Scientists debate controversial theory predicting the end of humanity

Scientists are revisiting a controversial mathematical theory known as the "Doomsday Argument," which posits that humanity has a finite lifespan and could face extinction in roughly 17,100 years. While this prediction may sound alarming, the theory's proponents emphasize it does not specify a cause for extinction but rather estimates a potential end date based on statistical probability.

The argument, first proposed by astrophysicist Brandon Carter in 1983, is rooted in the Copernican Principle, suggesting humans do not hold a special place in the universe or history. It uses an individual's position within the total number of humans who have ever lived as a statistical benchmark. Assuming approximately 117 billion people have lived to date, and with a 95% probability that we are not in the earliest stages of human existence, the theory estimates the total number of future births may not exceed 2.34 trillion.

If current birth rates continue, this number could be reached in about 17,100 years. However, the theory's authors stress this is not a definitive prediction of extinction but a probabilistic warning. It suggests a 95% chance that humanity will cease to exist before reaching that total population milestone. Potential causes for extinction, though not predicted by the theory itself, often cited by scientists include nuclear war, climate change, pandemics, asteroid impacts, and artificial intelligence.

Despite its intriguing premise, the Doomsday Argument faces significant criticism from many scientists, mathematicians, and statisticians. They argue that its assumptions are too uncertain. Critics point out that future population numbers will be influenced by numerous factors, such as declining birth rates, medical advancements, economic shifts, and technological development, rather than mere chance. Furthermore, the theory often fails to consider the possibility of humanity establishing permanent settlements on other planets.