Enlarge/ The Notre-Dame de Paris has been under restoration since a devastating fire destroyed the main spire and roof in April 2019.
There’s rarely time to write about every cool science-y story that comes our way. So this year, we’re once again running a special Twelve Days of Christmas series of posts, highlighting one science story that fell through the cracks in 2023, each day from December 25 through January 5. Today: The Notre Dame cathedral in Paris has been undergoing extensive renovation in the wake of a devastating 2019 fire. Previously hidden portions of its structure have revealed the use of iron reinforcements in the earliest phases of the cathedral’s construction, making it the earliest known building of its type to do so.
On April 15, 2019, the world watched in collective horror as the famed Notre Dame cathedral in Paris was engulfed in flames. The magnificent cathedral’s roof and its support structure of 800-year-old oak timbers were destroyed when the main spire—750 tons of oak lined with lead—collapsed in flames, landing on the wooden roof. French President Emmanuel Macron vowed to rebuild the cathedral, and that work has continued steadily in the ensuing years; the current planned re-opening will occur on December 8, 2024.
If there is a silver lining to the destruction, it’s that the damage has revealed parts of the cathedral’s structure that were previously inaccessible, telling archaeologists and conservationists more about the materials originally used to construct Notre Dame in the mid-12th century. According to a March 2023 paper published in the journal PLoS ONE, the original builders used iron reinforcements during the initial phases, making Notre Dame the earliest building of its type to do so.
“The fire has shed light on certain uses of iron, such as the staples on the top of the upper walls which were totally hidden by the framework,” co-author Maxime L’Héritier of Université Paris told Gizmodo. “We could not have seen them without the blaze or a huge restoration. We believed that [the] great building yards of the 13th century had invented these construction processes using iron armatures, but now it seems that it all occurred at Notre Dame.”
Although no original plans for Notre Dame Cathedral exist, a couple of centuries after Notre Dame’s construction, other building projects left behind documents called building accounts or fabric accounts, which include information like materials purchases and payments to masons. But in the late 12th century, written documents weren’t yet widely used. In the early 1800s, the cathedral was crumbling, and architects Eugène Viollet-le-Duc and Jean-Baptiste-Antoine Lassus received a royal contract to restore the medieval structure. Working with relatively simple tools, Viollet-le-Duc left behind detailed, accurate drawings of the original architecture and his own restoration work.
Two hundred years later, art historian Stephen Murray and the late architectural historian Andrew Tallon of Vassar College carried laser scanners through the entire cathedral, including the space above the vault and several out-of-the-way spiral staircases, passages, and other hidden spaces. As for the cathedral’s much-praised acoustics, a group of French acousticians made detailed measurements of Notre Dame’s “soundscape” a few years before the fire. All of that data has been instrumental in helping architects and conservationists reconstruct the cathedral.
Enlarge/ The 2019 fire exposed iron staples in the top walls, inside a column in the nave, and in the tribunes of the choir.
M. L’Heritier et al. 2023
Other medieval French cathedrals built after Notre Dame, such as in Chartres, Bourges, or Reims, all used iron armatures, tie-rods, and chains. But until now, it hasn’t been clear to what extent the original builders of Notre Dame used iron in its construction. Harnessing and scaffolding gave researchers access to the upper parts of the cathedral, although some parts remained inaccessible. Still, L’Héritier et al. found extensive use of iron staples at different levels, with the lowest being two rows of staples in the floors of the second-level tribunes above the arches, as well as in the nave and choir.
Per the authors, some iron reinforcements clearly dated back to reconstruction efforts during the 19th century, most notably iron chains and tie rods in the top walls of the choir and above its upper vaults. The real question was just how old the other iron staples might be. The team mapped and measured all those that were accessible, totaling roughly 170 staples for the upper walls and 100 for the tribunes. They also took samples for the metallographic analysis from iron staples that were already broken or damaged by the fire. The team used a new method for characterizing metal, combined with radiocarbon dating, to determine the age and possible provenance of those samples.
L’Héritier et al. concluded that the iron staples in the floor of the tribunes dated back to the early 1160s, i.e., the earliest phases of construction. “So far, these series of staples are the earliest known example of iron armatures used in the initial design of a Gothic monument,” they wrote, a good 40 years before the iron reinforcements used to build the Chartres or Bourges cathedrals. The staples found at the top of the great lateral walls date to the early 13th century, indicating that the architects of that period also relied on iron reinforcements.
As for the iron itself, the metal analysis showed that the iron alloys used to make the staples were common to the Middle Ages and of similar quality to those found at Chartres, Troyes, and similar cathedrals. What makes the Notre Dame staples unusual is the presence of welding lines, indicating that several pieces of iron of different provenances were welded together to form each staple. Tracking those supply sources could shed light on the iron trade, circulation, and forging in 12th and 13th century Paris.
“Compared to other cathedrals, such as Reims, the structure of Notre Dame in Paris is light and elegant,” Jennifer Feltman of the University of Alabama, who was not involved in the research, told New Scientist. “This study confirms that use of iron made this lighter structure at Paris possible and thus the use of this material was crucial to the design of the first Gothic architect of Notre Dame.”
Enlarge / Daniel Simons and Christopher Chabris are the authors of Nobody’s Fool: Why We Get Taken In and What We Can Do About It.
Basic Books
There’s rarely time to write about every cool science-y story that comes our way. So this year, we’re once again running a special Twelve Days of Christmas series of posts, highlighting one science story that fell through the cracks in 2023, each day from December 25 through January 5. Today: A conversation with psychologists Daniel Simons and Christopher Chabris on the key habits of thinking and reasoning that may serve us well most of the time, but can make us vulnerable to being fooled.
It’s one of the most famous experiments in psychology. Back in 1999, Daniel Simons and Christopher Chabris conducted an experiment on inattentional blindness. They asked test subjects to watch a short video in which six people—half in white T-shirts, half in black ones—passed basketballs around. The subjects were asked to count the number of passes made by the people in white shirts. Halfway through the video, a person in a gorilla suit walked into the midst of the players and thumped their chest at the camera before strolling off-screen. What surprised the researchers was that fully half the test subjects were so busy counting the number of basketball passes that they never saw the gorilla.
The experiment became a viral sensation—helped by the amusing paper title, “Gorillas in Our Midst“—and snagged Simons and Chabris the 2004 Ig Nobel Psychology Prize. It also became the basis of their bestselling 2010 book, The Invisible Gorilla: How Our Intuitions Deceive Us. Thirteen years later, the two psychologists are back with their latest book, published last July, called Nobody’s Fool: Why We Get Taken In and What We Can Do About It. Simons and Chabris have penned an entertaining examination of key habits of thinking that usually serve us well but also make us vulnerable to cons and scams. They also offer some practical tools based on cognitive science to help us spot deceptions before being taken in.
“People love reading about cons, yet they keep happening,” Simons told Ars. “Why do they keep happening? What is it those cons are tapping into? Why do we not learn from reading about Theranos? We realized there was a set of cognitive principles that seemed to apply across all of the domains, from cheating in sports and chess to cheating in finance and biotech. That became our organizing theme.”
Ars spoke with Simons and Chabris to learn more.
Ars Technica: I was surprised to learn that people still fall for basic scams like the Nigerian Prince scam. It reminds me of Fox Mulder’s poster on The X-Files: “I want to believe.“
Daniel Simons: The Nigerian Prince scam is an interesting one because it’s been around forever. Its original form was in letters. Most people don’t get fooled by that one. The vast majority of people look at it and say, this thing is written in terrible grammar. It’s a mess. And why would anybody believe that they’re the one to recover this vast fortune? So there are some people who fall for it, but it’s a tiny percentage of people. I think it’s still illustrative because that one is obviously too good to be true for most people, but there’s some small subset of people for whom it’s just good enough. It’s just appealing enough to say, “Oh yeah, maybe I could become rich.”
