My maths desk, with filing folder open for work on Euler angles and rotation of xyz coordinate axes.
On the working papers is one of my two sets of double coordinate axes,
with "Eins-Zwei-Drei" wooden sticks for the fixed axes
and "Blue-Green-Red" drinking straws for the manipulable axes.
(At the moment, the Blue-Green-Red axes have in one possible choice of Euler-angle terminology
undergone a z rotation and an x rotation, and are about to undergo a further z rotation.)
Behind the row of ten-sided dice, showing the current date (namely, 2016-07-11),
is the 2003 Toronto Globe and Mail obituary of my 1971 univariate-analysis teacher, Max Edelstein.