Who developed the idea of uniformitarianism?

In geology, uniformitarianism has included the gradualistic concept that "the present is the key to the past" and is functioning at the same rates, though many modern geologists no longer hold to a strict gradualism. Coined by William Whewell, it was originally proposed in contrast to catastrophism by British naturalists in the late 18th century, starting with the work of the Scottish geologist James Hutton. Hutton's work was later refined by John Playfair and popularised by Charles Lyell's Principles of Geology in 1830. 

From my friends report

this age may represent the age of the earth's accretion, of core formation, or of the material from which the earth formed. this dating is based on evidence from radiometric age-dating of meteorite material and is consistent with the radiometric ages of the oldest-known terrestrial and lunar samples.

you can have just about every answer you can think of