What did I get for Christmas (mathematically, at least)? My big present was an Acme Klein Bottle, whose website claims it to be one of “the finest closed, non-orientable, boundary-free manifolds sold anywhere in our three spatial dimensions”. This is a 3D representation of a 4D Klein bottle; a pale shadow, of course, although the cheerful and entertaining information leaflet that came with the bottle claims this an advantage: “You can actually hold an Acme Klein Bottle in your hand. Those highfalutin’ 4-dimensional ones can only be held in your mind”. Here is a photo of mine:
I also got a set of physical puzzles which are nice to have a supply of. I find I am sometimes laying puzzles on a table for students to play with and solid, physical puzzles, while perhaps not the most mathematically interesting, are certainly an attractive draw. People can’t resist picking up and playing with wooden blocks, it seems!
I got a copy of The Great Mathematicians by Raymond Flood and Robin Wilson, a past and present President of BSHM, which claims to present “mathematics with a human face, celebrating the achievements of the great mathematicians in their historical context”. You can watch a lecture given by Raymond and Robin at the launch of the book at Gresham College.
As a bit of Christmas day craft, inspired by the escapades of the Manchester Maths Jam, we made dodecahedron star lanterns. Unlit, these are like this:
And lit they come alive like this:
Merry Christmas everyone! What mathematical presents did you receive and what mathematical activities did you do this year?