This week more than seventy thousand people are gathering in the middle of the desert in Nevada for Burning Man - part festival, part counter-culture phenomenon. This year it's the event's thirtieth anniversary - and we've been speaking to founder and Chief Philosophical Officer Larry Harvey about how they first got started.Picture: Dancers at the 1998 'Burning Man' festival create patterns with fireworks in the Black Rock Desert of Nevada just prior to burning a five-story, neon-lit effigy of a man on the last night of the week-long festival (MIKE NELSON/AFP/Getty Images)