The world of physics is excited about strong but early evidence about the behavior of muons, paricles identical to electrons only 200x more massive (heavier), which once born take 2.2 microseconds to decay into an electron, and which spin like tops. In a new, extremely precise measurement, they were made to wobble using magnetic fields but they unexpectedly wobbled quite significantly faster than the Standard Model suggests they would. They might spin so fast due to an unknown force caused by an unknown particle, and this is what is so exciting.
“We found that a muon … is not in agreement with our current best theory of physics at the subatomic level, and … it potentially points to a future with new laws, new particles and new forces in physics which we haven’t seen to date,” said Professor Mark Lancaster at U of Manchester.
“The main goal of the experiment is to make the measurement and compare with the theory, and if they disagree then it’s telling us that there’s something in nature which is not in the theory,” explained James Mott at Fermilab.
The four known forces of nature (gravity, electricity, two nuclear forces: strong and weak interactions) have left scientists without an answer for some observed phenomena, such as the speed at which galaxies spin (faster than the best model suggests). Therefore, they continue to search for glitches in their already-tight models which might point them things they don’t yet know about.
The most recent work was done at Fermilab (Muon g-2 experiment), but a similar experiment was already done earlier at the Large Hadron Collider. These tools accelerate particles in large rings at close to the speed of light.
The evidence needs more tests for greater certainty, particularly to rule out the possibility of a systematic error, and particularly with a new, independent experiment, but physicists will be chasing this line of experiment eagerly.
“This is outstanding confirmation of experimental technique, and very, very suggestive of the possibility of new physics,” noted scientist David Hertzon of U of Washington.
A substance from a previously unknown blue-green alga, also known as cyanobacteria, that lives on ground nettles in freshwater lakes is responsible for making various birds and other animals sick, according to research by teams at the University of Halle-Wittenberg in Germany and the University of Georgia.
The harmful substance finds its way into herbivorous fish, water birds, and turtles, which were eventually eaten by the bald eagles, say the researchers, solving the long-running mystery of the mass extinction of bald eagles in the southeastern US. Since the 1990s scientists have been searching for the “eagle killer poison” that causes nerve disorders in the birds which then lose control of their bodies and die.
Though it remains unclear why the bacteria produces the poison in some lakes but not in others, a unique bromine compound may be responsible, say researchers. It turns out that the bacteria need bromine to produce their poison and the scientists point out that a herbicide containing bromine is used in some lakes to destroy the invasive ground nettle.
A recent study by U of Bern researchers has identified the major causes of increasing endangerment of plant species in the country.
Anne Kempel, author of the study that involved 420 botanists and worked together with the Swiss data and information center Info Flor, said that micropollutants, fertilizer pollution, the loss of natural flow dynamics due to river straightening, the use of rivers as a source of electricity, and the draining of bog areas are all troublesome for these plants.
At least a significant portion of their supporters, according to U of Aarhus researchers.
When two competing political parties in Denmark reversed their policy stance on an issue — suddenly they both supported reducing unemployment benefits — their voters immediately moved their opinions by around 15% into line with their party.
The same thing happened when one of these parties shifted from opposing to supporting ending Denmark’s early retirement.
The researchers were studying how public opinion is formed. Their recent paper sheds light on how much influence political parties have over their supporters, according to the researchers, who surveyed their panel of subjects in five successive waves between 2010 and 2011. They studied the same group of party supporters before, during and after a policy reversal.
“We can see that [the] welfare programs were actually quite popular … and many of the voters of the center-right party were in favor of these welfare programs,” commented one of the researchers, Rune Slothuus. “Nevertheless, we can see that they reversed their opinion from supporting these welfare programs to opposing these welfare programs.”
“I was surprised to see the parties appeared this powerful in shaping opinions,” Slothuus said. “Our findings suggest that partisan leaders can indeed lead citizens’ opinions in the real world, even in situations where the stakes are real and the economic consequences tangible.”
The researchers pondered Western democracy in light of their findings: “If citizens just blindly follow their party without thinking much about it, that should lead to some concern about the mechanisms in our democracy. Because how can partisan elites represent citizens’ views if the views of citizens are shaped by the very same elites who are supposed to represent them?”
