Colonization

When I Googled colonization I found a really interesting article from the New York Times, called "A Survival Imperative for Space Colonization" by John Tierney. This article is about how scientists think humans on earth will only survive for 5,100 more years. Many scientists also think that we need to start up a colony on Mars in the next 46 years in order to survive. The scientist who predicted this number is Dr. Gott. Dr. Gott uses the Copernican formula to predict things like when all of mankind will be wiped out. He also uses the Copernican formula to predict things like political rulers will stop ruling. In the article I was reading they explained how to get your accuracy percent when wanteing to predict something like when political leaders resign, but i really did not understand it.