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The Symbol for Natural Log

Date: 06/28/2000 at 23:57:20
From: Adam Abrams
Subject: Natural law

Why is natural log abbreviated as "ln" and not "nl?" Please, I am just 

Adam Abrams

Date: 06/29/2000 at 12:56:17
From: Doctor Rick
Subject: Re: Natural law

Hi, Adam.

According to Jeff Miller's "Earliest Uses of Various Mathematical 
Symbols" (which you can find from our Dr. Math FAQ page) at:   

the symbol "ln" first appeared here: "ln (for natural logarithm) was 
used in 1893 by Irving Stringham (1847-1909) in _Uniplanar_Algebra_."

His name doesn't sound French, but my theory is that there is a French 
influence in this and other naming conventions. In French, the 
modifier "natural" would follow the noun "logarithm." In the same way, 
the International System of Units is called the SI, not the IS, 
because in French it's Systeme International d'Unites.

French influence or not, the way we use subscripts follows the same 
pattern. A subscript modifies the meaning of the main variable, and we 
put it *after* the variable. For instance, Avogadro's number is called 
N_A (N-subscript-A), not A_N; the A for Avogadro qualifies the N, and 
it is put after the N.

This way of writing is very natural to mathematicians; it makes sense 
to put the more general first, and the qualifiers or the more specific 

     "What are you talking about?" 
     "What KIND of logarithm?" 

So the notion of writing "nl" seems very odd to me, and "ln" is more 
natural (no pun intended).

- Doctor Rick, The Math Forum   
Associated Topics:
High School Definitions
High School Logs

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