"Il ciclotrone" is the weekly science programme of "Radio Popolare - Popolare Network". During the last 12 years, once or twice a month listeners have been able to directly ask questions to the guest scientists in the studios, or to express their point of view on some controversial scientific issue. Phone-ins at Radio Popolare are not filtered; regular and occasional listeners are used to communicate with or through the radio, and in doing so they contribute to the sense of spontaneity which characterise the programmes.