some etymology, why not?

Library/tips.json

 {"tips":[
+"The name “tessellation” comes from “tessera”, the word for a small, usually square, stone tile used to make mosaics",
 "Parallel lines can intersect in non-Euclidean spaces.",
 "Any B-Spline curve segment whose knots are either 0 or 1 in equal parts is also a Bézier curve.",
 "The boundary of a boundary is empty.",