The Ham Sandwich Theorem // 139
Pacioli, Rafael Bombelli and Tartaglia (Niccolo` Fontana) all used this symbol. The symbol Ö is in fact a distorted letter r. How mundane! It first appeared in print in the first German algebra text, Christoff Rudolff’s Coss of 1525, but it took several centuries to become standard. The site www.roma.unisa.edu.au/07305/symbols.htm discusses the history of many other mathematical symbols.
........................................... Please Bear with Me Q: What’s a polar bear?
........................................... A: A Cartesian bear after a change of coordinates.
The Ham Sandwich Theorem I’m not making this up: that’s what it is called. It says that if you make a ham sandwich from two slices of bread and a slice of ham, then it is possible to cut the sandwich along some plane so that each of these three components is divided exactly in half, by volume.
Start with this . . .
. . . to get this – easy!
This is fairly obvious if the bread and the ham form nice square slabs, neatly arranged. It is less obvious if you appreciate that mathematicians are referring to generalised bread and ham,