例二: Copernican principle The best theories are those that do not require the observerto live in a special place in the universe or at a special time in history in order to be true 25% 25% 2-5% 95% 1961 Berlin Wall story With 95% likelihood the future of In 1969. Dr Gott visit Berlin wall a thing will between 1/39 and and begin to use Copernican 39times as long as its past. principle. Result: in 50%o chance Homo sapiens(200,000 years) the wall will have at least 8/3 years We should last at least 5100 vears but not more than 24 year but less than 7. 8 million years The wall came down on Nov 1989The best theories are those that do not require the observer to live in a special place in the universe or at a special time in history in order to be true. 例二：Copernican principle Berlin Wall Story In 1969, Dr. Gott visit Berlin wall and begin to use Copernican principle. Result: in 50% chance the wall will have at least 8/3 years but not more than 24 year. The wall came down on Nov. 1989. 1961 With 95% likelihood, the future of a thing will between 1/39 and 39times as long as its past. Homo sapiens (200,000 years) We should last at least 5100 years but less than 7.8 million years