Playboy Interview: Carl Sagan

Playboy Interview: Carl SaganBillions and billions of years ago (about 15, give or take a few billion), the universe, in its present incarnation, was formed. To get a sense of how recently humans came onto the scene, imagine the history of the universe condensed into a single year. If the Big Bang that likely started it all was on New Year's Day, the Milky Way originated on May Day and the solar system on September ninth. Earth didn't show up until mid-September and, around November 15--halleluj...