Posted on 04/30/2007 4:38:09 PM PDT by blam
Comets and disaster in the Bronze Age
Cosmic impact is gaining ground as an explanation of the collapse of civilisations, writes Benny Peiser
At some time around 2300BC, give or take a century or two, a large number of the major civilisations of the world collapsed. The Akkadian Empire in Mesopotamia, the Old Kingdom in Egypt, the Early Bronze Age societies in Israel, Anatolia and Greece, as well as the Indus Valley civilisation in India, the Hilmand civilisation in Afghanistan and the Hongshan Culture in China - the first urban civilisations in the world - all fell into ruin at more or less the same time. Why?
A thousand years later, at around 1200BC, many of the civilisations of the same regions again collapsed at about the same time. This time, disaster overtook the Myceneans of Greece, the Hittites of Anatolia, the Egyptian New Kingdom, Late Bronze Age Israel, and the Shang Dynasty of China.
The reasons for these widespread and apparently simultaneous disasters - which coincided also with changes to cultures and societies elsewhere, such as in Britain - have long been a fascinating mystery. Traditional explanations included warfare, famine, and more recently systems collapse, but the apparent absence of direct archaeological or written evidence for causes, as opposed to effects, has led many archaeologists and historians into a resigned assumption that no definite explanation can be found.
Some decades ago, the hunt for clues passed largely into the hands of natural scientists. Concentrating on the earlier set of Bronze Age collapses, researchers began to find evidence that natural causes, rather than human actions, may have been initially responsible. There began to be talk of climate change, volcanic activity, and earthquakes - and some of this material has now found its way into standard historical accounts of the period.
Agreement, however, there has never been. Some researchers favoured one type of natural cause, others another, and the problem remained that no single explanation appeared to account for all the evidence.
Over the past 15 years or so, however, a new type of natural disaster has been much discussed and is beginning to be regarded, by many scholars, as the most probable single explanation for widespread and simultaneous cultural collapse, not only in the Bronze Age but at other times as well. The new theory has been advanced largely by astronomers, and remains almost completely unknown by archaeologists (notable exceptions include Prof Mike Baillie of Queens University, Belfast, and Dr Euan Mackie at Glasgow University). The new idea is that these massive cultural disasters were caused by the impact of comets or other types of cosmic debris on the Earth.
The hunt for natural causes for these human disasters began when the French archaeologist Claude Schaeffer published his book Stratigraphie Comparée et Chronologie LAsie Occidentale in 1948. Schaeffer analysed and compared the destruction layers of more than 40 archaeological sites in the Near and Middle East, from Troy to Tepe Hissar on the Caspian Sea and from the Levant to Mesopotamia. He was the first scholar to detect that all had been totally destroyed several times in the Early, Middle and Late Bronze Age, apparently simultaneously. Since the damage did not show signs of military or other human involvement, and in any case was too excessive, he argued that repeated earthquakes might have been responsible.
At the time he published, Schaeffer was not taken seriously. Since then, however, natural scientists have found widespread and unambiguous evidence for abrupt climate change, sudden sea level changes, catastrophic inundations, widespread seismic activity and evidence for massive volcanic activity at several periods since the last Ice Age, but particularly at around 2300BC, give or take 200 years. Areas such as the Sahara, and around the Dead Sea, were once farmed but became deserts. Tree rings show disastrous growth conditions at c 2350BC, while sediment cores from lakes and rivers in Europe and Africa show a catastrophic drop in water levels. In Mesopotamia, vast areas of land appear to have been devastated, inundated, or totally burned.
Scholars who, following Schaeffer, favour earthquakes as the principal cause of civilisation collapse argue that the world can expect vast earthquakes every 1,000-2,000 years, leading to widespread abandonment of sites; while scholars who prefer climate change as the principal cause argue that severe droughts caused agriculture to fail and that societies inexorably fell apart as a result.
Yet what was the cause of these earthquakes, eruptions, tidal waves, fire-blasts and climate changes? By the late 1970s, British astronomers Victor Clube and Bill Napier of Oxford University had begun to investigate cometary impact as the ultimate cause. Then in 1980, the Nobel prize-winning chemist Luis Alvarez and his colleagues published their famous paper in Science that argued that a cosmic impact had led to the extinction of the dinosaurs. He showed that large amounts of the element iridium present in geological layers dating from about 65 million BC had a cosmic origin.
Alvarezs paper had an immense influence and stimulated further research by such British astronomers as Clube and Napier, Prof Mark Bailey of the Armagh Observatory, Duncan Steel of Spaceguard Australia, and Britains best-known astronomer Sir Fred Hoyle. All now support the theory of cometary impact and loosely form what is now known as the British School of Coherent Catastrophism.
These scholars envisage trains of cometary debris which repeatedly encounter the Earth. We know that tiny particles of cosmic material penetrate the atmosphere every day, but their impact is insignificant. Occasionally, however, cosmic debris measuring between one and several hundred metres in diameter strike the Earth and these can have catastrophic effects on our ecological system, through multi-megaton explosions of fireballs which destroy natural and cultural features on the surface of the Earth by means of tidal-wave floods (if the debris lands in the sea), fire-blasts and seismic damage.
Depending on their physical properties, asteroids or comets that punctuate the atmosphere can either strike the Earths surface, or explode in the air. Those that strike leave an impact crater, such as the well-known Baringer Crater in Arizona caused by an asteroid made of iron some 50,000 years ago. At least ten impact craters are known around the world dating from after the last Ice Age, and no fewer than seven of these date from around the 3rd millennium BC - although none occurred in the Near East.
Air-explosions, however, can be more disastrous. A recent example - known as the Tunguska Event - occurred in 1908 over Siberia, when a bolide made of stone exploded about 5km above ground and completely devastated an area of some 2,000 km2 through fireball blasts. The bolide, although thought to have measured only 60m across, had an impact energy of about 40 megatons, three times as great as the Arizona example and equivalent to the explosion of about 2,000 Hiroshima-size nuclear bombs - even though there was no actual physical impact on the Earth. (The object that destroyed the dinosaurs, by contrast, is thought to have had a diameter of about 10km.) A smaller cometary blast occurred over the Brazilian rainforest in 1930.
In addition to the physical impact of comets, the British astronomers point to the occasional massive influx of cosmic dust high above the stratosphere which can cause a dramatic drop of global temperatures, leading to the suspension of agriculture; and also to the massive influx of cosmic chemicals (associated with dust) with, as yet, incalculable biochemical potentials. Until recently, the astronomical mainstream was highly critical of Clube and Napiers giant comet hypothesis. However, the crash of the comet Shoemaker-Levy 9 on Jupiter in 1994 has led to a change of attitudes. The comet, watched by the worlds observatories, was seen to split into 22 pieces and slam into different parts of the planet over a period of several days. A similar impact on Earth, it hardly needs saying, would have been devastating.
According to current knowledge, Tunguska-like impacts occur every 100 years or so. It is, therefore, not far-fetched to hypothesise that a super-Tunguska may occur every 2,000, 3,000 or 5,000 years and would be capable of triggering ecological crises on a continental or even global scale. In the past, sceptics have demanded the evidence of a crater before they would accept an argument of cosmic impact, but it is now becoming understood that no crater is necessary for disastrous consequences to ensue. The difficulty this leaves scholarship, however, is that in a Tunguska Event no direct evidence is left behind. It may be impossible to prove that one ever took place in the distant past.
The extent to which past cometary impacts were responsible for civilisation collapse, cultural change, even the development of religion, must remain a hypothesis. But in view of the astronomical, geological and archaeological evidence, this giant comet hypothesis should no longer be dismissed by archaeologists out of hand.
Dr Benny J Peiser is a historian and anthropologist at Liverpool John Moores University. With Mark Bailey and Trevor Palmer, he is editing Natural Catastrophes during Bronze Age Civilisations (BAR, 1998, in preparation).
Most geologists have thought they were from a massive meteor or comet bombardment where the meteor(s) or comet(s) broke up into thousands of pieces like a scattergun shot.
Yer quick with those. LOL
Maybe Southern Iraq.
Yeah. And we knew you were going to say that, too.
Of course it had to be a catastrophic event — we’re all into Hollywood special-effect type explanations.
We know Roman civilization (empire, really) just kind of peetered out & ultimately succumbed to barbarian invasions. Why can’t this have happened elsewhere and in other eras? At a lower state of technological development, civilization & pastoral lifestyles (advanced herdsman) lived in a kind of delicate balance. A population explosion among the herdsman followed by a drought, and entire ‘nations’ are set in motion. It’s like a game of billiards (or dominoes falling).
I don’t think these timelines really sync the way they are suggesting they do, so I’ll stick with the more mundane theories.
The 5,000-year-old way of life of the Marsh Arabs, celebrated by Wilfred Thesiger among others, has long been under threat. Its final disappearance is documented in The Iraqi Marshlands edited by Emma Nicholson and Peter Clark, and published this week by Politico's. As the accompanying map suggests, Saddam Hussein's aggressive drainage programme in the 1990s, which had the dual purpose or reclaiming land and pursuing rebels hiding in the waterways, turned much of the marshland into desert, depopulating the area. Some 200,000 of the inhabitants fled, many of them to refugee camps in Iran. The damage is probably irretrievable.
Is that the hole they pulled Saddam out of?
Whoa, deja vu....
Problem is, the Sumerians, Akkadians and Chaldeans who inhabited that area for 2000 years were not arabs. The arabs were later inhabitants who came after Muhammed set them on the march of conquest.
science ping
The Conversion of Constantine
He said that about noon, when the day was already beginning to decline, he saw with his own eyes the trophy of a cross of light in the heavens, above the sun, and bearing the inscription, Conquer by this. At this sight he himself was struck with amazement, and his whole army also, which followed him on this expedition, and witnessed the miracle. (source: Eusebius, Life of the Emperor Constantine). An impact of the Sirente size can be seen at big distance as a strip of fire turning into a fireball and then generating a pyrotechnic show. There may be a proximity in space and time between the proposed Sirente impact and the vision that the emperor Constantine had before the famous Battle of Milvian Bridge. A possibile coincidence between these two events has been widely discussed in the popular press.
There are quite a few likely suspects. Arizona Crater is a famous example. Upheaval Dome might be another, in Utah.
blam should check for them in China.
According to the environazi's, that alone should be reason enough for invading Iraq and getting rid of Saddam.
Well, I’m sure that it will be president Bush’s fault when it happens because he didn’t do anything to prevent it.
An event of that magnitude, leaving a crater of that size would have been an incredible explosion, one which certainly would have been recorded by the historians of the day, of which in AD300-AD-325 were considerable.
Thanks.
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