Linkage

Trump administration claims the right to de-citizen people over minor mis-statements in their naturalization papers. As a naturalized citizen myself, this sort of thing makes me nervous.

Marine Le Pen is a plagiarist. Meanwhile our own plagiarist-in-high-places and actual Nazi, Sebastian Gorka, maintains his office as one of Trump’s top advisors.

The TCS Wikipedia project (G+), aiming to identify and fix shortcomings in Wikipedia’s coverage of theoretical computer science topics.

This year’s new National Academy of Sciences members include theoretical computer scientists Dan Spielman and Madhu Sudan. Congratulations!

Creating the never-ending bloom, a making-of video for John Edmark’s 3d mathematical sculptures which, when rotated at the right speed and stroboscopically illuminated, appear to grow and bloom much like the tip of a plant stem.

How to tie water in a knot. 3d-printed hydrofoils create knotted vortices, which then twist around themselves and uncross.

Fibonacci jigsaw puzzle based on the spiral patterns of sunflowers and other plants, can also be reassembled to have a missing piece or an extra piece.

Checking whether one polygon is contained within another (G+) is trickier than it looks. It doesn’t work to simply test containment at the vertices; you have to look for the edge crossings. But a (complicated) linear time algorithm is possible.

Roundup of links on the Purdue–Kaplan merger of public and corporate education and an editorial calling it a massive blunder.

MathJax shrink-o-matic helps you choose the good parts version of a much longer work.

Steve Mould and Matt Parker describe the different types of crystal defects (G+) with some help from ball bearings and ball-pit balls.

Octagonal paving tiles (G+) can only work if they’re non-convex and have some vertices where only two tiles meet, but are actually used in some places. I’ve also seen decagonal tiles (in the shape of a convex octagon with a square glued to one side).

Josh Millard decorates his home office with artfully painted fractals.

Why telling good journals from bad ones in fields other than your own is not always easy (G+) and why bad-journal lists such as Beall’s may be necessary.