NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Location Center of Responses thus Far
From: George Huxtable
Date: 2001 Jul 23, 4:15 PM
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. > >Hmmmm... > >Daniel K. Allen >danallen@nwlink.com >http://www.nwlink.com/~danallen/ >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.u-net.com George Huxtable, 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. Tel. 01865 820222 or (int.) +44 1865 820222. ------------------------------
