THERE WERE PRIOR CIVILIZATIONS ON EARTH BEFORE US, OR NOT. YOU GET TO DECIDE.

Scientists like astrophysicist Adam Frank and climatologist Gavin Schmidt explored this concept not to prove the existence of a past civilization, but to understand what evidence such a civilization might leave behind and to help refine the search for life on other planets.

Lack of Evidence: The primary argument against previous advanced civilizations is the complete absence of physical evidence. We have uncovered fossils of dinosaurs from over 100 million years ago, and we find stone tools and skeletal remains of early hominids dating back millions of years. We have found no evidence of technology, complex structures, or widespread industrial activity that would indicate an advanced, non-human civilization.
Geological Record Limitations: Earth’s surface is constantly being recycled through tectonic activity, erosion, and sedimentation. Over tens of millions of years, most physical artifacts on the surface would be destroyed or buried deep within the crust. The oldest exposed large-scale surface on Earth is only about 1.8 million years old, a tiny fraction of the planet’s history.
Geochemical Signatures: An industrial civilization would leave behind a global “geochemical fingerprint” in the form of specific pollutants, synthetic chemicals (like plastics or PCBs), or unusual isotopic ratios from burning fossil fuels and nuclear processes. Scientists have not found any such anomalies in the geological record before the current human-driven Anthropocene era.

While the vastness of geological time allows for the possibility that evidence was lost, there is currently no scientific evidence to suggest that any advanced civilizations existed on Earth before our own.

2. Ancient Sumerian Knowledge of the Cosmos