Jeppsons appear to have missed the obvious answer. If the maps are designed
for use by aviators and the maps only display units of measure that are used by
aviators on the grounds that additional units would compromise safety, then I
would reluctantly agree that they have a case. However the case that they put
is a load of rubbish.
----- Original Message -----
From: Bill Hooper
To: U.S. Metric Association
Sent: Tuesday, March 06, 2007 4:37 AM
Subject: [USMA:38082] Re: Map Scale
On 2007 Mar 5 , at 10:47 PM, Pierre Abbat wrote:
I found the figure of 24,901.55 miles for the equatorial
You should know this in metric,
I DO know it
that figure (the equatorial circumference of the Earth) in metric, to the
nearest megametre. That wasn't the problem here. I was trying to trace the
reasoning from the given data which started with miles and nautical miles.
But, even if I had wanted to start with metres (or megametres), the precision
with which the information was given required a more precise value of the
Earth's equatorial circumference than is provided by the old approximate 40,000
km (or 40 Mm). The more precisely known value is 40,075.16 km which can be
found on the same web page where I got the figure of 29,901.55 miles.
Regards,
Bill Hooper
Fernandina Beach, Florida, USA
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SImplification Begins With SI.
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