When asked to describe his journey with The Ocean Cleanup in a single word, Boyan Slat paused only briefly."Solvable."It is perhaps not the answer one would expect from someone who has spent the last 12 years trying to tackle one of the world's biggest environmental challenges.After all, plastic pollution is often spoken about as if it were inevitable—too vast, too complex, and too deeply embedded in modern life to ever truly fix.Slat disagrees.…