To help visualize that massive heap of trash, Wilson divides by a "supertanker" - that is, a giant ship that could theoretically sail through the seas, skimming out the plastic junk as it goes (much of which hovers down to 90 feet below the surface).
No such ship has been outfitted to skim plastic. But let's say it did, and it could hold 500 million pounds of plastic. You'd need 630 of them to do the job, or about 17 percent of the planet's current fleet of oil tankers.
To make it a little more personal, every American produces about 600 pounds of garbage each year. The proportion of plastic varies from household to household, but overall about half of all waste is synthetic. Some of that probably ends up in landfill, or recycled (Wilson says only about 3 percent of virgin plastic gets recycled).
Either way, the pile of plastic you inadvertently dump into the ocean each year is probably more than you can lift.
The point of the calculations is this: cleaning up the plastics in the ocean ain't gonna happen. Well-intentioned programs designed to take the fight to the high seas, like Project Kaisei and the Environmental Cleanup Coalition, for example, are exercises in futility.