negative numbers were not geometrically meaningful.
Multiplication of two lengths
produced an area.
Numbers were more understandable as geometric quantities
than as Alexandrian numerals.
Elements
Letters (elements in the Greek)
label points in the diagrams
so that the text can simply reference them.
That the signifier is not the signified dissolves in memory.
Etymology persists as meaning.
Your name becomes you.
A smell can evoke everything.
When the magician or comedian points,
pay attention to the end of his finger.
(Ha ha. Just kidding!)
Euclidean geometry assumes parallel lines never intersect,
which is true of latitudinal lines on a globe, but not true of
longitudinal lines. Today we know that all space is curved.
Einstein showed that physical space affected by gravity is
non-Euclidean.
The first Greek to divide a circle into 360 degrees was
Hipparchus.
Alexandrian numerals were similar to Roman numerals, an
additive decimal system with values given to letters of the Greek
alphabet. The Greek letter Epsilon (Ε) was 5; Nu (Ν)
was 50; Phi (Φ) was 500, so that ΦΝΕ (added
together) was 555.
Euclidean geometry assumes parallel lines never intersect, which is true of latitudinal lines on a globe, but not true of longitudinal lines. Today we know that all space is curved. Einstein showed that physical space affected by gravity is non-Euclidean.
The first Greek to divide a circle into 360 degrees was Hipparchus.
Alexandrian numerals were similar to Roman numerals, an additive decimal system with values given to letters of the Greek alphabet. The Greek letter Epsilon (Ε) was 5; Nu (Ν) was 50; Phi (Φ) was 500, so that ΦΝΕ (added together) was 555.
See also in The book of science:
Readings on wikipedia: