Tom Griffiths is the W K Hancock Professor of History at the Australian National University and has written a history of Antarctica entitled Slicing the Silence: Voyaging to Antarctica. In January this year he joined the centennial voyage to Mawson's huts in Antarctica. Tom's books and essays have won prizes in literature, history, science, politics and journalism, most recently the Prime Minister's Prize for Australian History in 2008 and the 2009 Alfred Deakin Prize for an Essay Advancing Public Debate. TEDxSydney 2012 took place on Saturday 26 May 2012 at Carriageworks. Tens of thousands of people enjoyed the day: 800 in the theatre, over 1,000 via big screen simulcast in The Forum, many thousands online via YouTube and ABC Big Ideas ... and up to 80,000 tuning in to ABC Radio National. Watch Tom's presentation. Photo: Fe Lumsdaine, Lumsdaine Photography .