The brain interprets sounds as they contrast with its expectations; it recognizes patterns of sounds faster when they’re in line with what it is predicting it will hear, but it only encodes sounds when they contrast with expectations, according to Technische U researchers.
The researchers showed this by monitoring the two principal nuclei of the subcortical pathway responsible for auditory processing: the inferior colliculus and the medial geniculate body, as their subjects listened to patterns of sounds which the researches modified so that sometimes they would hear an expected sound pattern, and other times something unexpected.
Source: Alejandro Tabas, Glad Mihai, Stefan Kiebel, Robert Trampel, Katharina von Kriegstein. Abstract rules drive adaptation in the subcortical sensory pathway. eLife, 2020; 9 DOI: 10.7554/eLife.64501
When several research subjects were instructed to explore an empty room, and when they were instead seated in a chair and watched someone else explore the room, their brain waves followed a certain pattern, as recorded by a backpack hooked up to record their brain waves, eye movements, and paths. It didn’t matter if they were walking or watching someone else, according to UC researchers led by Dr Matthias Stangl.
The researchers also tested what happened when subjects searched for a hidden spot, or watched someone else do so, and found that brain waves flowed more strongly when they had a goal and hunted for something.
Source: Matthias Stangl, Uros Topalovic, Cory S. Inman, Sonja Hiller, Diane Villaroman, Zahra M. Aghajan, Leonardo Christov-Moore, Nicholas R. Hasulak, Vikram R. Rao, Casey H. Halpern, Dawn Eliashiv, Itzhak Fried, Nanthia Suthana. Boundary-anchored neural mechanisms of location-encoding for self and others. Nature, 2020; DOI: 10.1038/s41586-020-03073-y
Extroverts use ‘positive emotion’ and ‘social process’ words more often than introverts, according to new research conducted at Nanyang Technological U.
‘Love,’ ‘happy,’ and ‘blessed’ indicate pleasant emotions, and ‘beautiful’ and ‘nice’ indicate positivity or optimism, and are among the words found to be used more often by extroverts. So too are ‘meet,’ ‘share,’ and ‘talk,’ which are about socializing. Extroverts use personal pronouns — except ‘I’ — more too, another indication of sociability.
The correlation, however, was small, and the researchers think that stronger linguistic indicators need to be found to achieve their general goal, which is improving machine learning approaches to targeting consumer marketing.
Source: Jiayu Chen, Lin Qiu, Moon-Ho Ringo Ho. A meta-analysis of linguistic markers of extraversion: Positive emotion and social process words. Journal of Research in Personality, 2020; 89: 104035 DOI: 10.1016/j.jrp.2020.104035
A new law of science has been found to beautifully explain crowd movements for first time. The as-yet unnamed law, which is a mathematical, universal power law for human interactions, was found by U of M researchers who analyzed complex datasets that have only recently been available. The movement of crowds is fundamentally anticipatory in nature, according to the researchers, and the new, simple energy law expresses, in the words of its lead author, “the beauty of human nature.”
“Nowadays, though, in the era of big-data there is a plethora of publicly available human crowd data. By analyzing such data, we found that, unlike particle-based interactions, the interactions between pedestrians are anticipatory in nature,” Karamouzas told us, referring to previous models that had attempted to predict crowd behavior with data based on repulsive particles rather than humans.
“To be more specific, when two particles interact the amount of energy that they have to expend to avoid colliding with each other depends on how close they are. In contrast, when two pedestrians interact, their energy depends on the ‘time-to-collision,’ i.e., the time that it takes for the pedestrians to collide assuming that they do not change course; as a collision becomes more imminent, this energy increases drastically.”
Karamouzas and his team have discovered a universal parameter based on single variable that explains crowd movement.
“Surprisingly, the relationship between interaction energy and time-to-collision consistently follows a simple mathematical law stating that the degree to which two pedestrians are willing to respond to each other is inversely proportional to the square of their projected time-to-collision.”
Karamouzas elaborated on the types of crowd phenomena that could be explained by the new law.
“This law is broadly applicable as it consistently holds across different crowd settings; we analyzed both sparse and dense human crowds and found that pedestrian interactions follow the same power-law relationship. Our law has allowed us to gain a better understanding into how human behave and interact in a crowd.
