[meteorite-list] Cox crisply comments; full text of "No evidence"; Comet theory carbonized, Rex Dalton, nature.com; fungus found abstract: Rich Murray 2010.08.31
From: Rich Murray <rmforall_at_meteoritecentral.com>
Date: Tue, 31 Aug 2010 22:28:22 -0600 Message-ID: <FF9E243EFDB54C4085A5751DA61A7227_at_ownerPC> Cox crisply comments; full text of "No evidence"; Comet theory carbonized, Rex Dalton, nature.com; fungus found abstract: Rich Murray 2010.08.31 http://rmforall.blogspot.com/2010_08_01_archive.htm Tuesday, August 31, 2010 [ at end of each long page, click on Older Posts ] http://groups.yahoo.com/group/astrodeep/message/65 [you may have to Copy and Paste URLs into your browser] _______________________________________________ http://cosmictusk.com/new-paper-greenland-ice-sheet-shows-diamond-rich-layer-at-younger-dryas-boundary#comments Dennis Cox August 31st, 2010 at 12:05 am Pinter's work is immaterial. In the final analysis, the NDs will be seen as minor clues only. But don't be to quick to dismiss them. Even though it's turning into a circular case of 'we said, they said'. Who's correct? Are the NDs valid? If, in fact, the NDs are really there, then they describe a violent set of minimum atmospheric conditions. We can test this easily enough if we work from the postulate that they can be thought of as a barometer and pyrometer, rolled into one. If such exogenic thermal explosive conditions were real, and they were directed downwards at the ground, then there was enough heat and pressure to make stone flow like water for a moment. The NDs are not the only blast affected materials of the powerful explosive events they formed in. Those explosions most certainly left their marks. And they aren't craters. If they formed in airburst impact vortices, then the Boslough simulation predicts the temps, pressures, and rotation speeds of a single impact down-blast vortex. Working from the postulate that the events of the YDB were caused by the impact storms of the debris streams of the fragmented Taurid progenitor -- the YD impact hypothesis as it stands, describes tens of thousands of such airbursts in a little over an hour. And acompanied by clouds of particles down to the size dust grains falling into the atmosphere at something like 30 km/second. Sounds too fantastic? Stay with me here. I'm on a roll. Firestone and friends proposed destructive forces equivalent to as much as 10^9 megatons of TNT -- or in ordinary English, a million, billion tons of TNT. Temps hotter than the surface of the sun. Is our comet predicted to have been big enough to account for such devastation? Judge for yourself. Before its breakup, the Taurid progenitor is estimated at 10^15 gm total mass. Yeah, I know, using a gram scale to weigh a giant comet is like giving the distance to moon in inches. It works out to well over 1.1 billion tons. And between 50 and 100 km in diameter. Since the YD hypothesis has become a fully fledged theory that gives a specific description of the exact nature of the impactors, then it follows that we can also predict the nature and severity of the blast affected materials. Only the first fragments to fall would have gone into cold atmosphere. The rest would have fallen into already superheated impact plasma and just cranked up the heat and pressure. We aren't looking for craters where a solid bolide hit the ground. We are looking for the signatures, whatever they might be, of a 'Perfect Storm' of thermal impact plasma. A full blown magneto-hydrodynamic-plasma storm, with winds gusting to supersonic, and the gusts hotter than the surface of the sun. The surface of the Earth didn't get smashed and broken. It was flash melted and blown away. The overpressures of the blasts would have tossed whole mountain ranges like clumps of flour on a bakers table. And flash melted them like chunks of wax under a high pressure blowtorch. 10^9 mega tons TNT of destruction doesn't seem like such a stretch when you work out how big the comet was. Extraordinary hypotheses require extraordinary proofs. If the Younger Dryas Impacts were, in fact, the multiple airburst impact storms of the Taurid Progenitor, then there should be a hundreds of thousands cubic miles of flash melted rock and blast affected materials on this continent, as pristine as the day they first cooled -- with no giant volcanic system to blame for them. Fortunately this is not a problem. Trust and believe, that the world hasn't been shown all the lines of evidence yet. http://craterhunter.wordpress.com http://www.scribd.com/doc/36697955/no-evidence-of-nanodiamonds-in-Younger-Dryas-sediments-to-support-an-impact-event 6 pages free full text, click on Download, then go to your download file folder, and R click the document name to get to the Menu to then click Print http://www.nature.com/news/2010/100831/full/news.2010.441.html Published online 31 August 2010, Nature, doi:10.1038/news.2010.441 News Comet theory carbonized Sediment studies rule out impact as cause of ancient cold spell. Rex Dalton The idea that a comet impact triggered a widespread climate chill has taken another hit. MIKE AGLIOLO/SCIENCE PHOTO LIBRARY The controversial theory that a comet impact sent Earth into a sudden climate chill nearly 13,000 years ago has been dealt a serious blow, according to scientists who have analysed sediments from the time. The cool period, known as the Younger Dryas, coincided with the disappearance of the Clovis culture of North American humans and the large mammals they hunted. Most scientists think that the cold snap was triggered by a flood of fresh water from a breaching lake that disrupted the northern Atlantic ocean circulation. But an alternative theory claims that sediments from that time contain a host of evidence -- including carbon spherules and iridium -- implicating a massive comet impact as the culprit (see Nature 447, 256-257; 