Wanderlust

Maybe it's because I'm fundamentally a home body, but I find it really hard to understand what could have driven our distant ancestors to head out into uncharted territory -- no GPS to guide them, no guarantee of safety, no knowledge of what they might meet along the way.

A couple of years ago I wrote a piece about the extraordinary island-hopping accomplished by the ancient Polynesians -- going from one tiny speck of land to another, crossing thousands of kilometers of trackless ocean in dugout canoes.  We don't know what motivated them, whether it was lack of resources on their home islands, being driven away by warfare, or simple curiosity.  But whatever it was, it took no small amount of skill, courage, and willingness to accept risk.

The wanderings of the ancestral Polynesians, though, are hardly the only example of ancient humans' capacity for launching out into the unknown.  Two papers this week look at other examples of our forebears' wanderlust -- still, of course, leaving unanswered the questions about why they felt impelled to leave home and safety for an uncertain destination.

The first, which appeared in PLOS-One, looks at the similarity of culture between Bronze-Age Denmark and southwestern Norway, and considers whether the inhabitants of Denmark took a longer (but, presumably, safer) seven-hundred-kilometer route, crossing the Strait of Kattegat into southern Sweden and then hugging the coast until they reached Norway, or the much shorter (but riskier) hundred-kilometer crossing over open ocean to go there directly.

While the direct route was more dangerous, it seems likely that's what they did.  If they'd skirted along the coastline, you'd expect there to be more similarity in archaeological sites along the way, in the seaside areas of southern Sweden.  There's not.  It appears that they really did launch off in paddle-driven boats across the stormy seas between Denmark and Norway, four thousand years ago.

"These new agent-based simulations, applied with boat performance data of a Scandinavian Bronze Age type boat," the authors write, "demonstrate regular open sea crossings of the Skagerrak, including some fifty kilometers of no visible land, likely commenced by 2300 B.C.E., as indicated by archaeological evidence."

Considering people twice as far back in time, a paper this week in Nature describes evidence that seafarers from what is now Italy crossed a hundred kilometers of ocean to reach the island of Malta.  A cave in Latnija, in the northern Mellieħa region of Malta, has bones of animals that show distinct signs of butchering and cooking -- and have been dated to 8,500 years ago.

[Image licensed under the Creative Commons Frank Vincentz, Malta - Mellieħa - Triq il-Latnija - Paradise Bay 05 ies, CC BY-SA 3.0]

"We found abundant evidence for a range of wild animals, including Red Deer, long thought to have gone extinct by this point in time," said Eleanor Scerri, of the University of Malta, who was the paper's lead author.  "They were hunting and cooking these deer alongside tortoises and birds, including some that were extremely large and extinct today...  The results add a thousand years to Maltese prehistory and force a re-evaluation of the seafaring abilities of Europe's last hunter-gatherers, as well as their connections and ecosystem impacts."

What always strikes me about this sort of thing is wondering not only what fueled their wanderlust, but how they even knew there was an island out there to head to.  I know that patterns of clouds can tell seafarers they're nearing land, but still -- to launch off into the open ocean, hoping for the best, and trusting that there's safe landing out there somewhere still seems to me to be somewhere between brave and utterly foolhardy.

I guess my ancestors were made of sterner stuff than me.  I'm okay with that.  Being a bit of a coward has its advantages.  As Steven Wright put it, "Eagles may soar, but weasels don't get sucked into jet engines."

So if y'all want to, you can take off in your dugout canoes for parts unknown, but I'm gonna stay right here where it's (relatively) safe.  I suppose it's a good thing our forebears had the courage they did, because it's how we got here.  And I hope they wouldn't be too embarrassed by my preference for sitting on my ass drinking coffee with cream and sugar rather than spending weeks at sea nibbling on dried meat and hardtack and hoping like hell those clouds over there mean there's dry land ahead.

Chacun à son goût, y'know?

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The riddle of the sun stones

When you think about it, it's unsurprising that our ancestors invented "the gods" as an explanation for anything they didn't understand.

They were constantly bombarded by stuff that was outside of the science of their time.  Diseases caused by the unseen action of either genes or microorganisms.  Weather patterns, driven by forces that even in the twenty-first century we are only beginning to understand deeply, and which controlled the all-important supply of food and water.  Earthquakes and volcanoes, whose root cause only began to come clear sixty years ago.

Back then, everything must have seemed as mysterious as it was precarious.  For most of our history, we've been at the mercy of forces we didn't understand and couldn't control, where they were one bad harvest or failed rainy season or sudden plague from dying en masse.

No wonder they attributed it all to gods and sub-gods -- and devils and demons and witches and evil spirits.

As much as we raise an eyebrow at the superstition and seeming credulity of the ancients, it's important to recognize that they were no less intelligent, on average, than we are.  They were trying to make sense of their world with the information they had at the time, just like we do.  That we have a greater knowledge base to draw upon -- and most importantly, the scientific method as a protocol -- is why we've been more successful.  But honestly, it's no wonder that they landed on supernatural, unscientific explanations; the natural and scientific ones were out of their reach.

The reason this comes up is a recent discovery that lies at the intersection of archaeology and geology, which (as regular readers of Skeptophilia know) are two enduring fascinations for me.  Researchers excavating sites at Vasagård and Rispebjerg, on the island of Bornholm, Denmark, have uncovered hundreds of flat stone disks with intricate patterns of engraving, dating from something on the order of five thousand years ago.  Because many of the disks have designs of circles with branching radial rays extending outward, they've been nicknamed "sun stones."  Why, in around 2,900 B.C.E., people were suddenly motivated to create, and then bury, hundreds of these stones, has been a mystery.

Until now.

[Image credit: John Lee, Nationalmuseet, Copenhagen, Denmark]

Data from Greenland ice cores has shown a sudden spike in sulfates and in dust and ash from right around the time the sun stones were buried -- both hallmarks of a massive volcanic eruption.  The location of the volcano has yet to be determined, but what is clear is that it would have had an enormous effect on the climate.  "It was a major eruption of a great magnitude, comparable to the well-documented eruption of Alaska’s Okmok volcano in 43 B.C.E. that cooled the climate by about seven degrees Celsius," said study lead author Rune Iversen, of the Saxo Institute at the University of Copenhagen.  "The climate event must have been devastating for them."

