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Earth Science

Earth's Inner Core Rotation Slower Than Estimated 223

Posted by CmdrTaco from the don't-get-dizzy dept.
intellitech writes "Scientists at the University of Cambridge believe they have achieved the first accurate estimate of how much faster Earth's core is rotating compared to the rest of the planet. The rate — about one degree every million years — is much slower than previously thought and arises from the complex dynamic between Earth's inner and outer core, which generates Earth's geomagnetic field. Without our magnetic field, Earth's surface would not be protected from charged particles spewing from the Sun, and life would not be able to exist."
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Earth's Inner Core Rotation Slower Than Estimated More

Earth's Inner Core Rotation Slower Than Estimated

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  • oh GAWD NO! (Score:4, Funny)

    by Thud457 ( 234763 ) on Tuesday February 22, 2011 @02:22PM (#35281788) Homepage Journal
    we have to quickly assemble a team to tunnel to the center of the Earth with nuclear bombs to restart the core's rotation!
  • And yet everything is still working. How many other 'estimations', such as distances to distant stars, etc, can be off by a small percentage that would result in a large amount of actual distance? We're human and we do the best we can at estimating.

    • so how far is the date / year off?

    • yeah, if some of the standard candles [wikipedia.org] they use to estimate cosmic distances are off by more than a little bit, the error could propagate outwards in a big way. These include things like Cepheid variables and certain types of Supernovae. However if some of your distance scales overlap, it gives some confidence in the numbers and a way to cross-check the estimates.

    • ...How many other 'estimations', such as distances to distant stars, etc, can be off by a small percentage that would result in a large amount of actual distance?

      Umm, I'll estimate 30%... it would be larger but sales and marketing departments have not yet become involved in things like interstellar distance and core super-rotation.

  • I have exactly the same problem. (Score:3)

    by gestalt_n_pepper ( 991155 ) on Tuesday February 22, 2011 @02:27PM (#35281846)

    My inner core rotation is much slower than it should be, especially after a biggish lunch.

  • Or ... (Score:5, Interesting)

    by PPH ( 736903 ) on Tuesday February 22, 2011 @02:30PM (#35281884)

    Earth's surface would not be protected from charged particles spewing from the Sun, and life would not be able to exist.

    ... life would have evolved in such a manner or in a location so as to tolerate the particle flux. In the ocean, for example.

    • Re:Or ... (Score:5, Funny)

      by kabloom ( 755503 ) on Tuesday February 22, 2011 @02:32PM (#35281918) Homepage

      You mean... "God would have created us in such a manner or in a location so as to tolerate the particle flux. In the ocean, for example." Right?

      • The particle flux is part of God's creation too. We wouldn't 'tolerate' it, we would rejoice in it as evidence of his bountiful provision of life-affirming radiation for us, his children. For without it we wouldn't be as we would be, and what are the chances of that happening through accidental evolution? Not much!

        • Behold! He's coming with the clouds! And every eye shall be blind with his glory! Every ear shall be stricken deaf to hear the thunder of his voice! Come forth and drink the waters of the Glow, for this ancient weapon of war is our salvation, it is the very symbol of Atom's glory! Give your bodies to Atom, my friends. Release yourself to his power, feel his Glow and be Divided. There shall be no tears, no sorrow, no suffering, for in the Division, we shall see our release from the pain and hardships of this

        • He's just testing us. You know, like how fossils and Darwin were put here just to test our faith.

        • Re: (Score:2)

          by vlm ( 69642 )

          The particle flux is part of God's creation too.

          Which god? A particle flux sounds like the kind of thing Prometheus would steal from Hephaestus for humanities (ab)use.

      • AOL voice: "Congratulations! You found the 'God particle'."

    • In the ocean, for example

      But then Avitar would have been about giant, 3D, blue dolphins instead.

      • And yet the story still would've sucked, proving that there are some things that are constant across the many earths in the Multiverse.