There was a profile in the New Yorker of a clinical psychologist who fell for it. There are people who, for whatever reason, are either desperate or have the idea that they deserve to inherit a lot of money. But there are a lot of scams that are much less obvious than that one, selecting for the people who are most naive about it. I think the key insight there is that we tend to assume that only gullible people fall for this stuff. That is fundamentally wrong. We all fall for this stuff if it’s framed in the right way.
Christopher Chabris: I don’t think they’re necessarily people who always want to believe. I think it really depends on the situation. Some people might want to believe that they can strike it rich in crypto, but they would never fall for a Nigerian email or, for that matter, they might not fall for a traditional Ponzi scheme because they don’t believe in fiat money or the stock market. Going back to the Invisible Gorilla, one thing we noticed was a lot of people would ask us, “What’s the difference between the people who noticed the gorilla and the people who didn’t notice the gorilla?” The answer is, well, some of them happened to notice it and some of them didn’t. It’s not an IQ or personality test. So in the case of the Nigerian email, there might’ve been something going on in that guy’s life at that moment when he got that email that maybe led him to initially accept the premise as true, even though he knew it seemed kind of weird. Then, he got committed to the idea once he started interacting with these people.
Christopher Chabris
So one of our principles is commitment: the idea that if you accept something as true and you don’t question it anymore, then all kinds of bad decisions and bad outcomes can flow from that. So, if you somehow actually get convinced that these guys in Nigeria are real, that can explain the bad decisions you make after that. I think there’s a lot of unpredictableness about it. We all need to understand how these things work. We might think it sounds crazy and we would never fall for it, but we might if it was a different scam at a different time.
What draws us to choose romantic partners? A sweeping new meta-analysis suggests we gravitate toward certain shared traits.
There’s rarely time to write about every cool science-y story that comes our way. So this year, we’re once again running a special Twelve Days of Christmas series of posts, highlighting one science story that fell through the cracks in 2023, each day from December 25 through January 5. Today: a broad meta-analysis spanning over a century of studies finds that opposites don’t really attract when it comes to choosing a mate.
We’ve all heard the common folk wisdom that when it comes to forming romantic partnerships, opposites attract. Researchers at the University of Colorado, Boulder, contend that this proverbial wisdom is largely false, based on the findings of their sweeping September study, published in the journal Nature Human Behavior. The saying, “birds of a feather flock together,” is a more apt summation of how we choose our partners.
“These findings suggest that even in situations where we feel like we have a choice about our relationships, there may be mechanisms happening behind the scenes of which we aren’t fully aware,” said co-author Tanya Horwitz, a psychology and neuroscience graduate student at UCB. “We’re hoping people can use this data to do their own analyses and learn more about how and why people end up in the relationships they do.”
Horwitz et al. conducted a systematic review of peer-reviewed studies in the English language involving comparisons of the same or similar complex traits in partners, all published before August 17, 2022, with the oldest dated 1903. They excluded same-sex/gender partners, maintaining that these partnerships warranted a separate analysis since the patterns could differ significantly. The meta-analysis focused on 22 distinct traits. The team also conducted a raw data analysis of an additional 133 traits, drawing from the UK’s Biobank dataset, one of the largest and most detailed in the world for health-related information on more than 500,000 people. All told, the study encompassed millions of couples spanning over a century: co-parents, engaged pairs, married pairs, and cohabitating pairs.
The personality traits included were based on the so-called Big Five basic personality traits: neuroticism, extraversion, openness, agreeableness, and conscientiousness. (The Big Five is currently the professional standard for social psychologists who study personality. Here’s a good summary of what those traits mean to psychologists.) The other traits studied included such things as educational attainment, IQ score, political values, religiosity, problematic alcohol use, drinking, quitting smoking, starting smoking, quantity of smoking, smoker status, substance use disorder, BMI, height, waist-to-hip ratio, depression, diabetes, generalized anxiety, whether they were breastfed as a child, and age of first intercourse, among others.
The meta-analysis and Biobank analysis revealed that the strongest correlations for couples were for birth year and traits like political and religious attitudes, educational attainment, and certain IQ measures. Couples tend to be similar when it comes to their substance use, too: heavy drinkers tend to be with other heavy drinkers, and teetotalers tend to pair with fellow teetotalers. There were a handful of traits among the Biobank couples where opposites did seem to attract, most notably whether one is a morning person or a night owl, tendency to worry, and hearing difficulty.
The weakest correlations were for traits like height, weight, medical conditions, and personality traits, although these were still mostly positive, apart from extroversion, which somewhat surprisingly showed almost no correlation. “People have all these theories that extroverts like introverts or extroverts like other extroverts, but the fact of the matter is that it’s about like flipping a coin,” said Horwitz. “Extroverts are similarly likely to end up with extroverts as with introverts.”
Horwitz et al. cautioned that even the strongest correlations they found were still fairly modest. As for why couples show such striking similarities, the authors write that there could be many reasons. Some people might just be attracted to similar sorts, or couples might become more similar over time. (The study also found that the strength of the correlations changed over time.) Perhaps two people who grow up in the same geographical area or a similar home environment might naturally find themselves drawn to each other.
The authors were careful to note several limitations to their meta-analysis. Most notably, most of those partners sampled came from Europe and the United States, with only a handful coming from East and South Asia, Africa, Latin America, and the Caribbean. Furthermore, all participants in the UK Biobank dataset were between the ages of 40 and 69 when they were originally recruited, all of whom were less likely to smoke, be socioeconomically deprived, or drink daily. The studies included in the meta-analysis also varied widely regarding sample sizes used to draw correlations across traits. For these reasons, the authors caution that their findings “are unlikely to be generalizable to all human populations and time periods.”
There’s rarely time to write about every cool science-y story that comes our way. So this year, we’re once again running a special Twelve Days of Christmas series of posts, highlighting one science story that fell through the cracks in 2020, each day from December 25 through January 5. Today: Archaeologists found two stone engravings in Jordan and Saudi Arabia that may represent the oldest architectural plans for desert kites.
During the 1920s, aerial photographs revealed the presence of large kite-shaped stone wall mega-structures in deserts in Asia and the Middle East that most archaeologists believe were used to herd and trap wild animals. More than 6,000 of these “desert kites” have been identified as of 2018, although very few have been excavated. Archaeologists found two stone engravings—one in Jordan, the other in Saudi Arabia—that they believe represent the oldest architectural plans for these desert kites, according to a May paper published in the journal PLoS ONE.
“The discovery of these very ancient representations highlights the question of the methods used by kite builders,” the authors wrote. “Kites are large material structures that could not be designed without what we call today planning. The ability to transpose large spaces into a small two-dimensional surface represents a milestone in intelligent behavior. Such structures are visible as a whole only from the air, yet this calls for the representation of space in a way not seen at this time.”
The eight kites at Jibal al-Khashabiyeh in Jordan were discovered in 2013, and archaeologists began excavations in 2015 and 2016. Looters had targeted one such site, so archaeologists conducted a rescue excavation, noting numerous carved cigar-shaped limestones scattered around the surface. One such stone had a very well-preserved engraving. The engraving’s shape is characteristic of the two desert kites at Jibal al-Khashabiyeh that are nearest to where the engraved rock was found, and the authors estimate the age of the engraving to be about 7,000 years old.