The idea that the volcanic eruption in 2,900 B.C.E. altered the climate worldwide got a substantial boost with the analysis of tree rings from wood in Europe and North America.  Right around the time of the sulfate spike in the Greenland ice cores, there's a series of narrow tree rings -- indicative of short growing seasons and cool temperatures.  Wherever this eruption took place, it wrought havoc with the weather, with all of the results that has on human survival.

While the connection between the eruption and the sun stones is an inference, it certainly has some sense to it.  How else would you expect a pre-technological culture to respond to a sudden, seemingly inexplicable dimming of the sun, cooler summers and bitter winters with resultant probable crop failures, and even the onset of wildly fiery sunrises and sunsets?  It bears keeping in mind that our own usual fallback of "there must be a scientific explanation even if I don't know what it is" is a relatively recent development. 

So while burying engraved rocks might seem like a strange response to a climatic change, it is understandable that the ancients looked to a supernatural solution for what must have been a mystifying natural disaster.  And we're perhaps not so very much further along, ourselves, given the way a substantial fraction of people in the United States are responding to climate change even though the models have been predicting this for decades, and the evidence is right in front of our faces.  We still have plenty of areas we don't understand, and are saddled with unavoidable cognitive biases even if we do our best to fight them.  As the eminent science historian James Burke put it, in his brilliant and provocative essay "Worlds Without End":

Science produces a cosmogony as a general structure to explain the major questions of existence.  So do the Edda and Gilgamesh epics, and the belief in Creation and the garden of Eden.  Myths provide structures which give cause-and effect reasons for the existence of phenomena.  So does science.  Rituals use secret languages known only to the initiates who have passed ritual tests and who follow the strictest rules of procedure which are essential if the magic is to work.  Science operates in the same way.  Myths confer stability and certainty because they explain why things happen or fail to happen, as does science.  The aim of the myth is to explain existence, to provide a means of control over nature, and to give to us all comfort and a sense of place in the apparent chaos of the universe.  This is precisely the aim of science.

Science, therefore for all the reasons above, is not what it appears to be.  It is not objectively impartial, since every observation it makes of nature is impregnated with theory.  Nature is so complex, and sometimes so seemingly random, that it can only be approached with a systematic tool that presupposes certain facts about it.  Without such a pattern it would be impossible to find an answer to questions even as simple as "What am I looking at?"

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The man with the golden nose

The history of science is full of strange characters, but surely one of the most peculiar was Danish astronomer Tycho Brahe.  Born in 1546 in Knutstorp, Sweden (then owned by Denmark), he came from a long line of wealthy and noble landowners.  Best known for his contributions to observational astronomy, his pinpoint-accurate measurements of the positions of stars and planets firmly convinced him of the correctness of the Copernican heliocentric model -- and were what allowed his contemporary Johannes Kepler to devise his three laws of planetary motion.  (Themselves instrumental in allowing Isaac Newton to develop his own three laws of motion, and more importantly, the Universal Law of Gravitation, a century later.)

He used his wealth and influence to good purpose.  He built the observatory of Uraniborg, the best of its kind at the time, on the island of Ven not far from Copenhagen.  His mapping of stellar and planetary positions, all done painstakingly by hand, had a staggering average precision of one arcminute.  Because his work was so careful, it gave Kepler no room to hang on to his precious "everything in the heavens moves in perfect circles" notion, and forced him to acknowledge that orbiting objects travel in ellipses -- a great example of the quip by Thomas Henry Huxley that "the great tragedy of science is the slaying of a beautiful hypothesis by an ugly fact."  Brahe's reputation as a careful observer was unimpeachable.

He was also, however, a very odd man.  At age twenty, he was at the engagement party of a friend and quarreled with his cousin Manderup Parsberg over (I shit you not) who was the better mathematician.  The only way for two mathematicians to settle such a quarrel was, of course, a duel in the dark with swords, and Brahe got the end of his nose cut off.  After receiving medical care, he had a local goldsmith fashion a golden nose for him that he attached to his face with glue -- he apparently also had silver and brass ones for everyday use, reserving the gold one for special occasions.  (He and Parsberg evidently made it up afterward, and remained friends.  I don't know if they ever settled who was the better mathematician, but my money is on Brahe, given that hardly anyone knows who Parsberg is anymore.)

Tycho Brahe by Eduard Ender [Image is in the Public Domain]

He owned a tame elk, that he kept in the castle with him -- until one day it drank too much beer, fell down the stairs, and died.  He had the odd combination of loving luxury and simultaneously disdaining it; I guess if you're ridiculously wealthy, you can afford to be contemptuous of money.  Offered a lucrative position at the court of the Danish king, Frederick II, he turned it down, telling a friend, "I did not want to take possession of any of the castles our benevolent king so graciously offered me. I am displeased with society here, customary forms and the whole rubbish."  Critics of his scientific publications were met with stinging rebuttals, and given his skill as an astronomer, Brahe was usually proven right.  However, his abrasive personality finally caught up with him -- when Frederick died in 1588, he was succeeded by his son Christian IV, who didn't like Brahe and ultimately forced him into exile.

Brahe's death was as peculiar as his life.  In October of 1601, the story goes, he was at a banquet in Prague and had to pee, but thought it was rude to excuse himself even for something that quick.  When he returned home, he found he couldn't pee, and died in horrible agony eleven days later.  The blame was laid on his stubbornness at refusing to leave the banquet, but the truth is, that can't be responsible for his death.  You can't injure yourself by holding it -- ultimately your sphincter just refuses to cooperate and you wet your pants.  It's almost certain that Brahe had a physiological problem like a urethral blockage or prostate hypertrophy, and that's what ultimately caused his demise.