    • Possibly - there are some theories which suggest that the solar wind might have blown our atmosphere away were it not for the magnetic field, Mars' thin atmosphere is supposed to be an example of this because its magnetic field is weaker than Earth's.

      • Re: (Score:3, Insightful)

        by mister_playboy ( 1474163 )

        Venus manages to have an atmosphere 93 times more massive than Earth's while having no intrinsic magnetic field and being subjected to a stronger solar wind.

        There is still much we have to learn.

        • Re:Or ... (Score:4, Informative)

          by blair1q ( 305137 ) on Tuesday February 22, 2011 @03:50PM (#35282852) Journal

          Venus' atmosphere is heavier (almost all CO2) and is constantly replenished by outgassing at the 800F surface.

          Venus also does have a magnetic field large enough to disperse the solar wind.

    • Re: (Score:2)

      by mnmn ( 145599 )
      Holy assumptions in the original article. It links the core's relative rotation to the magnetic field. The magnetic field exists because a huge mass of ferroelectric material rotates.

      Now which do you think affects the magnetic field more, the cores RELATIVE rotation speed (a few degrees in a million years?) or the overall Earth rotation (roughly 365 degrees in a day)? This is like putting a magnet in a plastic cup, rotating the magnet, and rotating the cup SLIGHTLY slower, and saying the resulting magnetic
  • Attempts by scientists to measure the earth's rotation at its core failed previously due to motion sickness. However, after desensitizing researchers on The Zipper carnival ride, they were able to reach instruments without puking.

    • Ahh, The Zipper. I took my then-girlfriend on that ride once, she instantly became sick and refused to move for hours. Wouldn't even ride the damn Ferris wheel. I would have been bored if it wasn't for the good old Gravitron... which spins around, much like the Earth's core. Back on topic!

  • This is an estimate, you'll note. But not just any estimate, it's the first accurate estimate.

    Were previous estimates wild guesses made just for a laugh, with no expectation of accuracy?

    And won't the next estimate researched be able to claim the same milestone, for all the same reasons?

  • Life is more robust than that... (Score:5, Interesting)

    by mpthompson ( 457482 ) on Tuesday February 22, 2011 @02:36PM (#35281988)

    It bothers me how often I hear absolutes with regards to "If not for XXX, life would not exist on Earth." Life has proven to be a lot more robust than such simple statements imply. Certainly, without a magnetic field, life on Earth would look a lot different than it does today as it would have adapted to a much different environment, but it would most certainly still exist with all other things being equal.

    • Yep there would probably still be life deep in the oceans, especially near volcanic vents where the water would be warm and chemotrophic organisms could survive on the chemicals that spew out.

      Remind me again of why anyone would want to explore Mars instead of Europa?

      • What oceans?
        No magnetic field means there's nothing to stop solar winds from stripping earth of it's atmosphere.
        With no atmospheric pressure, the oceans would boil at 0C (and the water vapor would then be blown off into space too).
        Also, no magnetic field implies little to no plate tectonics, meaning volcanism is nonexistant, meaning no tasty little geothermal vents for microbes to snack on.

        Make no mistake - without a magnetic field, life would most definitely not exist on this planet. This is not a case of

        • With no atmospheric pressure, the oceans would boil at 0C (and the water vapor would then be blown off into space too).

          Oh, good point 8-(

        • Re:Life is more robust than that... (Score:4, Informative)

          by Lumpy ( 12016 ) on Tuesday February 22, 2011 @03:40PM (#35282728) Homepage

          "What oceans?
          No magnetic field means there's nothing to stop solar winds from stripping earth of it's atmosphere.
          With no atmospheric pressure, the oceans would boil at 0C (and the water vapor would then be blown off into space too)."

          Let me fix that for you.

          Wild speculation has it that our atmosphere will be stripped off without a magnetic field. Most experts now disagree as Venus is proof that that is not true. Venus uses a ionopause (as does Mars) but it is generated a different way than Earth's magnetic field. Mars is a special instance because something catastrophic happened at one point. The atmopshere had enough pressure to hold liquid water (it can now, but only in low lying areas or short amounts of time), enough for oceans. What kind of atmosphere makes a difference too. Hydrogen verses carbondioxide for example.

