Nova (11/18/03) Re: the Magnetism of the Earth

Discussion in 'After Hours Lounge (Off Topic)' started by Jay H, Nov 19, 2003.

  1. Jay H

    Jay H Producer

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    Anybody see this last night? Pretty interested cause I never heard about the switching of Earth's magnetic fields (which goes from the southern hemisphere to magnetic north) that is predicted to occur sooner or later (in Earth time)...

    I hope it's a 180deg change or our compasses will go wacky. Plus they talk about the period of time when there could be multiple magnetic poles rather than the dipole system we have now but to make a long story short, they are noticing a weakening in the magnetic pull of the earth within the last few centuries and research indicates it may be an indication of a complete change of the magnetic flow in the earth. Our compasses may start to point south rather than north and stuff like that. Solar radiation will not be deflected during the period of reversal causing more cancer deaths although not predicted to be catastrophic but on the order of 100k more deaths due to cancer than normal. On the plus side, they say the aurora borealis (aka the Northern Lights) will be able to be seen around the world rather than predominantly in the northern latitudes.

    Neat show, glad I caught it. I hope I don't need new topo maps! [​IMG]

    Jay
     
  2. LewB

    LewB Screenwriter

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    Same here, leave it to Nova to give my zapping finger a much deserved rest. Fascinating show. Keep in mind that these changes are said to happen over 100's or thousands of years. I don't think any of us need to worry about it in our lifetimes.
     
  3. NickSo

    NickSo Producer

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    It happens every 500,000 years i beleive... I cant remember exactly from my geography class...

    But that is one way how scientists estimated how old the earth is, they look for iron in the earth, and they found that the magnetisms was not the same throughout, they alternated. With that they figured out how old it was by counting how many times it reverses...
     
  4. Jay H

    Jay H Producer

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    The one guy from Oregon measured the rock from some cliff at the time it was happening. He was claiming that the pole changed at a rate of 6° per day.

    Jay
     
  5. CharlesD

    CharlesD Screenwriter

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    Haven't seen the show yet, but its in my Tivo.

    The pole reversals happen, on average, every 250,000 years or so, but its not very regular. Its been something like 1,000,000 since the last one IIRC. As Nick mentions the pole reversals are a useful geo-physical tool. In fact the reversals provided the first proof of continental drift.
    When they do occur they tend to happen quite quickly on a geologic scale. If we are coming up on a pole reversal now, it will be quite interesting to say the least.
     
  6. ChrisMatson

    ChrisMatson Cinematographer

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    I hate to be fatalisitic, but I don't think us humans will be around to witness the next flipping of the poles. We'll obliterate ourselves, get hit by an asteroid, succumb to a super volcano, or be infected by some emergent virulent pathogen.

    It is an interesting phenomenon. Also of note is that the currenet magentic poles do not equal the geographic poles.
     
  7. Christ Reynolds

    Christ Reynolds Producer

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