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Earth's Gravitational Field Is Getting Flatter

RJG2 writes "MSNBC has an article stating that Earth's gravitational field has changed, becoming stronger towards the equator, thus becoming flatter. The cause has yet to be determined, but it is assumed changes in ocean levels are responsible."

22 of 270 comments (clear)

  1. Yo mamma by wilburdg · · Score: 3, Funny



    Yo mamma so big that... n/m

  2. Shorter and Fatter by Tall+Rob+Mc · · Score: 5, Funny

    Judging by the diagram, this means that the Earth is getting shorter and fatter. Is this news? Thats what happens when you get older...

  3. Awesome! by sdo1 · · Score: 3, Funny

    Cool! I can loose weight not by dieting, but by just moving further north!

    -S

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  4. Re:This reminds me. by budalite · · Score: 4, Funny

    Dunno. Who cookin' the Poles?

  5. Whew! by r_j_prahad · · Score: 4, Funny

    I've been blaming my weight gain on candy bars and junk food. What a relief to find out it's actually just more gravity!

    And maybe the shrinking waistband in all my pants is due somehow to the warping effect the extra gravity is having on space?

  6. Change In Time? by ackthpt · · Score: 5, Interesting
    I've been hearing about this on the BBC for the past couple of days. The thought that occurred to me was this: if mass is moving from the poles to the equator, will the rotation of the earth slow, even a tiny amount, but enough that we have to adjust time in a few years?

    I expect so.

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    1. Re:Change In Time? by Fenris2001 · · Score: 3, Interesting

      In short - yes. But it won't have any major effect. The number of seconds in a year already fluctuates as large weather systems (El Nino) change the amount of water vapor in the atmosphere. Like a spinning ballet dancer extending her arms, excess water in the atmosphere near the Equator causes the Earth's rotation to slow. However, the total change is miniscule - something like half a nanosecond per year. Particle physicists and others who need extremely accurate measures of time make adjustments for these effects. The rest of us don't notice.

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  7. Back to the Future quote by uncoveror · · Score: 5, Funny

    "There's that word again, heavy. Is there a problem with the Earth's gravitational pull?"

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    The Uncoveror: It's the real news.
  8. Re:Magnetic Pole Changing by Foxxz · · Score: 3, Funny

    PS-We could probably fix this if we all degauss our monitors at 0900 hours tomarrow :P

  9. Ocean levels? by Arandir · · Score: 3, Interesting

    What changes in ocean levels? Did this just happen yesterday or something?

    Considering that I live at an altitude of 20 feet and one mile from the ocean, I would think I would be one of the first people to know if the ocean level was changing. From what I can tell, the level of the Pacific Ocean is still the same as it was when I was a kid.

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  10. Ask my ex workmate, it's the NT7 :) by jukal · · Score: 4, Funny

    My ex-workmate is rather convinced (don't ask me why :))) that changes like this are caused by the NT7 asteroid which, he believes, will shift earth's magnetism that everything will basicly destroy. Yup, he belives it does not hit the earth, it just passes by so that everything gets wicked. He might be almost blind, but he is a hellable coder. So prepare to get extincted!

  11. Ummm. no. by Zone5 · · Score: 3, Interesting

    If you're referring to a differential gravitational attraction similar to that involved in Roche Limit" deformation of orbiting bodies, then no. What you're suggesting implies that the gravitational pull on the equator is significantly stronger than that on the polar regions. Since gravitational attraction drops off exponentially as the distance between the two bodies increases, that kind of differential pull only occurs when the gravitational bodies are relatively-speaking quite close together.

    Perhaps if the moon had suddenly increased in mass a thousand-fold, but not possible due to distant stars or planets.

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  12. Re:If Global Warming is true, then... by dnoyeb · · Score: 3

    No.

    Where does the melted ice go? -> equator.
    What makes gravity? -> mass.

    More mass at the equator means more gravitational force.

  13. Mid life crisis? by CrazyDwarf · · Score: 4, Funny

    It could be worse, we could be combing Ozone over from areas around the north pole.

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  14. State borders? by OutsideBoston · · Score: 3, Funny

    In related news, officials from North Stonington, CT and Hopkinton, RI have cited their recent border confusion on the "fattening" of the Earth.

    ~N

  15. Re:Magnetic Pole Changing by Zone5 · · Score: 4, Interesting

    Actually, the polarity supposedly switches roughly every 200,000 years, and according to that school of thought we're currently way overdue to the tune of about 780,000 years. See here.

    Assuming you believe all that, of course. As far as I know it's just a theory.

