Final Reports - Noon Day Project March-April, 2007
Posted: 27 Apr 2007 01:22
Our Report from Bar Harbor's Fifth Graders

Our school is called Conners-Emerson. It is a K-8 school. We are in fifth grade reading Gifted. We live on an island of the coast of Maine. It’s location is lat. 44.39 N and long. 68.21W.

To figure out the circumference of the Earth, we figured out when high noon would be on the Equinox and at that time we got together with our sun-shadow apparatus and watched the shadow until it got as short as it would. To see a picture of us, and a diagram we made of our apparatus, please go to our school gt website:$139

If we could do anything differently then, we would have made our meter stick steadier because it wasn’t at a right angle. It was a really windy day, and the wind really made it hard to keep the stick vertical. We learned that if you are a few degrees off, the measurements are really a few thousand kilometers off.

To find the circumference of the Earth, our calculations looked like this:

1. Our Sun Angle (44.00) minus Fox Focus’ Sun Angle (34.25) equals 9.75°

2. To find the North-South distance we subtracted Our Latitude (44.39N) minus Fox Focus’ Latitude (34.01N) which equals 10.38. Because we know that 1° equals 111 km, we multiplied the difference in latitude (10.38°) by 111 and got 1152.18 km, our North-South distance.

3. Then (remember the Sun angles?) we divided 360° by the difference of Fox Focus’ Sun Angle and Our Sun Angle (9.75°). Multiply that by 1152.18 km, and you get the Earth’s circumference, 42531.84 km!!!

4. The difference between our measurement and the real circumference is 2,466 km.