That black hole that was going to eat the Earth? Forget about it, and keep making the mortgage payments — those of you who still have them. A new particle accelerator, the Large Hadron Collider scheduled to go into operation this fall outside Geneva, is no threat to the Earth or the universe, according to a new safety review approved Friday by the governing council of the European Organization for Nuclear Research, or Cern, which is building the collider. “There is no basis for any concerns about the consequences of new particles or forms of matter that could possibly be...