What is the Earth’s circumference? Ask any student at Marwari Vidyalaya High School, Girgaum, and they’ll happily tell you it’s approximately 40,000 km. For, after a year of preparation, the school participated in an international experiment spanning 23 countries to measure the girth of the planet on July 27.

For two hours, the students took readings of the shadow cast by this stick and compared the observations with schools from across the globe to reach the final result