The working signs

Math and typographic symbols

Notation with a first use. The feeling was added later.

1. 1
   Golden ratioA cut where the whole stands to the larger part as that part stands to the smaller.
2. 2
   PiHow many diameters fit around a circle. The letter came later, from a printer’s book.
3. 3
   EqualsTwo parallels of one length, because nothing is more equal than that.
4. 4
   Radical signThe check that asks what number, times itself, makes this one.
5. 5
   ThereforeThe hinge between a reason and the line that follows.
6. 6
   AlephAn infinity with a size. Not the same as an infinity you pray to.
7. 7
   DeltaA triangle that is a letter. Change, in a mathematician’s hand.
8. 8
   Ω
   OmegaThe last letter of the Greek alphabet. Later, a unit of resistance.
9. 9
   §
   Section signThe mark that means “section,” built like two S letters.
10. 10
    &
    AmpersandA tied-together “et.” The word ampersand is a schoolroom joke that stuck.
11. 11
    HeartA suit of cards that became the picture of love. Not a diagram of the organ.