„I think you can understand time just by the fact that everything, everything changes. Everything ages. You’re born, you die. The living beings as the objects if they are new, then they become old. Even the stones, even in our Earth, aged four and a half billion years, has changed enormously. So we can define time only thanks to the fact that everything changes.“
Interview with Euronews' Claudio Rocco in 2011; as quoted in " Science says 'ciao' to Italy's Margherita Hack: the 'lady of the stars'", euronews.com (1 July 2013) https://www.euronews.com/2013/07/01/science-says-ciao-to-italy-s-margherita-hack-the-lady-of-the-stars.