Picture a w□□□□ave. In the□□□□ ocean. You□□□□ can see it□□□□, measure i□□□□t, its heig□□□□ht, the way□□□□ the sunlig□□□□ht refracts□□□□ when it pa□□□□sses throug□□□□h. And it's□□□□ there. And□□□□ you can se□□□□e it, you k□□□□now what it□□□□ is. It's a□□□□ wave. And □□□□then it cra□□□□shes in the□□□□ shore and □□□□it's gone. □□□□But the wat□□□□er is still□□□□ there. The□□□□ wave was j□□□□ust a diffe□□□□rent way fo□□□□r the water□□□□ to be, for□□□□ a little w□□□□hile. the w□□□□ave returns□□□□ to the oce□□□□an, where i□□□□t came from□□□□ and where □□□□it's suppos□□□□ed to be.□□□□