Shadow Propagation Speed
The farther the distance from the object blocking the light to the surface of projection, the larger the silhouette (they are considered proportional). Also, if the object is moving, the shadow cast by the object will project an image with dimensions (length) expanding proportionally faster than the object's own rate of movement. The increase of size and movement is also true if the distance between the object of interference and the light source are closer. This, however, does not mean the shadow may move faster than light, even when projected at vast distances, such as light years. The loss of light, which projects the shadow, will move towards the surface of projection at light speed.
The misconception is that the edge of a shadow "moves" along a wall, when in actuality the increase of a shadow's length is part of a new projection, which will propagate at the speed of light from the object of interference.
Since there is no actual communication between points in a shadow (except for reflection or interference of light, at the speed of light), a shadow that projects over a surface of large distances (light years) cannot give information between those distances with the shadow's edge.
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Famous quotes containing the words shadow and/or speed:
“Hemingway is great in that alone of living writers he has saturated his work with the memory of physical pleasure, with sunshine and salt water, with food, wine and making love and the remorse which is the shadow of that sun.”
—Cyril Connolly (1903–1974)
“Spig Wead: I’ve been thinking what a heel I’ve been about you and about my own kids. I don’t know, when I do something, I go all the way. Living. Gambling. Flying. I tap myself out. I guess that’s the way I want it to be. Maybe even the way I am.
Minne Wead: Star-spangled Spig. Damn the martinis, full speed ahead and don’t give up the ship.”
—Frank Fenton, William Wister Haines, co-scenarist, and John Ford. Spig Wead (John Wayne)