The Math Forum



Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.


Math Forum » Discussions » Inactive » Historia-Matematica

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: [HM] Orientation of the Number Line
Replies: 5   Last Post: Jun 10, 2004 5:35 AM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
James A Landau

Posts: 217
Registered: 12/3/04
Re: [HM] Orientation of the Number Line
Posted: Jun 9, 2004 9:17 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply


There is a theory as to why Hebrew writing runs right-to-left and why Greek
runs left-to-right.

The Hebrew alphabet, or more likely the Semitic alphabet of roughly 1500 BC
which is the immediate ancestor of Hebrew, was devised for inscriptions to be
cut into stone. Now a right-handed stonecutter holds his chisel in his left
left and strikes it with the hammer in his right hand. Hence he prefers to cut
letters from the right side of a line to the left, so that his left hand
(holding the chisel) does not cover up what he has just cut. Hebrew and the other
Semitic alphabets, including the Arabic alphabet which is so geographically
wide-spead, kept this right-to-left orientation out of tradition, long after
stone-cut inscriptions became only a small minority of all writings.

The Greek alphabet, although descended from some stone-cutting Phoenician
alphabet, was used from the beginning by scribes writing on papyrus, and thus it
was developed as a penman's alphabet. A right-handed penman holds his pen (or
stylus or pencil or whatever) in his right hand and, not wishing to cover up
or smudge what he has just written, prefers to go from left to right so that
his right hand does not rest on or cover up what he has just written. This
explains why the boustrophedon system (left to right on one line, then right to
left on the next, then left to right again etc.) did not catch on---the slight
increase in writing speed from not having to pick up and move the right hand
all the way back to the left margin after each line did not make up for the
number of lines that were ruined because the penman's right hand, when moving
right to left, smudged the ink that had not quite dried when the hand moved on to
the next letter.

Latin, Cyrillic, and the other descendants of the Greek alphabet carried on
this left-to-right tradition.

This theory makes sense, even though Re: [HM] Orientation of the Number
Lineit does not explain why those prolific Roman stonecutters (the ones who carved
"U" as "V" Re: [HM] Orientation of the Number Line, a tradition still
sometimes seen today on stone carvings) did not rebel and start carving from right to
left, or why the scribes who hand-wrote Jewish Torah scrolls never complained
that left-to-right made more sense.

What does this have to do with the Orientation of the Number Line? Maybe
very little, but it does suggest the question: were the first number lines cut
into stone with hammer and chisel, or were they written on papyrus with a pen?

Also another question: most of the world today uses the "Arabic numeral"
(more correctly, "Hindu-Arabic numerals") which were acquired by Europe from the
Arabs. Numbers in Arabic numerals are invariably written with the most
significant digit to the left, not to the right, even by people whose native
language and alphabet are Hebrew. (I do not know how Arabs write numbers).
Considering that the Arabic alphabet is written right-to-left, did the Arabs write
numbers most-significant-digit-to-the-left, and if so, why? If they did not,
then did the earliest European advocates of Arabic numerals reverse the
orientation so as to match the orientation used in Roman numerals?

Off-topic: if the Hebrew and Arabic alphabets are so closely related, why do
they look so different? That is because the ancient rabbis laid down a rule
that letters were not to be "ligatured", that is, there were to be no
connecting lines between letters. The intent was to make sure that each individual
letter was to be carefully formed so as to be recognizable. The developers of
the Arabic alphabet had no such rule and went in the other direction, with all
the letters in each word to be ligatured together.

- James A. Landau






Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2018. All Rights Reserved.