Nathalie Cabrol — Astrobiologist and director of the Carl Sagan Center at the SETI Institute. She explores Earth's harshest environments, including high-altitude volcanic lakes, and holds the women's world record for diving at altitude (both scuba and freediving).
The gist
Nathalie Cabrol explains how studying extreme environments on Earth, especially high-altitude volcanic lakes in the Andes, helps scientists understand what life on early Mars might have looked like and how to detect it. The conversation ranges across the origin and nature of life, why she believes the search should shift from finding life to understanding the universal 'nature' of life, and how life may be the universe's way of fighting entropy. She and Lex debate AI, humanity's growing pains as a 'teenager' civilization, UFOs versus the science of SETI, and the Fermi Paradox. She also tells a harrowing first-person account of free diving near-disasters and surviving an earthquake and volcanic eruption during a summit expedition, and closes on grief for her late husband and love as a driving force.
Big reveals
- States that if we are alone in the universe it would be a 'statistical absurdity,' and says she has no doubt the universe is teeming with life.
- Suggests the extraterrestrial 'message' may be all around us and the way to find it is by studying life here on Earth.
- Reveals there is still no government agency funding the SETI search for messages; it remains privately funded due to UFO folklore stigma.
- Recounts a free-diving near-death when trapped air in her dry suit pinned her upside down underwater at 20,000 feet.
- Describes surviving a magnitude 7.8 earthquake 50 meters from a volcano summit, then a neighboring volcano beginning to erupt.
- Describes a transcendent dive experience where she felt no separation between herself, the water, and the volcano.
- Openly discusses having attempted suicide as a young person and the lesson to 'give tomorrow a chance.'
- Shares that her husband, 44 years her senior, died the previous August, calling grief 'the toughest mountain I ever climbed.'
Things worth remembering
- After Mariner 9 arrived, a planet-wide dust storm hid Mars for three months before revealing volcanoes, valleys, and channels.
- It took roughly 82 percent of Earth's geological history to go from simple microbial life to animal complexity.
- Stromatolites, rock formations built by microbes, are a key recognizable trace life leaves behind.
- References Jeremy England's theory that life is the inevitable result of thermodynamics, the best way to fight entropy.
- Argues human language is structured exactly like life, atoms to molecules mirrored by letters to words, a 'fractal universe.'
- Used Navy SEAL commando rebreathers (pure oxygen) to avoid the bends while diving at 20,000 feet.
- After 20 years, the rugged cyanobacteria she studies are nearly identical to organisms that made Earth's first fossils 3.5 billion years ago.
- Andean bacteria keep their UV defenses on permanently, while California cyanobacteria switch them on and off daily.
- Mars may have formed faster and had water earlier than Earth, possibly making it habitable before Earth was.
- Current human choices are driving the disappearance of about 150 species every single day, part of a sixth mass extinction.