The engraving was likely carved with a lithic tool, employing a combination of fine incisions to mark out the contours of the kite and pecking. The kite-shaped engraving comprises two primary converging curved lines, which the researchers interpreted as representing driving lines. These lead to a carved star-shaped enclosure with eight circular cup marks at the circumference representing pit traps. The characteristics are typical of desert kite structures in southeastern Jordanian kites. The archaeologists remain puzzled by a zigzagging chevron pattern running perpendicular to the corridor, but hypothesize that it might represent a slope break feature.
The kites at Jebel az-Zilliyat in Saudi Arabia were discovered in 2014 and excavated the following year. The engraved sandstone boulder in this case—found during rock art surveys—was studied in situ and dated to around 8,000 years ago. The carving was likely made by pecking the contours using a lithic tool or a handpick. While the eastern engraving on the boulder was very readable, the western one had been badly damaged by erosion. Both feature the same two short, widely spaced driving lines that gradually converge into a star-shaped enclosed surface surrounded by six cup marks (pit traps). Once again, the authors noted clear similarities between the engraved representations of kites on the boulder and actual desert kite shapes nearby.
There have been other maps, plans, or representations in human history, per the authors, such as Upper Paleolithic engravings in Europe that seem to be maps of hunting strategies, or a mural in Turkey from about 6600 BCE that seems to depict a village. There is even a reed-bundle boat found in Kuwait, dated 5000 BCE, that is considered to be the oldest three-dimensional model of a large-scale object. However, the two engravings found in Jordan and Saudi Arabia are unique because they were done to scale: approximately 1: 425 and 1: 175, respectively.
As for why the engravings were made, the authors considered three hypotheses: it was a detailed kite construction plan; it was a plan for preparing hunting activities; or it could be more symbolic—a means of passing on knowledge of the pace and/or its function. Of those, the authors consider the second to be the most credible, given the careful graphical representation of the functional elements of the trap, but cannot rule out the other two possibilities.
“A map would most probably be used here as a means of communication (almost like an ancestral way of writing) and would enable the collective interaction required for the smooth running of hunting operations,” the authors concluded. “These two major innovations, i.e., building what would become the largest structures in human history at that time and making cartographic representations to scale, are closely linked by a common point: mastering the three-dimensional perception of a space, and translating it into an inscribed form of communication.”
There’s rarely time to write about every cool science-y story that comes our way. So this year, we’re once again running a special Twelve Days of Christmas series of posts, highlighting one science story that fell through the cracks in 2020, each day from December 25 through January 5. Today: Using markerless motion capture technology to determine what makes the best free throw shooters in basketball.
Markerless motion-capture technology shows the biomechanics of free-throw shooters. Credit: Jayhawk Athletic Peformance Laboratory.
Basketball season is in full swing, and in a close game, the team that makes the highest percentage of free throws can often eke out the win. A better understanding of the precise biomechanics of the best free-throw shooters could translate into critical player-performance improvement. Researchers at the University of Kansas in Lawrence used markerless motion-capture technology to do just that, reporting their findings in an August paper published in the journal Frontiers in Sports and Active Living.
“We’re very interested in analyzing basketball shooting mechanics and what performance parameters differentiate proficient from nonproficient shooters,” said co-author Dimitrije Cabarkapa, director of the Jayhawk Athletic Performance Laboratory at the University of Kansas. “High-speed video analysis is one way that we can do that, but innovative technological tools such as markerless motion capture systems can allow us to dig even deeper into that. In my opinion, the future of sports science is founded on using noninvasive and time-efficient testing methodologies.”
Scientists are sports fans like everyone else, so it’s not surprising that a fair amount of prior research has gone into various aspects of basketball. For instance, there has been considerable debate on whether the “hot hand” phenomenon in basketball is a fallacy or not—that is, when players make more shots in a row than statistics suggest they should. A 1985 study proclaimed it a fallacy, but more recent mathematical analysis (including a 2015 study examining the finer points of the law of small numbers) from other researchers has provided some vindication that such streaks might indeed be a real thing, although it might only apply to certain players.
Some 20 years ago, Larry Silverberg and Chia Tran of North Carolina State University developed a method to computationally simulate the trajectories of millions of basketballs on the computer and used it to examine the mathematics of the free throw. Per their work, in a perfect free throw, the basketball has a 3 hertz backspin as it leaves the player’s fingertips, the launch is about 52 degrees, and the launch speed is fairly slow, ensuring the greatest probability of making the basket. Of those variables launch speed is the most difficult for players to control. The aim point also matters: Players should aim at the back of the rim, which is more forgiving than the front.
There was also a 2021 study by Malaysian scientists that analyzed the optimal angle of a basketball free throw, based on data gleaned from 30 NBA players. They concluded that a player’s height is inversely proportional to the initial velocity and optimal throwing angle, and that the latter is directly proportional to the time taken for a ball to reach its maximum height.
Enlarge/ Graphic showing the contrast in release angles between proficient and nonproficient shooters.
Jayhawk Athletic Performance Laboratory.
Cabarkapa’s lab has been studying basketball players’ performance for several years now, including how eating breakfast (or not) impacts shooting performance, and what happens to muscles when players overtrain. They published a series of studies in 2022 assessing the effectiveness of the most common coaching cues, like “bend your knees,” “tuck your elbow in,” or “release the ball as high as possible.” For one study, Cabarkapa et al. analyzed high-definition video of free-throw shooters for kinematic differences between players who excel at free throws and those who don’t. The results pointed to greater flexion in hip, knee, and angle joints resulting in lower elbow placement when shooting.
Yet they found no kinematic differences in shots that proficient players made and those they missed, so the team conducted a follow-up study employing a 3D motion-capture system. This confirmed that greater knee and elbow flexion and lower elbow placement were critical factors. There was only one significant difference between made and missed free-throw shots: positioning the forearm almost parallel with an imaginary lateral axis.
There’s rarely time to write about every cool science-y story that comes our way. So this year, we’re once again running a special Twelve Days of Christmas series of posts, highlighting one science story that fell through the cracks in 2020, each day from December 25 through January 5. Today: Archaeologists relied on chemical clues and techniques like FTIR spectroscopy and archaeomagnetic analysis to reconstruct the burning of Jerusalem by Babylonian forces around 586 BCE.
Archaeologists have uncovered new evidence in support of Biblical accounts of the siege and burning of the city of Jerusalem by the Babylonians around 586 BCE, according to a September paper published in the Journal of Archaeological Science.
The Hebrew bible contains the only account of this momentous event, which included the destruction of Solomon’s Temple. “The Babylonian chronicles from these years were not preserved,” co-author Nitsan Shalom of Tel Aviv University in Israel told New Scientist. According to the biblical account, “There was a violent and complete destruction, the whole city was burned and it stayed completely empty, like the descriptions you see in [the Book of] Lamentations about the city deserted and in complete misery.”
Judah was a vassal kingdom of Babylon during the late 7th century BCE, under the rule of Nebuchadnezzar II. This did not sit well with Judah’s king, Jehoiakim, who revolted against the Babylonian king in 601 BCE despite being warned not to do so by the prophet Jeremiah. He stopped paying the required tribute and sided with Egypt when Nebuchadnezzar tried (and failed) to in invade that country. Jehoiakim died and his son Jeconiah succeeded him when Nebuchadnezzar’s forces besieged Jerusalem in 597 BCE. The city was pillaged and Jeconiah surrendered and was deported to Babylon for his trouble, along with a substantial portion of Judah’s population. (The Book of Kings puts the number at 10,000.) His uncle Zedekiah became king of Judah.
Zedekiah also chafed under Babylonian rule and revolted in turn, refusing to pay the required tribute and seeking alliance with the Egyptian pharaoh Hophra. This resulted in a brutal 30-month siege by Nebuchadnezzar’s forces against Judah and its capital, Jerusalem. Eventually the Babylonians prevailed again, breaking through the city walls to conquer Jerusalem. Zedekiah was forced to watch his sons killed and was then blinded, bound, and taken to Babylon as a prisoner. This time Nebuchadnezzar was less merciful and ordered his troops to completely destroy Jerusalem and pull down the wall around 586 BCE.
There is archaeological evidence to support the account of the city being destroyed by fire, along with nearby villages and towns on the western border. Three residential structures were excavated between 1978 and 1982 and found to contain burned wooden beams dating to around 586 BCE. Archaeologists also found ash and burned wooden beams from the same time period when they excavated several structures at the Giv’ati Parking Lot archaeological site, close to the assumed location of Solomon’s Temple. Samples taken from a plaster floor showed exposure to high temperatures of at least 600 degrees Celsius
Enlarge/ Aerial view of the excavation site in Jerusalem, at the foot of the Temple Mount
Assaf Peretz/Israel Antiquities Authority
However, it wasn’t possible to determine from that evidence whether the fires were intentional or accidental, or where the fire started if it was indeed intentional. For this latest research, Shalom and her colleagues focused on the two-story Building 100 at the Giv’ati Parking Lot site. They used Fourier transform infrared (FTIR) spectroscopy—which measures the absorption of infrared light to determine to what degree a sample had been heated—and archaeomagnetic analysis, which determines whether samples containing magnetic minerals were sufficiently heated to reorient those compounds to a new magnetic north.
The analysis revealed varying degrees of exposure to high-temperature fire in three rooms (designated A, B, and C) on the bottom level of Building 100, with Room C showing the most obvious evidence. This might have been a sign that Room C was the ignition point, but there was no fire path; the burning of Room C appeared to be isolated. Combined with an earlier 2020 study on segments of the second level of the building, the authors concluded that several fires were lit in the building and the fires burned strongest in the upper floors, except for that “intense local fire” in Room C on the first level.
“When a structure burns, heat rises and is concentrated below the ceiling,” the authors wrote. “The walls and roof are therefore heated to higher temperatures than the floor.” The presence of charred beams on the floors suggest this was indeed the case: most of the heat rose to the ceiling, burning the beams until they collapsed to the floors, which otherwise were subjected to radiant heat. But the extent of the debris was likely not caused just by that collapse, suggesting that the Babylonians deliberately went back in and knocked down any remaining walls.
Furthermore, “They targeted the more important, the more famous buildings in the city,” Shalom told New Scientist, rather than destroying everything indiscriminately. “2600 years later, we’re still mourning the temple.”
While they found no evidence of additional fuels that might have served as accelerants, “we may assume the fire was intentionally ignited due to its widespread presence in all rooms and both stories of the building,” Shalom et al. concluded. “The finds within the rooms indicate there was enough flammable material (vegetal and wooden items and construction material) to make additional fuel unnecessary. The widespread presence of charred remains suggests a deliberate destruction by fire…. [T]he spread of the fire and the rapid collapse of the building indicate that the destroyers invested great efforts to completely demolish the building and take it out of use.”
There’s rarely time to write about every cool science-y story that comes our way. So this year, we’re once again running a special Twelve Days of Christmas series of posts, highlighting one science story that fell through the cracks in 2020, each day from December 25 through January 5. Today: Pirates! Specifically, an interview with historian Rebecca Simon on the real-life buccaneer bylaws that shaped every aspect of a pirate’s life.
One of the many amusing scenes in the 2003 film Pirates of the Caribbean: The Curse of the Black Pearl depicts Elizabeth Swann (Keira Knightley) invoking the concept of “parley” in the pirate code to negotiate a cease of hostilities with pirate captain Hector Barbossa (Geoffrey Rush). “The code is more what you’d call guidelines than actual rules,” he informs her. Rebecca Simon, a historian at Santa Monica College, delves into the real, historical set of rules and bylaws that shaped every aspect of a pirate’s life with her latest book. The Pirates’ Code: Laws and Life Aboard Ship.
Simon is the author of such books as Why We Love Pirates: The Hunt for Captain Kidd and How He Changed Piracy Forever and Pirate Queens: The Lives of Anne Bonny and Mary Read. Her PhD thesis research focused on pirate trails and punishment. She had been reading a book about Captain Kidd and the war against the pirates, and was curious as to why he had been executed in an East London neighborhood called Wapping, at Execution Dock on the Thames. People were usually hung at Tyburn in modern day West London at Marble Arch. “Why was Captain Kidd taken to a different place? What was special about that?” Simon told Ars. “Nothing had been written much about it at all, especially in connection to piracy. So I began researching how pirate trials and executions were done in London. I consider myself to be a legal historian of crime and punishment through the lens of piracy.”
Enlarge/ (left) Fanciful painting of Kidd and his ship, Adventure Galley, in New York Harbor. (right) Captain Kidd, gibbeted near Tilbury in Essex following his execution in 1701.
Public domain
Ars Technica: How did the idea of a pirates’ code come about?
Rebecca Simon: Two of the pirates that I mention in the book—Ned Low and Bartholomew Roberts—their code was actually published in newspapers in London. I don’t where they got it. Maybe it was made up for the sake of readership because that is getting towards the tail end of the Golden Age of Piracy, the 1720s. But we find examples of other codes in A General History of the Pyrates written by a man named Captain Charles Johnson in 1724. It included many pirate biographies and a lot of it was very largely fictionalized. So we take it with a grain of salt. But we do know that pirates did have a notion of law and order and regulations and ritual based on survivor accounts.
You had to be very organized. You had to have very specific rules because as a pirate, you’re facing death every second of the day, more so than if you are a merchant or a fisherman or a member of the Royal Navy. Pirates go out and attack to get the goods that they want. In order to survive all that, they have to be very meticulously prepared. Everyone has to know their exact role and everyone has to have a game plan going in. Pirates didn’t attack willy-nilly out of control. No way. They all had a role.
Ars Technica: Is it challenging to find primary sources about this? You rely a lot trial transcripts, as well as eyewitness accounts and maritime logs.
Rebecca Simon: It’s probably one of the best ways to learn about how pirates lived on the ship, especially through their own words, because pirates didn’t leave records. These trial transcripts were literal transcriptions of the back and forth between the lawyer and the pirate, answering very specific questions in very specific detail. They were transcribed verbatim and they sold for profit. People found them very interesting. It’s really the only place where we really get to hear the pirate’s voice. So to me that was always one of the best ways to find information about pirates, because anything else you’re looking at is the background or the periphery around the pirates: arrest records, or observations of how the pirate seemed to be acting and what the pirate said. We have to take that with a grain of salt because we’re only hearing it from a third party.
Ars Technica: Some of the pirate codes seemed surprisingly democratic. They divided the spoils equally according to rank, so there was a social hierarchy. But there was also a sense of fairness.
Rebecca Simon: You needed to have a sense of order on a pirate ship. One of the big draws that pirates used to recruit hostages to officially join them into piracy was to tell them they’d get an equal share. This was quite rare on many other ships. where payment was based per person, or maybe just a flat rate across the board. A lot of times your wages might get withheld or you wouldn’t necessarily get the wages you were promised. On a pirate ship, everyone had the amount of money they were going to get based on the hierarchy and based on their skill level. The quartermaster was in charge of doling out all of the spoils or the stolen goods. If someone was caught taking more of their share, that was a huge deal.
You could get very severely punished perhaps by marooning or being jailed below the hold. The punishment had to be decided by the whole crew, so it didn’t seem like the captain was being unfair or overly brutal. Pirates could also vote out their captain if they felt the captain was doing a bad job, such as not going after enough ships, taking too much of his share, being too harsh in punishment, or not listening to the crew. Again, this is all to keep order. You had to keep morale very high, you had to make sure there was very little discontent or infighting.
Enlarge/ “The code is more like guidelines than actual rules”: Geoffrey Rush as Captain Hector Barbossa in Pirates of the Caribbean: The Curse of the Black Pearl (2003).
Walt Disney Pictures
Ars Technica: Pirates have long been quite prominent in popular culture. What explains their enduring appeal?
Rebecca Simon: During the 1700s, when pirates were very active, they fascinated people in London and England because they were very far removed from piracy, more so than those who traded a lot for a living in North America and the Caribbean. But it used to be that you were born into your social class and there was no social mobility. You’re born poor because your father was poor, your grandfather was poor, your children will be poor, your grandchildren will be poor. Most pirates started out as poor sailors but as pirates they could become wealthy. If a pirate was lucky, they could make enough in one or two years and then retire and live comfortably. People also have a morbid fascination for these brutal people committing crimes. Think about all the true crime podcasts and true crime documentaries on virtually every streaming service today. We’re just attracted to that. It was the same with piracy.
Going into the 19th century, we have the publication of the book Treasure Island, an adventure story harking back to this idea of piracy in a way that generations hadn’t seen before. This is during a time period where there was sort of a longing for adventure in general and Treasure Island fed into this. That is what spawned the pop culture pirate going into the 20th century. Everything people know about pirates, for the most part, they’re getting from Treasure Island. The whole treasure map, X marks the spot, the eye patch, the peg leg, the speech. Pirate popularity has ebbed and flowed in the 20th and 21st centuries. Of course, the Pirates of the Caribbean franchise was a smash hit. And I think during the pandemic, people were feeling very confined and upset with leadership. Pirates were appealing because they cast all that off and we got shows like Black Sails and Our Flag Means Death.
Ars Technica: Much of what you do is separate fact from fiction, such as the legend of Captain Kidd’s buried treasure. What are some of the common misconceptions that you find yourself correcting, besides buried treasure?
Rebecca Simon: A lot of people ask me about the pirate accent: “Aaarr matey!” That accent we think of comes from the actor Robert Newton who played Long John Silver in the 1950 film Treasure Island. In reality, it just depended on where they were born. At the end of the day, pirates were sailors. People ask about what they wore, what they ate, thinking it’s somehow different. But the reality is it was the same as other sailors. They might have had better clothes and better food because of how often they robbed other ships.
Another misconception is that pirates were after gold and jewels and treasure. In the 17th and 18th centuries, “treasure” just meant “valuable.” They wanted goods they could sell. So about 50 percent was stuff they kept to replenish their own ship and their stores. The other 50 percent were goods they could sell: textiles, wine, rum, sugar, and (unfortunately) the occasional enslaved person counted as cargo. There’s also a big misconception that pirates were all about championing the downtrodden:they hated slavery and they freed enslaved people. They hated corrupt authority. That’s not the reality. They were still people of their time. Blackbeard, aka Edward Teach, did capture a slave ship and he did include those slaves in his crew. But he later sold them at a slave port.
Enlarge/ Female pirates Anne Bonny and Mary Read were a deadly duo who plundered their way to infamy.
Public domain
Thanks to Our Flag Means Death and Black Sails, people sometimes assume that all pirates were gay or bisexual. That’s also not true. The concept of homosexuality as we think of it just didn’t exist back then. It was more situational homosexuality arising from confined close quarters and being very isolated for a long period of time. And it definitely was not all pirates. There was about the same percentage of gay or bisexual pirates as your own workplace, but it was not discussed and it was considered to be a crime. There’s this idea that pirate ships had gay marriage; that wasn’t necessarily a thing. They practiced something called matelotage, a formal agreement where you would be legally paired with someone because if they died, it was a way to ensure their goods went to somebody. It was like a civil union. Were some of these done romantically? It’s possible. We just don’t know because that sort of stuff was never, ever recorded.
Ars Technica: Your prior book, Pirate Queens, focused on female pirates like Anne Bonny and Mary Read. It must have been challenging for a woman to pass herself off as a man on a pirate ship.
Rebecca Simon: You’d have to take everything in consideration, the way you dressed, the way you walked, the way you talked. A lot of women who would be on a pirate ship were probably very wiry, having been maids who hauled buckets of coal and water and goods and did a lot of physical activity all day. They could probably pass themselves off as boys or adolescents who were not growing facial hair. So it probably wasn’t too difficult. Going to the bathroom was a a big thing. Men would pee over the edge of the ship. How’s a woman going to do this? You put a funnel under the pirate dress and pee through the funnel, which can create a stream going over the side of the ship. When it’s really crowded, men aren’t exactly going to be looking at that very carefully.
The idea of Anne Bonny and Mary Read being lesbians is a 20th century concept, originating with an essay by a feminist writer in the 1970s. There’s no evidence for it. There’s no historical documentation about them before they entered into piracy. According to Captain Charles Johnson’s highly fictionalized account, Mary disguised herself as a male sailor. Anne fell in love with this male sailor on the ship and tried to seduce him, only to discover he was a woman. Anne was “disappointed.” There’s no mention of Anne and Mary actually getting together. Anne was the lover of Calico Jack Rackham, Mary was married to a crew member. This was stated in the trial. And when both women were put on trial and found guilty of piracy, they both revealed they were pregnant.
Enlarge/ Rebecca Simon is the author of The Pirates’ Code: Laws and Life Aboard Ships/
University of Chicago Press/Rebecca Simon
Ars Technica: Pirates had notoriously short careers: about two years on average. Why would they undertake all that risk for such a short time?
Rebecca Simon: There’s the idea that you can get wealthy quickly. There were a lot of people who became pirates because they had no other choice. Maybe they were criminals or work was not available to them. Pirate ships were extremely diverse. You did have black people as crew members, maybe freed enslaved or escaped enslaved people. They usually had the most menial jobs, but they did exist on ships. Some actively chose it because working conditions on merchant ships and naval ships were very tough and they didn’t always have access to good food or medical care. And many people were forced into it, captured as hostages to replace pirates who had been killed in battle.
Ars Technica: What were the factors that led to the end of what we call the Golden Age of Piracy?
Rebecca Simon: There were several reasons why piracy really began to die down in the 1720s. One was an increase in the Royal Navy presence so the seas were a lot more heavily patrolled and it was becoming more difficult to make a living as a pirate. Colonial governors and colonists were no longer supporting pirates the way they once had, so a lot of pirates were now losing their alliances and protections. A lot of major pirate leaders who had been veterans of the War of the Spanish Succession as privateers had been killed in battle by the 1720s: people like Charles Vane, Edward Teach, Benjamin Hornigold, Henry Jennings, and Sam Bellamy.
It was just becoming too risky. And by 1730 a lot more wars were breaking out, which required people who could sail and fight. Pirates were offered pardons if they agreed to become a privateer, basically a government-sanctioned mercenary at sea where they were contracted to attack specific enemies. As payment they got to keep about 80 percent of what they stole. A lot of pirates decided that was more lucrative and more stable.
Ars Technica: What was the most surprising thing that you learned while you were researching and writing this book?
Rebecca Simon: Stuff about food, oddly enough. I was really surprised by how much people went after turtles as food. Apparently turtles are very high in vitamin C and had long been believed to cure all kinds of illnesses and impotence. Also, pirates weren’t really religious, but Bartholomew Roberts would dock at shore so his crew could celebrate Christmas—perhaps as an appeasement. When pirates were put on trial, they always said they were forced into it. The lawyers would ask if they took their share after the battle ended. If they said yes, the law deemed them a pirate. You therefore participated; it doesn’t matter if they forced you. Finally, my PhD thesis was on crime and the law and executions. People would ask me about ships but I didn’t study ships at all. So this book really branched out my maritime knowledge and helped me understand how ships worked and how the people on board operated.