“Looking into the future, I believe that such a law will have broad applications into our everyday life, from simulating in a more accurate way pedestrian behaviors in games, training simulators and animated movies, to designing safer buildings and pedestrian facilities.”
Karamouzas also explained how a law could so simply cover such range in speeds, densities and situations.
“That’s the beauty of the human nature! Every person in a crowd is certainly unique with his/her own desires and individual goals. What our law captures is how people adapt their courses in response to others around them. And such adaptations directly follow from the psychology of anticipation. As we move through a crowd our brain is able to process visual and acoustic cues and recognize the future consequences of our actions allowing us to react accordingly. And it’s the interaction between each person’s individual goals and our inferred law that allows pedestrians to exhibit such a large variety of behaviors.”
The law could not have been found in the past, due to the complexity required of the analysis.
“When we move in a crowd, we typically experience a complex system of competing forces,” said Karamouzas. “On one hand we have a goal that we are tying to reach–e.g. grocery store–and on other hand we try not to bump into other people. On top of that, we hardly ever walk alone but in small groups–such as couples, families, friends, etc. As such, we have to account for all these factors and continuously make our own decisions, which makes very hard to isolate/identify the primary rule that describes our interactions in a crowd. Much of the work in our paper was developing a new analysis technique which can account for the effect of all these forces simultaneously. Because the technique we employed was statistical in nature, we needed to analyze thousands of trajectories to robustly determine the pedestrian interaction law.”
Karamouzas went into detail about how his team found the law.
“We turned into a large collection of publicly available pedestrian datasets that are nowadays available thanks to the advances in automated tracking and computer vision,” said Karamouzas. “Overall, we analyzed six datasets consisting of students walking in college campuses, pedestrians interacting at commercial streets, and a few controlled experiments where participants navigate through narrow bottlenecks.
Previously, there had been formidable challenges facing researchers who wanted to find an accurate and general rule for pedestrian behavior.
“To overcome the challenges that I mentioned already and robustly quantify the interaction law of pedestrians we employed a novel approach rooted in condensed matter physics. We initially measured the probability that any pair of pedestrians in the data has of maintaining a certain separation distance. We basically hypothesized that similar to charged particles, the interaction between pedestrians is distance-dependent. However, we found that the probability plots were very different for different walking speeds; when two pedestrians approach each other very fast they tend to maintain a larger separation distance than when they move slowly, as opposed to particles. As such, we started looking into different variables that can describe the interactions between pedestrians and we found that the time-to-collision is a sufficient descriptor. The probability plots were the same for different speeds as well as different orientations at which pedestrians approach each other. In addition, the time-to-collision measure naturally accounts for pedestrians coming relatively close to one another when moving in roughly the same direction–e.g. a pair of friends walking line-abreast. Eventually, by analyzing all the data, we inferred a simple energy law for the interactions between pairs of pedestrians.”
The research is considered to hold new promise for improved public architecture and spaces, the failings of which in the past have caused deaths.
“First of all, the nice thing about our newly identified law is that it directly implies an accurate model of simulating crowd flows. And through such simulations, we can design safer buildings as well as improve the efficiency of existing facilities–e.g., better egress times at a stadium. Furthermore, our novel way of analyzing crowd data and directly measuring the “interaction energy” between pairs of pedestrians opens interesting avenues for future work. For example, we would like to analyze crowd data from mass gatherings, such as concerts, and see how the interaction energy can be used to identify critical areas preventing the likelihood of crowd disasters–like the Love Parade in 2010).
Karamouzas commented on what he thought may be the most important thing for readers to understand of the research.
“The main take-away message is that a lot of the complexity of pedestrian interactions can be captured using simple mathematical equations. The universality of how pedestrian respond to each other is really surprising, and understanding this can lead to more accurate simulations, safer building designs, and shed some light into the anticipatory nature of human interactions.
The development of a new metal matrix composite foam may tip the balance back towards metal materials in the construction of marine vehicles — in addition to offering heat resistance well beyond that of the fiberglasses common in the industry today. According to NYU engineers, the first lighter-than-water metal construction foam can withstand significant pressure and three times as much heat as fiberglass.
