Re: [meteorite-list] Re:Comet hit Britain in mid sixth, century, AD?
-making astrologer, yet equal areas are swept out in equal times, nevertheless. As far as short-term climatic fluctuation is concerned, there is much more cause to look at variations in solar flux as a possible explanation . I want to stop and savor this moment when we agree almost perfectly. That's obviously not a frequent event. What better way to explain SHORT-TERM solar flux variation than the short but intense dumping of opaque (or reflective) particulate matter into the Earth's atmosphere? It would settle on a time scale much shorter than what we know of innate solar variation. You see, I think you, and perhaps some neo-catastrophists, think of the term impact in a much too restricted sense. A dust grain stumbling into the Earth's atmosphere and getting stuck there is a kind of cosmic impact. Enough dust in a short enough time could be more catastrophic than anyone imagines. We just don't appreciate the role of dust, but we're learning. I reference the recent discovery of supernovae iron isotopes in sediments only 2.3 million years old, the heavy dust layer deposited on the Earth 8.3 million years ago by the breakup of the Veritas asteroid family. The 2.2-2.3 mya dust event has been proposed as the cause of a marine mass extinction at that time. And then, there's even more recent isotope anomalies discovered by Firestone, over which we disagreed, I recall. His hypothesis was utterly ridiculous, a comet formed in a supernovae. OK, he's an idiot (outside of his expertise) with a perfectly idiotic explanation of how these materials got here, mammoths being shot with interstellar particles and becoming extinct. Because it was so silly, you questioned totally the validity of their presence and dating on depositational arguments, wanting to dump the whole thing, dismissing the isotopic evidence as irrelevant and proving nothing, but these isotopes have since been found and similarly dated in Antarctic ice cores, where depositational issues are moot. They fell out of the atmosphere. They're almost certainly the dust from supernovae, possibly the Scorpius-Centaurus supernovae complex, possibly a closer former supernovae as yet undiscovered. Not all catastrophes are Hollywood-style. If you insist on a Hollywood spectacular, Google up HR 8210 (aka IK Pegasi B). Could it find an extra 0.15-0.27 solar mass in dust or a stray super-Jupiter-body and let go tomorrow? It would certainly be spectacular, during the interval when we were still alive, that is. Granted, wisps of interstellar dust or sudden effusions of asteroidal or cometary dust or even a swarm of small weak bodies breaking up in the Earth's upper atmosphere are not as picturesque nor as suitable for Hollywood movies as big splashy impacts, but they can deliver as much or more disruption as all but the best of the planet crashers. Of course, direct exposure to a nearby supernovae is a spectacular possibility, but interstellar drifts of supernova dust can be almost as bad, not only unspectacular but hardly noticeable... until it's too late. Since I've disagreed with you (and extensively), I'll apologize in advance for annoying you again, Marco. Isn't strange how everybody doesn't agree on everything? Sterling K. Webb --- - Original Message - From: Marco Langbroek [EMAIL PROTECTED] To: meteorite list meteorite-list@meteoritecentral.com Sent: Saturday, July 22, 2006 5:54 AM Subject: [meteorite-list] Re:Comet hit Britain in mid sixth, century, AD? Sterling K. Webb wrote: The scientist you're referring to is Michael Baillie, an Irish dentrochronologist (not Bailey). Too many Bailey'/Baillie's around, sorry... And its dendrochronologist, not dentrochronologist. Their suggestion arose from uncovering a 19th century account of an excavation on the island of Anglesey (which is the least forested portion of the UK, less than 0.5%) of an ancient forest which had been flattened and crushed wholesale and apparently instantaneously and which to them greatly resembled a naive description of the flattened forest on the Tungus River caused by the Tunguska object, only much larger. Which is a naive Pompei Premise about general taphonomic processes and ignores that in the 19th century, taphonomic and post-depositional processes were concepts still completely ignored. And catastrophic thinking reigned those days. Have you ever been to a peat excavation? It looks like Tunguska allright, fallen tree trunks everywhere. Only it isn't. Yes, Marco, History is Change. But there are also those with a known fetish AGAINST impacts or any other physical event as a source for any historical change. The sudden collapse of the Byzantine or eastern Roman Empire after 534 AD is without known social, political, economic, military nor other human cause. It is the sudden commencement of the Dark Ages
Re: [meteorite-list] Re:Comet hit Britain in mid sixth century, AD?
