Skeptophilia (skep-to-fil-i-a) (n.) - the love of logical thought, skepticism, and thinking critically. Being an exploration of the applications of skeptical thinking to the world at large, with periodic excursions into linguistics, music, politics, cryptozoology, and why people keep seeing the face of Jesus on grilled cheese sandwiches.
Showing posts with label forensics. Show all posts
Showing posts with label forensics. Show all posts

Monday, March 21, 2022

Dowsing for corpses

Back when I was teaching, I ran into students with a lot of fringe-y beliefs, or at least unscientific ones.  But if you had to pick which one students were the most reluctant to abandon, I bet you'd never guess.

Dowsing.

Dowsing, also called water-witching, is the belief that you can use a forked stick (more modern dowsers use a pair of metal rods on a swivel) to locate stuff.  It started out being used to find underground water for a well (thus the appellation "water-witching"), but has since progressed (or regressed?  Guess it depends upon your viewpoint) to being used to find all sorts of things, including -- I kid you not -- marijuana in kids' lockers in a high school.

"But it works!" students said, when I told them there was no scientific basis for it whatsoever.  "My dad hired a guy to come tell us where to dig our well, and we hit water at only thirty feet down!"

Yeah, okay.  But this is upstate New York, one of the cloudiest, rainiest climates in the United States.  Unless you're standing on an outcropping of bedrock, there's gonna be groundwater underneath you.  In fact, only about twenty miles from here, there's a hillside with a natural artesian spring -- someone put a pipe into it, and people stop and fill up water bottles from the clear water gushing out.  So it's entirely unsurprising that you hit water where the dowsing guy indicated.  You'll hit water pretty much anywhere around here if you dig down a ways.

[Image is in the Public Domain]

What's funniest are the quasi-scientific explanations the dowsers give as to why it (allegedly) works.  An example is that you should always make your dowsing rod from a willow branch, because willows grow near water, so the wood remains attracted to it.  Even though I'm yet to see how a dead branch could respond that way.  Or any way, honestly.

Given that it's dead.

Every scientifically-valid study of dowsing has resulted in zero evidence that it works.  This doesn't mean the dowsers are deliberately cheating; they may honestly think the stick is moving on its own.  This is called the ideomotor effect, where small movements made unconsciously by the practitioner convince him/her (and the audience) that something real, and supernatural, is going on.  (The same phenomenon almost certainly accounts for spiritualist claims like Ouija board divination and table-turning.)

But despite these sorts of arguments, I fear that I convinced few students to change their beliefs.  "I saw it happen!" is a remarkably powerful mindset, even once you accept that we're all prone to biases, and that we're all easily fooled when it comes to something we want to believe.

So this is why I was unsurprised but disheartened to read an article from Mother Jones sent to me by a long-time loyal reader of Skeptophilia.  In it, we read about one Arpad Vass, a guy who believes that you can use dowsing rods...

... to find dead bodies.

This would just be another goofy belief, and heaven knows those are a dime a dozen, but he has somehow convinced the people who run the National Forensic Academy in Oak Ridge, Tennessee that his technique is scientifically sound.  He has some kind of cockeyed explanation of how it works -- that the effect is due to piezoelectricity, a phenomenon where certain crystalline substances develop a charge when they're subjected to mechanical stress.  Piezoelectricity is real enough; it's the basis of quartz watches, inkjet printing, and electric guitar pickups.  But even if decomposing bone can generate some net static charge, it would leak away into the soil it's buried in -- there's no mechanism by which it could exert a pull on some bent wires several meters away.  (Actually, Vass claims he's successfully found corpses this way from a hundred meters away.  If the static charge is that high, you shouldn't need a dowsing rod to detect it -- a plain old boring volt meter would work.  Funny how that never happens.)

And, of course, there's the problem that it doesn't work for everyone.  Vass has an answer for that, too.  "If people don’t have the right voltage, it’s not going to work," he says.  "Everything in the universe vibrates at a very specific frequency.  Gold has a gold frequency, silver has a silver frequency, and your DNA has your frequency."

I guess bullshit has a specific frequency, too.

The problem is that Vass isn't just playing around, or doing something that isn't a huge deal if it doesn't work (like finding a well drilling site).  This is injecting pseudoscience into police investigation.  And recently, he's gone one step further; he has invented, he said, a "quantum oscillator" that supposedly picks up a person's "frequency" from something like a hair sample or fingernail clippings, and then beams that frequency out, and it will somehow interact with the person (or his/her corpse), and send back a signal to the device...

... from up to 120 kilometers away.