The metal matrix composite is a magnesium alloy reinforced with spherical silicon carbide particles. The density — 0.92 grams per cubic centimeter versus water’s 1.0 – still allows the material to withstand 25,000 pounds per square inch of pressure before rupturing.
Some of the strength of the material is due to the hallow particles embedded in the material, which absorb energy during a fracture. With different measures of spheres added to the matrix, various densities can be created.
“The spheres are manufactured by our industrial partner Deep Spring Technology, Toledo, OH, USA,” noted Gupta, an expert in mechanical and aerospace engineering.
Spheres were the shape of choice for the foam. “This company also has capabilities of manufacturing hollow particles of many other shapes,” said Gupta, who referred to two other types of particle shapes — made of silicon carbide [gray color] and alumina [white color].
“Spherical particles have advantage that their properties are the same from any side. Particles of different shapes need to be used with more caution with regard to loading them along their strongest direction.”
The light-weight heat-resistant material is also expected to offer potential improvements in fuel economy for land transportation. The ability of metallic materials to withstand high temperatures is one of the main selling points, Gupta noted.
“Some of the competing materials are polymer matrix composites, commonly known as ‘fiberglass.’ One of the limitations of fiberglass materials is that they cannot be used over 150 degrees Celsius because polymer will degrade or burn. In addition, fire, smoke, and toxicity are concerns when polymers are exposed to high temperature. Magnesium and Magnesium matrix composites can be used up to about 500 degrees Celsius. Automotive components such as pistons, connecting rods, exhaust systems and structural components can be made of lightweight Mg matrix composite materials. High temperature in many of these components prohibits use of polymer matrix composites.
“The Magnesium-hollow sphere composites that we have developed also absorb a large amount of energy under compression. This property is desirable in automotive energy absorber components in cursing zones. These foams can also be filled in A and B-pillars of cars, and doors for side impact energy absorption.”
The technology may be put into use in prototype automobiles and boats within three years, as well as in amphibious vehicles developed by the US military, where currently the trend is toward other materials, although experts consider that the new lightweight product may again give metals a material advantage.
“Weight reduction in transportation applications can help in reducing the fuel consumption,” Gupta told us. “In addition, the high energy absorption capability per unit mass in these materials can also help in making vehicles safer. However, one material cannot be used to make all components, we need to find the components that will benefit the most from these new materials.
A recent study by Dutch design aesthetics researchers has discovered that women closely guard their fragrance identity to the point that they will keep it secret from the entire world if they can — so secret that even their friends cannot copy their personal scent, and they certainly won’t buy perfumes they like for their friends.
“The question here is not only: how do you express you identity? But it is: what types of items can someone else buy for you?” Dr. Rick Schifferstein of Delf University of Technology in the Netherlands told The Speaker. Schifferstein and his team were studying what effects packaging has on fragrance purchase when they made the somewhat unexpected discovery.
“Everyone expresses their identity through their appearance and their actions,” he explained. “Apparently, your identity is not only expressed through the way you dress or your haircut, but also by the fragrance you wear.
Women won’t buy perfumes for each other, the team found, unless they don’t like the scent themselves, or when they may have previously liked the scent but no longer have a purpose for it. Actually, the researchers found, women tend to “sabotage” their friends when they give this type of gift. Women will buy a scent they like for themselves or their boyfriend — which is something women like to do, the findings showed — but will only buy scents they dislike for their female friends.
“While women hold fragrances as personally intimate and respect other women’s intimate choices, they happily want to influence what fragrances men wear,” Dr Bryan Howell, co-author of the study, said. “Assuming it is for a spouse or boyfriend, they want to pick fragrances they also like since they’ll be around that person often.”
The issue is more complicated than a simple concept of “sabotage” though, according to the researchers, and has to do with the importance of personal identity. Schifferstein explained some of the complexity of the issue by referring to the gift motivations, concerns and preferences of women.
“Giving someone a fragrance might suggest that they need one because they smell bad. This could cause unwanted questions to occur between friends. Women prefer to avoid that possibility and look for a gift that is safer to share.”
