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David Green
Lived in carlsbad, ca
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David Green

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I've reached level 8 as an #Ingress agent.
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Souk Nomichith (iRefugee)'s profile photoDavid Green's profile photo
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Thanks and agreed!
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David Green

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I like it
Matthew Baggott originally shared:
 
Animating the Mathematical Logic of M.C. Escher For his 1956 Prentententoonstelling (Print Gallery), M. C. Escher started with "the idea that it must…be possible to make an annular bulge,” “a cyclic expansion ... without beginning or end.” He created a recursive drawing of a gallery displaying prints. One print in the gallery shows a seaport containing the original print gallery. He projected this image onto a cyclically expanding grid with curved lines folding inward.

A cool 2003 article in Notices of the AMS shows his original grid, an 'unfolded' version of the Escher drawing, and various permutations of the basic concept. As a companion to their 2003 article, B. de Smit and H. W. Lenstra have created a rad website and animations, one of which I have converted from AVi to GIF using VirtualDub for our viewing pleasure.

This picture-within-itself strange loop imagery is sometimes called mise en abyme or, more commonly, the Droste effect, after the recursive label on a brand of Dutch cocoa powder. Thanks to the mathematical exposition by de Smit and Lenstra, you can now find tutorials for creating your own images using programs like GIMP or Photoshop. A flickr group exists for such images.

article: http://www.ams.org/notices/200304/fea-escher.pdf
website: http://escherdroste.math.leidenuniv.nl/index.php?menu=intro

(h/t to +Philip Smith for pointing me to the website)
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Love his work. Thanks for sharing!
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David Green

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Not much to say about this President really that hasn't already been said.
What about prosecuting the crooks? - thats for the attorney general to speak to, not the President. Everything else is the fault of Congress. This is the leader of the US....
President Barack Obama said the growing protest movement against Wall Street, spreading across the nation, are voicing a widespread frustration about the country's financial system.
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John took part in the protest here in Dallas this morning.
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David Green

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I've reached level 8 as an #Ingress agent.
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David Green

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Hi all, I'm new here. Cheers
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How is life in TX
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David Green

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New Years Eve
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David Green

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David Green

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Speaks for itself
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carlsbad, ca - Plano, TX - Arlington, TX - Cape Town, South Africa - Brighton, England - Crawley, England
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