But there's no doubt that the bizarre story of his death adds to his already notorious reputation for being peculiar.

The reason Brahe comes up -- besides his just being an interesting person -- is that there's a new analysis of the stuff left behind in his alchemical laboratory at Uraniborg.  He had a less-well-known fascination with alchemy, and ran a laboratory in the basement that conjures up images of the mad scientist, with a dungeon lab with stone walls and floors and various liquids bubbling and fuming in glass retorts.  When Brahe fell out of favor, and (especially) after his death, Uraniborg was pretty well taken apart, but there were bits and pieces left behind -- in particular, some glass shards from his alchemy equipment that still contained residues of the materials they'd last held.

A new analysis of the shards at the University of Southern Denmark has found significant traces of nickel, copper, zinc, tin, antimony, tungsten, gold, mercury, and lead.  Some of them, such as gold, lead, and mercury, are unsurprising; those were stock raw materials for the alchemists' eternal dream of turning base metals into gold.  Others, though, are more puzzling.

"[T]ungsten is very mysterious," said Kaare Lund Rasmussen, co-author of the study.  "Tungsten had not even been described at that time, so what should we infer from its presence on a shard from Tycho Brahe's alchemy workshop?"

In fact, it wouldn't be isolated for almost two centuries, when chemist Carl Wilhelm Scheele was able to extract it in pure form, something he was also the first to do with molybdenum and barium.  But it's possible that Brahe accidentally stumbled upon a method for extracting it -- or, perhaps, that it simply remained behind as an impurity in some other mixture he was concocting.

So Brahe was an odd amalgam in another way -- a dedicated and exacting empirical astronomer, and a subscriber to one of the weirdest discredited models humans have ever come up with.  "It may seem strange that Tycho Brahe was involved in both astronomy and alchemy, but when one understands his worldview, it makes sense," said Poul Grinder-Hansen, who also co-authored the study.  "He believed that there were obvious connections between the heavenly bodies, earthly substances, and the body's organs.  Thus, the Sun, gold, and the heart were connected, and the same applied to the Moon, silver, and the brain; Jupiter, tin, and the liver; Venus, copper, and the kidneys; Saturn, lead, and the spleen; Mars, iron, and the gallbladder; and Mercury, mercury, and the lungs.  Minerals and gemstones could also be linked to this system, so emeralds, for example, belonged to Mercury."

Once again illustrating that the scientific method only works where you choose to apply it.

In any case, the recent study shines more light on the life and work of one of the strangest scientists who ever lived -- Tycho Brahe, the man with the golden nose, whose work so profoundly inspired such greats as Kepler and Newton.  That he was also involved in alchemy may seem weird, but you can't be right all the time.  And given his reputation for oddity, I guess we shouldn't be surprised that he continues to confound our expectations, over four centuries after his death.

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Lord of frenzy

I'm sure most of you have heard of the Norse god Odin, at least from his appearance in the Marvel universe.  My first exposure to this bit of mythology came from my near-obsession with the book D'Aulaire's Book of Norse Myths, which I checked out from my elementary school library approximately 538 times.  This, in fact, is why to this day when I think of the trickster god Loki, I picture this:

And not this:

Be that as it may, the Norse pantheon is a fascinating bunch, and unusual amongst the gods of myth and legend in being mortal.  In fact, one of the most famous parts of the mythos is the tale of Ragnarök -- literally, "the doom of the gods" -- in which Loki unleashes chaos and destruction by causing the death of Baldr, the beloved god of light and joy.  The whole thing is described in brilliant detail in the Prose Edda and Poetic Edda of the thirteenth-century Icelandic scholar Snorri Sturluson, to whom we owe much of what we know about the beliefs of pre-Christian Scandinavia.

Odin (or Wōden, as he was called in Saxon England; this form of his name is the origin of the word Wednesday), the "All-Father," was one of the principal figures in the Germanic pantheon.  His name comes from a reconstructed Proto-Germanic root *Wōðanaz, which means "lord of frenzy."  There are dozens of curious stories about him -- that he hanged himself from Yggdrasil, the "World Tree," in order to gain the knowledge of the runes and writing; that he created the first man and woman from an ash and a birch tree, respectively; that he gave one of his eyes in order to drink from the well of wisdom; and that he rode upon an eight-legged horse called Sleipnir, that was the offspring of the stallion Svaðilfari and Loki, who had taken the form of a mare.

Odin on Sleipnir (from Den ældre Eddas Gudesange by Lorenz Frølich, 1895) [Image is in the Public Domain]

What I didn't know, though, was that the earliest actual attestation of Odin from any written record is comparatively recent.  A friend and loyal reader of Skeptophilia sent me a link about a study of a gold disk from Denmark that contains the first certain reference to Odin, and I was surprised to see that it dates to only the fifth century C.E.  The disk is called the Vindelev bracteate -- it was found near the town of Vindelev, and a bracteate is a flat pendant.  It states, in runic lettering, "He is Odin's man," presumably referring to some unknown chieftain or leader.

Given the complexity of the legends surrounding Odin and the other Norse gods, presumably their worship goes a lot further back; but I honestly didn't realize how much less we have in the way of early attestations of the Norse pantheon as compared to (for example) the Greek, Roman, Babylonian, Indian, and Chinese assemblages of deities.  Just about everything we know comes from the eighth century and later, the point at which the Vikings kind of exploded out of Scandinavia and did their best to take over all of northern Europe.  They did a damn good job; not only was all of eastern England under Danish control for a time, so were the Hebrides and Orkneys, Normandy (the name itself means "northman-land"), and a good part of what is now western Russia, Ukraine, and Belarus.  (Perhaps you know that the name Russia itself comes from the Rus, a group of Norse traders who ruled the entire region for a while, with their capital at Kyiv.)

So the dating of the Vindelev bracteate to the fifth century certainly doesn't mean that's when the worship of Odin began, only that this is the first certain example of anyone writing about it.  His influence on the beliefs of the pre-Christian Germanic world is immense.  As an Old English runic poem from the ninth century put it:

Wōden is the origin of all language
wisdom's foundation and wise man's comfort
and to every hero blessing and hope.