534 AD is without known social, political, economic, military nor other human cause. It is the sudden commencement of the Dark Ages for no apparent reason. Dark Ages are rare, and always without apparent explanation (1200 BC to 800 BC is another, and there was another about 4000 years ago, too). Some things are just not worked out yet. In the longer term, there is the unexplained history of eustatic sea level changes. Eustatic sea level changes are the rise and fall of sea level on a timescale too rapid to be caused by the elevation or subsidence of continents or the displacement of water by growing mid-oceanic ridges. 50 years ago and more, most geologists worked for oil companies and their data was secret. In the 1970's, the great geologist Vail talked his oil company into letting him divulge their vast records of eustatic sea level changes to other geologists. To get eustatic changes you have to radically change the amount of water in the oceans, pretty difficult to do... There are great sharp drops in the Earth's sea level, as great or greater than those of the severest ice ages (when water is tied up in glaciers miles thick covering vast swathes of continents) that only lasted a few years to perhaps 500-1000 years, far too short for an ice age (which takes many thousands of years). They have never been explained, because the only plausible cause would be a vast world-wide glaciation in which most of the planet froze over instantly and caused the atmospheric water to fall out as snow or ice but only for a very few years, then took up to centuries to melt all that ice after the climate returned to normal. These odd, potentially super-cooling, events are NOT associated with extinctions nor any other known phenomenon (vulcanism, magnetic reversals, etc.). They are completely out of the blue (and fortunately quite rare) and very difficult to explain. They are sometimes called false ice ages, a totally ridiculous term. At least for the last 35 years, they have been impossible to explain. I got no theory, except that I tend look up at the sky for big nasty unexplained events. After-thought: Ever hear of the form of ice called diamond dust? Google that, too. Now, there's a really nasty possibility... Sterling K. Webb --- meteorite-list@meteoritecentral.com Sent: Friday, July 21, 2006 11:59 AM Subject: Re: [meteorite-list] Re:Comet hit Britain in mid sixth century, AD? Baileys comet impact hypothesis is quite contested, it certainly is not an accepted main stream hypothesis. So I quite surprised by the tone of that newspaper clipping that suggested so. The astrophysicist supporting it are, by the way, astrophysicists with a known fetish for impacts as a source for every historical change. Thanks Marco, In general, I think the theory is very dubious. The guy was trying to explain how small numbers of Anglo-Saxon migrants replaced a much larger indigenous Celtic/British population both genetically and linguistically. But if the Britons were dying off in the 530s because of poor crop yields and cold nights or whatever caused by cometary dust in the atmosphere, then the Anglo-Saxons would too. Unless of course somebody postulates an actual impact which wiped out a large part of the (British) population on the west side of the island, but was survived by larger numbers on the east which is where the Anglo-Saxons were. But then that's not a good model either, because Ireland is where it would have hit... and there is no evidence of such an event from there. Just as a matter of interest if someone has time to fiddle with it, what parameters would such a hypothetical body have to have to kill people within a radius of 300 km (so along the whole western coast of England and Wales) but leave those beyond still alive? [I could not get the Arizona Earth Impact Effects Program http://www.lpl.arizona.edu/impacteffects/ to give the result I wanted - just curious]. Paul Barford __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Re:Comet hit Britain in mid sixth, century, AD?