2007). The proposition was attractive, as it claimed to explain both the rapid climate change, and the sudden die-off of humans and animals at the time. A series of publications has since challenged each piece of cometary evidence, save one - nanodiamonds, supposedly created by the comet's impact shock. Stony silence Materials scientist Tyrone Daulton of Washington University in St Louis, Missouri, and his colleagues now say that these nanodiamonds are actually aggregates of the carbon materials graphene, graphane and their oxides 1. "I believe the earlier reports are in error," says Daulton. "If you don't pay close attention, you can fool yourself to think something is a diamond when it is not." The study, published in Proceedings of the National Academy of Sciences (PNAS), "is a very convincing analysis by a world expert", says Peter Heaney, a mineralogist at Pennsylvania State University in University Park, who was not involved in the research. But the lead author of two earlier comet-impact papers, Douglas Kennett, an archaeologist at the University of Oregon in Eugene, calls the study "fundamentally flawed science". "The claim we misidentified diamonds is false, misleading and incorrect," he adds, although he declined to specify his objections. Daulton's paper comes hot on the heels of work by Nicholas Pinter, a geoarchaeologist at Southern Illinois University in Carbondale and a co-author on the PNAS study. Pinter and his colleague Andrew Scott of the Royal Holloway, University of London in Egham went to three of the sites where Kennett's team had found nanodiamonds. As well as providing samples for Daulton's study, they also looked for carbon spherules. What they found instead was hardened fungal material and faecal matter from arthropods that looked similar to carbon spherules 2. Kennett and his team also dispute this finding, and he says that they will be writing to PNAS to "expose the major flaws in the Daulton paper". References Daulton, T. L. , Pinter, N. & Scott, A. C. Proc. Natl Acad. Sci. USA doi:10.1073/pnas.1003904107 (2010). Scott, A. C. et al. Geophys. Res. Lett. doi:10.1029/2010GL043345 (2010). http://www.agu.org/pubs/crossref/2010/2010GL043345.shtml GEOPHYSICAL RESEARCH LETTERS, VOL. 37, L14302, 5 PP., 2010 doi:10.1029/2010GL043345 Fungus, not comet or catastrophe, accounts for carbonaceous spherules in the Younger Dryas "impact layer" Andrew C. Scott Department of Earth Sciences, Royal Holloway University of London, Egham, UK Nicholas Pinter Department of Geology, Southern Illinois University, Carbondale, Illinois, USA Margaret E. Collinson Department of Earth Sciences, Royal Holloway University of London, Egham, UK Mark Hardiman Department of Geography, Royal Holloway University of London, Egham, UK R. Scott Anderson School of Earth Sciences and Environmental Sustainability, Northern Arizona University, Flagstaff, Arizona, USA Anthony P. R. Brain Centre for Ultrastructural Imaging, King's College London, London, UK Selena Y. Smith Museum of Paleontology and Department of Geological Sciences, University of Michigan, Ann Arbor, Michigan, USA Federica Marone Swiss Light Source, Paul Scherrer Institut, Villigen, Switzerland Marco Stampanoni Swiss Light Source, Paul Scherrer Institut, Villigen, Switzerland Institute for Biomedical Engineering, ETH Zurich, Zurich, Switzerland A claim attributes the onset of the Younger Dryas climate interval and a range of other effects ?12,900 years ago to a comet airburst and/or impact event. One key aspect of this claim centers on the origin of carbonaceous spherules that purportedly formed during intense, impact-ignited wildfires. Samples from Pleistocene-Holocene sedimentary sequences in the California Channel Islands and other sites show that carbon spherules and elongate forms are common in samples dating to before, during, and well after the 12,900-year time horizon, including from modern samples. Microscopic studies show that carbon spherules have morphologies and internal structures identical to fungal sclerotia (such as Sclerotium and Cenococcum). Experimental charring of fungal sclerotia shows that their reflectance increases with temperature. Reflectance measurements of modern and late Pleistocene spherules show that the latter indicate, at most, low-intensity burning. These data cast further doubt upon the evidence suggesting a catastrophic Younger Dryas impact event. Received 25 March 2010; accepted 1 June 2010; published 20 July 2010. _______________________________________________ 3 times more downward energy from directed force of meteor airburst in 3D simulations by Mark B. E. Boslough, Sandia Lab 2007.12.17: Rich Murray 2010.08.30 http://rmforall.blogspot.com/2010_08_01_archive.htm Monday, August 30, 2010 [ at end of each long page, click on Older Posts ] http://groups.yahoo.com/group/astrodeep/message/63 [you may have to Copy and Paste URLs into your browser] excellent Google Earth and ground views of shallow oval craters worldwide, Pierson Barretto: Rich Murray 2010.08.22 http://rmforall.blogspot.com/2010_08_01_archive.htm Sunday, August 22, 2010 [ at end of each long page, click on Older Posts ] http://groups.yahoo.com/group/astrodeep/message/60 [you may have to Copy and Paste URLs into your browser] Rich Murray, MA Boston University Graduate School 1967 psychology, BS MIT 1964, history and physics, 1943 Otowi Road, Santa Fe, New Mexico 87505 505-501-2298 rmforall at comcast.net http://groups.yahoo.com/group/AstroDeep/messages http://RMForAll.blogspot.com new primary archive http://groups.yahoo.com/group/aspartameNM/messages group with 146 members, 1,609 posts in a public archive http://groups.yahoo.com/group/rmforall/messages participant, Santa Fe Complex www.sfcomplex.org _______________________________________________ Received on Wed 01 Sep 2010 12:28:22 AM PDT |
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