<< There is no local cue distinguishing inside from outside of the big loop! >> It ain't so: the magenta on the exterior side is broken by cyan blobs which nearly touch the black ribbon, whereas on the interior they are more distant. WFL On 9/22/17, Bill Gosper <billgosper@gmail.com> wrote:

Out of exasperation with xmission.com's proscription of attachments, I sent the following just to the Eavesdroppers.

gosper.org/redliner.nb contains two images of a TrinskyXYPlot of a slightly squashed Penrose marking. Here's just the png. <http://gosper.org/redliner.png> Expand the .nb window until the images stop expanding. Note the big blackish "star" seems to have a bright red inner lining. Stars of other colors seem to have reddish(?) inner or outer linings which disappear on close inspection. The bright red is illusory as well.

But wait a minute! There is no local cue distinguishing inside from outside of the big loop! Why do we see it inside of both the deep concavities and the prominent convexities?? The loop is cropped without even closing!

Without due credit, I used Jack Holloway's superior rendition of this pattern on my G4G12 Exchange Gift card <http://gosper.org/Bill Gosper Card.pdf>. I'm bugging everybody again, having just noticed two unforgivable typos: Ziegler Hunts is misspelled, and worse, the URL to the Minskys and Trinskys pdf (+ ton of images), which should be gosper.org/Minskys/ . --rwg _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com https://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun