[BITList] The Enemy of My Enemy - Opinionator Blog - NYTimes.com

[HUGH]

Mike,

The Chinese had no problem with negative numbers.  They had calculating rods - red for positive and black for negatives - but they didn't allow a negative as the solution to an equation.  On the other hand, the Indians - Brahmagupta, fl 628 - allowed negative roots of quadratic equations.  I was taught that, if zero is the ground level, the stairs going down were negative numbers, and those going up were positive.  We weren't encouraged to get metaphysical about it.  A certain amount of maths is axiomatic, ie, does not require proof, indeed, no proof is possible.  These axioms are used to build higher level results.  I noted the reference in a comment about the NYT - a "Bolshevik" paper.  Dear God !

Hugh.
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