Roundest Object

Discussion in 'General Science' started by Metalmann, Jan 27, 2014.

  1. Metalmann

    Thread Starter Active Member

    Dec 8, 2012
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  2. Sparky49

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    Jul 16, 2011
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    If one were to be picky; the Earth is round. :p

    Taken from the Oxford Dictionary:

    "1.2 shaped like a sphere"

    Like a sphere suggesting that it shares, but is not limited to the exact qualifications of a [perfect] sphere.

    So it would seem that to call the Earth round or spherical would be acceptable, but any mention of the Earth being exactly round or exactly spherical would not.

    Also, cool video. :D I find the processes in making something more exacting than ever before very intriguing. A lot of clever people. :)

    Sparky
     
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  3. Georacer

    Moderator

    Nov 25, 2009
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    In GPS technology, the exact shape of the Earth is called a "geoid". Quite suitable IMO.

    Spheres are not used to approximate the shape of the Earth, but ellipses are used instead.
    However, each authority publishes its own ellipsoid, depending on where the ellipsoid surface is wanted to be a more accurate fit of the surface of the Earth. This has geographical criteria.

    The world standard right now, the WGS84, is about 120 meters off over India!
     
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  4. Sparky49

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    Jul 16, 2011
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    Cool shape Geo.

    Found a cool pic from wikipedia which is quite interesting.

    [​IMG]
     
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  5. Metalmann

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    "Also, cool video. :D I find the processes in making something more exacting than ever before very intriguing. A lot of clever people."



    I remember thinking that, when I first learned to turn a true sphere on a lathe.;):D:cool:
     
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  6. atferrari

    AAC Fanatic!

    Jan 6, 2004
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    Last time I looked, it was round enough to be able to come back home after navigating around it.
     
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  7. atferrari

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    One of the best videos ever!

    Everything is well done there. Worth to spend time in watching it!
     
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  8. #12

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    Nov 30, 2010
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    120 meters...math math math...393.4 feet.
    I've mentioned this before but, the first time I had a falling out with my teacher was when I was 7 years old and the latest news from satellite measurements was "600 feet larger circumference in the southern hemisphere". I assume, over 50 years later, they are still teaching that our planet is, "round" in third grade. No child left behind, lowest common denominator, don't confuse them with facts, etc. I really must get over my false expectation that the American public schools will eventually catch up with reality.
     
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  9. Sparky49

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    Jul 16, 2011
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    By definition of 'round', it is perfectly acceptable to say it is round.

    To say that it is perfectly round, however, is not.
     
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  10. paulktreg

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    Jun 2, 2008
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    It's round. Don't complicate matters.

    I personally think it's flat and if I go further than London I'll fall off! :D
     
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  11. Sparky49

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    Jul 16, 2011
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    I did hear a rumour about this place called "up north". :D ;)
     
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  12. strantor

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    Oct 3, 2010
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    That guy was pretty excited to cup the ball.
     
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  13. NetDoc

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    Jan 6, 2014
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    Time to break out the bull doziers... Key Largo is way too low. :D
     
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  14. spinnaker

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    Wouldn't they also need to define an exact spot on the earth where a measurement is taken in order for it to be equal to the official kilogram?
     
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  15. t_n_k

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    Perhaps that's why it was made "down under".:rolleyes:
     
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  16. spinnaker

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    What??? Where was it mentioned where it was made? I don't ge it.
     
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  17. t_n_k

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    Down under = Australia. It was made by the Australian national research organisation - CSIRO.

    Google The Avogadro Project.
     
    Last edited: Jan 27, 2014
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  18. spinnaker

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    Yes I know what it means. I do not recall it being mentioned where it was made.
     
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  19. JoeJester

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    Apr 26, 2005
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    There is a spot that marks the geodetic center of the U.S. in Kansas. There are plenty of datums. In the U.S. there is NAD-27, NAD-83, WGS-84, et al.

    Google earth uses WGS-84 as the data as far as I can tell. I will say that due to the flattening of the earth, you will not land on a WGS-84 marker accurately.

    There is a Hawaii datum as well. So each country decides on their standard, and should the world decide on a standard, the political infighting will decide on the marker.

    I had a friend who stood on the prime meridian in Greenwich with his GPS. It was off until he changed his datum marker from U.S. to Great Britain.
     
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  20. t_n_k

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    It was pretty subtle. A small title bar came across the screen at the commencement of the video. Ms Katie Green spoke with an Australian accent and it seems works for the Precision Optics division of CSIRO. In any event I was aware of the project a long time ago. I live in Australia.
     
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