Displaying astronomical alignments in academic papers

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[Cross-posted to i-Science]

Segesta alignment
Astronomical align­ment at Segesta

There’s a couple of paper which have come out recently which use dif­fer­ent tech­niques for indic­at­ing astro­nom­ical align­ments at archaelo­gical sites. The image above is one I put together for a poster to show why hori­zon alti­tude is import­ant as well as azi­muth. It’s quite tight, so it’d be no good if you wanted to see where sun­rise was in mid­sum­mer for instance, and chart­ing the paths of astro­nom­ical bod­ies over a site is a prob­lem. By and large you can treat a site as a small flat area, so there’s not usu­ally any car­to­graphic prob­lems in account­ing for the curvature of the earth. The sky in con­trast is very curved over every archae­olo­gical site, so how to you dis­play that in a paper?

The Megalithic Portal put me on to an inter­est­ing art­icle pub­lished in Information Visualization: A Sky Dome visu­al­isa­tion for iden­ti­fic­a­tion of astro­nom­ical ori­ent­a­tions by Georg Zotti. The abstract includes:

This paper presents a novel dia­gram com­bin­ing archae­olo­gical maps with a folded-apart, flattened view of the whole sky, show­ing the local hori­zon and the daily paths of the Sun, Moon and brighter stars. By use of this dia­gram, inter­est­ing group­ings of astro­nom­ical ori­ent­a­tion dir­ec­tions, for example, to cer­tain sun­rise and sun­set points could be iden­ti­fied, which were evid­ently used to mark cer­tain days of the year.

Unfortunately Information Visualization isn’t a journal archae­olo­gists get, and it costs $30 to down­load the paper. What I can talk about though is a con­fer­ence paper on his own site: A Sky Dome Visualisation for Identification of Astronomical Orientations, which includes in the abstract:

This paper presents a novel dia­gram com­bin­ing archae­olo­gical maps with a folded-apart, flattened view of the whole sky, show­ing the local hori­zon and the daily paths of sun, moon and brighter stars. By use of this dia­gram, inter­est­ing group­ings of astro­nom­ical ori­ent­a­tion dir­ec­tions, e.g. to cer­tain sun­rise and sun­set points could be iden­ti­fied, which were evid­ently used to mark cer­tain days of the year.

The two look as though they’re likely to be similar.

The idea is actu­ally rather clever and I’ll go through a very sim­pli­fied ver­sion of a dia­gram based on his method.
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Three links

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There will be a longer write-up but I’m mak­ing a quick note for when I get home. For now there’s just three links.

http://​news​.bbc​.co​.uk/​1​/​h​i​/​u​k​/​5​1​0​7​9​1​2​.​stm
http://​news​.bbc​.co​.uk/​1​/​h​i​/​w​a​l​e​s​/​s​o​u​t​h​_​e​a​s​t​/​4​6​1​8​2​0​9​.​stm
http://​www​.thes​.co​.uk/​c​u​r​r​e​n​t​_​e​d​i​t​i​o​n​/​s​t​o​r​y​.​a​s​p​x​?​s​t​o​r​y​_​i​d​=​2​0​2​7​317

If you have deja-vu I covered this earlier this year.

update 5 mins later: and a fourth link which also points to another Arnall for­mula I hadn’t seen.

The Economics of Bad Archaeology

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On May 8, about 100 Town Meeting voters approved tak­ing key parts of an approved 3-lot devel­op­ment on an 11-acre par­cel to save what some claim is tied to an ancient Native American culture.

This land abuts the 90-acre town-owned King Philip’s Cave land off Mansfield Street. To fin­ance this tak­ing by emin­ent domain (or nego­ti­ation with the developer), the town will bor­row $600,000.

In these lean times, the town has post­poned many pro­jects, but to save this par­cel, it will likely cost $721,000 over 10 years at cur­rent interest rates and reduce next year’s cap­ital budget by $600,000.

The aver­age annual debt ser­vice of $72,100 would pay the salary of a full time exec­ut­ive assistant-planner, or a senior teacher or six times the amount needed to main­tain the library’s accred­it­a­tion annually.

Since Prop 2 1/2 was adop­ted by the state, Sharon’s Town Meeting required that even a few dol­lars added to an oper­at­ing budget requires bal­an­cing reduc­tions but the mod­er­ator does not sub­ject bor­row­ing to any such bar­rier. Hence, when just over 100 voters out of Sharon’s 11,548 registered voters showed up on the third night, they were free to vote any amount they deemed necessary.

So what moved this hand­ful of voters?

Frederick Martin, a pro­fes­sional phys­i­cist and a Dedham-based ama­teur archae­olo­gist, has been advoc­at­ing the town “to pre­serve the hill where the equi­nox sun rises dir­ectly at its sum­mit, where the sol­stice sun­rises occur at either end, and where sky­line stones exist” since the devel­op­ment pro­posal first came to Planning Board in 2001.

Martin believes Native Americans aligned stones at the site to meas­ure time more than 2,000 years ago, but pro­fes­sion­als ques­tion the legit­im­acy of his claim.

TownOnline​.com — Opinion & Letters: Bailey: Article 19, a $600K les­son in Town Meeting style democracy

There’s much more to be read on this story.

There seem to be two con­nec­ted issues here. One is “Is a Native American site worth spend­ing $600K to pre­serve?” I don’t know. I haven’t seen the site. If it’s a couple of rocks then maybe not, but if it’s a hitherto unre­cog­nised major site then the people of Sharon may have got them­selves a bar­gain. Slightly more press­ing is whether or not the site is what it’s claimed to be. I get wary when equi­noc­tial alig­ments are claimed for sites. If the people are fully informed, and choose to spend the money any­way, then it’s their money. But if this is a fantasy then it’s a fantasy that leaves $600K + interest for future gen­er­a­tions to pick up.

If you’re inter­ested in see­ing the site, Mansfield Street is at lat­it­ude 42.074420° and lon­git­ude –71.179640° and covered well by Google Earth. The site is some­where around that.

When in Rome did they start doing as the Romans did?

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Archived from Revise and Dissent


Julian Forum. Photo by Gauis Caecilius.

You may have noticed a the news story that the skel­eton of a 30-year-old woman had been uncovered dur­ing excav­a­tions in the Julian Forum. They tend to share a head­line which sug­gests that the skel­eton is 300 years older than Rome. This is pecu­liar. The LA Times for instance says that the skel­eton dates from the tenth cen­tury BC. Rome was said to have been foun­ded in 753 BC, which is the eighth cen­tury BC. Mathematical puzzles aside, how do the archae­olo­gists know this woman dates from before Rome?

As it hap­pens she was found with a neck­lace and some pins, and she’s not alone. There are many crema­tions, so there’s plenty of ways of giv­ing a rough date to the burial. It’s not the date of the burial that I’m ques­tion­ing. It’s the found­a­tion of Rome. Famously it wasn’t built in a day, but does it really make sense to say it was built in a spe­cific year either?

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Bryn Celli Ddu

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Bryn Celli Ddu. Photo by AJ Bear.

An archae­olo­gist has dis­covered that the pas­sage into a burial mound on Anglesey was built to catch the rising sun on the sum­mer solstice.Steve Burrow said he was “elated” when the sun filtered in through trees as he sat in the Bryn Celli Ddu chamber.

BBC NEWS | Wales | North West Wales | Ancient monu­ment aligned to sun

I thought this was known already, but it seems not every­one accep­ted Lockyear’s meas­ure­ments. I’m sur­prised that it was thought the meas­ure­ments were the prob­lem. I would have expec­ted it to be the inter­pret­a­tion that was the prob­lem. I’ll blog on this tomor­row at Revise and Dissent and i-Science. Right now I’m test­ing Flock.

History: A Very Short Introduction by John Arnold

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A post from Revise and Dissent archived here. You can add your com­ment on this at HNN.

History VSIAt Leicester there’s a small group of people who will evan­gel­ise to who­ever will listen about the Very Short Introduction series. In recent years the series, pub­lished by OUP has gained the ulti­mate in accol­ades. The format has been ripped-off by other pub­lish­ers. The concept, a pocket-sized intro­duc­tion to the prob­lems of an aca­demic field is easy enough to copy, but there is more to the suc­cess of the series than that. The writ­ing is usu­ally extremely good and History: Very Short Introduction by John Arnold is an excel­lent example.

The book opens with an action sequence. It con­cerns Guilhem Déjean, a man on the trail of Cathars in Languedoc. His arrival in the vil­lage Tarascon sets in train a series of events which leads to the murder of Déjean at the hands of heretics who seek to hide from the Catholic church. It’s a pacey and well-written start that wouldn’t be out of place in a Bond film, if James Bond relo­cated to 14th cen­tury France.

The point of the graphic open­ing is to give the reader a piece of the past to work with. Certainly there’s a story to be told, but is that it? Arnold asks “Is his­tory the truth of the past re-told in the present?” In this book Arnold aims to show that his­tory is not syn­onym­ous with the past. As David men­tioned earlier, History is an invest­ig­a­tion and this book tackles the ques­tions of what we invest­ig­ate and how we can do it. He also chal­lenges the reader to think about what his­tory is for, a point to which he returns at the end of the book.
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More Bosnian Trigonometry

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You can read an over­iew of some of the other flaws in the Bosnian Pyramid saga at Revise and Dissent in the post­ing Bosnian Pyramids: Absence of Evidence is not Evidence of Atlantis

Thanks, if that’s the right word, go to Doug Weller for passing along a bet­ter map of the equi­lat­eral tri­angle con­nect­ing the peaks of the Bosnian pyr­am­ids. It turns out that Bosnianpyramids​.com is not an offi­cial site, so my meas­ure­ments based on that don’t neces­sar­ily dis­prove the claim that the peaks of the pyr­am­ids mark the ver­tices of a tri­angle with “not one minute dif­fer­ence”. So I’ve looked at this map.

triangle

What I’m inter­ested in is whether or not there are three equal angles. The easi­est way for me to check is to meas­ure the lengths of the sides and cal­cu­late from there. What I’ve done is put the map into Google Earth, placed it over the ocean, to ensure I’m meas­ur­ing it flat and meas­ured the three sides. The lengths of the sides will not be accur­ate, but their rel­at­ive lengths will because their lengths will all be out by the same factor.

sun-moon-flatmoon-dragonDragon-Sun

Measuring the three sides I get:
Sun — Moon : 2563
Moon — Dragon : 2638
Dragon — Sun : 2598
If you click on the pho­tos you’ll see those meas­ure­ments are metres, but in real­ity that’s mis­lead­ing because the over­lay is almost cer­tainly not scaled cor­rectly. It’s just the rel­at­ive lengths that mat­ter because the ver­tical and hori­zontal scal­ing will be out by the same factor.

You can work out the angles in degrees for the tri­angle through the Cosine Rule which will work because it’s inde­pend­ent of units. Alternatively you could use the Triangle Calculator which does the same thing with much less effort. Using this I get angles (con­ver­ted from decimal degrees to degrees and minutes):

Sun: 61º 29′
Moon: 59º 55′
Dragon: 58º 37′

Is that an equi­lat­eral tri­angle?
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