Garmin’s Swedish Grid Confusion

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I’ve been using Garmin’s handheld GPS navigators since the spring of 2005; two models running the same firmware. They have been invaluable in archaeological fieldwork, pinpointing finds and test pits swiftly and accurately in situations where you would once have counted steps to the nearest landmark and put an X on a small-scale map. GPS has also helped me a lot when driving, and lured me to seek out over 600 geocaches.

But recently I discovered a really annoying glitch in Garmin’s firmware, having to do with the coordinate readout.

The machine is able to use many tens of different coordinate systems, allowing me for instance to offer coordinates in the Hungarian national grid. The standard grid system used by Swedish surveyors (and archaeologists) is named “RT90 2,5 gon väst” and commonly known simply as “RT90” or “rikets nät”, the national grid. The Garmin firmware offers a choice between RT90 and rikets nät. This makes no sense, but as both are indicated as using RT90 when referencing your position to the built-in map, it would appear that both menu alternatives give an identical result.

They don’t. I found out during fieldwork last September that coordinates in the two grids differ by about nine meters at Sättuna and about seven at Djurhamn. This is a problem because it means that when you write coordinates on a find bag or in a list of test pits, as I have for four whole fieldwork seasons, you must also make note of which mode your machine is working in at that moment. And I switch a lot to and fro because geocaches are usually pinpointed in good old long-and-lat.

Garmin’s Swedish representative hasn’t been able to explain this to me. But Mät-Niklas has.

Apparently, the first handheld GPS navigators came equipped with a slightly faulty geometrical model of the RT90 grid. After a few years, this was corrected. What has happened in the Garmin case is apparently that they added the corrected model (“RT90” in the menu) but forgot to delete the faulty one (“Rikets nät”). And so their machines come equipped with a built-in boobytrap for anyone who records coordinates in the Swedish national grid.

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Concert Review: of Montreal in Stockholm

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Monday night me and Moomin went to an of Montreal gig at Medborgarplatsen in Stockholm. Amazing stuff. Seven musicians on stage, everybody swapping instruments all the time, three mimes prancing around in weird masks, psychedelic animated films on the backdrop, and a solid 90 minutes of intricate pop music, everything tightly rehearsed. I’m glad I had done my homework on the new album, because this isn’t the kind of music that you get the first time around — particularly not with so-so live sound quality.

The last time I caught the band live, they ended their set by covering Sabbath’s “War Pigs”. This time they covered another great song for an encore. The choice of song however — Nirvana’s “Smells Like Teen Spirit” — and the searing lead vocals did nothing to calm my fears for of Montreal central-figure Kevin Barnes’s long-term emotional sustainability.

And I forget
Just what it takes
And yet I guess it makes me smile
I found it hard
It’s hard to find
Oh well, whatever, nevermind

The kid who wrote those lines ain’t with us any more.

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Hey There, Berghs Students

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Every once in a blue cheese, a son of Ming the Merciless invites me to speak at an advertising school in Stockholm, Berghs School of Communication. (Yes, they have adopted an English name to sound cooler. No, they didn’t put the genitive apostrophe in. I find that really painful.) I talk about cyberculture, on-line communities and what advertising people need to know about the web.

As this entry comes on-line, I am standing in front of 30 fresh-faced Macbook-toting hipsters who will soon learn, to their horror, that Firefox allows you to kill all ad banners and flash clips.

During my talk, I’m using a link page that some people may find useful.

Happy 90th Erik Nylén

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Erik Nylén in 1987, holding a ship’s vane inspired by 11th century ones, standing in front of Krampmacken, a replica of a 12th century sailing boat. “Krampmacken” means “the brine shrimp”. Photograph by Rune Edberg. Thanks Rune!

One of my archaeological heroes turned 90 last Saturday.

Professor Erik Nylén is huge in Swedish archaeology. His name is associated with any number of important fieldwork and publication projects, and also with a strongly pro-science movement during the 60s and 70s where fieldwork and labwork methods were greatly improved. One of Erik’s big ideas was wholesale photographic documentation using turrets for vertical photography.

