This is an aggregated collection of entries from archaeology blogs. The list is comprised of blogs from:
- Past Horizons - written by Maggie and David (BAJR)
- BAJR - written by David (BAJR)
- ArchaeoGeek - written by Jo Cook, Information Systems Coordinator, Oxford Archaeology
- Online Archaeology - written by Steve White
- Theoretical Structural Archaeology - written by Geoff Carter
If you want to nominate a blog to be included in this aggregated list please get in touch.
Getting into GitHub
Yesterday I did a couple of talks at the AGI Northern Group Showcase in York, one of which was titled “A Beginners Guide to GitHub for Geospatial Folk”. Given that, for various reasons, I was managing on 3 hours sleep and fuelled by caffeine and jammy dodger biscuits, it seemed quite well-received, so I thought I’d expand on it a bit here.
There are definitely some major hurdles for “beginners” to overcome when faced with going public on GitHub. Yes, there are tutorials to help you understand the syntax and workflow, but they tend to be of the “Hello World” variety, or they are focused on the collaborative coding workflow, which might not be appropriate for the casual user. Then you have to beware of the trolls, or at the very least, the people who don’t understand the need for constructive criticism.
My quick suggestion for an easy way in, which also happens to do the world a great service, is to use GitHub for hosting presentations. Not only is this a safe way of learning to use Git/GitHub without exposing any coding inexperience, but you help rid the world of powerpoint, one presentation at a time!
So… go find Big, or Reveal.js and clone it to your local machine. Write your talk (yes write it- none of this gui nonsense). When you’re happy with it, push it up to your own GitHub repository. Use the nifty GitHub pages functionality to create a hosted version of your talk. There’s no need to worry about versions of powerpoint, you just access your hosted talk, or take along a local copy. This is just html, so every browser in the world will render it (in some form)– even lynx) *.
GitHub may or may not be the most important social network or place to put your CV, but if you’re put off from getting involved because of the learning curve or the public nature of it all, then this is one way to do it. Then once you’re happy with the interface, find yourself some non-controversial repositories to contribute to- my first pull request was to the Vaguely Rude Place Names Map of all things! Other good projects you can contribute to are related to documentation, such as the QGIS Training Manual. Again, these are an easy way in- no one will complain if you fix a typo!
*I know this because I’m nerdy enough to have installed Git on my Nexus 10 tablet via the super Terminal IDE app and instructions from DamGit…
|09 Feb 2016|
|Theoretical Structural Archaeology|
A blogging Carnival; Grand Challenges for Archaeology; reverse engineering Stonehenge
|#blogarch|In response to the latest blog Carnival organised by Doug Rocks-Macqueen, the champion of archaeological blogging, over at Doug’sArchaeology, I am posting about the challenges of modelling a prehistoric roof structure in 3D. My work is based on the idea that archaeological buildings are mathematical structures which can be detected and understood using the same principles that underpin the engineering of the built environment. As regular readers will know, I have had the misfortune to have discovered how, in theory, the large Neolithic / EBA structures represented by postholes known as Class Ei buildings  worked, at least in plan and section. The next stage is to model the structure in 3D to understand its assembly; the initial challenge is finding an appropriate starting point, since the value of everything else, and many man hours is dependent on this decision. What is also challenging, at least in an abstract sense, is that the Ei building I am currently modelling at moment is Stonehenge, the well-known ritual monument and mystery at heart of British faith-based archaeology. While I have established, by what might be called conventional means, that these arrangements of postholes represented the footprint of buildings, listing 12 fairly straightforward observations that demonstrate this, it was necessary to develop a more complex understanding to explain precisely how these posts might support a roof. I called this structural system Interlace Theory; just how complex it is, may be judged by the fact that I first grasped the principle almost exactly 6 years ago, [although to be fair on myself I have been otherwise engaged during most of the intervening period]. Woodhenge has been my principle case study because it is by far the best data set, however, Stonehenge is a much simpler structure and it has an elevation which can serve as the necessary starting point. A tale of two analogies
While I am happy to discuss a myriad of minor matters arising from interlace theory, it would be a somewhat monotonous monologue, - you know the bit after you tell the taxi driver that you are not aware of a secret room under the sphinx - so I will find a different way of explaining this stage of the research.
As an archaeologist, I might find pieces of kitted fabric, and while it is possible to reverse engineer the process of knitting, how you construct garments out of a fabric is a very different question. Just like buildings, garments vary in pattern, size and style, which cannot be fully extrapolated from the basic technique. Interlace theory explains how the structural might fabric work, but not necessarily how it was used to construct a particular building; as with garments, this involves different and more flexible rules.
However, if we find a piece of a tailored cloth then it might be possible to reconstruct the type of garment, or, a better analogy might be finding a piece of metal, which luckily it is recognised as the base plate from a watch. Each of the holes in the plate correspond to the location of a component, which, with a knowledge of watch-making, you could reverse engineer the mechanism. However, while you could demonstrate it was part of a watch by modelling how it worked, what it actually looked like would not necessarily be apparent. Regrettably, If you do not understand horology it will remain a ritual object.
