This podcast episode explores the possibility of technologically advanced species existing on Earth before humans. It challenges the conventional belief and raises questions about how we would detect traces of a previous civilization and if evidence can be found in Earth's history. The concept of deep time, the extensive duration of Earth's history before humans, is discussed, highlighting the challenges of imagining the existence of ancient species. The podcast also explores how humanity's presence will be recorded in the geologic history of the Earth and the importance of understanding our impact on the geologic record. The concept of the Anthropocene, a period in which human activities have impacted the geologic record, is examined, and the challenge of distinguishing between natural occurrences and signs of human impact is raised. The episode concludes by discussing the ongoing search for evidence of advanced civilizations before humans and the need for sustainable civilizations.