Archive website of the Eratos eTwinning projects since 2005 :


00.eTwinning project description

Short description:
Students from all continents join together to reproduce one of the science's 10 most beautiful experiments of all time: Eratosthenes' measurement of the Earth's circumference.
Aims :
This project is the 10th in the series of  Eratosthenes eTwinning projects "measuring the circumference of the Earth" . It is based on the experience of Eratosthenes, curator of the library of Alexandria, that 2200 years ago, calculated in a simple way, the circumference of the Earth by comparing two shadows.
Work process:
Since Eratosthenes 2010 project, the twinspace is organized upon a civil year (January to December)
Activity : Documentation. The administrators of the twinspace publish the links to the previous projects and pedagogical units.
Activity :Forum & FAQ  is the place to discuss about technics and planning (forum) and to find informations in the Frequently Asked Questions from the previous years (wiki).
Activity : Spotlight on the schools
Each school introduces itself with the location (latitude – longitude) and a group photo with the instruments and an earth globe showing the location of the school. A google map is created.
The fixed experimental activities correspond to the astronomical dates of the equinoxes (spring and autumn) and solstices (summer and winter)
Other experimental activities are planned at the request of schools in connection with festivals: Science Mela in India, feria de ciencia in South America, fête de la francophonie.
The planification of an event by the teachers can be done exchanging messages in the twinspace or better , using the social network group
For each measure experimental data are exchanged (latitude, longitude,date, UTC time of the measure, length of the shadow, height of the gnomon)
For each measure , the schools exchange photos showing the gnomon and its shadow with the students. They can also publish a video of their measure in the twinspace blog
Then each school finds which is its best partner school , using an excel  sheet. The best partnership is the one that gives the most accurate calculation of the circumference of the Earth.
The students can draw the geometric figure or use a Geogebra construction for calculating the circumference of the Earth with 2 basic notions (alternate interior angles and proportions)
The final step of an event is a video conference in which students communicate their results
Expected results:
Measurements and observations will be written on the website and informations and results will be exchanged on the Twinspace and viconferences.
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