The sounds of the cosmos: introducing gravitational waves to the public at a public science festival

The rapid growth of scientific knowledge creates a widening gap between formal science education and ‘frontier science’, i.e. cutting-edge discoveries and methods that have not yet been systematically incorporated into school curricula. In this paper, we investigate how informal science exhibitions can help address this challenge by using gravitational wave astronomy as a paradigmatic frontier-science topic. We present the design and evaluation of Sounds of the Cosmos, an interactive installation developed for the Athens Science Festival to introduce the public to gravitational waves and related astrophysical concepts. Over 1,000 visitors engaged with the installation's seven interactive stations, which combined physical models, visual media and a virtual tour of the Virgo interferometer. Tracking of 745 visitors showed high completion rates and an average dwell time of 11.8 min, while 111 exit questionnaires indicated strong interest and perceived learning but modest quiz performance. These results suggest that informal exhibitions can make frontier science approachable and emotionally engaging, especially when facilitated and multimodal, but that they are unlikely on their own sufficient to secure robust conceptual change. We therefore argue for integrating such experiences with pre- and post-visit activities that connect explicitly to formal curricula.