Sterling K. Webb wrote: The scientist you're referring to is Michael Baillie, an Irish dentrochronologist (not Bailey). Too many Bailey'/Baillie's around, sorry... And its dendrochronologist, not dentrochronologist. Their suggestion arose from uncovering a 19th century account of an excavation on the island of Anglesey (which is the least forested portion of the UK, less than 0.5%) of an ancient forest which had been flattened and crushed wholesale and apparently instantaneously and which to them greatly resembled a naive description of the flattened forest on the Tungus River caused by the Tunguska object, only much larger. Which is a naive Pompei Premise about general taphonomic processes and ignores that in the 19th century, taphonomic and post-depositional processes were concepts still completely ignored. And catastrophic thinking reigned those days. Have you ever been to a peat excavation? It looks like Tunguska allright, fallen tree trunks everywhere. Only it isn't. Yes, Marco, History is Change. But there are also those with a known fetish AGAINST impacts or any other physical event as a source for any historical change. The sudden collapse of the Byzantine or eastern Roman Empire after 534 AD is without known social, political, economic, military nor other human cause. It is the sudden commencement of the Dark Ages for no apparent reason. Dark Ages are rare, and always without apparent explanation (1200 BC to 800 BC is another, and there was another about 4000 years ago, too). Don't lecture me that condescendingly man. Who's got the PhD in prehistoric archaeology here? The point is that many (pre-) historic events indeed DON'T HAVE and DON'T NEED TO HAVE a clearly identifiable prime-mover. Thinking in prime-movers only to explain (pre-)historic change is utterly simplistic. That's why the whole neo-catastrophic movement of primarily ASTROPHYSICISTS who bring up cosmic impact as a prime-mover in far too many cases of (pre-)historic change is just a too simplistic look on (pre-)history, and in my opinion is pseudo-science. Complex societies are inherently instable. There's no need for a clear-cut external prime-mover to make such a society collapse. Volcanic super eruptions, cosmic impacts and other natural disasters happen. And when they happen, they can have a profound impact on human society in the affected area, no doubt (an appendix to my own dissertation explores the possible effekts of the Australasian impact for early Asian Homo erectus, in fact). And there are some good historic examples of that too (for the case of volcanic eruptions at least). But some people use them as Dei ex Machinae to explain everything we don't readily understand. Large impact phenomena come with a suit of identifiable things. If there was such an event in Britain as recent as AD 540, then where are the ejecta layers, the dust layers, the spherule layers, the impact glasses, the shocked quartz, the impact craters, the extinction events in flora and fauna? There is no reason why these should have vanished from the geological record in this case. A set of narrow tree rings that can have multiple causes is not enough to see an impact evidenced. And its all we have here. A very meagre set of proxy data by all means. I do not doubt Baillie's tree ring analysis, but the whole hypothesis attached to it I do doubt for it is founded on very flimsy multi-interpretable proxy data. As far as short-term climatic fluctuation is concerned, there is much more cause to look at variations in solar flux as a possible explanation than to impact. Clube, Napier, Steel and such have their own agenda to see impacts in history and recent pre-history everywhere. It ties in with their idea's on the evolution of the Taurid meteor complex as being derived from the arrival and breakup of a giant comet a few millenia ago. They believe this showered the earth with impact fragments. As a result, they have a strong tendency to see everything which in their perception is odd in the history of the past few millenia as evidence for their theory. Even Stonehenge is a giant memorial to celestial Taurid displays in e.g. Steels opinion. In my opinion, this conceptually is very near to Von Däniken seeing Alien influence and references to Alien visitors everywhere as its the result of a similar simplistic and biased idee-fixe look at (pre-) history. And please note that Dark age is an often misused and misunderstood concept. It says more about our inability to access the character of that period, than about that period itself. - Marco - Dr Marco Langbroek Dutch Meteor Society (DMS) e-mail: [EMAIL PROTECTED] private website http://home.wanadoo.nl/marco.langbroek DMS website http://www.dmsweb.org - __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Re:Comet hit Britain in mid sixth, century, AD?
On Sat, 22 Jul 2006 12:54:04 +0200, you wrote: Large impact phenomena come with a suit of identifiable things. If there was such an event in Britain as recent as AD 540, then where are the ejecta layers, the dust layers, the spherule layers, the impact glasses, the shocked quartz, the impact craters, the extinction events in flora and fauna? There is no reason why these should have vanished from the geological record in this case. I'm not defending the comet hit Britian theory, but there CAN be a (fairly) widely deadly hit without leaving (much) evidence that would be visible hundreds of years later. Look at Tunguska. For how many miles radius would it have killed (either instantly or over days or weeks from internal trauma) if it had been over a populated area? The British Isles are pretty small-- I'm guessing that a Tunguska would wipe out a large percentage of the population. __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
RE: [meteorite-list] Re:Comet hit Britain in mid sixth, century, AD?
If you're talking about catastrophic events during the Dark Ages, wasn't there an episode where major outgassing from volcanoes (fluorine and other nasty volcanic gases) in Iceland poisoned most of the viable cropland there, and the effects were felt up to several hundred miles away? I vaguely recall a timeframe of around 500-600 (maybe 700?) a.d. First the grass all died, crops were poisoned, the cattle couldn't get enough to eat and eventually died, either from starvation or poisoning, then it was the people's turn... Tracy Latimer __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Re:Comet hit Britain in mid sixth century AD?
Hi, .Just as follow-up to Paul's email re the 6th C. possible meteorite, can I just give you a couple of quotes from The Anglo-Saxon chronicles, which were contemporary notes compiled over a period starting about 800ad to 1100ad by the monastic population here in the UK. First thing that becomes apparent to me when I read over the mss. is that for most of the period covered by the Anglo-Saxon chronicles, it is a time when there are actually gaps in the nearly perfect consecutive records, and that all the source documents (remember, several copies of the records were made in several monasteries). 538(ad): Here 14 days before 1 March the sun grew dark from early morning until 9am. (Winchester Mss, Cambridge, Corpus Christie MS173, ff 1(v)32(r)) 540: Here on 20 June the sun grew dark and stars appeared for well-nigh half a hour after 9am (Winchester Mss, Cambridge, Corpus Christie MS173, ff 1(v)32(r)) For possible causes see Stothers Rampino, Volcanic eruptions in the Mediterranean before A.D. 630, 6357-71 (6362). for a simple list of such phenomena see Britton, Meteorological Chronology, passim. It's a lot easier to read than the Germanic middle English/Latin it was originally written in, believe me! You don't have to learn a new language! Almost the same quote is in the Peterborough manuscript (Oxford, Bodleian Library MS Laud 636) Note that there 2 separate events here described here, separated by 2 years and borne out by dendrochronological work carried out in oak from Irish bogs which show something certainly happened, but who knows what?! As if life in those days was not hard enough! Sorry for OT post. Best! dave IMCA #0092 Sec. BIMS www.bimsociety.org __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Re:Comet hit Britain in mid sixth century, AD?
538(ad): Here 14 days before 1 March the sun grew dark from early morning until 9am. (Winchester Mss, Cambridge, Corpus Christie MS173, ff 1(v)32(r)) 540: Here on 20 June the sun grew dark and stars appeared for well-nigh half a hour after 9am (Winchester Mss, Cambridge, Corpus Christie MS173, ff 1(v)32(r)) Both refer to normal solar eclipses. Note that of course if there is enough dust in the air to block the sun, stars would never be visible. Baileys comet impact hypothesis is quite contested, it certainly is not an accepted main stream hypothesis. So I was quite surprised by the tone of that newspaper clipping that suggested so. The astrophysicist supporting it are, by the way, astrophysicists with a known fetish for impacts as a source for every historical change. - Marco - Dr Marco Langbroek Dutch Meteor Society (DMS) e-mail: [EMAIL PROTECTED] private website http://home.wanadoo.nl/marco.langbroek DMS website http://www.dmsweb.org - __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Re:Comet hit Britain in mid sixth century, AD?
