Am I Brilliant Blue? Lapis Lazuli Embedded in a 1000-Year-Old Woman’s Teeth

      The earth is abundant with brown, green, red, and yellow pigments but  “finding a stable blue is like willing a river to stop flowing.” In 2017, a chemist made headlines around the world for discovering the first new blue in 2 centuries, named YInMn Blue.”

         Lapis lazuli in a 1000-year-old woman’s teeth indicate she was likely a manuscript scribe who mixed her saliva with the precious ground ultramarine or lapis lazuli as she copied ancient texts.

     

    In 2014, archaeologist Dr. Anita Radini was studying the dental calculus of bodies buried in a medieval church. This hardened plaque, or tartar, is a challenge to a modern dentist, but it’s crucial evidence for researchers peering into the past. While other body parts disintegrate, teeth often stubbornly remain, and the chemical components of these teeth can offer a glimpse into our daily lives.

          At the time, Dr. Radini was scraping old teeth in pursuit of calcified starches, a useful proxy for diet. Her colleague, Dr. Christina Warinner, an expert in the evolution of ancient microbes at the Max Planck Institute, hoped to better understand oral bacteria. But, something in the mouth of specimen B78 distracted both researchers from their initial pursuits: scattered specks of a brilliant blue.

     “Can you imagine the kind of cold calls we had to make in the beginning?” Dr. Warinner told The Atlantic. “‘Hi, I’m working with this thing on teeth, and it’s about 1,000 years old, and it has blue stuff in it. Can you help me?’ People thought we were crazy.”



     Drs. Warinner and Radini assembled a multidisciplinary color detection squad. Dr. Monica Tromp, a New Zealand-based expert in particle analysis with the Max Planck Institute, took on the task of identifying the blue hue’s origin. Dr. Alison Beach, a history professor at The Ohio State University, a Smith College graduate, and an expert in medieval German women’s role in copying illuminated manuscripts, offered essential cultural context. Drs. Warinner and Radini also consulted a scholar of medieval trade about the economic context in which B78 lived. What they found brought smiles to everyone’s faces

    B78, the authors determined, was a woman who lived sometime between 997 and 1162 A.D. She died in middle age, between 45 and 60 years old. Except for the blue color in her mouth, she “was otherwise unexceptional,” according to the study authors. But in a new paper published this week in the journal Scientific Advances, the color detectives showed B78 had lapis lazuli in her mouth—evidence she was a highly-skilled manuscript scribe in a time when most people assumed illumination was the exclusive domain of men.

     “It didn’t surprise me, it thrilled me,” says Dr. Beach,  co-author in the study. Dr. Beach has studied female manuscript makers since graduate school, hoping to make the public understand their role in producing some of the most elaborate artworks of the age. But because most of the volumes are unsigned—and the few that are signed were signed by men—making the case for women’s role in these spaces has always been a challenge. But the blue found in B78’s teeth is stronger evidence than one might expect.

A self-portrait of Guda, a 12th century nun and illuminator, signed "Guda, a sinful woman, wrote and painted this book." The source of the blue-green color is unknown.

   
     "Blue was, is, and will continue to be the hardest color to find or create."

      In the medieval period, artists had five sources of the color: ultramarine, azurite, Egyptian blue, smalt, and vivianite. The most prized of these was ultramarine, more commonly known in its ground and purified form as lapis lazuli. Found only in one region of Afghanistan, for millennia lapis lazuli demanded the same price as gold. It wasn’t, in other words, something you’d expect to find in random medieval dental calculus. “This isn’t a kind of paint you just give to someone who’s learning,” Dr. Beach says (contrary to the suggestion of an outside reader evaluating the paper before publication, who believed the woman was just a janitor cleaning up after the real manuscript makers).

     The study entertains other possibilities—that B78 was undergoing lapidary medicine, where she swallowed pigments for her health, or that she engaged in “devotional osculation,” where Christians kissed paintings as part of worship. But the way the blue pigment was distributed deep into the teeth, in fairly consistent layers over time, indicated B78 was one of the “modest and pious women who quietly produced the books of medieval Europe,” the authors wrote. Specifically, Dr. Beach thinks B78 and her colleagues would have been narrowing the point on their fine-tipped brushes with their mouths, mixing lapis lazuli into their dental plaque in the process.

