Serbian archaeologists say a 7,500-year-old copper axe found at a Balkan site shows the metal was used in the Balkans hundreds of years earlier than previously thought. The find near the Serbian town of Prokuplje shifts the timeline of the Copper Age and the Stone Age's neolithic period, archaeologist Julka Kuzmanovic-Cvetkovic told the independent Beta news agency. 'Until now, experts said that only stone was used in the Stone Age and that the Copper Age came a bit later. Our finds, however, confirm that metal was used some 500 to 800 years earlier,' she said. The Copper Age marks the...