Perhaps the All-Father would not be upset that this is the way he's remembered, that his association with frenzy and battle was superseded by wisdom and hope, just as the people who once worshiped him settled down to become some of the most peaceful, progressive, and prosperous nations in the world. 

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Buried treasure

Maybe I need to get myself a metal detector.

The reason I say this is that it's apparently an auspicious time for treasure hunters, at least judging by two discoveries I found out about (once again!) from my friend and fellow writer Gil Miller, without whom in the last couple of weeks I wouldn't have had much to write about here.

The first one was a discovery in Norway made by an amateur treasure hunting enthusiast, using his newly-purchased metal detector for the first time (maybe there's something to beginner's luck after all...).  The fortunate fellow is named Ole Ginnerup Schytz, and I have to point out that (1) no, I am not making this name up, and (2), yes, this is from a reputable source, specifically the National Museum of Denmark.

In any case, the discovery, made a couple of months ago near the town of Jelling but only announced recently, is absolutely stupendous.  It's a collection of gold artifacts dating from the Danish Iron Age, about seventh century C.E.  It consists primarily of bracteates -- rune-decorated medallions thought to have not only a decorative but a magical purpose.  This new collection has bracteate designs the archaeologists say they've never seen before.

"It is the symbolism represented on these objects that makes them unique, more than the quantity found," explained Mads Ravn, director of research at the Vejle Museum.

As far as Schytz, he was as stunned as everyone else by his discovery.  "When the device activated, I knelt down and found a small, bent piece of metal," he said.  "It was scratched and covered in mud.  I had no idea, so all I could think of was that it looked like the lid of a can of herring."

One of the bracteates from the Jelling cache

"It was the epitome of pure luck," Schytz said.  "Denmark is 43,000 square kilometers, and then I happen to choose to put the detector exactly where this find was."

One thing I find fascinating about the discovery is that it contained gold coins from the Roman Empire that had been converted into jewelry, and a medallion depicting Constantine the Great (ruler of the Eastern Roman Empire from 306 to 337 C.E.).  So even though the cache seems to have been buried in the seventh century, some of the artifacts are a good three hundred years older than that.  Jelling, apparently, was the center of trade back then -- including trade from over two thousand kilometers away.

The second discovery was made on the other side of the world, in Colombia.  Recently archaeologists discovered a trove of gold and emeralds, filling eight ceramic jars of a type made by the Muisca people, an indigenous group known for their find goldsmithing (and who may have inspired the legend of the city of El Dorado).  The jars are thought to have been buried about six centuries ago, but this is much less certain than the Jelling cache's date, because there were no obvious historical benchmarks here as there were in Denmark.

One of the jars from the Muisca site

A lot of the pieces from this discovery are figurines in the shape of snakes and other animals, as well as people wearing headdresses and carrying staffs and weapons.  This has prompted the leader of the team which made the discovery, Francisco Correa, to conclude that the site may have been associated with the worship of ancestor spirits and animal totems.

In any case, both the Danish and the Colombian find are staggeringly precious, not just because of the monetary value of the gold and jewels, but because of what it tells us about the cultures that created these beautiful pieces.  So like I said, if you believe in auspices, maybe it's time to go out and get yourself a metal detector.

I probably won't bother.  Not only do I not believe in strings of good fortune, I don't think there's any gold buried around here.  About the only use I've seen people make of metal detectors in this area is sweeping the village fairgrounds after the annual fair wraps up, looking for lost pocket change.

And frankly, I don't think the return on that investment would be enough to justify the time and expense.

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Like graphic novels?  Like bizarre and mind-blowing ideas from subatomic physics?

Have I got a book for you.

Described as "Tintin meets Brian Cox," Mysteries of the Quantum Universe is a graphic novel about the explorations of a researcher, Bob, and his dog Rick, as they investigate some of the weirdest corners of quantum physics -- and present it at a level that is accessible (and extremely entertaining) to the layperson.  The author Thibault Damour is a theoretical physicist, so his expertise in the cutting edge of physics, coupled with delightful illustrations by artist Mathieu Burniat, make for delightful reading.  This one should be in every science aficionado's to-read stack!

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

The bones speak

Yesterday I ran into two unrelated studies that are kind of interesting in juxtaposition.

The first was in the journal Heritage Science, and was authored by a team led by Kaare Lund Rasmussen of the University of Southern Denmark.  It describes analysis of bones taken from 17th century Franciscan friaries in Italy and Denmark, looking specifically at trace element levels as an indicator of wealth, diet, medical treatments, and pollutants. 

The similarities were as fascinating as the differences.  In both places, bones from tombs of wealthy patrons were lower in strontium and barium than were bones from the cloisters, where the rank-and-file monks were buried.  This was likely due to the better (and more meat-rich) diet of nobles; ordinary folks ate a great deal more in the way of cereals and grains, which tend to have higher amounts of those trace elements.

On the other hand, the Italian bones had over twenty times the amount of copper that the Danish bones, regardless of social standing.  This was almost certainly because of cookware traditions; there was a long history of Italians of all classes using copper cook pots and storage vessels, whereas the Danes rarely did.

Lead followed the opposite pattern from strontium and barium; the wealthier people had higher amounts of lead in their bones, regardless of where they were from.  Rich people had pewter vessels and serving ware, earthenware coated with lead-based glazes, and (in some cases) lead water intake pipes for indoor plumbing and lead sheets on the roofs of their houses.  Plus -- something that I'd never heard of -- fine wine sometimes had added lead salts, put in to stop it from spoiling.

It worked, apparently, with the downside that if you drank it, you got lead poisoning.

I guess you can't have everything.

