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Biblical Chronology and Scientific Knowledge
From: Cambridge University Press
| By:
Cherry Lewis |
EDITOR'S INTRODUCTION |
 The contemporary debate between those who interpret the Bible literally and those who seek other explanations for the empirical world has a long and colourful history. One episode in that debate has revolved around the age of the Earth itself. As part of her account of the work of the geologist Arthur Holmes, Cherry Lewis (right) here provides a lively tale of the evolution of ideas from the seventeenth century to the nineteenth century. |
 n 1650 it was widely accepted that, as stated in the Bible, God had created the World (and the heavens, then considered part of the World) in six days. So James Ussher, the Archbishop of Armagh in Ireland and a well known biblical scholar, decided to try and calculate not only the year in which God (the Christian God) had created the World, but also in which month, and on what day of the week. He worked it out by adding up the ages of all the important people mentioned in the Bible who had lived since the time of Adam, the first person created by God, and established that the World was created four thousand and four years before the birth of Christ, on the evening of the 22nd October, which was a Saturday. This date, 4004 BC, for the Creation of the World as determined by Ussher was then printed as a note in Genesis, the first chapter of the Bible, whereupon it became 'gospel' and accepted without question in Christian teaching for several centuries. |
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| James Ussher: in the seventeenth century he calculated that the world was created on the evening of Saturday 22 October 4004 BC. | |
Other religions had very different ideas. Zoroaster, a Persian prophet who lived in the sixth century BC, believed that the world had been in existence for over twelve thousand years; the Roman writer Cicero relates that the venerable priesthood of Chaldea in ancient Babylonia held the belief that the Earth emerged from chaos two million years ago, while the old Brahmians of India regarded Time and the Earth as eternal. It seems that Ussher's famous estimate probably represents the shortest period ever assigned to the age of the Earth. However, at that time Christianity in Europe was a powerful force, and a literal interpretation of the Bible dominated the understanding of science and the way people looked at the natural world. The result was a distorted explanation of geological phenomena as naturalists tried to cram millions and millions of years of Earth history into less than 6000 years, and those few individuals whose observations suggested that this interpretation might not be scientifically reliable were branded as heretics. |
Fossils and Noah's Flood
Another big geological problem for biblical scholars was the explanation of fossils. For thousands of years, ever since the Greeks and probably long before, people had observed objects trapped in rocks and wondered what they could be. For example, Leonardo Da Vinci, writing five hundred years ago, accurately deduced how fossils are preserved by closely observing what happened around him: he saw shapes in the rocks that looked like shells found on the sea shore, he saw rivers carrying large volumes of mud down to the sea, and by putting two and two together he deduced that fossils were once organisms living in the sea that had been buried by mud from rivers and turned to stone. He made sense of the world around him without needing to invoke magic vapours or the works of the devil, which was how many people in the Middle Ages explained fossils. But even when it was widely recognised that fossils were the remains of creatures that had once lived on the Earth or in the sea, it was nevertheless still problematic to find the remains of fishes and other sea-dwelling creatures on the tops of mountains. |
Once again the answer came from a literal interpretation of the Bible. The story of Noah's Flood tells how God saw that the wickedness of Man was great, that He repented having made him in His image and so decided to destroy him. Only Noah was good enough to be saved. So God told Noah to build an Ark in which he was to take his wife, his sons and his sons' wives, plus a pair of every living thing on the Earth because He was going to cause it to rain for 40 days and nights and, in a fit of pique, destroy every living thing. So, even though Noah was 600 years old at the time, he built the Ark as God told him to and saved 'Life' for future generations. |
The waters rose up and covered the mountains and every living thing was destroyed. The violence of the Flood was so great that the bottom of the oceans was stirred up, all soil was washed off the land, they were mixed together and then redeposited, even on the top of mountains, to form the stratified rocks we see today containing the remains of all the poor creatures who perished. And thus we got fossils on the top of mountains. With this explanation all rocks and fossils were supposedly laid down at the same time, and adherents to the 'Noachian Deluge' hypothesis dominated geological thought until the end of the eighteenth century. |
There were, however, a few who attempted to explain the Flood by means other than the wrath of God. In 1696 William Whiston wrote a 'New Theory of the Earth' in which he explained how, on the 2nd of December, 2926 BC, a comet a quarter of the size of the Earth cut the plane of the Earth's orbit only nine thousand miles away. Whiston considered that the effect of this comet passing so close to the Earth generated a giant tide in the sea and in waters within the Earth; thus were the 'fountains of the great deep broken up' and unleashed upon the Earth. As the comet passed, water was discharged from its tail, which was how it rained for 40 days. According to Whiston, the result of all this water on the Earth was a flood six and a quarter miles deep. Undoubtedly a comet passing that close would wreak havoc on the Earth's weather and tides and Whiston's idea seems as plausible as that of a meteorite impact wiping out the dinosaurs. |
Whiston, however, could not prevail over the biblicists, so the Noachian Deluge theory triumphed and did even more harm to the development of geology as a science than Archbishop Ussher. Gradually though, a few men, understanding the significance of what they observed in the rocks, were prepared to stand up to the theologians, and an adherence to a strict interpretation of the Bible slowly gave way to the need for longer and longer periods of time to explain geological and biological processes. |
Geological timeframes
