Using a video camera to measure the radius of the Earth
A simple but accurate method for measuring the Earth’s radius using a video camera is described. A video camera was used to capture a shadow rising up the wall of a tall building at sunset. A free program called ImageJ was used to measure the time it took the shadow to rise a known distance up the building. The time, distance and length of the sidereal day were used to calculate the radius of the Earth. The radius was measured as 6394.3 +/- 118 km, which is within 1.8% of the accepted average value of 6371 km and well within the experimental error. The experiment is suitable as a high school or university project and should produce a value for Earth’s radius within a few per cent at latitudes towards the equator, where at some times of the year the ecliptic is approximately normal to the horizon.
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|Item Type:||Journal Article|
|Keywords:||earth, radius , video, eratosthenes|
|Subjects:||Australian and New Zealand Standard Research Classification > EDUCATION (130000) > CURRICULUM AND PEDAGOGY (130200) > Science Technology and Engineering Curriculum and Pedagogy (130212)|
|Divisions:||Current > Schools > School of Chemistry, Physics & Mechanical Engineering
Current > Institutes > Institute for Future Environments
Current > QUT Faculties and Divisions > Science & Engineering Faculty
|Deposited On:||19 Mar 2014 22:08|
|Last Modified:||21 Mar 2014 00:50|
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