Publishers tell one that each equation one includes in a book halves its sales. Hence the phenomenon of completely incomprehensible books which would have made sense if the author had only been allowed to say what he was talking about: João Magueijo and Marcus du Sautoy are notable victims.

The back page of La Recherche, always a good source of the information that really matters (it once reported a paper which established a negative correlation between designer stubble and life expectancy), now weighs in on the other side. A new paper reports that adding a random line of nonsense mathematics to the abstract of an academic paper on sociology or anthropology made the paper seem more authoritative – though the effect seemed to be confined to non-mathematical readers.