Sorry 40.231.264 Kilometers best regards Hank Axel
From: [email protected] To: [email protected]; [email protected] Date: Mon, 19 Mar 2012 12:52:18 +1100 Subject: RE: Eratosthenes [SEC=UNCLASSIFIED] Hello Axel, I think you have made a mistake with the number 40231.264 (miles?). If you take the formula for size of a latitude degree, as you stated: dx/d theta = 111.133+0.559*cos(2*theta) km per degree latitude if we integrate this formula with respect to theta from 0 to 360 X = 111.133 * ( 360 - 0) + 2*0.559 * (sin(2 * 360) - sin (2 * 0)) the two terms with sin equate to 0, so X = 360 * 111.133 = 40007.88 km Cheers Hank From: [email protected] [mailto:[email protected]] On Behalf Of axel törnvall gonzalez Sent: Monday, 19 March 2012 11:42 To: Sundials Subject: Eratosthenes I am studying a subject related to the Greek Eratosthenes, as measured by the circumference of the earth, but I have a problem with measuring the distance between 2 points (coordinates) formulas I used were taken from writings of Carl Sabanski, who says that books are ancient astronomy. No further information; 1 ° latitude = 111,133 to 0,559 cos (2 x latitude) [km] 1 ° longitude = 111,413 cosine (latitude) - 0.094 cos (3 x latitude) [km] By calculation using the formula 1 ° latitude, for each grade, from 0 ° to 90 ° for the southern hemisphere and 1 ° to 90 ° for the northern hemisphere the result is 40,231.264 miles, and as I read the value is 40,009.15 km I have not found more formulas or ways of doing the calculation to get a better result. I will thank answers Best Regards Axel
--------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
