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    Re: Location Center of Responses thus Far
    From: George Huxtable
    Date: 2001 Jul 23, 4:15 PM

    Dan Allen wrote-
    >The following people have replied so far to my request for location:
    >NAME             LAT     LON
    >Allen Dan        47.482  121.798
    >Arrouye Yves     37.892  122.997
    >Emerson Rick     40.245   75.252
    >Gilbert Greg    -35.167 -138.75
    >Hogan Dan        33.147  117.958
    >Huxtable* George 51.6      1.28
    >Murdoch* Bill    36.548   82.562
    >Ouvry Philip     42.43    -3.15
    >Sher* Russell   -33.933  -18.367
    >Simmonds John   -37.353 -143.635
    >Smith Peter      42.217   71.283
    >Talge Gordon     34.052  117.253
    >Taylor* Chuck    47.9    122.3
    >Tripp Steven     37.5   -140
    >* = Position approximated by looking up city in Encarta World Atlas
    >(North and West are positive, South and East are negative)
    >Using these 14 data points, the average latitude is 24.6 North,
    >and the average longitude is 27.7 West, a spot 487 nautical miles
    >north of Mindelo, Cape Verde islands in the central Atlantic ocean.
    >This is quite a distance from the nearest restaurant.
    >The nearest spot on a continent is Nouakchott, Mauritania, 761 nmi SE.
    >It is 1177 nautical miles NE to Casablanca in Morocco.
    >Daniel K. Allen
    >Measure | Analyze | Communicate
    I have been pondering on what would be a meaningful way to define a centre
    of gravity for individuals members scattered over the surface of a sphere.
    Somehow, I doubt whether averaging latitudes and then separately averaging
    longitudes provides the best answer. It should be possible to do the job
    properly, for anyone with a bit of time on his hands. Here is a suggested
    mechanical analogy.
    Take a globe of the world, that will float. For example, I have a beachball
    printed with the World on its surface, crudely marked with lat and long. If
    you put it into a pool, it will float any way up, like most spheres.
    Now glue on to its surface a set of identical coins or weights, one for
    each member, in the spot where they live, and chuck it into the pool again.
    Now, the lowest point of this globe represents in some way a centre of
    concentration of the members.
    It should be possible to devise a computer analogy to avoid having to do
    the physical experiment. Would it produce the same answer as Dan Allen's
    method? I wonder...
    Just a thought,
    George Huxtable.
    George Huxtable, 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.
    Tel. 01865 820222 or (int.) +44 1865 820222.

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