Sources
Help build the largest human-edited directory on the web.
Submit a site - Become an editor
Wikipedia. Licensed under the GNU Free Documentation License.
Are you an expert in this subject? Join the discussion and share your knowledge at Wikipedia.org.
Skywriting
From Wikipedia, the free encyclopedia
Skywriting is the process of using a small aircraft, able to expel special smoke during flight, to fly in certain patterns as to create writing readable by someone on the ground.
The typical smoke generator consists of a pressurized container holding a low viscosity oil. The oil is injected into the hot exhaust manifold causing it to vaporize into a huge amount of dense white smoke.
Skywriting is never a permanent process. Winds and dispersal of this smoke cause the writing to blur, usually rapidly. However special "skytyping" techniques have been developed to write in the sky in a dot-matrix fashion, and are legible in spite of the inevitable blurring effect caused by winds.
One of the earliest mass media exposures of sky writing came in the movie version of "The Wizard of Oz" (1939), when the wicked witch of the West writes in the skies over Oz "Surrender Dorthy". (Unfortunately, the population of Oz, not knowing what a dorthy is, panics. It is not clear if the message was supposed to command the people of Oz to take action against Dorthy, or if Dorthy was supposed to give in to the witch.)
This is one of the earliest memories of sky writing most children are exposed to.
