The Tiles of Infinity (2009)

It is interesting to note that there are tiles with which one can simulate a Turing machine. The tiles can tile the plane iff the TM never stops.

https://en.wikipedia.org/wiki/Wang_tile

Saudi Aramco World is probably my most favourite periodical - more consistently insightful and fascinating than NatGeo for me. Ironically, I also find it far less commercial than NatGeo.