Enlarge/ The bundengan (left) began as a combined shelter/instrument for duck hunters but it is now often played onstage.
There’s rarely time to write about every cool science-y story that comes our way. So this year, we’re once again running a special Twelve Days of Christmas series of posts, highlighting one science story that fell through the cracks in 2020, each day from December 25 through January 5. Today: the surprisingly complex physics of two simply constructed instruments: the Indonesian bundengan and the Australian Aboriginal didgeridoo (or didjeridu).
The bundengan is a rare, endangered instrument from Indonesia that can imitate the sound of metallic gongs and cow-hide drums (kendangs) in a traditional gamelan ensemble. The didgeridoo is an iconic instrument associated with Australian Aboriginal culture that produces a single, low-pitched droning note that can be continuously sustained by skilled players. Both instruments are a topic of scientific interest because their relatively simple construction produces some surprisingly complicated physics. Two recent studies into their acoustical properties were featured at an early December meeting of the Acoustical Society of America, held in Sydney, Australia, in conjunction with the Australian Acoustical Society.
The bundengan originated with Indonesian duck hunters as protection from rain and other adverse conditions while in the field, doubling as a musical instrument to pass the time. It’s a half-dome structure woven out of bamboo splits to form a lattice grid, crisscrossed at the top to form the dome. That dome is then coated with layers of bamboo sheaths held in place with sugar palm fibers. Musicians typically sit cross-legged inside the dome-shaped resonator and pluck the strings and bars to play. The strings produce metallic sounds while the plates inside generate percussive drum-like sounds.
Gea Oswah Fatah Parikesit of Universitas Gadja Mada in Indonesia has been studying the physics and acoustics of the bundengan for several years now. And yes, he can play the instrument. “I needed to learn to do the research,” he said during a conference press briefing. “It’s very difficult because you have two different blocking styles for the right and left hand sides. The right hand is for the melody, for the string, and the left is for the rhythm, to pluck the chords.”
Much of Parikesit’s prior research on the bundengan focused on the unusual metal/percussive sound of the strings, especially the critical role played by the placement of bamboo clips. He used computational simulations of the string vibrations to glean insight on how the specific gong-like sound was produced, and how those vibrations change with the addition of bamboo clips located at different sections of the string. He found that adding the clips produces two vibrations of different frequencies at different locations on the string, with the longer section having a high frequency vibration compared to the lower frequency vibration of the shorter part of the string. This is the key to making the gong-like sound.
This time around, Parikesit was intrigued by the fact many bundengan musicians have noted the instrument sounds better wet. In fact, several years ago, Parikesit attended a bundengan concert in Melbourne during the summer when it was very hot and dry—so much so that the musicians brought their own water spray bottles to ensure the instruments stayed (preferably) fully wet.
Enlarge/ A bundengan is a portable shelter woven from bamboo, worn by Indonesian duck herders who often outfit it to double as a musical instrument.
Gea Oswah Fatah Parikesit
“A key element between the dry and wet versions of the bundengan is the bamboo sheaths—the material used to layer the wall of the instrument,” Parokesit said. “When the bundengan is dry, the bamboo sheaths open and that results in looser connections between neighboring sheaths. When the bundengan is wet, the sheaths tend to form a curling shape, but because they are held by ropes, they form tight connections between the neighboring sheaths.”
The resulting tension allows the sheaths to vibrate together. That has a significant impact on the instrument’s sound, taking on a “twangier” quality when dry and a more of metallic gong sound when it is wet. Parikesit has tried making bundengans with other materials: paper, leaves, even plastics. But none of those produce the same sound quality as the bamboo sheaths. He next plans to investigate other musical instruments made from bamboo sheaths.“As an Indonesian, I have extra motivation because the bundengan is a piece of our cultural heritage,” Parikesit said. “I am trying my best to support the conservation and documentation of the bundengan and other Indonesian endangered instruments.”
Coupling with the human vocal tract
Meanwhile, John Smith of the University of New South Wales is equally intrigued by the physics and acoustics of the didgeridoo. The instrument is constructed from the trunk or large branches of the eucalyptus tree. The trick is to find a live tree with lots of termite activity, such that the trunk has been hollowed out leaving just the living sapwood shell. A suitably hollow trunk is then cut down, cleaned out, the bark removed, the ends trimmed, and the exterior shaped into a long cylinder or cone to produce the final instrument. The longer the instrument, the lower the pitch or key.
Players will vibrate their lips to play the didgeridoo in a manner similar to lip valve instruments like trumpets or trombones, except those use a small mouthpiece attached to the instrument as an interface. (Sometimes a beeswax rim is added to a didgeridoo mouthpiece end.) Players typically use circular breathing to maintain that continuous low-pitched drone for several minutes, basically inhaling through the nose and using air stored in the puffed cheeks to keep producing the sound. It’s the coupling of the instrument with the human vocal tract that makes the physics so complex, per Smith.
Smith was interested in investigating how changes in the configuration of the vocal tract produced timbral changes in the rhythmic pattern of the sounds produced. To do so, “We needed to develop a technique that could measure the acoustic properties of the player’s vocal tract while playing,” Smith said during the same press briefing. “This involved injecting a broadband signal into the corner of the player’s mouth and using a microphone to record the response.” That enabled Smith and his cohorts to record the vocal tract impedance in different configurations in the mouth.
Enlarge/ Producing complex sounds with the didjeridu requires creating and manipulating resonances inside the vocal tract.
Kate Callas
The results: “We showed that strong resonances in the vocal tract can suppress bands of frequencies in the output sound,” said Smith. “The remaining strong bands of frequencies, called formants, are noticed by our hearing because they fall in the same ranges as the formants we use in speech. It’s a bit like a sculptor removing marble, and we observe the bits that are left behind.”
Smith et al. also noted that the variations in timbre arise from the player singing while playing, or imitating animal sounds (such as the dingo or the kookaburra), which produces many new frequencies in the output sound. To measure the contact between vocal folds, they placed electrodes on either side of a player’s throat and zapped them with a small high frequency electric current. They simultaneously measured lip movement with another pair of electrics above and below the lips. Both types of vibrations affect the flow of air to produce the new frequencies.
As for what makes a desirable didgeridoo that appeals to players, acoustic measurements on a set of 38 such instruments—with the quality of each rated by seven experts in seven different subjective categories—produced a rather surprising result. One might think players would prefer instruments with very strong resonances but the opposite turned out to be true. Instruments with stronger resonances were ranked the worst, while those with weaker resonances rated more highly. Smith, for one, thinks this makes sense. “This means that their own vocal tract resonance can dominate the timbre of the notes,” he said.
Enlarge/ The final approximation of the Incan girl dubbed “Juanita” wearing clothing similar to what she was wearing when she died.
Dagmara Socha
There’s rarely time to write about every cool science-y story that comes our way. So this year, we’re once again running a special Twelve Days of Christmas series of posts, highlighting one science story that fell through the cracks in 2023, each day from December 25 through January 5. Today: Swedish forensic artist Oscar Nilsson combined CT scans of frozen mummified remains with skull measurements and DNA analysis to reconstruct the face of a 500-year-old Inca girl.
In 1995, archaeologists discovered the frozen, mummified remains of a young Inca girl high in the mountains of Peru, thought to have died as part of a sacrificial ritual known as Capacocha (or Ohapaq hucha). In late October, we learned how she most likely looked in life, thanks to a detailed reconstruction by Swedish forensic article Oscar Nilsson. A plaster bust of the reconstruction was unveiled at a ceremony at the Andean Sanctuaries Museum of the Catholic University of Santa Maria in Arequipa, Peru, where the girl’s remains (now called Juanita) have been on near-continuous display since her discovery.
