In 1650, James Ussher (1581-1656), Archbishop of Armagh was really bored. His boss (John Lightfoot, Vice-Chancellor of Cambridge University) made him take time off each year so he couldn't save it all up and have a decent holiday once every few years. He'd already whacked off that morning, and was left with an overwhelming feeling of not knowing what to do next.
A bible lying on the floor caught his eye. As is the way on these kind of days, he began flicking through it, he'd read all the articles in his porn magazines, you see. He happened to flick to a page so mind-bogglingly boring that no-one had ever lingered on it for more than 20 microseconds. For some reason, lost in the haze of time, he read it. The general gyst went something like this;
Adam begat Seth Seth begat Enos Enos begat Cainan Cainan begat Mahalaleel (they ran out of good names pretty quickly) Mahalaleel begat Jared Jared begat your mum
As has already been mentioned, James was extremely bored. He was also an abacus nerd. These two facts combined to lead to the inescapable conclusion that the world, nay, the universe was created in 4004 BC!
Ussher leapt out of his bath, and ran through town shouting "eureka!" like a fucktard. His sound scientific conclusion has withstood rigourous testing since, and it is now taught to all children during their schooling.
James's theory/fact overthrew the idea that the universe was created in kind of large explosion of space itself ca. 13,700,000,356 years ago (adjusted to 2006 from 1650). This didn't allow enough time for two widely held beliefs of the time (biology's evolution and geology's gradualism) to occur.
Prior to James's discovery, evolution had been the leading theory for the creation of the diverse range of life observed on Earth. This was described as "change in the genetic composition of a population during successive generations". However, thetime constraint unearthed by James did not allow enough generations to pass for this theory to be true. With this theory overthrown, a new scientific theory known as creationism was proposed.
Geologists pre-1650 believed that contemporary landforms were the products of observable phenomena occuring over immense periods of time. Unfortunately for them, their beliefs were wrong, as the earth had only been in existance for 5,654 years. Their theory was replaced by the theory of catastrophism - the theory that landforms had been created violently by an intelligent being 5,654 years ago.
"It was widely believed that the Earth's potential duration was 6,000 years (4,000 before the birth of Christ and 2,000 after) corresponding to the six days of Creation, on the grounds that "one day is with the Lord as a thousand years, and a thousand years as one day" (2 Peter 3:8), a view almost completely abandoned in 1997 (6001 years after 4004BC)." (http://en.wikipedia.org/wiki/Ussher-Lightfoot_Calendar)