Mercury was an interesting one.  Mercury-based "medicine" was used to treat leprosy and syphilis in the Middle Ages.  Like the lead/wine-spoilage thing, the medicine worked only in the sense that you died, after which you no longer had leprosy or syphilis.  What the researchers found was that in Italian bones, the greater the socioeconomic status, the higher the likelihood of having mercury in the bone tissue; not, apparently, that the lower classes didn't get syphilis or leprosy, but that they had less access to treatment when they did.  Danish bones, however, showed no such trend.  The availability of medical treatment for the Danes was much more even-handed -- although, as I pointed out, that was not necessarily a good thing.

It's fascinating that we can analyze four-hundred-year-old bones and make some shrewd guesses about the cultural and social context their former owners lived in.  What they had to contend with -- good and bad -- left a clear record in their graves, still discernible four centuries later.

Then there's the second study, which appeared this week in the journal Environmental Hazards.  Entitled "Gulf Coast Parents Speak: Children's Health in the Aftermath of the Deepwater Horizon Oil Spill," by Jaishree Beedasy, Elisaveta Petkova, and Jonathan Sury (of Columbia University), and Stephanie Lackner (of the University of Madrid), the paper describes a study of 720 families in the part of coastal Louisiana hit by the spill, looking particularly at children's health as a function of proximity.  Turns out 60% of parents reported their children having health and/or psychological/emotional problems following exposure, and those who had come into direct physical contact with the spilled oil showed a 4.5 times higher rate of problems than those who had not.

[Image is in the Public Domain]

As the press release about the study in Science Daily put it:

Although natural disasters don't discriminate, they do disproportionately harm vulnerable populations, such as people of color and people with lower incomes.  Children are another vulnerable group, because their coping and cognitive capacities are still developing, and because they depend on caregivers for their medical, social, and educational needs.  A growing body of evidence demonstrates that disasters are associated with severe and long-lasting health impacts for children.

Having just read the story about the Danish and Italian bones, what it immediately got me thinking was, what will future archaeologists say about us when they unearth and analyze our bones?  Will they be able to detect traces of our self-poisoning reliance on fossil fuels?  Will the years from 2016 to 2020 show an uptick in pollutants because of Donald Trump's systematic weakening of environmental protections in favor of zero restrictions on industry and corporate interests?

What will that say to them about our priorities as a society?

Sorry to end on an elegiac note, but since we started with bones buried in cloisters, I suppose it's natural enough.  People eventually wised up to the point that they stopped using lead water intake pipes and cookware, and stopped treating diseases with mercury salts.  They did that, by the way, because of science -- the patient study of cause-and-effect that linked lead and mercury to chronic poisoning.  Let's hope that humanity today starts listening to the scientists today who are warning us about climate change and the health effects of pollution.

Otherwise our distant descendants will make the same judgments of our intelligence as we do of the medievals who put lead compounds in their bottles of wine.

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This week's Skeptophilia book of the week is for anyone fascinated with astronomy and the possibility of extraterrestrial life: The Sirens of Mars: Searching for Life on Another World, by Sarah Stewart Johnson.

Johnson is a planetary scientist at Georgetown University, and is also a hell of a writer.  In this book, she describes her personal path to becoming a respected scientist, and the broader search for life on Mars -- starting with simulations in the most hostile environments on Earth, such as the dry valleys of central Antarctica and the salt flats of Australia, and eventually leading to analysis of data from the Mars rovers, looking for any trace of living things past or present.

It's a beautifully-told story, and the whole endeavor is tremendously exciting.  If, like me, you look up at the night sky with awe, and wonder if there's anyone up there looking back your way, then Johnson's book should be on your reading list.

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

Chewing gum and talking about talking

Earlier this week I looked at three cool archaeological discoveries -- cave art in Indonesia, and two finds in Egypt, one of a bone from someone killed in the battle recorded on the Rosetta stone, and the other about a researcher who found that the practice of tattooing has been around for a very long time.

But we're not done with mind-blowing archaeological stories, apparently, because there are two more that I just found out about, and which (if anything) are even cooler than the ones I wrote about Monday.

I learned of the first one from my friend, novelist and blogger Andrew Butters, whose blog Potato Chip Math is a must-read.  In this one, we find out that a team of geneticists have sequenced the DNA of a girl who lived in Denmark 5,700 years ago...

... from a wad of chewing gum.

Well, technically, it was birch sap, but same idea.  They were able to extract her DNA from the gum and sequence her entire genome, which allowed them not only to figure out what ethnic group she was from, but to make a good shot at her appearance.  She had dark skin and hair, they found, and blue eyes.  Here's an artist's reconstruction of what she might have looked like:

[Reconstruction by Tom Björklund]

The authors write:

Analysis of the human reads revealed that the individual whose genome we recovered was female and that she likely had dark skin, dark brown hair and blue eyes.  This combination of physical traits has been previously noted in other European hunter-gatherers, suggesting that this phenotype was widespread in Mesolithic Europe and that the adaptive spread of light skin pigmentation in European populations only occurred later in prehistory.  We also find that she had the alleles associated with lactase non-persistence, which fits with the notion that lactase persistence in adults only evolved fairly recently in Europe, after the introduction of dairy farming with the Neolithic revolution.

The period she lived in was when northern Europe was taken over by people known as the "Funnel Beaker Culture," so named because of their characteristic narrow-based, highly-ornamented pottery:

The 5,200 year old Skarpsalling vessel [Image is licensed under the Creative Commons Nationalmuseet, Skarpsallingkarret DO-9665 original, CC BY-SA 3.0]

"It is amazing to have gotten a complete ancient human genome from anything other than bone,'' said study lead author, evolutionary geneticist Hannes Schroeder, of the University of Copenhagen, in an interview with Science Alert.  "The DNA is so exceptionally well preserved that we were able to recover a complete ancient human genome from the sample… which is particularly significant since, so far, no human remains have been recovered from the site."

The second story goes back a great deal further in time than the little Neolithic Danish girl, though.  In fact, it kind of crosses the line from archaeology into paleontology, because in a paper in Science Advances we find out that the ability to speak might have been around in primates for twenty million years.