Doin’ the math
While watches are complicated, they are small compared to a building, which may have simpler engineering, but a lot more components, creating its own complexities for modeller and builder alike. While a modern building might get away with a hundred standard mass produced components, most of the components in a prehistoric structure are bespoke and made to fit, which is time consuming and resource intensive.
It is also worth noting that most drawing systems are set up of assumption you will be modelling rectilinear structures, in which for example, the rafter pairs are at right angles or parallel to the main axis. By contrast, in a circular building the rafters are radial and all at different angles relative to whatever serves as the principle axis. We can do a simple guestimation to demonstrate how complex roofing a structure the size of Stonehenge might become; just like the builder you have to work up from the lowest components, which in terms of the roof is the outer edge represented by the 30 Y posts.
The footprint of a building is was not circular, neat or regular, it is 30 sided, an irregular Triacontagon; to cover it would take the equivalent of 4 roofs with a combined width of 180’, which, if we want a rafter every 6’ along the edge need about 90 rafter pairs or 3 supported per Y post. Each pair has a tie so that’s 3 per post along with the 3 horizontal plates or elements, which is actually 6 because they run between 2 Y posts. So that is 9 horizontal components per post, which we could double if a clerestory or widows are indicated, which is why with a guestimated 270 or 540 components to be attached to the 30 Y posts and fitted together, before we reach the 90 or 180 pairs of rafters which form this outer part of roof, which is why where you start is so important.
However you figure it, it’s is going to be a complex challenge to assemble such a structure successfully so that components don’t pass through each other, which is why Interlace Theory was necessary. It is also why I am working on Stonehenge, since structures are supported at their lowest point, the stone components particularly the stanchions [trilithons] give us a significant clue to the position of the lowest parts of the structure and a starting point.
In the model I have created and positioned 90 individual ties, now the challenge is too fit them together systematically, this could take some time.
Snapshot from a 3D model of a ritual monument showing 90 roof ties.
The Challenges of reverse engineering
Strange as it might seem, it is important not to think about what the structure looked like, but while it is actually hard not to speculate, and if pressed I could tell you all sorts of things about this type of roof, the problem is that I would almost certainly turn out to be wrong, and this is not about guess work. Reverse engineering an archaeological structure is an evidence based deductive process, so, in an ideal world, it is not;
Problematically, the latter is a basic building block of much scholarship which considers plan “shape” to be of primary importance regardless of form, function, scale, technology and cultural or environmental context.
- how I would have done it;
- the best way of doing it;
- the simplest way of doing it;
- how someone else does it, or did it, whether locally, or on the other side of the world.
This in turn has resulted in a visual culture of the past for which there is no real evidence. This has given rise to the biggest challenge faced by structural archaeology - peoples' imagined “pictures” of the past; being told that Stonehenge was a largely wooden building is a bit like trying to imagine a different coloured Jesus.
Post University Challenge.
It is often said that employers or institutions want people who can think for themselves, while what they actually want is people think like themselves. Universities invest in and monetise accepted ideas, thus new ones are not welcome, as they disrupt the market, and so research that does not support the existing narrative is of no inherent value.
In later periods people dug postholes for buildings, and pits to shit in, but apparently, in the British Neolithic they did both to communicate complex ideas to supernatural forces and post-processualists. Thus, while research into “...how postholes served as focus for structured deposition in a wider ritual landscape..” could be funded and even peer reviewed, evidence based reverse engineering will remain way too challenging for Universities, but freely available in the blogosphere.
. . . and on a lighter note
As a gesture to the Gods indicating we intend to try and keep on going, TSA has rescued a new member of staff; Tiny is in charge of destructive testing, spatial redistribution, disciplining the printer, and pest control. This year, I was trying to teach him structural archaeology, but his responses are a bit incoherent, and he is still coming to terms with the concept of gravity; however, he is young, so we have decided it would be best if he concentrated on his master’s degree in post-processual thinking, at least until his brain develops further.
 Neolithic houses in northwest Europe and beyond’ (1996) (Oxbow monograph 57) [Paperback]. T.C. Darvill (Editor), Julian Thomas (Editor) [[Fig 6.9]].
|31 Jan 2016|
British archaeologists fight with Italian farmer to save ancient aqueduct
|In January father and son team Edward and Michael O’Neill discovered the headwaters of the aqueduct, which was built by the Emperor Trajan, hidden beneath a crumbling 13th century church north of Rome. A sophisticated example of Roman hydraulic engineering, the aqueduct, known as the Aqua Traiana, was inaugurated in 109AD and carried fresh water […]|
|06 Jun 2010|
|As you may have noticed, BAJR Blogging has remained unloved since December. This is because of the shiney new BAJR Federation site… http://www.bajrfed.co.uk get along there and enjoy… with news, galleries and forum to keep you up to date and … Continue reading |
|09 Feb 2010|
|Online Archaeology Blog|
OPEN ARCHIVE - a new web based system for accessing our past
|The wealth of information gathered by local archaeological groups and societies on excavations, surveys and documentary research is one of the important sources of data for the study of archaeology in the UK. Currently, this archive of British archaeology is stored locally, within libraries and local history centres as well as with the originating group [...]|
|16 Sep 2009|