If another advanced civilization lived on Earth before us, would we know?
6 hours ago
- Astrobiologist Adam Frank questioned whether alien civilizations experience climate change, leading to a collaboration with NASA scientist Gavin Schmidt.
- Schmidt challenged the assumption that no prior advanced civilizations existed on Earth, sparking the 'Silurian hypothesis'—named after a fictional race from 'Doctor Who'.
- The hypothesis explores if an ancient industrial civilization on Earth could have left detectable traces in the geological record after millions of years.
- Evidence such as urbanization, fossils, and chemical changes (e.g., carbon pollution) is examined, but Earth's dynamic processes (e.g., tectonics, erosion) erase most surface features.
- The Paleocene-Eocene Thermal Maximum (55 million years ago) is noted for its similarity to modern human-driven climate change, though its cause is likely natural.
- Scientists conclude that indirect traces like plastics, artificial hormones, and heavy metals could persist in sediments, but a 100,000-year civilization would be hard to detect.
- The hypothesis is a thought experiment to question civilization sustainability, with Frank suggesting humans may fail to manage climate impacts despite technological advances.
- Geologist Jan Zalasiewicz argues that modern human activities (e.g., energy use, waste) leave unmistakable footprints, ruling out a prior similar civilization.
- The research aims not to prove the hypothesis but to encourage high-resolution searches for past civilizations, highlighting the need for planetary stewardship.