A Silicon Valley startup claims it can turn mercury into gold. San Francisco, California-based Marathon Fusion is proposing a process that uses nuclear fusion to turn mercury into gold — something that has been sought by people for thousands of years. "Unlike previous attempts, our method is massively scalable, pragmatically achievable, and economically irresistible," Marathon Fusion said on its website. "Using our approach, power plants can generate five thousand kilograms of gold per year, per gigawatt of electricity generation (~2.5 GWth), without any compromise to fuel self-sufficiency or power output." In a Cornell University scientific paper submitted July 17, Marathon...