Much of the material I worked with for my thesis was digs he presided over on Gotland in the 50s and 60s, whose documentation has effectively unlimited resolution thanks to all the photos. (As a wry corrective to technological over-optimism, it turned out that the glue Erik’s staff used at the time didn’t keep well, so all his photo mosaics had to be renovated by archivists in the 90s to keep from falling apart.) I once took a trunkful of this documentation to Stockholm from Visby, where it had gotten stuck after Erik had an argument with central archives. The archivists didn’t much like Erik’s A3 format ring binders full of mixed media, and so he didn’t much like them.

Through his forceful personality, Erik is the stuff of legends. Colleagues still tell tales of how he would show up at his underlings’ digs, wearing riding gear and roaring astonishingly colourful expletives at the top of his voice. Last time I met him, a few years back, he had a fine suntan from his daily horseback rides, which were sometimes sped up with the aid of replica Viking Period spurs. The man is larger than life.

Happy 90th, Erik!

R.U. Sirius Heads New Transhumanist Zine

i-1930d145d94fdde15ffb0ead0e571255-cover_1.jpgi-5e84568ece3a3d19083d77286f7c3100-rusirius.jpgAfter over a year’s near-invisibility on the net, cyberculture guru R.U. Sirius resurfaces as editor of H+ Magazine, a web zine about transhumanism. Explains Wikipedia, transhumanism is a “movement supporting the use of science and technology to enhance human mental and physical abilities and aptitudes, and overcome what it regards as undesirable and unnecessary aspects of the human condition, such as disability, suffering, disease, aging, and involuntary death”. Shades of R.A. Wilson!

The first issue has loads of interesting content including an interview with hyperclocked science fiction writer Charles Stross. Go check it out!

Fornvännen’s Autumn Issue

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Fornvännen (“the Friend of Ancient Things”) is one of the main journals of Scandy archaeology and Medieval art. It’s been issued 4-6 times a year since 1906, for the past several decades on a quarterly schedule, and I’ve been a co-editor since 1999. The first 100 volumes have been scanned and are available on-line. Later issues are appearing on-line too with a 6-month delay, though we haven’t quite ironed out the routines for that yet.

Issue 2008:3 recently came from the printers. Here’s what’s in it:

  • Hans Olsson and Katherine Bless Karlsen present an Early Mesolithic (c. 6900 cal BC) site with hut foundations, very unusual for the wooded province of Värmland.
  • Andreas Toreld publishes and discusses new documentation of an engraved stone slab in my ancestral parish of Tanum in Bohuslän (pic above). Is it a Neolithic stele?
  • Ole Thirup Kastholm argues, against received opinion, that there is in fact a number of details in Scandinavian ship finds suggesting technological continuity from the Last Millennium BC to the 1st Millennium AD.
  • Anna Linderholm and her colleagues present and discuss stable isotope analyses on 11th and 12th century burials from Björned in Ångermanland. They suggest that the burials represent a Christian congregation that migrated to the area from elsewhere. (This paper has also been published in Linderholm’s recent PhD thesis.)
  • Reports from three recent conferences: one on bogs in BorÃ¥s, TAG US in New York and WAC in Dublin.
  • Finally, fifteen book reviews.

Fornvännen is a really good read for anyone with an interest in our subjects. Most of the contributions are written in Scandy languages and English. I enjoy working with it a lot!

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Genius on the Edge

I worry about of Montreal’s musical motor, pop genius Kevin Barnes. He first got records out in 1997-98, when he was an elegantly naivistic singer of sad love songs. Then he shot like a lysergic rocket straight into Pepperland with four beatlesque albums in 1999-2004. On his 2005 album he suddenly said goodbye to his old band members, returned to confessional mode and sang the praises of married life and parenthood in Norway of all places. And two other new themes appeared: 80s-style electronica and deep depression. That’s where he still is.

