It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Wednesday, February 26, 2025
Problem-based learning helps students stay in school
Education experts at the University of South Australia are encouraging schools to consider problem-based learning (PBL) in a move to improve engagement and creativity among high school students.
The call follows new Productivity Commission data that shows national school attendance rates over the past year have decreased from 88.8% in Year 7 to 84% in Year 10. Government schools are worst hit, with only 73% of public-school students completing year 12, as compared with nearly 80% in 2017.
New UniSA research demonstrates how hands-on, community-based projects can deliver successful learning outcomes for disengaged students.
Using a problem-based learning model, disengaged Year 13 Design and Technology students researched, planned, and built a playground for a low-income school.
UniSA’s Dr Chris Chimwayange says by linking learning to a real-life challenge, the project demonstrated how their academic content is applied within their community.
“Up to 20% of Australian and 25 to 30% of New Zealand students struggle with disengagement from school, which is often due to coursework that lacks real-world application,” Dr Chimwayange says.
“By looking at teaching and learning practices differently, we can find alternatives that can help students who are not engaging with the typical curriculum or might be slipping through the cracks.
“Here, we sought to create a project and environment that empowered learners through project-based learning and service to their community.
“Through this approach, students learned to set achievable goals for their project, conducted market research to understand existing solutions and identify potential needs, and explored a wide range of design options to arrive at the best possible solution for the community.
“By giving students choice and autonomy over their learning process, they not only increased their critical thinking, confidence and self-esteem, but also their collaboration, teamwork and leadership.
“They also learnt how to respectfully express their perspectives, how to evaluate contributions without putting each other down, and how they can positively contribute to their local community.”
Remarkably, the project reignited the passion for learning among previously disengaged students, helping them successfully complete their coursework.
Dr Chimwayange says while this project focussed on design and technology skills, the same principles can be applied across other disciplines.
“We strongly believe that disengaged students will participate more in learning if they can see how it relates to the real world, how it can help their communities, and when given the chance to make their own decisions,” Dr Chimwayange says.
“With student disengagement on the rise, it's time to rethink traditional learning. We encourage educators and policymakers to explore problem-based community learning as a solution to declining engagement.”
Promoting student engagement using project based learning as service-based skills development
WHY DEI WHY CRT
In preparing children for a racially unequal society, families of colour can benefit from more support, study finds
Researcher says parents should double down on key messages, which focus on feeling pride, valuing diversity and recognizing and responding to discrimination
In preparing children for a racially unequal society, families of colour can benefit from more support, study finds
Researcher says parents should double down on key messages, which focus on feeling pride, valuing diversity and recognizing and responding to discrimination
A McGill-led team of researchers has gained insight into how parents of colour in the United States approach discussions with their children aimed at teaching them the skills they need to survive and thrive in a racially unequal society.
A key finding of the recent paper in Developmental Psychology is that parents are especially in need of information, support and guidance when it comes to preparing their children to face discrimination and bias.
“One of our goals was to identify the most important messages around race and ethnicity that parents are already giving their children, so that people can really focus on them and get the most bang for their buck,” said Keita Christophe, lead author of the paper and an assistant professor in the Department of Psychology at McGill University.
The researchers surveyed a total of close to 600 Black, Latinx and Asian families with adolescent children in the United States in the fall of 2020. By using a system that relies on algorithms to identify interconnected and recurring elements in conversation, they were able to pinpoint three main types of messages that act as the linchpins of what many parents of colour teach their children about race, ethnicity and racism. These messages focus on teaching children to feel pride in their ethnicity and history, to value diversity and to be prepared to identify, and cope with, possible discrimination.
“It is crucial for parents of colour to engage in ethnic-racial socialization, since we’ve known for about 20 years that receiving these messages leads to positive mental health and can help youth build a strong, positive identity, which prepares them to navigate our world,” Christophe said.
One of the goals of the research is to provide new information to improve existing videos or online sites that have been developed by psychologists, social workers and others over the past five or six years to help families of colour have these challenging conversations with their children.
“The videos and online sites don't tell parents exactly what to say because it's so individual and depends on what group they're from and the age of the kid. But they're meant to help empower the parents to start the process of having these conversations with kids because we know the benefits in terms of their ability to cope with discrimination when they face it.”
In addition to looking at the substance of the parental messages, the researchers were interested in understanding how a parent’s level of comfort or discomfort with the contents of their messages might influence the information they shared with their children.
“Parents of colour often feel very comfortable having conversations with their children around pride in their group’s values, traditions and holidays. But they tend to have a lot more difficulty talking to their kids about the discrimination that they may potentially face. This might lead parents to avoid having these discussions or not approach them in a way that will get their message across,” Christophe explained.
