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Researchers Develop the Most Detailed Map of Gravitational Variations Ever

Posted by samzenpus on from the he's-not-heavy dept.

schliz writes "An Australian-German team of researchers has developed the most detailed map of gravitational variations ever, using satellite data, gravitational readings and small-scale topographical models. They say the data will help civil engineers and miners, and will be available for free online. Gravitational fields vary because the Earth isn't perfectly spherical. According to the new map, the field is 0.7% greater near the North Pole (9.83ms-2) than at Peru's Nevado Huascaran summit (9.76ms-2). The difference is 40% more than previously expected."

18 of 88 comments (clear)

  1. direct link by schneidafunk · · Score: 5, Informative

    Here is a direct link to the map if you are wondering where you'll be the lightest :)

    --
    Some people die at 25 and aren't buried until 75. -Benjamin Franklin
    1. Re:direct link by Cryacin · · Score: 4, Funny

      The important question: Are they attracting tenure with the weight of their research?

      --
      Science advances one funeral at a time- Max Planck
    2. Re:direct link by LWATCDR · · Score: 2

      Probably should be most detailed map released to the public. The Military of both the US and Russia/USSR have been working on maps of gravitational variations for decades.

      --
      See my blog http://ilovecookes.blogspot.com/ for light hearted technical information.
    3. Re:direct link by rwise2112 · · Score: 2

      Probably should be most detailed map released to the public. The Military of both the US and Russia/USSR have been working on maps of gravitational variations for decades.

      It would also be only the most detailed measured using sattelites. More detailed maps can be made using measurements from airborne gravimeters or surface measurements. They are used often for oil and mineral exploration.

      --

      "For every expert, there is an equal and opposite expert"
  2. Your Mom's House by Esion+Modnar · · Score: 4, Funny

    The gravity field spikes hard there.

    --

    They say the first thing to go is your penis. Well, it's either that or your brain. I forget which...
    1. Re: Your Mom's House by camperdave · · Score: 3, Interesting

      True, but the real question is whether the increase in gravitational pull due to the extra mass of the mountain is greater than or less than the decrease in gravitational pull you experience by being further away from the center of the Earth due to the height of the mountain.

      --
      When our name is on the back of your car, we're behind you all the way!
    2. Re: Your Mom's House by Anonymous Coward · · Score: 2, Interesting

      If you RTFA...

      All quantities are given at the Earth’s surface as defined through the SRTM (Shuttle Radar
      421 Topography Mission) topography. Users wishing to use geoid heights instead of quasigeoid
      422 heights can do so by applying standard conversion as described, e.g., Rapp [1997].

      If you want a more generic explanation of gravity anomalies? Perhaps this will help... http://www.cage.curtin.edu.au/~will/grav_anoms.htm

  3. this is just the first step. by nimbius · · Score: 4, Funny

    the more challenging and involved effort will be the calculus of integrating this detailed graviton map into future "your mother is so fat" jokes.

    --
    Good people go to bed earlier.
  4. Don't know their science by Daimanta · · Score: 2, Informative

    From the article: That means a 100kg person weighs 700g more near the North Pole, where gravity is 9.83ms-2, than at Peru’s Nevado Huascaran summit, where gravity is 9.76ms-2.

    They are implying that mass is a function of gravity. Everybody who has had the most basic fundamentals of physics knows that mass doesn't change, only weight(measured in newtons)

    --
    Knowledge is power. Knowledge shared is power lost.
    1. Re:Don't know their science by RichMan · · Score: 3, Insightful

      Grocery stores "weigh" everything in grams. Grams might be mass but the general populace uses mass interchangeably with weight.

      Hmm, can we use the map to get global scale calibrations to a normal mass. It would seem to be unfair that the same amount of material might cost more or less in different places due to scale errors that measure weight and use it blindly as mass.

    2. Re:Don't know their science by i+kan+reed · · Score: 2

      Secretly, regular people who live in SI countries don't use or understand Newtons unless they're scientists.

    3. Re:Don't know their science by Dunbal · · Score: 2

      No, they are implying that here on earth, scales measure weight not mass, and the unit for weight and mass is one and the same on this planet. Tell me who actually uses the Newton to express their weight, outside a physics/engineering context?

      --
      Seven puppies were harmed during the making of this post.
    4. Re:Don't know their science by Kjella · · Score: 5, Interesting

      Hmm, can we use the map to get global scale calibrations to a normal mass. It would seem to be unfair that the same amount of material might cost more or less in different places due to scale errors that measure weight and use it blindly as mass.

      For weights that are comparing against a known mass there is no problem. The 1 kg of material you want to buy will always weigh the same as the 1 kg on the other side of the scale weight, no matter if it's 9.76 or 9.83 newtons on each side. So these "global scale calibrations" just involve transferring around known masses and has been done for centuries. The only way the scale would be off would be if one arm was on the North Pole and the other in Peru.

      --
      Live today, because you never know what tomorrow brings
    5. Re:Don't know their science by rwise2112 · · Score: 2

      From the article: That means a 100kg person weighs 700g more near the North Pole, where gravity is 9.83ms-2, than at Peru’s Nevado Huascaran summit, where gravity is 9.76ms-2.

      They are implying that mass is a function of gravity

      Not really. They specifically say "weighs", which is weight, not "masses".

      --

      "For every expert, there is an equal and opposite expert"
    6. Re:Don't know their science by jalopezp · · Score: 2

      Actually, they are not. No one thinks mass depends on gravity. What the article actually says is:

      That means a 100kg person weighs 700g more near the North Pole

      Weighs 700g more. Weighs. They are merely saying that weight is a function of gravity, which is of course, true.

      You are confused by the units they are using. This is actually the kilogram-force, a non-SI unit of weight, which converts to about 9.8N or 2.2lb. Cool, no?

  5. no key or legend by Gravis+Zero · · Score: 2

    it's great and all that they posted a pretty picture but they forgot to add a key or a legend of some kind. a color gradient scale with some kind of metric is the least they could do, even the weather channel knows that!

    i'm sure the people who made this are the same damn kids that keep walking on my! </rant>

    --
    Anons need not reply. Questions end with a question mark.
    1. Re:no key or legend by AJWM · · Score: 3, Informative

      Of course there isn't. That's why boats float.

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      -- Alastair
  6. Re:"most detailed" too strong a claim by Voice+of+satan · · Score: 2

    Indeed,

    The US, the French and probably the Russians have their own classified gravity maps. Essential to improve inertial guidance of ICBMs so the ones launched by submarines match the precision of ground based ones. I had a colleague whose works on acoustics where classified by NATO. It means he was forbidden to publish his work. I Guess this hasn't changed a lot and that a too precise gravity map could not be released even today.