“I thought I’d never know what her face looked like when she was alive,” archaeologist Johan Reinhardt told the BBC. Reinhardt had found the remains with Peruvian mountaineer Miguel Zárate at an altitude of 21,000 feet (6,400 meters) during an expedition to Ampato, one of the highest volcanos in the Andes. “Now 28 years later, this has become a reality thanks to Oscar Nilsson’s reconstruction.”
According to Reinhardt, Spanish chroniclers made reference to the Inca practice of making offerings to the gods: not just statues, fine textiles, and ceramics, but also occasionally human sacrifices at ceremonial shrines (huacas) built high on mountain summits. It’s thought that human sacrifices of young girls and boys were a means of appeasing the Inca gods (Apus) during periods of irregular weather patterns, particularly drought. Drought was common in the wake of a volcanic eruption.
During those periods, the ground on summits would unfreeze sufficiently for the Incas to build their sites and bury their offerings. The altitude is one reason why various Inca mummified remains have been found in remarkable states of preservation.
Earlier discoveries included the remains of an Inca boy found by looters in the 1950s, as well as the frozen body of a young man in 1964 and that of a young boy in 1985. Then Reinhardt and Zárate made their Ampato ascent in September 1995. They were stunned to spot a mummy bundle on the ice just below the summit and realized they were looking at the frozen face of a young girl. The body was surrounded by offerings for the Inca gods, including llama bones, small carved figurines, and bits of pottery. Juanita was wrapped in a colorful burial tapestry and wearing a feathered cap and alpaca shawl, all almost perfectly preserved. Reinhardt and Zárate subsequently found two more ice mummies (a young boy and girl) the following month, and yet another female mummy in December 1997.
Enlarge/ Reconstructing the face of the Incan “ice maiden” took nearly 400 hours.
Oscar Nilsson
It was a bit of a struggle to get Juanita’s body down from the summit because it was so heavy, the result of its flesh being so thoroughly frozen. That’s also what makes it such an exciting archaeological find. The remains of meal of vegetables were in her well-reserved stomach, although DNA analysis from her hair showed that she also ate a fair amount of animal protein. That, and the high quality of her garments, suggested she came from a noble family, possibly from the city of Cusco.
There were also traces of coca and alcohol, likely administered before Juanita’s death—a common Inca practice when sacrificing children. A CT scan of her skull revealed that Juanita had died from a a sharp blow to the head, similar to the type of injury made by a baseball bat, causing a massive hemorrhage. This, too, was a common Inca sacrificial custom.
Nilsson was able to draw upon those earlier analyses for his reconstruction, since he needed to know things like her age, gender, weight, and ethnicity. He started with the CT scan of Juanita’s skull and used the data to 3D print a plastic replica of her head. He used wooden pegs on the bust to mark out the various measurements and added clay to mold the defining details of her face, drawing on clues from her nose, eye sockets, and teeth. The DNA indicated the likely color of her skin. “In Juanita’s case, I wanted her to look both scared and proud, and with a high sense of presence at the same time,” Nilsson told Live Science. “I then cast the face in silicone [using] real human hair [that I] inserted hair by hair.”
Enlarge / Who doesn’t thrill to the sight of a microscopic cross-section of a beetle’s rectum? You’re welcome.
Kenneth Veland Halberg
There’s rarely time to write about every cool science-y story that comes our way. So this year, we’re once again running a special Twelve Days of Christmas series of posts, highlighting one science story that fell through the cracks in 2023, each day from December 25 through January 5. Today: red flour beetles can use their butts to suck water from the air, helping them survive in extremely dry environments. Scientists are honing in on the molecular mechanisms behind this unique ability.
The humble red flour beetle (Tribolium castaneum) is a common pantry pest feeding on stored grains, flour, cereals, pasta, biscuits, beans, and nuts. It’s a remarkably hardy creature, capable of surviving in harsh arid environments due to its unique ability to extract fluid not just from grains and other food sources, but also from the air. It does this by opening its rectum when the humidity of the atmosphere is relatively high, absorbing moisture through that opening and converting it into fluid that is then used to hydrate the rest of the body.
Scientists have known about this ability for more than a century, but biologists are finally starting to get to the bottom (ahem) of the underlying molecular mechanisms, according to a March paper published in the Proceedings of the National Academies of Science. This will inform future research on how to interrupt this hydration process to better keep red flour beetle populations in check, since they are highly resistant to pesticides. They can also withstand even higher levels of radiation than the cockroach.
There are about 400,000 known species of beetle roaming the planet although scientists believe there could be well over a million. Each year, as much as 20 percent of the world’s grain stores are contaminated by red flour beetles, grain weevils, Colorado potato beetles, and confused flour beetles, particularly in developing countries. Red flour beetles in particular are a popular model organism for scientific research on development and functional genomics. The entire genome was sequenced in 2008, and the beetle shares between 10,000 and 15,000 genes with the fruit fly (Drosophila), another workhorse of genetics research. But the beetle’s development cycle more closely resembles that of other insects by comparison.
Enlarge/ Food security in developing nations is particularly affected by animal species like the red flour beetle which has specialized in surviving in extremely dry environments, granaries included, for thousands of years.
Kenneth Halberg
The rectums of most mammals and insects absorb any remaining nutrients and water from the body’s waste products prior to defecation. But the red flour beetle’s rectum is a model of ultra-efficiency in that regard. The beetle can generate extremely high salt concentrations in its kidneys, enabling it to extract all the water from its own feces and recycle that moisture back into its body.
“A beetle can go through an entire life cycle without drinking liquid water,” said co-author Kenneth Veland Halberg, a biologist at the University of Copenhagen. “This is because of their modified rectum and closely applied kidneys, which together make a multi-organ system that is highly specialized in extracting water from the food that they eat and from the air around them. In fact, it happens so effectively that the stool samples we have examined were completely dry and without any trace of water.” The entire rectal structure is encased in a perinephric membrane.
Halberg et al. took took scanning electron microscopy images of the beetle’s rectal structure. They also took tissue samples and extracted RNA from lab-grown red flour beetles, then used a new resource called BeetleAtlas for their gene expression analysis, hunting for any relevant genes.
One particular gene was expressed sixty times more in the rectum than any other. Halberg and his team eventually honed in a group of secondary cells between the beetle’s kidneys and circulatory system called leptophragmata. This finding supports prior studies that suggested these cells might be relevant since they are the only cells that interrupt the perinephric membrane, thereby enabling critical transport of potassium chloride. Translation: the cells pump salts into the kidneys to better harvest moisture from its feces or from the air.
Enlarge/ Model of the beetle’s inside and how it extracts water from the air.
Kenneth Halberg
The next step is to build on these new insights to figure out how to interrupt the beetle’s unique hydration process at the molecular level, perhaps by designing molecules that can do so. Those molecules could then be incorporated into more eco-friendly pesticides that target the red flour beetle and similar pests while not harming more beneficial insects like bees.
“Now we understand exactly which genes, cells and molecules are at play in the beetle when it absorbs water in its rectum. This means that we suddenly have a grip on how to disrupt these very efficient processes by, for example, developing insecticides that target this function and in doing so, kill the beetle,” said Halberg. “There is twenty times as much insect biomass on Earth than that of humans. They play key roles in most food webs and have a huge impact on virtually all ecosystems and on human health. So, we need to understand them better.”
