The PastPhone uses artificial intelligence to make phone calls with people from the past. These conversations take place via a voice interface, making the interactions feel authentic and lively. This makes exhibitions interactive and playful. The PastPhone also serves as an introduction to the use of AI for school classes, teaching how the technology works and how it can be used. The PastPhone is currently on display in the «Wealth» exhibition at Ritterhaus Bubikon, where visitors can talk to a knight, an abbess and a medieval child.