(Roughly) Daily

Teach your children well…

Your correspondent is headed again across the Dateline (where he loses all track of what day it actually is), thus (R)D will be in abeyance until March 9 or 10, when “service” will resume again.

In the meantime, a message from the past to the future…

In 1959, philosopher, logician, mathematician, historian, and social critic Bertrand Russell appeared on the BBC interview program Face-to-Face.  As the program came to its final two minutes, he was asked a valedictory question: “What would you tell a generation living 1,000 years from now about the life you’ve lived and the lessons you’ve learned?”…

[TotH to Open Culture]

As we do our level best to take good advice, we might recall that it was on this date in 1611 (81 years before the beginning of a case Russell might have cited, the Salem Witch Trials, on this date in 1692) that John Pell was born.  An English mathematician of accomplishment, he is perhaps most remembered for having introduced the “division sign”– the obelus: a short line with dots above and below– into use in English.  It was first used in German by Johann Rahn in 1659 in Teutsche Algebra; Pell’s translation brought the symbol to English-speaking mathematicians.  Indeed, Pell was an important influence on Rahn, and edited his book– so may well have been, many scholars believe, the originator of the symbol for this use.  (In any case the symbol wasn’t new to them:  the obelus [derived from the word for “roasting spit” in Greek] had already been used to mark passages in writings that were considered dubious, corrupt or spurious…. a use that surely seems only too familiar to legions of second and third grade math students.)

John Pell (source)

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