With his recent album, Skeletal Lamping, Barnes has turned into a open-heartedly suicidal incarnation of early Prince. Yes he is extremely lewd, yes he is psychedelic, yes he has a plastic synth sound, and dammit I’m afraid the man’s gonna kill himself. I mean, look at this:

“… the hope of another wet nightmare is all we have to live for …”

“Why am I so damaged girl
Why am I such poisoned goods
I don’t know how long I can hold on
If it’s gonna be like this forever

Why am I so damaged
Why am I so troubled girl
I don’t know how long I can hold on
If it’s gonna be like this forever”

“Don’t be afraid lille ven of violence
I’m only poisoning you, not gonna stab you.
Don’t be afraid lille ven of my troubled mind
I’m just poisoning you a little
With my gloom”

There’s some early Bowie and late Lennon in the mix too, and everything’s overlaid with Barnes’s inimitable multitracked vocal harmony. The sunny Brian Wilson influences and Pepperisms are no more. And there’s no getting around it: we’re dealing with a severely depressed musician who somehow manages to release one brilliant album a year and go on tour regularly.

Barnes and his new (-ish) band are playing in Stockholm on Monday, and I’ll be there. He has recorded his latest few albums alone at home, producing reams of highly intricate studio pop. I look forward to hearing live versions of the songs! And I really hope it won’t turn out to be Last Chance To See.

Check out Rolling Stone’s recent interview with Kevin Barnes.

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Swedish Peace Activists Vandalise US Arms

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A few hours ago, activists broke into two Swedish arms factories and vandalised weapons destined for US and Indian military forces. Among other things, they rendered twenty m/48 Carl Gustaf bazookas inoperable.

This really takes me back. An older cousin of mine used to be an activist in the Plowshares Movement. In 1993 him and some friends broke into a military airfield outside Linköping and, using hammers, disarmed a number of JAS 39 fighter planes. They made no attempt to escape afterwards, quietly got arrested and spent a year in jail.

While in prison, my cousin was called “Jesus” by the other inmates. I corresponded briefly with him. When I voiced doubts about his actions he called me “more a passivist than a pacifist”. Not very charitable of him perhaps, but then, he was in a stressful situation. And he was way more idealistic than I am. Today he’s a priest in the Swedish church, working on a PhD thesis in theology, analysing the Gospel of Matthew from a post-colonial perspective.

Pacifist or passivist, I really don’t like the arms trade. I think it’s a disgrace that the state I’m a citizen of allows the selling of arms to nations at war. But I do like democracy and the rule of law. And so I’m no fan of destructive direct action. There’s nothing built into direct action that ensures that it will only be employed by people whose opinions I support. Indeed, I don’t think Swedish law should recognise adherence to my personal opinions as grounds for special rights. If we allow peaceniks to vandalise arms factories, then we can’t in all fairness forbid neonazis to vandalise synagogues or satanists to burn down Medieval churches.

So, to the people who just got arrested for pacifist vandalism: I admire your commitment, but I think you’re hurting our cause. Not least by getting thrown into jail where you can’t do any useful work for peace.

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Think Before You Radiocarbon

Recently I organised a few days’ excavation that didn’t turn up the kind of stuff I was hoping for. Still, I brought some materials home that may serve to shed some light on what exactly it was we dug into. All those nondescript little pits, all those sooty hearths full of cracked stone — when were they made and used?

Enter radiocarbon. This dating method works on anything organic, that is, anything with carbon in it. Running one sample costs about $500, so you have multiple reasons to be smart about which samples you send to the lab. I thought my thinking about this might interest you, Dear Reader.

We dug 175 sunken features, but I don’t have 175 samples. Most features yielded no datable material (in these situations, usually charcoal, other charred plant remains or bone). Of those that did, many also contained modern junk identifying them as recent refuse pits. I don’t want to spend any money dating them.

I have about 20 samples, and I’ve decided to date five. That’s not too bad for a 1000 square meter trench that contained nothing that appears relevant to my research project. I’m of course only running samples of which I know exactly what stratigraphic context they came from. I’m avoiding a few iffy ones that may have been contaminated, such as one that was collected from the sieve instead of from the feature’s section. I’m trying to cover different kinds of feature (hearth, posthole, pit), though charcoal is of course most abundant in hearths. And I want to spread the dated features out across the trench in order to catch any horizontal variation.

Radiocarbon dates the moment when the tissue concerned stopped receiving carbon from the environment. For a leaf, this is the moment it stopped photosynthesising. For the soft tissues of animals (who, through the food chain, receive carbon taken from the air by plants), it’s a matter of months. For bones, a bit more than that. And for dentine, the interior of teeth, it’s years or decades.