I was encouraged by the fact that the Mother Jones article came down fairly solidly on the side of the scientists, stating unequivocally that there is no evidence that any form of dowsing works.  They also highlighted the human side of this; Randy Shrewsberry, founder of the nonprofit Criminal Justice Training Reform Institute, was quoted as saying "Law enforcement regularly accepts the flaws of these practices despite the life-altering impacts that can occur when they’re wrong."  In one Virginia case, a man was convicted of murder even though no body of the victim was found -- in part, because of testimony from Vass that his device had found the victim's "frequency" in eight locations, indicating that her body had been dismembered.

Eric Bartelink, professor of anthropology at the University of California - Chico and former president of the American Board of Forensic Anthropology, was unequivocal.  "Vass is operating these services that are not scientifically valid.  It’s very misleading to families and law enforcement."

So at least some prominent voices in the field are speaking up to support the findings of every scientific study ever done on the practice of dowsing.  I'm still appalled that a forensic training academy has somehow been convinced to take Vass and his nonsense seriously; I guess being highly educated isn't necessarily an immunization against confirmation bias.  As for me, I'm calling bullshit on the whole practice.

Beam that into your "quantum oscillator," buddy.

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Saturday, February 20, 2021

Pharaonic forensics

I'm fascinated with history, and have always been especially interested in times and places for which we have few records and, therefore, not much way of knowing what really went on.

I'm not sure if this is because I'm a fiction writer and rely a lot on imaginary realms of the mind to fill in the gaps, or if I just have a perverse enjoyment of setting myself up with impossible tasks.  My favorite time and place to read about is western Europe during the Dark Ages, in the centuries after the fall-ish of Rome.  I phrase it that way because just as Rome wasn't built in a day, neither did it fall in a day, as if the Hordes of Barbarians went through the gates and the Romans basically just dropped their swords and said, "Okay, fuck it, we give up."  In fact, the aforementioned hordes weren't themselves a single unit; starting in the fourth century C.E., various tribes and sub-tribes of Celts, Goths, Huns, Scythians, et al. kind of chipped away at the empire until there wasn't much left of it.  The Western Roman Empire collapsed first, but the Eastern persisted for a while longer, devolving into chaos more than once -- nearly falling apart entirely during the mid-sixth-century Plague of Justinian, that wiped out a quarter of Europe's population and seems to have exceeded the both the fourteenth-century Black Death and the twentieth-century Spanish flu for sheer number of victims.  (I dealt with that topic, and what may have caused it, a couple of years ago, if you want to read about what historians call "the worst century in history.")

Another time and place I find intriguing is the early years of ancient Egypt, once again because so little is known for sure about it.  Our knowledge of the Old Kingdom, First Intermediate Period, and Middle Kingdom -- up until around the sixteenth century B.C.E. -- is hampered not only because it was a long time ago and a lot of the records haven't survived, but because what records were kept weren't all that accurate.  Just as with a lot of other theocratic cultures, the scribes of early pharaonic Egypt were as invested in depicting the rulers as gods as they were with writing down an accurate account of what happened.  The result was a mishmash of actual history, divine genealogies, miracle stories, and whitewashing that makes teasing the truth from the fiction damn near impossible.

Not that I blame the scribes, mind you.  Keeping monarchs in good humor is a full-time job, and often doesn't end well.  I've recently been re-reading the Shakespearean history plays, and he, like the scribes, knew which side his bread was buttered on.  Shakespeare was writing during the reigns of Elizabeth I and James 1, and if you take a look at works like Richard II, Henry IV (parts 1 and 2), Henry V, Henry VI (parts 1, 2, and 3), Richard III, and especially Henry VIII, you'll pretty quickly notice that any ancestors of the monarchs he was writing for are depicted as good guys, while ones who weren't -- like the villainous King Richard III of the play -- are the opposite.  I love the history plays, and that sort of treatment makes for great theater, but honestly, "history" is kind of the last thing they actually are.

So all of this is a long-winded way of leading up to a paper I stumbled upon yesterday in Frontiers of Medicine entitled, "Computed Tomography Study of the Mummy of King Seqenenre Taa II: New Insights Into His Violent Death," by renowned scholars of ancient Egypt Sahir Saleem (of Cairo University) and Zahi Hawass (former Egyptian Minister of Antiquities).  Pharaoh Seqenenre Taa II was the second-to-last pharaoh of the Seventeenth Dynasty, and ruled over part of Egypt during the chaotic Second Intermediate Period, when much of Egypt was controlled by a race of "warrior kings" from what is now Israel, Jordan, and southern Lebanon called the Hyksos.

The constant fighting, along with a long run of weak, short-lived rulers, makes the Second Intermediate Period hard to parse, because records from that time are even more sparse than they were from the preceding dynasties.  We know that the pharaoh in question, Seqenenre Taa II, was killed in battle with the Hyksos, and after a short reign by his elder son, Kamose, his younger son Ahmose I took over, overcame and drove out the Hyksos, and became the first pharaoh of both the Eighteenth Dynasty and the New Kingdom, which saw the peak of pharaonic power.

