2007 by astro.perbosc
school : Gimnazjum w Toszku
city : Toszek
country : Poland
address : ul.Dworcowa 17
postal code : 44-180
latitude : 50°27’ N = 50.450°
longitude : 18°32’ E = 18.533°
year : 2007
Gimnazjum in Toszek, Poland
date : 22/03/2007
gnomon : 100 cm
shadow : 121 cm
angle : 50,4°
We are a group of students from Gimnazjum in Toszek, who work in GLOBE Program. We are 13-16 years old. We decided to participate in the Noon Day Project because we were invited for the cooperation by the school in Bardejov in Slovakia.
The day of our shadow measurements (22 March, 2007) was quite clear and the sun finally came out after many days of rain and snow enabling us to perform the checks. We were afraid that we wouldn’t manage to take measurements, because clouds covered the sky every couple of minutes.
Four groups made shadow and angle measurements at 10 minute intervals using a vertically placed meter stick. We got the shortest shadow at 11:53.
For calculations of circumference of Earth we choosed data measured by:
· High School in Kankakee, Illinois (USA)
· Aanestad Homelearners, Ladysmith , British Columbia ( CANADA )
· ZS sidl.Vinbarg, Bardejov, Presovsky kraj (SLOVAKIA )
· Roemer Academy, Columbia, Missouri (USA)
· Hillcrest Middle School, El Paso, Texas (USA)
First, we calculated our sun’s angle using the tangent trig function. Having achieved the figures, we noted that our sun shadow measurements and our geographic latitude were nearly the same. Using the resulted angle and the one given by other partner schools we managed to find our central angle and the North/South distance. Finally, we found the circumference of the Earth.
Our best estimate of the circumference of the Earth was calculated to be 39958,7 km.
The percentage error was only 0.1%.
We think it is a very good result!
We would like to thank our partner schools for the cooperation.
This was an exciting project for us. Thanks. Gimnazjum in Toszek, Poland