          The magnetic field does more by keeping us from getting cooked by radiation than anything else.

        • Re: (Score:2)

          by 517714 ( 762276 )

          Make no mistake - without a magnetic field, life would most definitely not exist on this planet.

          That is a statement rooted in faith, not in science.

          • Conceded. It really should read that life as we know it would definitely not exist on this planet. It's far too speculative to say all life. My apologies.

      • Remind me again of why anyone would want to explore Mars instead of Europa?

        Because the monoliths told us to stay the hell away from Europa?

      • It's closer and you don't have to drag around an enormous drill.

      • Re: (Score:2)

        by 517714 ( 762276 )
        Because we can colonize Mars without displacing indigenous life.
    • If life really was so resilient we would have found ample traces of it on every other planet. The fact that we haven't yet found anything in our own solar system tells us that Earth itself has something very special which is absolutely necessary to life.

      • We haven't been able to look very closely. The jury is still out on the one place (Mars) we believe life is possible that we've been able to test repeatedly (at least robotically).

        We haven't even begun to examine Europa and have barely tested Titan... and that's only considering the places in the Solar System where we think life is possible based on our understanding of where and how life can exist, which itself is constantly being challenged and broadened.

        The Solar System might be teaming with life that w

        • Well, we're pretty sure that intelligent life isn't there - at least none that has anything similar to a technological base. Not even close. There would surely have been numerous signs by now.

          Decades down the line I may look like a fool for saying this, but I'm willing to stick my scrawny neck out and unequivocally state that there's no life on any planet other than Earth in our solar system.

          • Well, intelligent life that resembles us in any way, yeah, I would agree we can be pretty certain about that, but life in general, even if it's very simple? I think it will be a long, long time before we can rule that out.

            Of course, there's also the possibility that intelligent life could exist nearby in a form we would not be able to recognize.

      • Re: (Score:2)

        by blair1q ( 305137 )

        If life really was so resilient we would have found ample traces of it on every other planet.

        The fact that we can find it on even one planet implies that here it's pretty resilient. It also implies that here the conditions for it are in the survivable range of a fairly large number of parameters.

        • Re: (Score:2)

          by hesiod ( 111176 )

          That's a bit of a fallacy... Of course life exists here: if it didn't, we wouldn't be here to observe it. So the 1-out-of-1 so far doesn't say much about the probability of life existing elsewhere, unless we find some place very similar to Earth. Also, "fairly large number of parameters" isn't quite accurate since, on a galactic scale, any place on/in the Earth is within a relatively small set of parameters. From our perspective it's a lot, because it's all we've been able to experience so far, with the

        • I can tell from one single instance of a slashdot post by you, that you're a mother fucking genius. BRILLIANT! that is all i have, carry on.

      • Re: (Score:2)

        by 517714 ( 762276 )
        I didn't find any women in my bed this morning, they must not exist! Seriously, how extensive do you think the search has been? For life on other planets, that is?
        • If you didn't find a woman in your bed and you don't think there's a woman in your own house, I'm pretty sure I can trust your verdict. Given the large number of planets I'm sure that life existd but the point is that it's fashionable to say that life is resilient. It is up to a point, but no more.
    • Totally agree. If you actually look at Earth, it has several things going against it. For example, it has a relatively thin atmosphere, so the temperatures drop quickly at night (a thicker atmosphere, or a faster spin would be better). And it has a tilted axis causing extreme cold and heat at different times of the year (a smaller tilt or tidally-locked planet would have less changeable temperatures on the surface making life easier to cope). Because of periodic changes in its orbit, it's prone to long

    • Re: (Score:2)

      by radtea ( 464814 )

      Certainly, without a magnetic field, life on Earth would look a lot different than it does today as it would have adapted to a much different environment

      What would the differences in the environment be?