Fortunately for us history buffs, the Egyptians did leave behind one thing that helps us to figure out what was going on back then -- mummified bodies of their leaders.  And despite the chaotic conditions of the Seventeenth Dynasty, Seqenenre Taa II's body has survived for almost 3,600 years, and now Saleem and Hawass have done a CT scan to see if they can figure out more about him.

The hints from the records of the time that Seqenenre Taa II died in battle are almost certainly correct.  He had multiple injuries, including wounds that appear to have been made with an axe, a dagger, a club, and a spear.  (It's grimly amusing that several times in the paper, during the description of each injury, the authors say "this blow was probably fatal," as if the poor man got killed over and over.)  Most interesting, injury to his wrists suggests his hands had been tied behind his back -- and that he probably was captured in battle, possibly injured at the time, and afterward executed.

Pharaoh Seqenenre Taa II's skull, CT scan by Saleem & Hawass

"This suggests that Seqenenre was really on the front line with his soldiers risking his life to liberate Egypt," said study lead author Dr. Sahar Saleem, in a press release.  "In a normal execution on a bound prisoner, it could be assumed that only one assailant strikes, possibly from different angles but not with different weapons.  Seqenenre's death was rather a ceremonial execution."

Which is gruesome but fascinating, and illustrates that parts of history that have seemed like closed books may one day be understood using cutting-edge techniques from science.  And a bit of luck; the information about the unfortunate pharaoh only is available to us because his mummified body survived for three and a half millennia.  But it does mean that we haven't uncovered everything there is to study about cryptic and chaotic chapters in our history -- and that with diligence, ages that have appeared dark might eventually be illuminated.

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Back when I taught Environmental Science, I used to spend at least one period addressing something that I saw as a gigantic hole in students' knowledge of their own world: where the common stuff in their lives came from.  Take an everyday object -- like a sink.  What metals are the faucet, handles, and fittings made of?  Where did those metals come from, and how are they refined?  What about the ceramic of the bowl, the pigments in the enamel on the surface, the flexible plastic of the washers?  All of those substances came from somewhere -- and took a long road to get where they ended up.

Along those same lines, there are a lot of questions about those same substances that never occur to us.  Why is the elastic of a rubber band stretchy?  Why is glass transparent?  Why is a polished metal surface reflective, but a polished wooden surface isn't?  Why does the rubber on the soles of your running shoes grip -- but the grip worsens when they're wet, and vanishes entirely when you step on ice?

If you're interested in these and other questions, this week's Skeptophilia book-of-the-week is for you.  In Stuff Matters: Exploring the Marvelous Materials that Shape Our Man-Made World, materials scientist Mark Miodownik takes a close look at the stuff that makes up our everyday lives, and explains why each substance we encounter has the characteristics it has.  So if you've ever wondered why duct tape makes things stick together and WD-40 makes them come apart, you've got to read Miodownik's book.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]



Saturday, May 2, 2020

The stories the bones tell

The field of forensic anthropology has made amazing strides in the past decades.  Fifty years ago, about all we could count on was identification of gender and suspected ethnic origin, and an estimate of age at death.  Now we are able to use data from bones to reconstruct much of the person's life history.

And sometimes, that history is pretty unpleasant.

One of the first cases in which the entire arsenal of sophisticated analytical techniques was used was "Ötzi," the "Ice Man" of the Alps whose body had been hidden underneath the edge of a glacier in the Italian/Austrian Alps for over five thousand years.  What we now know about Ötzi and his origins is kind of mind-blowing.  From pollen grains found in his clothing, we know he died in early summer, but his last meal contains "einkorn" wheat and sloes, both of which are harvested in the fall -- leading to the conclusion that his people knew how to preserve food over the winter.  He had no less than 61 tattoos, all geometrical and presumably symbolic, perhaps representing magical rituals.  (Or maybe, like me, he had ink just because he thought it was cool.)  He had a copper knife and particles of copper residue in his hair, suggesting he or someone he lived very near was involved in copper smelting.  From an isotopic analysis of his tooth enamel, we even know a bit of his life history -- he appears to have spent his childhood near the present town of Feldthurns, Italy, but at some point in his youth went to a valley fifty kilometers farther north.

Things took a grim turn, however, when the forensic anthropologists started looking into how he died.  Initially it was suspected he'd died in a fall down the hillside, as he had cracked ribs and surface bruises -- possibly resulting in his being knocked unconscious and dying of exposure.  But the truth seems a good bit harsher.  Ötzi has an arrowhead lodged in his upper chest, near the upper lobe of his left lung.  This wasn't an old injury; his shirt had a tear at the same place as the entry wound.  The conclusion from the placement and apparent trajectory of the arrow is that it would have severed arteries in his left pectoral muscle, leading to his death from blood loss.

We humans have been doing bad things to each other for a very, very long time.

