<http://discovermagazine.com/2016/may/14-made-in-the-shade>.
Using a giant, flower-shaped shade, scientists hope to block out the glare of stars that obscures the view of exoplanets. In the following simulated illustration, the idea is to enhance the visibility of other worlds with a perfectly placed screen.
Photograph by Jay Wong
I found this article fascinating on many levels: from a photographic perspective, the mechanics of setting up a 30- to 50-meter diameter 'starshade' in outer space, and the daisy-like shape that was found to be best for cutting down star glare. Innovator, Webster Cash, experimented with a number of shapes to determine what was best for cutting down on the problem of light diffraction, or "it's tendency to bend around the edge of an optical barrier."
Photo by Matt Nager with starshade designer Webster Cash
Cash "experimented with 100 different equations, each associated with a different flower-like shape, to see how they did in combating diffraction." Initially, all of his flower shapes originated from a center point, then he added a central disk shape from which the "petals" fanned. The article does not explain how this made a difference, but I suspect it causes a wider diffraction of the star light? so we see what is being illuminated by the star without being blinded by its light.
– Martha McDaniel
great story, making the universe into the world's largest photo studio with the photographer's light shade. when I saw the shape the equations had arrived at, it looks so much like an ordinary flower -- indeed like a black daisy -- that it made me wonder if it could be coincidental. Did the shape of flowers, which after all shade sunlight (rather than starlight), serve a purpose related to light -- assuming they didn't evolve to provide a model for starshades!
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