Leading article: For a knight on the tiles

Attentive readers of this newspaper will recall the story of the professor and the toilet tissue. Last December - exclusively, as it happens - we revealed that one of Britain's most distinguished mathematicians, Sir Roger Penrose, FRS, Oxford professor of this, author of much, had come across his own "Penrose tiling" design on a packet of Kleenex Quilted Toilet Tissue. This non-repeating aperiodic pattern was no trivial solution to relieving the boredom of tiling the bathroom floor, nor some mathematician's doodle. It was a mind-boggling, preconceptions-shattering illustration of five-fold symmetry, "non-computability", and, quite possibly, the meaning of life. Sir Roger intended to sue. We were sympathetic.

Last week, a writ was duly issued against the toilet-paper makers, calling for the destruction of all stocks of the paper, and a man from Penrose's company made a pompous remark about the need to take a stand when the population of Great Britain wiped their bottoms on the work of a knight of the realm without his permission. We were slightly less sympathetic. For, while we are totally in awe of the big knighted brain, some credit appears due to the humbler one for seeing this application: that two rolls of the non-repeating pattern placed together would form a quilt until eternity.

Two years ago, a computer programmer patented two prime numbers in the US. The numbers satisfied the requirements of patentability by (a) having a use and (b) being so big that no one (apparently) had used them before. Patenting numbers? Ridiculous, the layman might think. As Sir Roger Penrose himself put it at the time: "It's absurd. Mathematics is out there for everybody."