If you needed further proof of this, consider the paper in Current Biology that came out two days ago, sent to me by a friend and loyal reader of Skeptophilia, and the reason I've gone into this rather morbid subject today.  In "Origin and Health Status of First-Generation Africans from Early Colonial Mexico," by a team led by Rodrigo Barquera of the Department of Archaeogenetics of the Max Planck Institute for the Science of Human History, we hear about three sixteenth-century skeletons recently found in Mexico that tell a horrific tale of abduction, slavery, and abuse.


The three individuals are clearly of African origin, based not only on skeletal morphology but on tooth-filing patterns that are characteristic of the Fang people of Equatorial Guinea, Cameroon, and Gabon.  Not only that, but one of them had a characteristically African strain of hepatitis B, and another had remnants of the bacteria species (Treponema pallidum ssp. pertinue) that causes the horrific tropical disease yaws (if you choose to investigate further into this disease, do not look at the photographs unless you have a strong stomach -- you have been warned), which is most common in west and central Africa.  In fact, the current presence of yaws in Latin America is almost certainly the result of its having been brought in by the African slave trade.

It only gets worse when you read about the evidence of abuse these skeletons show.  The authors write:
Osteological analyses of the three individuals reveal evidence suggesting a life experience of conflict and hardship.  Individual ML8 SL 150 (SJN001) was found with five buck shots and two healing needles (used in traditional medicine) in the thoracic cavity, as well as gunshot wounds.  Both SJN001 and SJN003 (ML8 SLU9B 296) presented porotic hyperostosis and cribra orbitalia, two pathological changes associated with a skeletal response to nutritionally inadequate diets, anemia, parasitic infectious diseases, and blood loss.  Individual ML8 San José 214 (SJN002) displayed several skeletal changes associated with intense labor and heavy manual activity, including enthesopathies on the clavicle and scapulae as well as osteophytic lipping on the joint surfaces with some additional joint contour deformation at the sternoclavicular joint of the clavicle.  Additionally, he suffered from a poorly aligned complete fracture in the right fibula and tibia, resulting in associated joint changes of the knee, including osteochondritis dissecans of the distal femoral surface with joint contour deformation and associated osteophytic lipping of the articular surface margin.  Furthermore, this individual displayed osteoarthrosis of the lumbar vertebrae in addition to signs of deficient oral health and cut marks on the frontal bone.
"All of us involved in the study were highly touched by the whole story about these three persons, everything that they went through," study lead author Barquera said.  "Knowing that they were first-generation enslaved Africans brings a new perspective on the whole subject because you know they were abducted.  You're seeing all these maltreatment signatures on the bones that came with this abduction, what they suffered for the rest of their lives."

And "the rest of their lives" turned out to be short.  All three of the individuals died in their early or mid-twenties.  Whether they died of disease, malnutrition, murder, or the cumulative abuse they'd suffered isn't known, because they show signs consistent with all possible combinations of the above.

All of it brings home once again the accuracy of Thomas Hobbes's words in his book Leviathan, wherein he characterizes the lives of our ancestors as having been "solitary, poor, nasty, brutish, and short."  It's true that a lot of the poorness and nastiness was circumstantial, and due to bad diet and the prevalence of (then-untreatable) diseases.

But a frightening piece of the "nasty, brutish, and short" part was due to the horrible mistreatment of humans by other humans, often for no better reason than territory, power, rivalries, and tribalism.  I wish I could tell you we've grown beyond all that.  I mean, there's been progress; I wouldn't trade my life here in the 21st century for what Ötzi or the owners of the Mexican skeletons endured.  But that insularity, suspicion, and tribalism is deep within our cultural genes, needing little more than a moment's adversity to bring it to the surface.

Bringing to mind another quote, this one from the Latin playwright Plautus -- Homo lupus homini est (man is a wolf to men).

Which, in my opinion, is slanderous toward the wolves.  They may be fierce, but I've yet to see a wolf enslave another wolf.  On the whole, their society seems a great deal more peaceable than ours is.

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This week's Skeptophilia book recommendation is an important read for any of you who, like me, (1) like running, cycling, and weight lifting, and (2) have had repeated injuries.

Christie Aschwanden's new book Good to Go: What the Athlete in All of Us Can Learn from the Strange Science of Recovery goes through all the recommendations -- good and bad, sensible and bizarre -- that world-class athletes have made to help us less-elite types recover from the injuries we incur.  As you might expect, some of them work, and some of them are worse than useless -- and Aschwanden will help you to sort the wheat from the chaff.

The fun part of this is that Aschwanden not only looked at the serious scientific research, she tried some of these "cures" on herself.  You'll find out the results, described in detail brought to life by her lucid writing, and maybe it'll help you find some good ways of handling your own aches and pains -- and avoid the ones that are worthless.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]