San Francisco Chronicle: After more than a decade of work and an investment of $3.5 billion, scientists at Lawrence Livermore National Laboratory say they have created a super laser that will enable them to build a miniature sun within the lab in the next two years. The U.S. Department of Energy certified the world’s largest laser on Tuesday, an instrument that will test the reliability of the nation’s nuclear weapons stockpile, explore the origins of the universe and seek to create nuclear fusion …