Charcoal is tricky. Every year ring in a tree has a different radiocarbon date. Chop down an old oak, sample the centre of its trunk and some of its leaves, date both samples, and you’ll get a discrepancy of centuries. This is because once a year-ring has formed, it ceases to receive carbon from the living parts of the tree. Therefore, I’ve left my selected charcoal samples to a wood anatomist. Often he can select young twigs or pieces of bark, with a low intrinsic age. Second best, he can select bits of charcoal from a tree species with a short maximum lifespan. Oaks live for centuries, but alders and aspens mostly don’t, so they’re better. Cereal grains and other seeds are excellent, no intrinsic age at all.

On the samples go to the radiocarbon lab, where they’re cleaned, processed and transformed into a graphite coating on little brass plugs. Then some of the graphite is oxidised to CO2 and sent into a particle accelerator. Heavy unstable carbon-14 lands on one detector, lighter and stable carbon-12 on another, and the ratio between them shows how long time has passed since that tissue stopped receiving carbon.

Or it would, if the availability of carbon-14 in the atmosphere were constant. Which it is not. But that can be compensated for.

Back to the tree rings. In warm years, all the trees lay down thick rings, and conversely in cold years. Therefore, I can convert the ring thicknesses of a tree I just cut down into a series of figures, like “thick – thick – medium – thin – thick – medium – thick” etc. With large enough a piece of wood (>50 year rings), I get a unique sequence of thickness estimates that has never occurred before or later in tree history. Armed with my graph (or, actually these days, my database and stat software), I then seek out an old building and saw off a chunk of wood that provides me with a similar dataset. When I find the part where the two datasets overlap (“thick – thick – medium – thin – thick” etc.), I end up with a combined dataset that reaches way back before the original tree I cut down had started to grow. And this process kan be, and has been, repeated until we have tree-ring datasets that extend thousands of years into the past.

We know exactly what year each of those thousands of tree rings formed. This allows us to cross-check their radiocarbon dates, which provides us with a calibration curve. This curve allows us to translate from apparent radiocarbon dates to actual calendar dates. Anybody can to this at home, the best Oxonian software and most recent datasets are freeware.

Without calibration, you miss your actual date by a thousand years in many parts of the past. Around the introduction of agriculture to Scandyland, c. 4000 BC, for instance, the error is a full millennium.

The need for calibration also means that the precision of radiocarbon is not uniform across the millennia. In the 7th century AD, the calibration curve has a shape that allows highly precise dating, e.g. AD 625+-15 years. In other eras, e.g. about 4000 BC sad to tell, the calibration curve forms plateaux where a range of different radiocarbon figures map onto the same calendar date after calibration, e.g. 3950 BC. This means that the entire Scandy process of neolithisation gets compressed, looking like it happened in 3950 BC. There simply aren’t any possible radiocarbon values that will point, after calibration, at 4050 BC or 3850 BC.

Now, what about those five samples of mine? I hope to get them dated in December once some funding paperwork has gone through. I expect them to land in the interval 500 BC to AD 400, because that’s the usual date of this kind of site with loads of pointless pits and hearths. However, I wouldn’t be surprised if I got one date at about AD 1900 and another one in the 6th Millennium BC, because those are the periods from which the dig actually produced any artefacts. I’ll get back to you on the subject when I know.

Questions?

Update 17 October: More fresh radiocarbon goodness in Swedish from Åsa of Ting & Tankar.

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Hopeful Buttons

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Dear Reader, it’s been nearly a year since I asked you to press any buttons. If you like Aard, and haven’t already done so, would you please do me the favour of pressing a few buttons in the left-hand column, right below my profile? Good grades make blogger happy! Thanks.

And while I’m at it: if you click on the headline of an Aard entry, you’ll find a version of the entry with a little button at bottom right labelled “Share This”. Clicking on it, you’ll find a menu of social bookmarking sites. If every once in a while you read something here that you really like, I’d be most grateful if you would use this feature to boost the entry in question on Digg, Reddit and Stumbleupon.