“Each gyre orbits at its own speed,” he continued. “And the length of an orbit is called a tone. Isn’t that beautiful? Like the music of the spheres. The longest orbital period is thirteen years, which establishes the fundamental tone. The Turtle Gyre has a half tone of six and a half years. The Aleut Gyre, a quarter tone of three. The flotsam that rides the gyres is called drift. Drift that stays in the orbit of the gyre is considered to be part of the gyre memory. The rate of escape from the gyre determines the half-life of drift
