From: kroach025_at_hotmail.com
Date: Tue Mar 22 2005 - 14:45:12 PST
Experiment Report for the Eratosthenes Project on http://youth.net/ School Name: King Open School School Location: Cambridge, Massachusetts (42:22:18N 71:05:30W) Email Address: kroach025_at_hotmail.com Experimenter: Kevin Roach (teacher) Latitude 42:22:18N Longitude: 71:05:30W Distance to Equator: 2858km Measured shadow angle in degrees: 40.39 Calculated Earth circumference: 25473.6 mi Comments: Since we couldn't do the experiment on the equinox, and it was cloudy the next day, we did the experiment at local noon (11:51)on Tuesday, March 22. Eighteen students measured the angle, our reported value of 40.39 was the mean value across the 18 students. Since we were two days late, we knew that at local noon the sun wouldn't be directly overhead at the equator anymore. We used the US Navy Observatory information to find that at local noon on 3/22 the sun would be directly overhead at 00:51N. So we calculated our distance to 00:51N (2858 mi) rather than to the equator (which would have been 2916 mi).