    --
    "So on one hand, honey is an amazingly sophisticated and efficient food source. On the other hand it's bee backwash."
  16. Nope, it flows to the equator by sterno · · Score: 3, Informative

    Since the earth is spinning, the water tends to be forced to the equator by centrifugal force (although I think more correctly it's centripedal force, but whatever). So no matter where the water comes from, it will tend to flow to the equator.

    Actually one likely side-effect of long term global warming is, ironically, an ice age. The water moves to the equator, and this causes the earth to spin slightly slower. The side-effect being that this cools the earth. I forget exactly why this is because I learned it in high school physics which was just over a decade ago.

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    1. Re:Nope, it flows to the equator by God!+Awful · · Score: 4, Informative


      Since the earth is spinning, the water tends to be forced to the equator by centrifugal force (although I think more correctly it's centripedal force, but whatever).

      IMHO, high school physics teachers really dropped the ball in explaining this one. A whole generation of high school graduates is confused about centrifugal vs. centripedal.

      A body that is spinning around an axis or orbiting around point must be under continual force. Otherwise, they would simply fly off in a straight line at a tangent to the curve. This is the centripedal force. The centrifugal force is a "pseudo force", which means that it only exists in a non-intertial frame of reference.

      Basically, what happens is that when you accelerate (whether in a straight line or in a circle), your inertia feels like a force in your frame of reference. When you sit in a moving car, from your point of view you feel like you are sitting still and the car is moving. We know that when an object is at rest, the forces on it are balanced. Therefore, in your frame of reference you feel a pseudo force which balances out the force that is being applied on the car. The pseudo force is really just the effect of your inertia.

      So how does this apply to the water? Well, everything on Earth has inertia, and this inertia wants to keep it going in a straight line, even though the Earth is rotating. Solid objects, such as humans are obviously kept in place by simple static friction and wind resistance. Water and air are more mobile and they are less subject to friction (although they are still very subject to air/water pressure). That is the main reason why wind and ocean currents are very obvious whereas continental drift takes centuries.

      So in reality, it is the inertia of the water that makes it more buoyant at the equator. The water at the equator is spinning faster than the water at the poles, so it is slightly less subject to gravity. Therefore it bulges out, "making room" for some extra water from the poles to move towards the equator.

      -a

  17. A reference on leap seconds by Adam+J.+Richter · · Score: 5, Informative
    The earth's rotation is slowing anyway. This is the reason that they insert those "leap seconds" every few years to compensate for the lost time.

    At first, I did not believe that such a small change could account for the leap seconds, but you're right :

    Through the use of ancient observations of eclipses, it is possible to determine the average deceleration of the Earth to be roughly 1.4 milliseconds per day per century.

    [...] Over the course of one year, the difference accumulates to almost one second, which is compensated by the insertion of a leap second into the scale of UTC with a current regularity of a little less than once per year. Other factors also affect the Earth, some in unpredictable ways, so that it is necessary to monitor the Earth's rotation continuously.

    In order to keep the cumulative difference in UT1-UTC less than 0.9 seconds, a leap second is added to the atomic time to decrease the difference between the two. This leap second can be either positive or negative depending on the Earth's rotation. Since the first leap second in 1972, all leap seconds have been positive and there were 22 leap seconds in the 27 years to January, 1999. This pattern reflects the general slowing trend of the Earth due to tidal braking.

    1. Re:A reference on leap seconds by j_w_d · · Score: 3, Funny

      Based on this information, if the earth loses about 1 second every year, and given: 60 secs/min *60 min/hr *24 hrs/day, there are 86,400 seconds in a day. It follows then that in 86,400 years, the earth stops and starts turning backwards. Obviously this has to be the explanation for geomagnetic reversals. The earth as a washing machine.

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  18. round or flat? by Lxy · · Score: 3, Funny

    It took centuries for explorers to convince the world that the earth was round. Now it's flat again. What are we supposed to teach our children?

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  19. Actually its pretty scary... by Evil+Pete · · Score: 5, Interesting

    There appears to be a movement of a huge mass from the poles to the equator over the last 4 years. The article describes how they excluded the obvious culprits: melting ice, earth movements, atmosphere etc. And finally concluded that it is related to ocean circulation. Now that gives me the creeps!

    Why the creeps? Because ocean circulation changes can happen relatively quickly and are implicated in the starting / stopping of ice ages. They are crucial indicators for climate change. And when the ocean circulation changes there is nothing humans can do about it.

    Hopefully it either isn't the oceans or if it is it wont have a serious effect (dont believe my own words here ... but it sounds comforting). Whatever, this requires some serious investigation, just hope they got it wrong.

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