The study, led by Louis-Jean Boë of the University of Grenoble, analyzes the mechanics of human speech, in particular how the morphology of the mouth, trachea, and larynx allow for the production of meaningful sound.  It's been thought for years that the advent of speech occurred when our ancestors' larynxes (voice boxes) gradually moved downward, pulling the back of the tongue backward and downward as well and giving the tongue more mobility to shape sounds.  But what Boë's team found was that even if you accept that as the hallmark of speech, it goes a long way further back than we'd realized.

"First, even among primates, laryngeal descent is not uniquely human," Boë and his team write.  "Second, laryngeal descent is not required to produce contrasting patterns in vocalizations.  Third, living non-human primates produce vocalizations with contrasting patterns.  Thus, evidence now overwhelmingly refutes the long-standing laryngeal descent theory, which pushes back 'the dawn of speech' beyond ~200 ka ago to over ~20 Ma ago, a difference of two orders of magnitude."

So that means that at least from a mechanical standpoint, our distant ancestors had the capacity for speech.  Whether their brains were developed enough to say anything particularly interesting is still a matter of conjecture.  But evolution is all about minuscule gains.  Once the upper respiratory tract becomes capable of modulating sounds in a meaningful way, this puts selective pressure on the brain to refine its ability to understand and convey meaning with those sounds -- which puts pressure on the vocal apparatus to become better at producing subtle differences in sounds, and so on and so forth.  Which, as comedian Paula Poundstone notes, may not be entirely a good thing:

Be that as it may, it's a pretty cool discovery.  As I pointed out in Monday's post, it's incredible how much we can infer about our distant ancestors' appearance, culture, and abilities from evidence that would have been a closed book only ten years ago.  Our techniques for carrying out this research are only going to improve, so keep watching the journals -- my sense is that the amazing discoveries in this field have only just begun.

*****************************

This week's Skeptophilia book recommendation is pure fun, and a perfect holiday gift for anyone you know who (1) is a science buff, and (2) has a sense of humor.  What If?, by Randall Munroe (creator of the brilliant comic strip xkcd) gives scientifically-sound answers to some very interesting hypothetical questions.  What if everyone aimed a laser pointer simultaneously at the same spot on the Moon?  Could you make a jetpack using a bunch of downward-pointing machine guns?  What would happen if everyone on the Earth jumped simultaneously?

Munroe's answers make for fascinating, and often hilarious, reading.  His scientific acumen, which shines through in xkcd, is on full display here, as is his sharp-edged and absurd sense of humor.  It's great reading for anyone who has sat up at night wondering... "what if?"

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

Political backfires

The good news from yesterday's post, wherein we learned some ways of fighting the backfire effect and convincing people to change their minds, was immediately counterbalanced by a new (and discouraging) study out of Denmark that showed that for politicians, the more data they have access to, the worse backfire effect becomes.

A team at Aarhus University led by Martin Baekgaard was studying motivated reasoning, which is the thought process we engage in when we are presented with information either supporting or refuting our prior beliefs.  In the first part of the experiment, test subjects were given test score data from two schools, A and B, and asked to evaluate which was more successful.  A different set of test subjects was given the same data, but one of the two schools was labeled "Public School A" and the other "Private School B" -- like in the United States, the relative merits of public vs. private schools is a topic of heated debate.

This first bit of research generated results that were unsurprising.  When the two schools were given anonymous tags, the data was evaluated fairly by both people who supported public schools and those who supported private schools.  When they were labeled, however, the backfire effect kicked in, and the test subjects' prior opinions skewed their analysis of the results.

So far, nothing we didn't already know.  But the second part of the experiment not only looked at the quantity of data provided, and compared the results of 1,000 test subjects from a variety of professions as compared to 954 career politicians.  And this gave some results that were, to put it mildly, interesting.  Let me give it to you in the authors' own words:

Does evidence help politicians make informed decisions even if it is at odds with their prior beliefs?  And does providing more evidence increase the likelihood that politicians will be enlightened by the information?  Based on the literature on motivated political reasoning and the theory about affective tipping points, this article hypothesizes that politicians tend to reject evidence that contradicts their prior attitudes, but that increasing the amount of evidence will reduce the impact of prior attitudes and strengthen their ability to interpret the information correctly.  These hypotheses are examined using randomized survey experiments with responses from 954 Danish politicians, and results from this sample are compared to responses from similar survey experiments with Danish citizens.  The experimental findings strongly support the hypothesis that politicians are biased by prior attitudes when interpreting information.  However, in contrast to expectations, the findings show that the impact of prior attitudes increases when more evidence is provided.

Yes, you read that right.  Politicians, like other people, are prone to falling into the backfire effect.  But unlike the rest of us, the more data they're given, the worse the backfire effect becomes.  Show a politician additional evidence, and all you're doing is making sure that (s)he stays planted even more firmly.

Baekgaard et al. propose a reason for this result, and I suspect they're correct; most politicians are, by their very nature, partisan, and have been elected because of strongly supporting a particular political agenda.  Since the backfire effect occurs when people double down on their beliefs because of feeling threatened, it stands to reason that politicians -- whose jobs depend on their beliefs being right -- would experience a greater sense of threat when they find they're wrong than the rest of us do.

But that leaves us with the rather alarming result that the people who are directing policy and making decisions for an entire electorate are going to be the ones whose response to the data is worst.

"The Great Presidential Puzzle" by James Albert Wales (1880) [image courtesy of the Wikimedia Commons]

And, of course, this result is borne out by what we see around us.  Here in the United States, it seems like every time new studies are performed and new data generated, the determination of politicians to shout "damn the facts, full speed ahead!" only gets stronger.  Which can explain why any of a number of crazy policies have been implemented, ones that fly in the face of every rational argument there is.

But in the words of Charlie Brown, "Now that I know that, what do I do?"  And my answer is: beats the hell out of me.  As I said in a previous post, I think nothing's going to change until the voters wise up, and that won't happen until we have a more educated citizenry.

And heaven only knows what it'll take for that to come about.

Speculation, conjecture, and the Sealand skull

One of my attitudes that I've found is remarkably uncommon in other humans is that I don't have the need to have an opinion about everything.

