Stefano Campana, an archaeologist at the University of Siena, and his team used ground-penetrating radar to scan the interior of Siena's cathedral during Italy's COVID-19 lockdown, revealing evidence of earlier structures buried beneath. This success inspired Campana to create an initiative called "Sotto Siena" (under Siena) to create a complete archaeological record of the city before more of its history is destroyed.

The ground-penetrating radar technology allows archaeologists to scan beneath the surface quickly and accurately, even while traveling at high speeds. Campana's goal is to scan all the squares, roads, and courtyards in Siena, as these areas are often under threat from modern construction and development.

Immo Trinks, an archaeologist in Vienna, takes this concept to an even grander scale. He envisions the creation of an International Subsurface Exploration Agency that would scan every mappable square meter of land in Europe, including the bottoms of lake beds. Trinks argues that this is a moral responsibility, as archaeological sites around the world are disappearing due to urbanization, economic development, climate change, and conflict.

However, this big-data approach to archaeology is not without controversy. Some experts argue that it may prioritize technology over interpretive rigor and that not everything detected by radar is actually archaeologically significant. Lawrence B. Conyers, a leading expert in ground-penetrating radar, cautions against relying too heavily on the newest machines and emphasizes the importance of understanding the behavior of radar energy in the Earth.

Despite the debates, geophysical tools like ground-penetrating radar are revolutionizing archaeology, allowing for the exploration of even the most ephemeral traces of human history. This technology offers the potential to uncover forgotten cultures and expand our understanding of human history across the globe. It enables us to see the past as an archive of electromagnetic shapes, revealing the hidden collections of our human past.