It sounds like something out of a science fiction movie; Up to 20 million tons of debris—including fridges, cabinets, televisions and a 20-foot-long fishing boat—and other remnants of the 2011 Japanese earthquake and tsunami are slowly drifting across the ocean toward Hawaii and the continental United States. The debris is expected to reach the Hawaiian islands within the next two years, and will take another year to reach California and the rest of the west coast…