When I don't have enough evidence, one way or the other, I simply don't know -- and that's that.  I find that this response especially annoys teenagers.  When one of my students asks me something like, "Is there life after death?" and I respond, "There's no definitive evidence, so I don't know," I frequently find that they come back with, "Yes, but what do you think?"  When I tell them that if I have nothing to go on, I don't think anything, I often find that they snort in my general direction and walk away.

It's not only a little mysterious that people feel obliged to form strong opinions about things for which they have no data whatsoever, it's mighty puzzling how they come to those opinions in the first place.  In the case of life after death, I suspect that a lot of it is wishful thinking.  The concept of simply being gone is, I have to admit, pretty disturbing, but I've found that the universe seems to be under no particular obligation to present me with reality that I happen to like.  So I'm sticking with "I don't know."  I'll find out sooner or later either way, and until then, I'm content in my state of ignorance.

So when a kid in my Critical Thinking class found a site about the "Sealand skull," and asked me what I thought about it, I had a similar reaction.  The Sealand skull was allegedly discovered by some workers repairing sewer pipes in a house in 2007, in the town of Olstykke on the Danish island of Sealand.  So without further ado, here is the skull in question:

So you can see why the question of "do you believe this?" would come up.  According to the story, the skull was taken to the Niels Bohr Institute in Copenhagen, and radiocarbon dated to between 1280 and 1200 B.C.E.  The skull is supposed to be larger than a typical human skull, and with the outsized eyes, people said that it must be the skull of an alien.

And that's the sum total of what we have to go on.  A photograph.  No hard evidence at all, since none of the sources mention where the skull currently is, who the scientists are who carbon-dated it, or anything else.  There's a brief mention of some group of oddballs called "The Order of the Light of Pegasus" who had a house in Olstykke and were reputed to be "the guardians of objects... believed to be mysterious," but searches for anything related to said Order all bring you back to websites having to do with the Sealand skull.

The whole thing has the hallmarks of a hoax, but do I know it is?  Nope.  To prove that it's a hoax -- or to prove anything else about it -- you'd need to have access to the skull itself.  It certainly seems to be an Extraordinary Claim, the sort of claim apropos of which Carl Sagan said you needed Extraordinary Evidence.  But we not only don't have extraordinary evidence, we don't even have your regular, garden-variety evidence.  We have no evidence at all.  At the moment all we have is an unsubstantiated story -- i.e., a tall tale.

This, of course, hasn't stopped people from spinning out all sorts of speculation about it, because nothing improves a zero-evidence claim like having zero-evidence conjectures derived from it.  So naturally, someone decided to do a facial reconstruction from the Sealand skull photograph, and came up with this:

So apparently, the original owner of the Sealand skull was Gollum.  Which is, honestly, rather surprising.  Didn't Gollum get fried in the lava pit in Mount Doom in the end, along with His Precious?  Because if so, it's hard to explain how his skull could have ended up in a house foundation in Denmark.

Be that as it may, however my intuition is that the Sealand skull is a fake, I know better than to rely on my gut for any kind of reliable approximation of what's real or not.  So I don't really have any conclusion about this, other than to say that if it is real, it'd be a pretty earthshattering discovery, bringing up the inevitable question of why the scientists who studied it weren't trampling each other to death to be the first people to write a paper on it.

But that, too, hardly constitutes proof of anything.  At the moment, the best we can say is that there's no evidence one way or the other for a claim made by an unknown individual about an alleged scientific study by unnamed scientists about a skull that may or may not exist.

So that's that.  Back to speculating about whether or not there's an afterlife, because even that has more going for it, as scientific support goes.

Hammer of the gods

For those of you who have found yourself distressed by the heavy topics that have appeared here in Skeptophilia over the last couple of weeks -- climate change, the anti-vaxxers, the persecution complex amongst many American evangelicals, the misrepresentation of science by charlatans -- I'm afraid that today I need to bring to your attention an even more serious threat to life and limb:

Someone has found Thor's hammer in Denmark.

Yes, the fearsome weapon Mjölnir, capable of leveling mountains in a single stroke, the bane of many a Frost Giant and evildoer.  It was a short-handled metal hammer, forged in Svartálfaheim by the dwarf brothers Sindri and Brokkr.  They also at the same time made a few other special offers, including Odin's spear Gungnir, and Freyr's magic boat Ski∂bla∂nir and golden boar Gullinbursti.

No, I don't know how you forge a pig.  But then, I'm not a dwarf, which probably has something to do with my lack of expertise.

Be that as it may, Thor's hammer was considered by the Norse gods to be the best of the gifts that the dwarves ever made, because not only did it smash anything you like to rubble (its name means "the pulverizer" in Old Norse), it returned to Thor's hand when it was thrown, which is pretty convenient.

[image courtesy of the Wikimedia Commons]

Of course, the problem is that it, like the spears and boats and golden pigs and (in fact) the Norse gods themselves, are mythological.  I.e., not real.  This is a point that seems to have escaped a lot of people, most notably Giorgio Tsoukalos (he of the amazing hair), who thinks that they were aliens.  The Norse people couldn't just have made them up, he says.  No way could people dream up valiant warriors and magical powers and epic battles between good and evil without it having some basis in the visitation of Earth by extraterrestrials.

Which therefore also presumably explains how Tolkien came up with Lord of the Rings.

So, according to the story over at Ancient Code that I linked above, we now have concrete proof that Thor existed, because they've discovered his hammer at an archaeological dig on the island of Lolland, in Denmark.  The hammer bears an inscription that says, "Hmar is" ("This is a hammer"), in case we weren't sure.

