Eddies

In fluid dynamics, an eddy is the swirling of a fluid and the reverse current created when the fluid flows past an obstacle. The moving fluid creates a space devoid of downstream-flowing fluid on the downstream side of the object. Fluid behind the obstacle flows into the void creating a swirl of fluid on each edge of the obstacle, followed by a short reverse flow of fluid behind the obstacle flowing upstream, toward the back of the obstacle. This phenomenon is most visible behind large emergent rocks in swift-flowing rivers.

Famous quotes containing the word eddies:

“Well, Pa, a woman can change better than a man. A man lives, sort of, well, in jerks. A baby’s born or somebody dies and that’s a jerk. He gets a farm or loses it and that’s a jerk. With a woman, it’s all in one flow, like a stream. Little eddies and waterfalls, but the river, it goes right on. A woman looks at it that way.”
—Nunnally Johnson (1897–1977)

“The elaborate star-light throws a reflection
On the dark stream,
Till all the eddies gleam;
And thereupon there comes that scream
From terrified, invisible beast or bird:
Image of poignant recollection.”
—William Butler Yeats (1865–1939)

“A sweetheart from another life floats there
As though she had been forced to linger
From vague distress
Or arrogant loveliness,
Merely to loosen out a tress
Among the starry eddies of her hair....”
—William Butler Yeats (1865–1939)