Unveiling the Oxygen Connection: From Alien Life to Earth's Origins
Astronomers argue that for technologically advanced extraterrestrial civilizations to exist, planets need to have significant atmospheric concentrations of oxygen, as it is crucial for open air combustion and metallurgy. The development of technology, including the ability to extract and purify metals, relies on easy access to fire. The presence of oxygen is also essential for the establishment of advanced technological civilizations that can be detected through astronomical observations. The authors suggest that the minimal amount of oxygen needed for complex life is less than that needed for combustion, implying that there might be planets with the right amount of oxygen for complexity and intelligence, but not enough for technology. The history of oxygen concentrations on Earth indicates that flammability could have been highly variable, potentially affecting the development of advanced technologies.