Coffee stain at the edges - structured surprises.

" A remarkable effect never witnessed before has been discovered in the ring-shaped stains of tiny dissolved particles ('coffee stains') that develop after a liquid has evaporated. While the particles on the outside of the ring are neatly organized, chaos reigns on the inside of the ring where the particles seem to have collected in a great hurry".

'Coffee stain' with ordering at the edge and disorder further within.
(Credit: Image courtesy of University of Twente)

-This could be rephrased: Normal fluidic disorder is found except at the initial boundary where particles have  aligned structurally.
-This 'never-before-witnessed' effect is science you could have done at home with a high school microscope and by using your noodle.
-This looks like the structured particle behaviour at water boundaries that was observed by Dr. Walter Pollack.  His water is not liquid lecture changed my thinking.  Key term: "colloidal suspension".  At the margins, water behaves like a liquid crystal within a thousands-of-ions distance from the edge.