A new study published on arXiv suggests that detecting advanced alien civilizations might be highly unlikely due to a “fine-tuning problem” related to their birth-to-death ratio. The study indicates that to successfully find extraterrestrial civilizations, their population dynamics must fall within a very specific range, but we currently have no way of knowing what this range might be.
Fine-Tuning Problem :
The research, led by astrophysicist David Kipping of Columbia University and Geraint Lewis from The University of Sydney, explores the delicate balance between the rate of emergence and extinction of civilizations. This balance needs to be just right for us to detect them. However, with no constraints on these rates, the exact ratio remains unknown.
Historical Context :
On Earth, the ratio of births to deaths has rarely been close to one. For instance, technologically advanced species like humans have existed for only about 100 years in a 4.6 billion-year-old planet. This limited window makes the detection of civilizations with a similar ratio even more challenging.
SETI’s Challenge :
The paper concludes that the birth-to-death ratio of extraterrestrial civilizations must be between 0.01 and 0.1 for SETI (Search for Extraterrestrial Intelligence) efforts to be successful. This narrow range reflects the “fine-tuning” required for detection.
Probability and Solutions :
Even if SETI surveys the entire galaxy, the absolute probability of finding extraterrestrial intelligence remains extremely low—estimated at once in 10 million trillion. The study suggests that overcoming these odds may require significant changes in our current understanding or a unique cosmic positioning, such as being in a quieter part of the galaxy.
Despite the bleak odds, the authors argue that SETI searches are still crucial. They emphasize that while the chances of success are slim, finding alien civilizations would be an unprecedented discovery. The paper also mentions alternative hypotheses, like the “Grabby Aliens” theory, which could offer hope for increasing the likelihood of success.