Parents should be starting to have these conversations earlier, because children are being exposed to racism at younger ages and don't know what to do when their parents haven’t yet given them the skills, Christophe added.
The study
“Network Analysis of Ethnic–Racial Socialization Competency and Content Among Diverse Parents of Color: An Eye Toward Intervention Targets” by N. Keita Christophe, et al was published in Developmental Psychology
Divya Tyagi, right, a Penn State engineering graduate student, shows her work on a century-old math problem to Sven Schmitz, a College of Engineering faculty member and Tyagi's adviser.
UNIVERSITY PARK, Pa. — A Penn State engineering student refined a century-old math problem into a simpler, more elegant form, making it easier to use and explore. Divya Tyagi’s work expands research in aerodynamics, unlocking new possibilities in wind turbine design that Hermann Glauert, a British aerodynamicist and the original author, did not consider.
Tyagi, a graduate student pursuing her master’s degree in aerospace engineering, completed this work as a Penn State undergraduate for her Schreyer Honors College thesis. Her research was published inWind Energy Science.
“I created an addendum to Glauert’s problem which determines the optimal aerodynamic performance of a wind turbine by solving for the ideal flow conditions for a turbine in order to maximize its power output,” said Tyagi, who earned her bachelor’s degree in aerospace engineering.
Her adviser, Sven Schmitz, the Boeing/A.D. Welliver Professor in the Department of Aerospace Engineering and co-author on the paper, said Glauert’s original work focused exclusively on the maximum attainable power coefficient, which measures how efficiently a turbine converts wind energy into electricity. However, Glauert did not account for the total force and moment coefficients acting on the rotor — the spinning unit with attached blades — or how turbine blades bend under wind pressure.
“If you have your arms spread out and someone presses on your palm, you have to resist that movement,” said Schmitz, a faculty member in the Institute of Energy and the Environment. “We call that the downwind thrust force and the root bending moment, and wind turbines must withstand that, too. You need to understand how large the total load is, which Glauert did not do.”
Schmitz said the simplicity of Tyagi’s addendum based on calculus of variations, a mathematical method used for constrained optimization problems, will allow people to explore new facets of wind turbine design.
“The real impact will be on the next generation of wind turbines using the new knowledge that has been unveiled,” Schmitz said. “As for Divya’s elegant solution, I think it will find its way into the classrooms, across the country and around the world.”
Tyagi said she sees her work as a step toward improving wind energy production and reducing costs.
“Improving the power coefficient of a large wind turbine by just 1% has significant impacts on the energy production of a turbine, and that translates towards the other coefficients that we derived relations for,” she said. "A 1% improvement in power coefficient could notably increase a turbine’s energy output, potentially powering an entire neighborhood."
During her senior year, Tyagi won the Anthony E. Wolk Award for her thesis on the addendum to Glauert’s work. The Wolk Award is presented to a senior in aerospace engineering who has developed the best thesis among aerospace engineering students.
Now pursuing her master’s degree, Tyagi is studying computational fluid dynamics simulations, analyzing airflow around a helicopter rotor.
“The goal is to integrate that with the complex flow around a ship to see how the ship airwake interacts with a helicopter trying to land on its deck,” she said.
Her U.S. Navy-supported research aims to improve flight simulation and pilot safety by better understanding these dynamic interactions.
Reflecting on her undergraduate research, Tyagi said proving her solution on paper was challenging.
“I would spend about 10 to 15 hours a week between the problem, writing the thesis and on research. It took a long time because it was so math intensive,” she said. “But I feel really proud now, seeing all the work I’ve done.”
Schmitz, who has contemplated Glauert’s problem for decades, credited Tyagi’s persistence in tackling it.
“When I thought about the Glauert problem, I thought steps were missing and it was very complicated,” Schmitz said. “There had to be an easier way to do it. That’s when Divya came in. She was the fourth student I challenged with looking at it, and she was the only one who took it on. Her work is truly impressive.”
This one-million-year-old star-forming region contains thousands of new stars and hundreds of planetary mass objects floating freely in the nebula, not orbiting stars.
Credit: NASA, ESA, CSA /M. McCaughrean, S. Pearson
A groundbreaking study published in Science Advances sheds new light on the mysterious origins of free-floating planetary-mass objects (PMOs)—celestial bodies with masses between stars and planets.
Led by Dr. DENG Hongping of the Shanghai Astronomical Observatory of the Chinese Academy of Sciences, an international team of astronomers used advanced simulations to uncover a novel formation process for these enigmatic objects. The research suggests that PMOs can form directly through violent interactions between circumstellar disks in young star clusters.