     Dr. Beach and other medieval historians are optimistic this method will apply broadly to other manuscript makers of the era. “I had never heard of using dental calculus as a window on somebody’s everyday life,” Dr. Beach says, but now that researchers know where to look, the possibilities are limitless. “There’s so few sources that medieval historians have for ordinary people. This one clue of the lapis lazuli opens a whole window on the life of an ordinary women in a period in which we have almost no sources,” Dr. Beach adds. “She’s not a queen, she’s not a duchess. She’s just a person who lived and worked and died.”

      Blue is my favorite color, Dr. Beach is a Smithie, and I enjoy mazarine minerals, especially lapis lazuli. How about you? 

       Happy Blue Year!

Steph

Nine ways to draw our ever bluer state:





Spirals: Golden or Not: Fib O’ Gnocchi?

      I attended a presentation recently that included a discussion of the Fibonacci number sequence and golden spirals. We have discussed Fibonacci numbers and golden spirals here at Partial Ellipsis of the Sun before.

        The Fibonacci number series begins as 0, 1, 1, 2, 5, 8, 13, 21, 34, 55, 89,144; each term is the sum of the previous two terms. The Golden Spiral is created using phi, the ratio of 1.6180.  In mathematics, two quantities are in the golden ratio if their ratio is the same as the ratio of their sum to the larger of the two quantities thus: 

       The illustrations in the presentation included spirals that looked like this:

      Of course, Golden Spirals look like this:

       No one else in the audience seemed bothered by equal spacing on the spiral; it drove me bonkers.  Folks commented on how beautiful the illustration was; but it was wrong!

      The Golden Spiral can be seen in the Milky Way:

And in storm patterns:

      It can also be used in image composition:

     I brought the spiral conundrum to the kindergartners who all saw immediately that the spiral had to grow so the chambered nautilus could grow, too.

      From the mouths of babes. . .

      Speaking of babes, a shout-out to my co-teacher who turned 60 on the 6th. The Babylonians considered 60 the most sacred number and a resetting of the odometer to zero in their base-60 number system. Happy sexagesimal reset, Mary!

     Does it drive you bonkers when illustrations are wrong? 

    ^^^Thanksgiving Square Chapel, Dallas, TX

Steph

Christmas Eve at Great Sand Dunes National Park and Preserve. It was an extraordinary day shared with a herd of 30 elk. See if you can find them.

Happy Sandy Holidays!

Cratonically Yours: Thinner Lithosphere and Crust in Western Antarctica Than in Eastern Antarctica

        The frozen landmass of Antarctica has been studied using satellite imagery to understand some of the  earth's tectonics, revealing  several hidden structures of the least-understood continent in research published 11/5/18.

      Due to its remote location and abundance of ice, charting the geological characteristics of Antarctica is complicated, but the Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) satellite can see what other satellites can't. GOCE precisely measured the pull of earth's gravity to map out hidden terrain.

     GOCE crashed out of orbit after running out of fuel in late 2013, but researchers are still poring over the data it collected. The researchers say it offers new insights into how Antarctica was formed, and how plate tectonics can function. See the colorful, newly-created video of continental movement.

      "In East Antarctica we see an exciting mosaic of geological features that reveal fundamental similarities and differences between the crust beneath Antarctica and other continents it was joined to until 160 million years ago," says one of the team, Dr. Fausto Ferraccioli from the British Antarctic Survey. The shape index, tectonic regularization, and crystal thickness were combined to create the above video.

      Antarctica was once part of the supercontinent Gondwana, which began to disintegrate about 130 million years ago, although the bond between Antarctica and Australia held together as recently as 55 million years ago.

      By combining GOCE readings with seismological data, the researchers were able to create 3D maps of Earth's lithosphere, made up of the crust and the molten mantle beneath. That lithosphere includes mountain ranges, ocean backs, and rocky zones or cratons, the leftovers of ancient continents embedded in continents as we know them today.

      
     "The satellite gravity data can be combined with seismological data to produce more consistent images of the crust and upper mantle in 3D, which is crucial to understand how plate tectonics and deep mantle dynamics interact," says researcher, Dr. Jörg Ebbing from Kiel University in Germany.

