Eratosthenes Photo Contest September 2018!


Welcome to the Eratosthenes Experiment platform!

  • Register by creating your account. If you have already created one in the past, just log in and check the Eratosthenes experiment September 2018 participation box.
  • Come in contact with a registered school at the same longitude with you (this info will be provided to you by the organizing team)
  • Join efforts with the matching school and record your data
  • Calculate the circumference of the Earth
  • Submit your data and take part to the Eratosthenes Photo Contest March 2018



The Eratosthenes experiment September 2018  will take place on Monday the 24th of September, one day after  the autumnal equinox day (Sunday, 23rd of September 2018), due to the fact thatschools are not open on the exact day day of the equinox. You can perform the experiment in collaboration with another school on the same longtitude, if no other schools can be found on the same longitude -  for your matchup – you can consider the existence of a virtual school on the equator with experimental data 0 (shade of a one-meter stick measured at local noon). This way you can also have an accurate outcome by conducting the experiment by yourself. Schools that register till Monday 17th of September 12:00 CET will receive on Tuesday 18th of September an e-mail with the coordinates of potential matching schools along with the information (email) of their contact persons, so that they can communicate and arrange their match-up during the day of the experiment. Schools that register till Thursday 20th of September 15:00 CET, will receive an email during the same day (after 16:00 CET).

If you would like to perform the experiment by yourself on a date other than the 24th of September, you can use this simulator  to find the exact angle from your school to the place where the sun rays are perpendicular to the ground. 

The Eratosthenes Experiment September 2018 is organised with the collaboration of the Hellenic Mathematical Society, the participation of the UNESCO regional bureau for Science and Culture in Europe, Venice (Italy) and is approved by the Department of Education in Greece.

The action of Eratosthenes Experiment September 2018  is taking place in the framework of the European Year for Cultural Heritage 2018 (EYCH) and has been officially awarded the relevant label. You can learn more about the European Year of Cultural Heritage here




Contest Winners





  • Dr. Angelos Lazoudis
  • Phone: +30.210.8176795
  • Email:


Ellinogermaniki Agogi
Research & Development Department
Dimitriou Panagea Street
GR 15351 Pallini