorance.

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    1. shawn_monty Post author

      The domains are somewhat arbitrary regions that have similar magnetic field alignments. Many materials don’t have delocalized electrons, so they aren’t as potentially magnetic.

      Remember: charges in motion produce magnetic fields. When you wrap a current-carrying wire (current is another example of delocalized electrons in motion) around a material, like iron, it aligns the magnetic fields creating a larger domain—a bar magnet. The nail should remain magnetic for some time until the domains become misaligned. The coil would generate a magnetic field without the presence of the nail too. Putting the wire and the nail together creates and additive effect.

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      1. kaptonok

        Thanks for the reply and explanation, it is all most curious to me.
        A magnet seems to have energy to pick up things , even to make them jump to it and hold them.
        I heard a program about Faraday and his experimentation in this area.
        What a remarkable man he was.

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      2. shawn_monty Post author

        A magnetic field applies force on moving charges. If a force produces motion through distance in the direction of the force, it does work. Energy is the ability to do work, so I guess you could say magnets have energy in a loose sense.

        Faraday was one of the greatest scientists. It’s a pity more people don’t know about him and his contributions. Have you seen “Einstein’s Big Idea”? It has a very flattering portrayal of Faraday. The video is based on Bodanis’ “E=mc^2”.

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      3. kaptonok

        I always find modern physics a bit difficult . It often seems to contradict common sense. Quantum theory seems a world of its own almost as if anything goes. If I did not have a great respect for these brilliant minds I would suggest they were making it up.

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      4. shawn_monty Post author

        Unfortunately, there’s very little in our common experience that we can use to model what happens at the quantum level. Modern physics was born late because too many people holding powerful positions in the scientific community refused to let go of common sense. Fundamental particles–electrons for example–follow the laws of probability in ways we find counter intuitive. Believe it or not, quantum physics was born as a last ditch attempt to explain the physical evidence, so quantum physics may be the farthest we can get from made up.

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      5. kaptonok

        From what I understand probability is connected to chance. It is an estimate of how likely it is for something to happen. It seems curious to me that science, that solid body of knowledge should rely on chance. I take the word of the experts but it seems to me chance is only there because we do not no enough to absolutely predict an outcome.
        The famous atheist Sam Harris believes everthing is predetermined and believes nuroscientists have proved it to be so.
        I agree even if something seems wrong we must accept it if it fits the facts.

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      6. kaptonok

        Yes it must be I think .
        Sam Harris a rather outspoken atheist he has his own site.
        He believes free will and the concept of self are illusions and all things are pretermined. It seems to tie into science but perhaps not quantum mechanics if quantum mechanics is complete.
        I profess I’m just a dabbling layman in all this stuff but I do my best to follow the latest theories.

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  2. shawn_monty Post author

    I’ve read a few of Harris’ books and I just had a look at his blog. I have yet to stumble across him discussing the predetermined nature of the universe. If you find it online, please send me a link.

    Thanks for your insightful commentary and questions.

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