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Thread: Earth's demise and the need to colonize other planets

  1. #1 Earth's demise and the need to colonize other planets 
    Forum Cosmic Wizard icewendigo's Avatar
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    Sorry for the long post
    In a nutshell, earth's magnetic field could vanish, one more reason why it would be better to colonize other planets.


    Ok, so we know by now that some rare events can wipe out a good portion of life on earth; Asteroid/Comet, Super Volcanos, (Galactic Gamma Burst?), etc.

    We also beleive the Sun will expand in the far future, scorching the surface and blowing away what's left of the atmosphere.

    Global warming could eventually cause a lot of damage, floods, famines, desertification and other event could reduce our ability to build a space colonization infrastructure.

    But there might be something else, that unlike Asteroid impact might be certain to happen, and unlike GHG global warming could not be fixed by changing policies...

    ...The cooling/solidification of earth core, or if you prefer the demise of earth's magnetic field.

    Unlike the sun's expansion which is unlikey to occur before millions of years, the immobilization of earth rotating core(or the depletion of fissionable uranium, depending on the theory) could occur, sooner than we think.

    When the magnetic field fades, we'll be seeing auroras in the sky and the earth will be receiving much more radiation. I dont know how plant life will cope with the increase in direct radiation in daytime. Should this come to pass before humans colonize on an other planet, it may be difficult to expand into space for some time and we'll need to colonize earth since it will no longer be as fertile as it once was (but lacking colonies and the derived technology will make it more difficult, hence fewer people will make it).

    Another aspect of an earth without a magnetic field is the erosion so to speak of the atmosphere from the solar wind. Earth might slowly loose some of its atmoshere over a long period of time.

    There are traces that Mars once had seas and rivers(perhaps thicker atmosphere as well?) and that it once had a magnetic field similar to earth, but it lost its magnetic field when the core cooled and later on appears to have lost some(or most?) of its water.

    Has anyone heard of the nuclear fission theory, according to which planets had uranium in their core generating energy through nuclear fission, but that once the uranium is depleted the core cools down much faster, smaller planets cooling faster than larger ones?

    There are probably people here who know a lot more about the planetary magnetic field generation and depletion than I(since I hardly know anything about it), so I'd like to read your comments about this (and about colonization of other planets in general).

    ' In a speech June 13 in Hong Kong, Hawking said the survival of the human race depends on its ability to find new homes elsewhere in the universe because there's an increasing risk that a disaster will destroy Earth. '
    (unrelated to the Magnetic Field but still interesting)


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  3. #2  
    Forum Professor
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    Even if the earth's magnetic field vanished, it would still be a FAR better place to live than another planet.


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  4. #3  
    Forum Senior silkworm's Avatar
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    Has anyone heard of the nuclear fission theory, according to which planets had uranium in their core generating energy through nuclear fission, but that once the uranium is depleted the core cools down much faster, smaller planets cooling faster than larger ones?
    I've heard of this, and while I certainly don't think it's true of all planetary bodies, I think it may be true of Earth. It makes sense, uranium is the heaviest element known to man, we have a pretty good amount of it here on Earth (meaning its been around), and I guess there is a lot of Helium that comes out of some geothermal vents, so it is gaining support.

    The origin of the Earth's magnetic field is still a bit of an enigma (as is eveything underneath our feet), but I don't think the current thinking is that it's generated in the Earth's core. Instead it may be generated via magma flow in the mantle.

    I agree that we need to leave Earth and spread out as soon as possible. We have all of our eggs in one basket, and we need to diversify our habitats to make it more difficult for us to become extinct. This is one of the many reasons why space programs are so important.
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  5. #4  
    Forum Isotope Zelos's Avatar
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    oh my god the mangetic field is disaphering, for the 200th time
    this happens every 200.000 years . exept this last time it have gone 750.000 years. its completly natural processes.
    I am zelos. Destroyer of planets, exterminator of life, conquerer of worlds. I have come to rule this uiniverse. And there is nothing u pathetic biengs can do to stop me

    On the eighth day Zelos said: 'Let there be darkness,' and the light was never again seen.

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  6. #5  
    Forum Ph.D.
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    Well a 15 mile-wide asteroid hitting the earth is "natural" also but that doesn't mean we wouldn't mind it happening. We don't want anything happening to that magnetic field.
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  7. #6  
    Forum Senior silkworm's Avatar
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    Quote Originally Posted by Zelos
    oh my god the mangetic field is disaphering, for the 200th time
    this happens every 200.000 years . exept this last time it have gone 750.000 years. its completly natural processes.
    That's true, however we weren't in our modern form the last time it's flipped. Look for increased cancer rates and other effects to increased exposure to solar radiation as a result. I'm sure we'll have many technological issues as well, however we'll probably adjust to them as time gets closer to having no magnetic field.
    "I would as soon vomit over him as buy him a hamburger."-Ophiolite about Richard Dawkins

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  8. #7  
    Forum Isotope Zelos's Avatar
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    life have surived it before, so will we
    I am zelos. Destroyer of planets, exterminator of life, conquerer of worlds. I have come to rule this uiniverse. And there is nothing u pathetic biengs can do to stop me

    On the eighth day Zelos said: 'Let there be darkness,' and the light was never again seen.

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  9. #8  
    Forum Cosmic Wizard icewendigo's Avatar
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    Even if the earth's magnetic field vanished, it would still be a FAR better place to live than another planet.
    That's correct, which is why we should colonize other planets (as opposed to an exodus).

    oh my god the mangetic field is disaphering, for the 200th time
    I agree the earth magnetic field diminishes during inversion of polarity and that this event occurs periodically, but I dont think this is a 100% guarantee the field will never vanish as it did on Mars. I dont know exactly what generates the magnetic field nor how much the core temperature is boosted by nuclear force(in which case what the amound of mantle movement caused by this energy), but it appears planets eventually cool down.

    Regarless of whether the field remains intact for millions of years or not, there's several extinction level event we know about and there may be a few we dont know about yet (I had never heard about Gamma Ray bursts until recently). Better safe than sorry. :wink:
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  10. #9  
    Forum Senior silkworm's Avatar
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    Oh yeah, I'm certainly not arguing that it will lead to our extinction (although it really depends on what the sun is doing at the time), but it certainly won't be healthy.
    "I would as soon vomit over him as buy him a hamburger."-Ophiolite about Richard Dawkins

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