In case women do give their friends fragrances, it may concern fragrances that are no longer working for themselves and that are passed on to their friends, in hopes that they will work for them. Alternatively, women may appreciate the personality or preference differences between themselves and their friends, and may decide to give them a fragrance that has a different character than what they would buy for themselves.
“Fragrance categories — for example, fruity, spicy, citrus, floral — may play an important role in this process: Some women identified themselves as belonging to a certain category and they would consider purchasing only fragrances from this category for themselves. Consequently, they would not recommend these fragrances for their female best friends.”
The gifts women choose for each other tend to be purchased with a strong motivation to play it safe: “The more intimate the item, the less likely it will be considered appropriate as a gift.” Gifts such as CDs, books, and flowers tend to suit this less intimate, more safe approach, Schifferstein told us.
Monopolization of community-based information networks by cartels of a few “super editors” among several risks that could lead to a diminished Wikipedia
Wikipedia’s quality benefits from high levels of free participation, but volunteer information databases like Wikipedia can be negatively effected by tendencies toward information monopolization, and, according to a recent study, this negative effect is more prevalent in more frequently edited articles — articles that could be considered to be more important.
In the study, researchers at the Korea Advanced Institute of Science and Technology and the Korea Institute for Advanced Study looked at how editors interact with each other as well as how they interact with articles, and integrated previously-ignored factors such as the consideration of real time — not just the number of edits used in previous studies to mark time.
Among the team’s findings: infrequently-referred articles grow faster than frequently-referred ones. Not only that, but articles that attracted a high motivation to edit actually reduced the number of participants. Yun and his colleagues inferred that this type of Wikipedia article participation decay results in inequality among community editors. The trend will become more severe as time goes on, they suspected:
“For the previous decade, many of these open-editing access movements have significantly affected the entire
society,” Jinhyuk Yun, a Ph.D. candidate at the Complex Systems and Statistical Physics Lab at the Korea Advanced Institute of Science and Technology in Daejeon, South Korea, told us.
“Wikipedia, Creative Commons Licenses, GNU, etc. To sustain such movements, they must maintain their motivations for participants, which might be taken away by monopolization.”
Yun explained how communal information databases like Wikipedia slow down.
“There are various reasons to participate in such ‘open-editing’ movements. Some are collective reasons shared in a society, and others are somewhat personal. Because the motivation is diverse, slowing down is also due to various causes. First, there can be a loss of necessity to contribute due to changes in society — or technology. Some GNU software based on old platforms no longer continue because the number of users of such software is getting smaller. In addition, there can be new barriers caused by governmental regulations — not about such communal databases, but considering the case of UBER. One particular candidate we discussed in the paper is the monopolization by few ‘super-editors.'”
Yun also commented on how we can consider the health of such community databases?
“It is very hard to quantify the ‘health’ of such database because of the ambiguity in the definition of health. In my point of view, the databases should meet the standard of accuracy and instantaneity. In other words, it should keep the trend, but it should not lose its accuracy in the contents. Although these databases are mainly based on the contribution of anonymous sources, it should also have reliable references to cross-check.”
However, data monopolization is not a black and white issue, Yun noted.
“To be honest, monopolization sometimes does good in particular occasions,” Yun told us, “yet it has many risks in most cases. Consider political issues in authoritarian governments, where media controlled by the government sometimes manipulates people’s opinions by a simple nudge or filtering. Such manipulation can also happen in Wikipedia — for example, by cartels of super-editors.”
Yun offered some possible remedies for content monopolization on Wikipedia:
“Based on our observations, Wikipedia could consider a reward program to recruit new editors. Simple achievement reward programs — like those in video games — at an early stage might be helpful, yet it should be done under strict supervision to avoid vandals. For instance, giving merit to editors who supply new reliable references might help to keep the quality of articles.”
It might not be a surprise to anyone who has ever used strong language in a difficult situation as part of their natural strategy for getting through it, but scientists have tested it.
They had people repeat swear words and perform physical tasks, like riding exercise bikes and squeezing hand grips. Compared with people who didn’t swear, those who used strong language had higher performance.
The research was done by Richard Stephens, a psychologist at Keele University.