Baileys comet impact hypothesis is quite contested, it certainly is not an accepted main stream hypothesis. So I was quite surprised by the tone of that newspaper clipping that suggested so. The astrophysicist supporting it are, by the way, astrophysicists with a known fetish for impacts as a source for every historical change. Thanks Marco, In general, I think the theory is very dubious. The guy was trying to explain how small numbers of Anglo-Saxon migrants replaced a much larger indigenous Celtic/British population both genetically and linguistically. But if the Britons were dying off in the 530s because of poor crop yields and cold nights or whatever caused by cometary dust in the atmosphere, then the Anglo-Saxons would too. Unless of course somebody postulates an actual impact which wiped out a large part of the (British) population on the west side of the island, but was survived by larger numbers on the east which is where the Anglo-Saxons were. But then that's not a good model either, because Ireland is where it would have hit... and there is no evidence of such an event from there. Just as a matter of interest if someone has time to fiddle with it, what parameters would such a hypothetical body have to have to kill people within a radius of 300 km (so along the whole western coast of England and Wales) but leave those beyond still alive? [I could not get the Arizona Earth Impact Effects Program http://www.lpl.arizona.edu/impacteffects/ to give the result I wanted - just curious]. Paul Barford __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Re:Comet hit Britain in mid sixth century, AD?
Just as a matter of interest if someone has time to fiddle with it, what parameters would such a hypothetical body have to have to kill people within a radius of 300 km (so along the whole western coast of England and Wales) but leave those beyond still alive? And not be recorded historically except in the most obscure and oblique fashion? And not leave any apparent geological or botanical effects? I'd say the parameters you are looking for would be supernatural. Chris * Chris L Peterson Cloudbait Observatory http://www.cloudbait.com - Original Message - From: Paul Barford [EMAIL PROTECTED] To: meteorite-list@meteoritecentral.com Sent: Friday, July 21, 2006 10:59 AM Subject: Re: [meteorite-list] Re:Comet hit Britain in mid sixth century, AD? Thanks Marco, In general, I think the theory is very dubious. The guy was trying to explain how small numbers of Anglo-Saxon migrants replaced a much larger indigenous Celtic/British population both genetically and linguistically. But if the Britons were dying off in the 530s because of poor crop yields and cold nights or whatever caused by cometary dust in the atmosphere, then the Anglo-Saxons would too. Unless of course somebody postulates an actual impact which wiped out a large part of the (British) population on the west side of the island, but was survived by larger numbers on the east which is where the Anglo-Saxons were. But then that's not a good model either, because Ireland is where it would have hit... and there is no evidence of such an event from there. Just as a matter of interest if someone has time to fiddle with it, what parameters would such a hypothetical body have to have to kill people within a radius of 300 km (so along the whole western coast of England and Wales) but leave those beyond still alive? [I could not get the Arizona Earth Impact Effects Program http://www.lpl.arizona.edu/impacteffects/ to give the result I wanted - just curious]. Paul Barford __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Re:Comet hit Britain in mid sixth century, AD?
And not be recorded historically except in the most obscure and oblique fashion? And not leave any apparent geological or botanical effects? I'd say the parameters you are looking for would be supernatural. I think it pretty obvious that if something this size had landed on Ireland in 530 AD, we would have heard about it from a lot further afield!! Sorry, in an effort to remain brief, I was not making myself clear. As far as I am concerned the sixth century comet/meteorite impact explanation of the observed effect is not a good one (there is another much more basic explanation, IMO everything suggests the genetic sampling at the core of the problem was faulty). I posted it here to see whether list-members had any comments on the idea as such. Some historians in the UK are discussing this and last time I looked some of them were apparently taking it seriously. My later question concerned the implications of the (IMO faulty) suggestion that a meteor might have done it. Remembering the all-too-vivid Japanese video we saw here a few weeks back (!) I was just curious what size body would have had the effect these historians are apparently proposing in all seriousness. The Arizona earth-impact program tells us what happens if a body this size and speed hits at such an angle? and so on... but I wanted to start from a hypothetical kill-zone 300 km radius to work back to what size body these historians would be imagining. Just out of curiosity, I was wondering whether anyone here had an idea. Paul Barford __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
