If you haven't already, meet the Great Pacific Garbage Patch, a collection of oceanic junk that has ballooned over the last four decades. No one is sure how big it is, but it's probably enormous. A new study in Science Magazine tried to pin down some firm numbers by digging into various data: waste generation per person, the portion of that waste that's plastics, the size of populations near the coast, and the quality of countries' waste management systems.