Calculation of the date of the flood based on literal interpretation of the old testament has been a scholarly activity for two millennia. The seventeenth century estimate of the Irish Bishop James Ussher has been accepted among many of the devout. The calculation is undertaken by adding the genealogies beginning in Genesis 11:10. This is the account of Shem: Two years after the flood, when Shem was 100 years old, he became father of Arphaxad. Arphaxad is then designated father to Shelah, Shelah to Eber, Eber to Pelg, and so on until Abram and his successors which eventually brings one to the division of the kingdom at the death of Solomon. In this way, Bishop Ussher computed that the earth had been created in 4004 BC and that the flood occurred in 2350 BC which was henceforth accepted as the "traditional" biblical date,( though there is rival literal interpretation similarly inspired, setting the date at 2459 BC). These traditional chronologies were acceptable among the learned until the foundations of religion were shaken by Darwin and a succession of natural historians including George Curier, William Buckland, and finally, that " high priest of uniformitarianism" Charles Lyell, who collectively contribute to the modern, predictable, comfortable, uniform, manageable version of the world that we know as science.
Until recently, biblically inspired chronologies were taken seriously enough by scientists to warrant solmn refutation. As recently as 1922 Science magazine had published an article entitled "The New Catastrophism and its Defender," about George McCready Price, who had emerged as the champion of, what he called New Geology, which argued that all geologic data could be interpreted within a biblical framework. In other words, Price set out to show that the bible was scientifically reliable. Price had written several books in which he attempted to retain the literal biblical explanation of a six day creation in the face of generally growing scientific skepticism. Stanford University's President, David Starr Jordan, always ready to do business in his kindly way with any kind of heathen, became one of Price's correspondents, attempting to convince him that his creation theories were based on "mistakes, omissions, and exceptions." Price was delighted, challenging this "foremost ichthyologist of the world" to prove the relative age of any two fossils and promising to convert the professor to evolutionism within 24 hrs. In a kind of intellectual boxing match. ( p. 89.)
Like Ignatius Donnelly before him (though Price would have of course claimed no association with the erratic Irishman) Price had read Bacon and Newton. As an amateur but earnest student of philosophy, he saw (in a strikingly post modern way) that science was a kind of accounting system with highly practical ends and that it did not really strive to approach some metaphysical truth even though the towering intellect and arrogance of its priestly practitioners often suggested that it was a replacement for religion. It would not be until several decades later in the century that a philosopher named Thomas Kuhn would formalize this same argument by describing the revolutions that would sweep science as powers of observation and communication changed the view of the universe. By the 1980's science was being described in college lecture halls as just another form of story telling, albeit one which differed from the older orally transmitted variety (which also had the laudable evolutionary objective of preserving desired norms of behavior) by virtue of its adherence to a strict written code, complete with priesthood charged with verifying what was and what was not "true".
Notwithstanding their insistence on literal interpretation of such biblical measures of the six days of creation, American fundamentalist creationists like Henry Morris, while resisting any attempt to push the creation back tens or hundreds of thousands of years, have been generally inclined to adopt a softer, non-literal interpretation of Genesis 11, introducing a number of complex arguments (the unlikelihood of Abram being one of triplet sons, whether or not the first cousins of Moses and Aaron could have begat 8500 offspring, the mysterious drop in life span of postdiluvial patriarchs from 433 to 239 years, etc) that need not concern us here but which arguably add some years to the time elapsed between the flood and the birth of Abram, amounting all told to perhaps several millennia. Morris, a hydraulic engineer enjoying good academic reputation in his field, had taught for many years at the University of Virginia.
Although the fundamental premise of the creationist approach emphasized the infallibility of literal reading of the bible, few were as aware as those who hold the bible as a daily guide to their lives that the good book was rife with improbabilities and in some cases outright contradictions. Whitcomb and Morris, in one of those necessary departures from literal reading of the scriptures that nonetheless surprise anyone trying to follow their reasoning, concluded that the traditional Ussher flood date of 2450 BC (or its variant of 2459 BC) is probably too recent. On the other hand, noting the similarity of the Sumerian and Biblical flood stories, they consider it impossible that the flood could be vastly older than the stories because the Sumerian version (having been passed on by mere oral tradition, rather than having its truth covered by a divine assurance) was so strikingly similar to the biblical account; surely it would never have retained its similarity to the biblical story if the two traditions had bifurcated many thousands of years before their respective recordings in the first millennium B.C.
Morris quotes one authority who places the date at 3835 BC (based on Abraham birth date of 2167 BC and 1688 years elapsed time between birth of Abraham and flood (John Urquhart, How Old is Man, 1904 Morris p 481)) Elsewhere Morris suggests that the date was in excess of 5000 years ago, though he allowed that some interpretations suggesting that as much as 5000 years had elapsed between the deluge and Abram, which pushes the date of the flood as far back as 7000 BC, stretched the limits of Genesis "almost to the breaking point."
Most ingenious of the recent creationist claims have been those of G.E. Aardsma whose recent paper (Radio carbon and Biblical Chronology ) argues that the Ussher chronology (flood at 2350 B.C.) is too short by exactly a millennium. According to this interpretation, Kings 6:1 should read "1480 years" not "480 years," Aardsma believes; correction of this apparent clerical error would then push Usshers flood date back to 3350 B.C.
For a graphical representation of soem of these key dates click HERE