Mark McClusky says for elite athletes today, pushing boundaries and breaking records is all about "the aggregation of marginal gains."
German Chancellor Angela Merkel arrived in Athens Tuesday amid draconian security measures and mass protests. It’s her first visit to Greece since the eurozone crisis started three years ago. Her visit is intended to show support for the Greek government as it implements strict austerity measures many Greeks feel were imposed on the country in order to get a bailout. The BBC’s Mark Lowen reports.