Imagine floating through the air, standing on the ceiling, or leaping upstairs in one big bound! An astronaut traveling through space can do all of these things. But on the earth, you can't. You...
High tide, low tide
It is early in the misty morning. You are standing on a cliff that overlooks the sea. Gulls soar overhead, calling to one another with shrill cries. Below you, the gray sea crashes against the shore....