      Radiation levels would be about the same. For every particle of any energy that is steared away from the Earth there is another one on the other side steered into the Earth. The poles get a bit more (non-solar) cosmic radiation than the equator because they come in more-or-less along the axis of the Earth's magnetic field. The magnetic pole is currently moving quite quickly somewhere in northern Alaska, and I haven't heard any reports of it leaving a swath

  • Comment removed based on user account deletion

  • ...w/o magnetic field. We have oceans which are miles deep. We also have microorganisms which have been found in active volcanoes and inside nuclear reactors. Even humans spend most of the time inside radiation-shielding buildings and have survived trips to moon inside thin metal shell. I think it's more fare to say that life forms would be slightly different without magnetic field.

    • Oceans which would boil at 0 Celsius without an atmosphere.

      • Re: (Score:2)

        by blair1q ( 305137 )

        Thus creating an atmosphere, clouding up, and cooling them down again.

        Could take some time before the whole run-out-of-water thing happens. Time enough to start up the magnetosphere again.

  • Why do people keep claiming that if any of the conditions on earth were slightly different, then "life would not be able to exist". Doesn't it make more sense to say that if life did exist, it would be different without a magnetosphere? Life has been shown to be able to exist under some pretty severe conditions.

    • Re: (Score:3)

      by jfengel ( 409917 )

      It's a nice way to punch up a news article or info piece. I think they may teach it in journalism school: people are really interested in death, and the apocalypse is a great way to attract eyeballs.

      Scientists usually don't say such things, and the Nature article doesn't. But apparently the person who submitted it figured that a one-sentence answer "Scientists do an experiment and come up with a slightly different number from last time" didn't quite cut it.

      Usually, it's the press who adds such things befo

  • We're all gonna die!

    Someday... =)

  • Okay, I understand it is important to note why some specific area of research (Earth's core speed) is important research (relates to magnetosphere, amongst other things). But can we please leave out stupid addenda to summaries like, "Without our magnetic field...life would not be able to exist." The interesting news story here relates to geology, geophysics, and planetary models (something becoming more and more relevant as we explore further portions of our solar system). I would much rather see a discuss

  • Deinococcus radiodurans takes your puny solar radiation, chews on it, and spits it out as not worthy of food. Go ahead, try and kill me!

    http://en.wikipedia.org/wiki/Deinococcus_radiodurans [wikipedia.org]

  • It was predicted by computer modeling the core dynamo by a Harvard group in the 1990s. At that time is was the frontier of supercomputing because you had to make the model cells rather small to accurately coupled elastic-electrodynamic equations. Ad a seismology group at Columbia claimed it saw super-rotation in 30 years of seismic records. Velocity anomalies (anisotropy) in the earths core appeared to have moved during just a few decades. Both these studies suggested the Earth's core had an "extra day"
  • http://arxiv.org/abs/astro-ph/0404580 [arxiv.org]

    "It is shown by kinematic estimates and three-dimensional plasma-neutral gas simulations that the solar wind can induce very fast a magnetic field in the previously completely unmagnetized Earth's ionosphere that is strong enough to protect Earth from cosmic radiations comparable to the case of an intact magnetic dynamo.

    Consequently, even in the case of a complete breakdown of the Earth’s dynamo, the biosphere is still shielded against cosmic rays, in particular

  • I'm a layman but I would expect that, after 4.5 billion years, friction would have slowed down the inner core's rotation to match that of the rest of the planet. Has anyone hypothesized why that hasn't happened?

    • Coriolis force. As dense matter settles toward the core it will carry angular momentum along. This implies that the magnetic field is ultimately driven by differentiation.

  • So, the core rotates 1degree faster than the surface every million years. That's not much.

    At the current rate of earth's rotation rate slowing, the surface will slow down some 30 degress in the next 400 years (this is a reasonably sound estimate used by people arguing against continuing "leap-seconds", that as the rotation rate slows geometrically, soon we'll be adding a leap second every month, then several a month, and so on. They suggest a leap-hour in 300 or 400 years.)

    So...this suggests that the soli

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