Alexander Rose - 10,000 Year Clock

Wallace talks to Alexander Rose, director of the Long Now Foundation, about a huge clock being built to go inside a mountain in Texas. It is designed to tick for 10,000 years and every so often it will chime a melody - but never the same one twice. It will mostly ring when somebody winds it, but sometimes it will ring itself - and nobody will be there to hear it. Alexander Rose tells Wallace about the project that's designed to make us think about the generations to come, and our responsibility to them.