The Bible tells us how the Great Flood happened, compelling Noah to herd all of animal life into his Ark.
The skies opened and it rained incessantly, in fact for 40 days and 40 nights. But some scientists have another theory altogether and this week an expedition will leave for the Black Sea to try to prove it.
Among the team will be Robert Ballard, the American underwater explorer who became famous when he found the Titanic beneath the Atlantic in 1985. He will be going with a special piece of equipment, a remote excavating submarine namedHercules.
No one disputes that the Black Sea was once a fresh-water lake that in ancient times became inundated by the salty Mediterranean. The arguments have been over how quickly it happened - was it only gradual? - and in what period. Until recently, most experts dated the flood to about 9,000 years ago.
But Mr Ballard thinks it was more recent, perhaps 7,500 years ago, which could more credibly make it the same flood that gave us the story of Noah. Moreover, he thinks it was sudden. As the ice age ended, sea levels rose and a strip of land dividing the Mediterranean and the Black Sea was breached.
It was, according to Mr Ballard, 61, a truly cataclysmic event. Previous expeditions tell us that the invasion of Mediterranean waters pushed up water levels in the Black Sea basin by about 500 feet (155 metres) and drowned about 60,000 square miles.
Mr Ballard thinks it was so rapid that salt water pushed in with 200 times the force of the Niagara Falls and that the rate of increase in the water level was six inches a day.
Demonstrating all of this is hard. And Mr Ballard faces scepticism from several quarters. Critics accuse of him pursuing the Noah's Flood legend for the sake of the inevitable publicity. He has never suggested that he will find the actual Ark. But even the vaguest possibility is enough to stir excitement.
Indeed, the $5m (£3.1m), two-week expedition, which begins from the Turkish Black Sea port of Sinop on Sunday, has been set up to garner maximum worldwide attention.
Its progress will be watched live by academics, archaeologists and even schoolchildren around the globe, thanks to a satellite link from the expedition's ship to a nerve-centre at the University of Rhode Island in the United States.
Mr Ballard says the relay is vital because it will allow as many specialists as possible to analyse what he uncovers. "Exploration by its very nature means you don't know what you're going to find," he said. "So in fact it's very probable you're not going to have the right mix of scientists when you make a discovery."
There will also be film crew on board and a full television series is planned for next year.
Sinop, a scenic and popular tourist destination, was chosen because it might have been an important hub for north-south trading across the Black Sea among ancient civilisations. Local populations may have sent olive oil, honey and iron in small amphora-like jars northwards in return for wine and other foods.
Archaeological activity became possible when the Black Sea was opened up with the collapse of the Soviet Union in 1991. The interest in exploring beneath its waves was all the more intense because the waters are not oxygenated, offering the prospect of shipwrecks and other remains that should be perfectly preserved. Indeed, what lies beneath the Black Sea could help archaeologists and historians to fill in blanks about periods of human existence going as far back as the Bronze Age and spanning the Roman and Byzantine empires.
Leading this latest expedition with Mr Ballard, is Fredrik Hiebert, a professor of archaeology at the University of Pennsylvania. He hopes to relocate wrecks that have already been identified, including one called "Shipwreck D", which has already revealed an intact and intricately carved mast protruding from the seabed.
He and Mr Ballard also plan to return to another earlier find - an arrangement of stones about 330 feet beneath the water that might have been a human dwelling. Critical to the venture is Hercules. A remote-controlled submersible, it is just 7 feet long from tip to tail and was built by Mr Ballard at the Robert Ballard Institute for Exploration, in Mystic, Connecticut. The plan is to send it down as far as the stone settlement. Equipped with lights and cameras, the vessel will send pictures to the ship and back to Rhode Island.
In addition, the Hercules has two remote-controlled arms, which will excavate around the site. "If we're successful with this, we're going to change the field of archaeology," Mr Hiebert said. "It's open coastlines all over the globe" for further expeditions.
Mr Ballard first located the stone settlement during an earlier expedition in 2000. It consists of quarried square stones arranged in a rectangle of 33 feet by 40 feet (10 by 12 metres) on a rocky outcrop.
He is hopeful that he will be able to trace the site to a period about 7,500 years - which would bolster his theory that there were human habitations on the shore of the old lake before the flood struck and the area was drowned. "Mother nature does not make square stones," he commented. "Humans make them."
Mr Ballard is not entirely alone in his beliefs. In 1997, the same theory to support the origin of the Noah legends was rehearsed in Noah's Flood, a book written by two leading American marine biologists, Walter Pitman and William Ryan. They concluded that the flood devastated the area 7,150 years ago. But there are problems with the idea. The Bible, for example, tells us that Noah lived in the arid deserts of Mesopotamia - in what is modern-day Iraq - whereas the Turkish shores of the lake where the Black Sea is today would have been lush with vegetation.
"The Noah's Flood idea is very sexy one, but it's wrong," Ali Aksu, a geologist at Memorial University in Newfoundland, told Newsweek.
He says that he can demonstrate that the Black Sea was already at current levels 7,500 years ago. Nor, he says, was there ever a dramatic and sudden flood.
Water from the Mediterranean, Mr Aksu counters, sloshed back and forth over countless years.Reuse content