[meteorite-list] 8000BC Big Dipper Petroglyph
From: MexicoDoug <mexicodoug_at_meteoritecentral.com>
Date: Mon, 12 Sep 2011 03:46:38 -0400 (EDT) Message-ID: <8CE3F373CACA337-19A0-27BC5_at_webmail-d101.sysops.aol.com> Dear List (still with Ron Hartman on my mind ... I think he would what I'm posting here). The maximum it will "deform" from our insignificant vantage point...the bowl by 5% and the entire asterism they might move up to 2%. So, yes - it will look basically the same unless you are an astronomer. If you wonder how I came up with that: Star motions are basically measured in milliarcseconds per year (mas). There are 3,600,000 mas in one degree. The Moon and Sun are both about a half degree, and they are pretty small (About 720 of them in a necklace would be required to circle the heavenly sphere). If you make believe you are looking at the inside face of a shell we are in, astronomers use two coordinates to locate any point (R.A. and declination). The is nothing much different in the motion of this stars in the range of motions in either, so let?s just for fun look at the most separation that could happen in 8000 years without trusting any canned software (nothing against them - they are great, but take the fun of learning out and replace it with a black box and results delivered on a silver platter). Here are the speeds of the motions of RA for each of the stars in the big dipper (the plough; el arado, el carro, the pan, etc.): Dubhe: 136 mas/yr Merak: 81 mas/yr Phecda: 108 mas/yr Megrez: 104 mas/yr Alioth: 112 mas/yr Mizar: 121 mas/yr Alkaid: 121 mas/yr If you assume the absolute worst case, of two stars running away from each other in opposite directions, that would be Dubhe (-136) and Alkaid (+121), you get a separation speed of 257 mas/yr. In 8000 years that gives you 2,000,000 mas. That is just a wee bit more than the angular diameter of the Sun or Moon - and that is worst case; declination actually looks less acute, but it is fine to estimate. In conclusion, each star at most has moved relative to each of its companions one half degree in the extreme. This compares to the size of the big dipper: the four stars in the "bowl" portion span about 10 degrees. From the end of the handle to the opposite tip of the bowl is about 25 degrees. So that's the maximum it will "deform" from our insignificant vantage point...the bowl by 5% and the entire asterism they might move up to 2%. So, yes - it will look basically the same unless you are an astronomer. A similar question came up with the 6000 (or whatever) year old Orion's belt stars when comparing them for the hypothesis that the three main pyramids in Giza were in the belt stars' configuration. I believe it was Rob who mentioned this controversial claim. I don't buy it, but it has been looked at ad naseum and the conclusion is that they are still close enough so it is a viable conjecture. Kindest wishes Doug. -----Original Message----- From: lebofsky <lebofsky at lpl.arizona.edu> To: bartraj <bartraj at time.net.my> Cc: epgrondine <epgrondine at yahoo.com>; meteorite-list <meteorite-list at meteoritecentral.com> Sent: Mon, Sep 12, 2011 12:30 am Subject: Re: [meteorite-list] 8000BC Big Dipper Petroglyph Hi Robert: I took "Starry Night," a planetarium program "back" about 8,000 years (6,000 BC) and, as I would have predicted, the 7 stars in the Big Dipper are not far off from what we see today. You would have to go back many 10s of thousands of years in order to see a big diffence. I remember seeing predictions of the dipper being more of a pan cake flipper in 100,000 and that 100,000 years ago, the bowl was much deeper and I think the handle flatter. I have not gone that far with the program (there might be a preset demo of it in the program, but it is late and have not looked for it). Larry > Hello Ed, Martin, Cris, List, > > There has been some discussion on meteorite-list about Chinese researcher > Wu Jiacai, who recently announced the finding of groups of petroglyphs in > Inner Mongolia. In his interpretation, the petroglyphs show that an > intellectually advanced ethnic group, the Chifeng people of the Hongshan > Culture, were forced to leave their homeland because of a singular > destructive event, perhaps comet- or meteorite-related. > http://www.globaltimes.cn/NEWS/tabid/99/ID/673451/Falling-meteor-depicted-in-5000-year-old-rock-carving-in-north-China.aspx > > While looking into this event, I came across reports of an earlier find by > Wu Jiacai, an early Neolithic depiction of the Big Dipper. See for example > http://www.megalithic.co.uk/article.php?sid=2146412586 > > It made the news in Chinese papers. Here is a summary of a 2010 interview > with Wu Jiacai in a Mongolian home town newspaper. > http://www.swcf.cn/wh/2010-01/12/content_900.htm The newspaper article > features a superimposed diagram of the shape of the Big Dipper in 8000BC. > Maybe some of the astronomers here can assess whether this shape is > plausible. > > ------------- > Summary > > After more than a year of on-site research at Baimiaozi Mt., Wu had > identified ten distinct groups of rock art, mostly depicting animals and > people. Among them was a 310 cm-long yam-shaped stone on which 19 clearly > visible stars had been chiseled and ground into the stone's upward-facing > side, with the markings depicting the seven stars of the Big Dipper on the > northern part of the face. > > [A better view of the stone, from Wu Jiacai's personal blog, is here > https://www.dropbox.com/gallery/18663629/1/Hongshan%20Culture?h=bdfa66 ] > > The total length of the Big Dipper is 119cm. The indentations marking the > stars are 6cm in diameter, with a maximum depth of 5 cm. The shape of each > star resembles an upside-down mantou (steamed bread), wide on the outside > and smaller within. The star-shapes are smooth, with rounded surface > [indentations] that also contain a natural-colored residue of dust and > body oil [from touching]. > > Following astronomers' reconstructions of star positions from 100,000 > years ago to today, Wu Jiacai found complete matches between the > configuration of the Big Dipper's seven stars 10,000 years ago and the > configuration of stars in the rock art. > > Gai Shanlin [a Manchu from Hebei], who is the regional archaeological > expert on rock art, inspected the inscribing-polishing methods. He > recognized the drawing of the seven stars of the Big Dipper as an early > Neolithic artifact by ancestral people. > > End Summary > > ------------ > > Regards > > Robert A. Juhl, Tokyo > > ______________________________________________ > Visit the Archives at > http://www.meteoritecentral.com/mailing-list-archives.html > Meteorite-list mailing list > Meteorite-list at meteoritecentral.com > http://six.pairlist.net/mailman/listinfo/meteorite-list > ______________________________________________ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list at meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list Received on Mon 12 Sep 2011 03:46:38 AM PDT |
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