Deep time
Deep time is a term introduced and applied by John McPhee to the concept of geologic time in his book Basin and Range (1981), parts of which originally appeared in the New Yorker magazine.The philosophical concept of geological time was developed in the 18th century by Scottish geologist James Hutton (1726–1797); his "system of the habitable Earth" was a deistic mechanism keeping the world eternally suitable for humans. The modern concept entails huge changes over the age of the Earth which has been determined to be, after a long and complex history of developments, around 4.55 billion years.