As we well know, many things seem continuous though their composition is discrete. I give lectures about this, starting with the bouncing molecules that make up our gases and liquids. The cover image of Trefethen’s Index Cards illustrates how impossible it can be, in borderline cases, to decide which is the right truth.

Atop your head is another good example. In English and Spanish your hair is singular, in French and German it’s plural.

[25 November 2024]