natural logarithm

noun

, Mathematics.

1. a logarithm having e as a base. : ln

natural logarithm

noun

1. a logarithm to the base e. Usually written log e or ln Also calledNapierian logarithm Compare e common logarithm

natural logarithm

1. A logarithm using base e. Natural logarithms are common in mathematics, especially in cases involving complex numbers. They are also called Napierian logarithms , after their inventor, English mathematician John Napier (1550–1617).
2. See more at eCompare common logarithm

Word History and Origins

Origin of natural logarithm¹

First recorded in 1810–20

Example Sentences

Here’s the conversion formula the scientists came up with: Human age is equal to 16 multiplied by the natural logarithm of the dog’s age, plus 31.

From Seattle Times

To calculate dog years, you must now multiply the natural logarithm of a dog’s age in human years by 16 and then add 31.

From New York Times

A more accurate conversion isn’t so easy to do in your head: Multiply the natural logarithm of the dog’s age by 16, then add 31.

From Washington Post

In maths, ln refers to the natural logarithm of a number.

From The Guardian

Momentum conservation implies that the terminal speed of the rocket is given by this exhaust speed times the natural logarithm of the ratio between the initial and final mass of the rocket.

From Scientific American