This is just thrilling the Ancient Aliens crowd to pieces.  Over at Arcturi Extraterrestrial Community, we read:

One intriguing mythological figures in human history when analyzing ancient aliens connection with past human evolution is one of the most well known Norse gods named Thor, god of thunder, whom [sic] wielded a powerful hammer-weapon that would allow him to destroy his enemies and protect humanity from the giants who roamed the earth. To better understand why Ancient Alien theory truly looks at this mythological figure as an intriguing character for ancient alien influence, one must have a basic understanding of who Thor was and his role on Earth, who his enemies were, and where his majestic and mythical hammer (named Mjollnir [sic]) came from... Could it be possible that
Thor's Hammer is some kind of ancient alien weapon that allowed him to reign throughout the lands and protect his people?

Furthermore, it was said that Thor's Hammer was made by two dwarfs. This really interested us because Ancient Alien theorist [sic] do believe in various alien races, which could lead us to believe that these dwarfs could have been Grey Aliens, commonly depicted as standing 3-4 feet in height and having an advance knowledge in technology which could be mistaken as magic to those who are unaware of the power behind the laws of the Universe. In addition, it seemed that the Hammer was made to be used with the aid of two "iron" gloves, perhaps giving some kind of a magnetic signal to the Hammer, so when thrown, the Hammer would return to Thor. Looking deep into the depictions of the use of this weapon, it really seems more like a modern day weapon, something conceivable to us today, but magical to those in the past.

So that sounds pretty amazing, and you can certainly see why this discovery has induced the Norse-gods-are-aliens aficionados to leap about making happy little squeaking noises.

But unfortunately, there's a problem with all of this, and although I hate to put a damper on their enthusiasm, but I feel honor-bound to mention it.  If you look at the photographs of the artifacts released by the National Museum of Denmark, you can see that the newly-discovered Mjölnir, fearsome hammer of the gods, bane of the giants...

... is only about five centimeters across.

For those of you who don't think well in metric, that's a little under two inches.  With a hammer that size, Thor would have been able to fell mice, and possibly a bunny, but not much more than that.  The Frost Giants, on the other hand, wouldn't have had much to worry about.  So the archeological find is probably just a piece of Norse jewelry, and all of the hype a bit anticlimactic.

Not that this will stop Giorgio Tsoukalos et al.  As we've seen over and over, it doesn't take much to get him excited.  Expect an episode on this amazing find on the This Really Isn't History Channel soon.

Seeds of doubt

C'mon, people, it's time to grow up a little.

When we're toddlers, we accept things without question.  If our parents say something, we pretty much believe that it must be true.  (Whether we do what they tell us afterwards, though, is another issue.)  After a time, we start experimenting, and testing the world -- sometimes with unfortunate results, such as when we decide to find out why Mommy says that Mr. Finger and Mr. LightSocket can't be friends.

But this highlights an important principle, which is that our first and best way to find out about things is by finding evidence.  "Show me why" is a pretty important first step to knowledge.

It's not the last step, though.  After the "show me why" stage we should move on to "but how do you know it's true?", which is a deeper and more sophisticated question.  Okay, from the evidence of my eyes, it looks like the Sun is moving across the sky.  In order to move past that to the correct explanation, we have to ask the question, "What if there is a better explanation that still accounts for all of the evidence?"

And in this case, of course, it turns out that there is.

There are other facets to this mode of inquiry.  What confounding factors could there be?  What if there are uncontrolled variables?  What if the person who made the original claim was lying?  What if my preconceived biases made me misjudge the evidence, or (perhaps) ignore some of the evidence entirely?  What if there is correlation between A and B, but instead of A causing B, B causes A -- or, perhaps, some third factor caused them both?

This whole process is what is collectively known as "Critical Thinking."  What is unfortunate, though, is that a lot of people seem to be stuck at the "I see evidence, so it must be true" stage, which is probably why the whole WiFi-kills-plants thing is making the rounds of social media... again.  Just a couple of days ago, a friend of mine ran across it, and asked the right question: "can this actually be true?"

The claim is that five ninth-graders from Denmark had noticed that if they slept near their WiFi routers, they "had trouble concentrating in school the next day."  Because clearly, if ninth graders are distracted, it must be because of WiFi.  So the kids allegedly set up an experiment with cress seeds, placed some near a router, and had others in a "room without radiation," and had the results pictured above.

Well.  The whole thing is suspect from the get-go, because we're told nothing about other conditions the seeds were experiencing -- light, humidity, temperature, air flow, and so forth.  Was the "room without radiation" well-lit?  Were the seeds near the router warmer than the supposed control group?  There are a hundred things about this so-called experiment that we're not being told, and yet we're supposed to buy the results -- in spite of the fact that "control all variables but one, or the results are suspect" is the first thing taught in high school science classes.  (For a nice take-apart of this "experiment," take a look here -- and note, especially, that attempts to replicate the girls' experiment have not produced any results.)

What else?  First, it's from Spirit Science, a notorious peddler of woo.  Second, unless they were in a lead-lined vault, I doubt whether the control seeds were actually in a "room without radiation."  Even if you're some distance from the nearest router, you (and your room) are constantly being pierced by radio waves, which pass easily through most solid objects (if they didn't, old-fashioned (i.e. pre-cable) televisions and almost all modern radios would not work inside houses or cars).  Then there's the issue of how many thousands of WiFi routers in the world are sitting near perfectly healthy house plants -- for years, not just for thirteen days.  And even if WiFi did kill cress seeds, there's no guarantee that it would have the same (or any) effect on humans.  Don't believe me?  Go for a nice swim in the ocean, and then pour a cup of seawater on your marigolds, and see if the results are the same.  (In all seriousness, researchers face this all the time when developing medications -- therapies that work well in vitro or on lab animals might have different effects on human subjects.)

So to the people who are unquestioningly passing this around, just stop.  Exercise something past the You-Showed-Me-A-Picture-So-It's-True level of critical thinking.  If you see something that seems suspect, ask someone who might know the answer (as my friend did with this claim).  Or, in this day of information accessibility, you could simply Google "cress seeds WiFi experiment debunked" and you'll find everything you needed to know.

We all were toddlers once, and no harm done, unless you count unfortunate encounters with light sockets.  But let's exercise a little higher-level thinking, here, and not just accept whatever comes down the pike.