“Welcome to the CMS Experiment. We are 100 metres underground and I will now pass by the eye scanner to take you for a virtual tour and show you our massive scientific machine,” said CMS physicist, Abdollah Mohammadi, to 200 enthralled students sitting in the hall in the Sharif University of Technology in Iran last Tuesday.
Each year, CERN welcomes around 100,000 visitors onsite. Many of these visitors take a short trip from the laboratory's main site in Meyrin to the French commune of Cessy to see one of humankind's modern scientific marvels: the CMS detector. The 14000-tonne detector is located in a vast cavern around 100 metres (or about 30 storeys) underground, with an adjacent cavern housing several data-collection and power-distribution devices.