Horizon: The 10 Million Pound Challenge

To celebrate its 50th birthday, Horizon invites the public to play a role in tackling the greatest challenges facing science today. This special episode launches the 10 million pound Longitude Prize 2014 to find solutions to a new scientific challenge. Horizon explores six potential challenges nominated by a new Longitude Committee, and launches a vote to determine which should be put forward as the new Longitude Prize. The question is 'if you had 10 million pounds to make one change to the world, what would you do?'