In 1785 James Hutton, frequently called the 'father of modern geology', stood before the learned and recently formed Royal Society of Edinburgh. He read to them an essay he had written entitled 'Theory of the Earth' in which he emphasised the immensity of geological time and the uniformity of geological processes which, over vast time periods, formed the Earth as we see it today. Hutton was scoffed at by his critics for 'running about the hill-sides with a hammer to find out how the world was made', but it was because of this long and critical study of rocks in the field that he recognised that the Earth we are standing on now must have been made from the rocks of past ages. He explained to his audience how the land of today had been fashioned by the seas and rivers of yesterday, and that the land of tomorrow was today forming at the bottom of the sea. He overthrew much of current thinking, which he knew would arouse theological opposition, and identified at least three cycles of land formation in the Earth's history, each of which were 'of indefinite duration'. He concluded his lecture with the famous words: 'The result therefore, of our present enquiry is that we find no vestige of a beginning,--no prospect of an end'. He considered that 'with respect to human observation' geological time was simply too long for us to imagine. Being so flatly in contradiction with the Scriptures, this led to him being accused of having 'deposed the Almighty Creator of the Universe from his Office', but Hutton was insistent: 'In nature' he writes, 'we find no deficiency in respect of time'. |
James Hutton died in 1797 before his theory had gained much credence, the year that Charles Lyell was born, a man destined to become one of the greatest influences in modern geology. When Lyell became a geologist (he originally trained to be a lawyer) he took up where Hutton had left off. He looked at the geological processes operating around him and realised that they were the key to understanding what had happened in the past. He considered that nothing could have occurred in the geological record that was not happening now, and that all that was required was a vast amount of time for geological processes to endlessly recycle and reshape the planet, eventually creating the world as we observe it today. But he had one significant advantage over Hutton. |
In the 1790s William Smith, then a surveyor working on building canals to carry coal, recognised that there was a regular and systematic order within the rocks of southern England. A self-educated man, Smith observed that not only were rocks ordered in a way that could be followed for miles across the country, but that the suites of fossils contained within those rocks 'always succeed one another in the same order' making it possible to correlate one rock with another that contained the same suite of fossils, even though they were miles, or even countries, apart. But Smith was unable to reconcile what he observed with an understanding of how it had occurred, so, resigning himself to this state of affairs, he got on with his work, believing that these matters were not of his concern: 'I have left off puzzling about the origin of Strata and content myself knowing that it is so ... The whys and wherefores cannot come within the Province of a Mineral Surveyor.' Nevertheless, he certainly had a feel for the immensity of time that was reflected in the rock strata he surveyed, declaring: 'The time required for [each] Perfection and Decay and subsequent formation into Strata ... would stagger the faith of many'. |
Smith made the first geological map of the 'Strata of England and Wales' which, had he been able to publish it immediately upon completion, would have put him closer to the forefront of geological fame. But he did not publish until 1815, and during the time that elapsed between making it and publishing it he discussed his ideas widely with his contemporaries such that the information he possessed became diffused throughout the geological community by word of mouth, contributing significantly to the progress of that science, but without its author getting due recognition. So by the time Charles Lyell was a geologist this crucial understanding that fossils allowed the rocks to be ordered one above the other in a chronological sequence had become an accepted meme. |
Volcanic evidence
During the course of his work Lyell examined the great volcano of Etna on Sicily and studied the historical records of its frequent eruptions. He noticed how each time it erupted a new layer of lava would be added on top of the previous one, causing the mountain to grow at a measurable rate. So by knowing the total height of the volcano, its approximate rate of growth and the frequency of eruptions, Lyell realised that it should be possible to estimate the age of the volcano. He did the calculations and determined that it must be several hundred thousand years old. While this in itself was an astounding revelation, the question remained, how much of geological time did a hundred thousand years represent? Had the volcano been growing ever since the world began, or was it a recent phenomenon? At the edge of the volcano, underneath the first lava flows, Lyell found fossil shells that were virtually identical to the shells of molluscs swimming in the Mediterranean at that time. From this he deduced that the fossils were geologically 'recent', that a hundred thousand years was geologically short, and that the age of the Earth must be immense. |
Lyell's approach to geology was persuasive and he soon became an important influence over many scientific figures of the time, one of whom was Charles Darwin. It is not always appreciated that Darwin was first and foremost a geologist. Having been fascinated by the subject as a boy he went from finding formal instruction on geology 'intolerably dull' to being a leading member of the Geological Society on his return from the voyage of the Beagle. Four out of every five pages of notes taken on the Beagle's voyage were on geological topics, and on the few occasions that Darwin referred to himself as a scientist, he called himself a geologist. |
From religion to evolution
From the time Darwin read Lyell's newly published book on board the Beagle in 1831, he recognised the significance of Lyell's work: 'I had brought with me the first volume of Lyell's Principles of Geology, which I studied attentively: and this book was of the highest service to me in many ways. The very first place which I examined showed me clearly the wonderful superiority of Lyell's manner of treating geology'. Within days of his return from the voyage Darwin got in touch with Lyell and they became lifelong friends. Through his geological observations, Lyell provided Darwin with the unfathomable amounts of time required to unfold the evolution of life. In the process Lyell influenced not only Darwin's geological conclusions, but ultimately those on the origin of species, because, in the words of Thomas Huxley, Darwin's great champion, 'biology takes its time from geology'. |
So at this point geology seemed to have turned full circle. From the theological time restrictions of 6000 years for the age of the Earth imposed by Archbishop Ussher, naturalists such as Hutton and Lyell had observed the world around them and conferred on geologists more time to play with than they knew how to manage. Or had they? |
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