There’s rarely time to write about every cool science-y story that comes our way. So this year, we’re once again running a special Twelve Days of Christmas series of posts, highlighting one science story that fell through the cracks in 2023, each day from December 25 through January 5. Today: how applying magnetic forces to individual “micro-roller” particles spurs collective motion, producing some pretty counter-intuitive results.
Enlarge/ Engineering researchers at Lehigh University have discovered that sometimes sand can actually flow uphill.
Lehigh University
We intuitively understand that the sand pouring through an hourglass, for example, forms a neat roughly pyramid-shaped pile at the bottom, in which the grains near the surface flow over an underlying base of stationary particles. Avalanches and sand dunes exhibit similar dynamics. But scientists at Lehigh University in Pennsylvania have discovered that applying a magnetic torque can actually cause sand-like particles to collectively flow uphill in seeming defiance of gravity, according to a September paper published in the journal Nature Communications.
Sand is pretty fascinating stuff from a physics standpoint. It’s an example of a granular material, since it acts both like a liquid and a solid. Dry sand collected in a bucket pours like a fluid, yet it can support the weight of a rock placed on top of it, like a solid, even though the rock is technically denser than the sand. So sand defies all those tidy equations describing various phases of matter, and the transition from flowing “liquid” to a rigid “solid” happens quite rapidly. It’s as if the grains act as individuals in the fluid form, but are capable of suddenly banding together when solidarity is needed, achieving a weird kind of “strength in numbers” effect.
Nor can physicists precisely predict an avalanche. That’s partly because of the sheer number of grains of sand in even a small pile, each of which will interact with several of its immediate neighboring grains simultaneously—and those neighbors shift from one moment to the next. Not even a supercomputer can track the movements of individual grains over time, so the physics of flow in granular media remains a vital area of research.
But grains of sand that collectively flow uphill? That is simply bizarre behavior. Lehigh University engineer James Gilchrist manages the Laboratory for Particle Mixing and Self-Organization and stumbled upon this odd phenomenon while experimenting with “micro-rollers”: polymer particles coated in iron oxide (a process called micro-encapsulation). He was rotating a magnet under a vial of micro-rollers one day and noticed they started to pile uphill. Naturally he and his colleagues had to investigate further.
For their experiments, Gilchrist et al. attached neodymium magnets to a motorized wheel at 90-degree intervals, alternating the outward facing poles. The apparatus also included a sample holder and a USB microscope in a fixed position. The micro-rollers were prepared by suspending them in a glass vial containing ethanol and using a magnet to separate them from dust or any uncoated particles. Once the micro-rollers were clean, they were dried, suspended in fresh ethanol, and loaded onto the sample holder. A vibrating motor agitated the samples to produce flattened granular beds, and the motorized wheel was set in motion to apply magnetic torque. A gaussmeter measured the magnetic field strength relative to orientation.
Uphill granular flow of microrobotic microrollers. Credit: Lehigh University.
The results: each micro-roller began to rotate in response to the magnetic torque, creating pairs that briefly formed and then split, and increasing the magnetic force increased the particle cohesion. This in turn gave the micro-rollers more traction and enabled them to move more quickly, working in concert to counterintuitively flow uphill. In the absence of that magnetic torque, the miro-rollers flowed downhill normally. The torque-induced action was so unexpected that the researchers coined a new term to describe it: a “negative angle of repose” caused by a negative coefficient of friction.
“Up until now, no one would have used these terms,” said Gilchrist. “They didn’t exist. But to understand how these grains are flowing uphill, we calculated what the stresses are that cause them to move in that direction. If you have a negative angle of repose, then you must have cohesion to give a negative coefficient of friction. These granular flow equations were never derived to consider these things, but after calculating it, what came out is an apparent coefficient of friction that is negative.”
It’s an intriguing proof of principle that could one day lead to new ways to control how substances mix or separate, as well as potential swarming microrobotics applications. The scientists have already started building tiny staircases with laser cutters and videotaping the micro-rollers climbing up and down the other. One micro-roller can’t overcome the height of each step, but many working collectively can do so, per Gilchrist.
Enlarge/ Shake, shake, shake: this adorable young child would love to guess what he’s getting for Christmas this year.
Johns Hopkins University
There’s rarely time to write about every cool science-y story that comes our way. So this year, we’re once again running a special Twelve Days of Christmas series of posts, highlighting one science story that fell through the cracks in 2023, each day from December 25 through January 5. Today: New research shows it’s incredibly easy for people watching others shake boxes to tell what they’re up to.
Christmas Day is a time for opening presents and finally ending the suspense of what one is receiving this year, but chances are some of us may have already guessed what’s under the wrapping—perhaps by strategically shaking the boxes for clues about its contents. According to a November paper published in the Proceedings of the National Academy of Sciences, if someone happened to see you shaking a wrapped gift, they would be able to tell from those motions what you were trying to learn by doing so.
“There are few things more delightful than seeing a child’s eyes light up as they pick up a present and wonder what might be inside,” said co-author Chaz Firestone of Johns Hopkins University, who studies how vision and thought interact. “What our work shows is that your mind is able to track the information they are seeking. Just as they might be able to tell what’s inside the box by shaking it around, you can tell what they are trying to figure out when they shake it.” Christmas presents are “the perfect real-life example of our experiment.”
According to Firestone et al., there is a large scientific literature devoted to studying how people represent and interpret basic actions like walking, reaching, lifting, eating, chasing, or following. It’s a vital ability that helps us anticipate the behavior of others. These are all examples of pragmatic actions with a specific aim, whether it be retrieving an object or moving from one place to the next. Other kinds of actions might be communication-oriented, such as waving, pointing, or assuming an aggressive (or friendly) posture.
The JHU study focused on so-called “epistemic” actions, in which one is seeking information: dipping a toe into the bathtub to see how hot is, for example, testing a door to see if it is locked, or shaking a wrapped box to glean information about what might be inside—like a child trying to guess whether a wrapped Christmas present contains Lego blocks or a teddy bear. “Epistemic actions pervade our lives, and recognizing them does, too,” the authors wrote, citing the ability to tell that a “meandering” campus visitor needs directions, or that someone rifling through shallow drawers is probably looking for keys or similar small objects.
People watched other people shake wrapped boxes for science.
For the first experiment, 16 players were asked to shake opaque boxes. In the first round, they tried to guess the number of objects inside the box (in this case, whether there were five or 15 US nickels). In the second, they tried to guess the shape of a geometric solid inside the box (either a sphere or a cube). All the players scored perfectly in both rounds—an expected outcome, given the simplicity of the task. The videos of those rounds were then placed online and 100 different study participants (“observers”) were asked to watch two videos of the same player and determine which video was from the first “guess the number” round and which was from the second “guess the shape” round. Almost all the observers guessed correctly.
This was intriguing evidence that the observers could indeed infer the goal of the shaking (what the game players were trying to learn) simply by interpreting their motions. But the researchers wondered to what extent the success of the observers relied on the game players’ success at guessing either the number or shape of objects. So they tweaked the box-shaking game to produce more player error. This time, the videotaped players were asked to determine first whether the box held 9, 12, or 16 nickels, and second, whether the box contained a sphere, cylinder, or cube. Only four out of 18 players guessed correctly. But the success rate of 100 new observers who watched the videos remained the same.
Firestone et al. ran three more variations on the basic experiment to refine their results. With each iteration, most of the players performed shaking motions that were different depending on whether the round involved numbers or shapes, and most of the observers (500 in total) successfully inferred what the players were trying to learn by watching those shaking motions. “When you think about all the mental calculations someone must make to understand what someone else is trying to learn, it’s a remarkably complicated process,” said Firestone. “But our findings show it’s something people do easily.”