     The GOCE satellite circled our planet for over four years, from March 2009 to November 2013. During that time it got unusually close to Earth – an altitude of just 225 km (140 miles) – to maximize the accuracy of its measurements.


     The International Space Station, by comparison, is about two times farther away from earth's surface.

      Among the findings from the new study was the discovery of a thinner crust and lithosphere under West Antarctica compared to East Antarctica.  The latter has a mosaic of older cratons interspersed with thinner regions of rock, similar to India and Australia, to which it was once joined.

      And the data is useful for more than just tracing the remnants of ancient continents across the past 200 million years: It can be used to help figure out how ice sheets above the underlying terrain might react to warmer temperatures.

     With so many variables to consider, predicting how ice melt might progress across Antarctica is a real challenge, so any help scientists can get will be welcome. GOCE is still proving its use long after its mission ended.

Antarctically yours,
Steph

Brussels Sprouts and Heirloom Tomato Omelette

Clock this: Dandelion Seeds Have a Vortex Floating Above Their Filaments

     "Dandelion seeds fly using a method that researchers thought would not work in the real world, according to a study published on October 17, 2018, in Nature." Here is a dandelion head, also called a dandelion clock:

     "When some animals, airplanes, or seeds fly, rings of circulating air called vortices form in contact with their wings or wing-like surfaces. These vortices can help to maintain the forces that lift the animal, machine, or seed into the air. 

     Researchers thought that an unattached vortex would be too unstable to persist in nature. Yet the light, puffy seeds of dandelions use vortices that materialize just above their surfaces and lift the seed into the air.

     Dandelion seeds bear filaments that radiate out from a central stalk like the spokes on a bicycle wheel, a feature that seems to be the key to their flight. Many insects harbor such filter-like structures on their wings or legs, suggesting that the use of detached vortices for flight or swimming might be relatively common, says study co-author Dr. Naomi Nakayama, a plant scientist at the U. of Edinburgh.

      As far as vortex rings go, the dandelion's is unusual. Normally, such air bubbles stay attached to an object or totally separate and disappear. But the dandelion’s bubble separates and hangs out above the seed. “When you show it to a fluid dynamicist, it blows their mind,” says study coauthor Dr. Cathal Cummins.

     Researchers were curious about how these bristly seeds of the pappus (the seed plus the filaments) stayed in the air because they looked so different from the wing-like seeds of other plants, such as maple trees. Those structures act like the wings of a bird or airplane, generating pressure differences above and below the wing to fly. To find the answer, Dr. Nakayama and her colleagues put dandelion seeds in a vertical wind tunnel and used a laser to illuminate particles that helped to visualize the airflow around the seed.

     That’s when they saw the vortex floating above the seeds. The amount of open space between the spokes of the seeds seems to be the key to the stability of these detached vortices, says Dr. Cummins. Pressure differences between the air moving through the spokes and the air moving around the seed creates the vortex ring.

     Previous studies have found that dandelion seeds always have between 90 and 110 bristles, says Nakayama. She described it as “extremely consistent”, and that consistency turns out to be very important.

     When the team designed small silicon discs to imitate these spokes, they produced models with a range of openings: from solid discs to ones that were 92% air, like the structures on the dandelion seeds. When the researchers tested these model seeds in their wind tunnel, they found that only the discs that best approximated dandelion seeds could maintain the detached vortex.

     If the number of openings in the discs was even 10% off of those in dandelion seeds, the vortex destabilized. The seed looks inefficient for flight because it has so much open space, says Dr. Nakayama, but these openings are what allow the unattached vortex ring to remain stable."

     “It’s great to see an analysis of something we see every day but didn’t fully understand,” says Dr. Richard Bomphrey, a comparative biomechanist at the Royal Veterinary College. “To discover that there were aerodynamic mechanisms that we didn’t already know — despite the fact that we can fly things at Mach 9 — is always exciting.”

        Wow, hanging vortices in a common flower. Nature sure is dandy!
Steph

Zoë had her Peace Corps gong out service, hitting the gong thrice to represent three years of service. Proud of her and looking ahead to what she'll do next!