Dr. Sophia Kremydi describes the history of her discipline, Numismatics, the study or collection of coins, paper currency, and medals. She tells us all about its origin and its evolution from the private to the public collections we admire today; and explains that the reason we collect ancient coins is not only, out of curiosity, but because they’re an important primary source of historical information that we can’t find from other sources. She also compares the ancient economies to the modern ones (simpler and more complex, at the same time) and tells us about her own research on ancient Macedonian coins; her two books to be published soon; as well as the creation of online databases on the subject, which will be shared and updated by researchers all over the world. Interviewed by Yannis Rizopoulos for Tech Talks Central.