An Etymological Dictionary of Astronomy and Astrophysics
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The logarithm in which the → base is the → irrational number e = 2.718281828.... Also called → Napierian logarithm. The natural logarithm is denoted ln, an abbreviation of logarithmus naturalis. Natural logarithms are related to → common logarithms through: ln x = (1/M) log x, with M = (1/ln 10) ≅ 0.434294.

→ natural; → logarithm.