The Mystery of Rogue Planetary-Mass Objects
PMOs are cosmic nomads, drifting freely through space, unbound to any star. The mass of these objects is less than 13 times that of Jupiter. They are often observed in young star clusters like the Trapezium Cluster in Orion. While their existence is well-documented, their origin has long puzzled scientists. Previous theories proposed that PMOs could be failed stars or planets ejected from their solar systems. However, these models fail to explain the large number of PMOs, their frequent binary pairings, and their synchronized motion with stars within clusters.
"PMOs don't fit neatly into existing categories of stars or planets," said Dr. DENG, corresponding author of the study. "Our simulations show they likely form through a completely different process—one tied to the chaotic dynamics of young star clusters."
A Cosmic Tug-of-War: How Disks Collide to Create PMOs
Using high-resolution hydrodynamic simulations, the researchers recreated close encounters between two circumstellar disks—rotating annuli of gas and dust surrounding young stars. When these disks collide at speeds of 2–3 km/s and distances of 300–400 astronomical units (AU), their gravitational interactions stretch and compress gas into elongated "tidal bridges."
These tidal bridges eventually collapse into dense filaments, which further fragment into compact cores. When these filaments reach a critical mass, they produce PMOs with masses of about ten times that of Jupiter. The simulations also revealed that up to 14% of PMOs form in pairs or triplets, with 7–15 AU separations, explaining the high rate of PMO binaries in some clusters. Frequent disk encounters in dense environments like the Trapezium Cluster could generate hundreds of PMOs, explaining the observed overabundance.
Why PMOs Are Unique
PMOs are distinct in their formation. Unlike ejected planets, they move in sync with the stars in their host clusters and inherit material from the outer regions of circumstellar disks. This results in a unique composition, with PMOs reflecting the metal-poor outskirts of these disks, where heavy elements are scarce. Many PMOs also retain gas disks up to 200 AU in diameter, suggesting the potential for lunar or even planetary formation around these rogue objects.
"This discovery partly reshapes how we view cosmic diversity," said co-author Prof. Lucio Mayer from the University of Zurich, "PMOs may represent a third class of objects, born not from the raw material of star-forming clouds or via planet-building processes, but rather from the gravitational chaos of disk collisions."
Looking Ahead
The team, including researchers from the University of Hong Kong, the Shanghai Astronomical Observatory, the University of California Santa Cruz, and the University of Zurich, plan further studies to explore the chemical makeup and disk structures of PMOs. Upcoming research on PMOs in various clusters will consolidate the theory of their formation and population properties.
The formation of binary PMOs via circumstellar disk encounters.
For centuries, lenses have worked the same way: curved glass or plastic bending light to bring images into focus. But traditional lenses have a major drawback—the more powerful they need to be, the bulkier and heavier they become. Scientists have long searched for a way to reduce the weight of lenses without sacrificing functionality. And while some slimmer alternatives exist, they tend to be limited in their capacity and are generally challenging and expensive to make.
New research from University of Utah engineering professor Rajesh Menon and colleagues at the Price College of Engineering offers a promising solution applicable to telescopes and astrophotography: a large aperture flat lens that focuses light as effectively as traditional curved lenses while preserving accurate color. This technology could transform astrophotography imaging systems, especially in applications where space is at a premium, such as on aircraft, satellites and space-based telescopes.
Their latest study, featured on the cover of the journal Applied Physics Letters, was led by Menon Lab member Apratim Majumder, a research assistant professor in the Department of Electrical & Computer Engineering. Coauthors include fellow Menon Lab members Alexander Ingold and Monjurul Meem, Department of Physics & Astronomy’s Tanner Obray and Paul Ricketts, and Nicole Brimhall of Oblate Optics.
If you’ve ever used a magnifying glass, you know that lenses bend light to make objects appear larger. The thicker and heavier the lens, the more it bends the light, and the stronger the magnification. For everyday cameras and backyard telescopes, lens thickness isn’t a huge problem. But when telescopes must focus light from galaxies millions of light-years away, the bulk of their lenses become impractical. That’s why observatory and space-based telescopes rely on massive, curved mirrors instead to achieve the same light-bending effect since they can be made much thinner and lighter than lenses.
Scientists have also tried to solve the bulkiness problem by designing flat lenses, which manipulate light in a different way. One existing type, called a Fresnel zone plate (FZP), uses concentric ridges to focus light, rather than a thick, curved surface. While this method does create a lightweight and compact lens, it comes with a tradeoff: it can’t produce true colors. Rather than bending all of the wavelengths of visible light at the same angle, the ridges of an FZP diffract them at different angles, resulting in an image with chromatic aberrations, or color distortions.
Enter Rajesh Menon and his team at the U. Their new flat lens offers the same light-bending power as traditional curved lenses while avoiding the color distortions of FZPs.
“Our computational techniques suggested we could design multi-level diffractive flat lenses with large apertures that could focus light across the visible spectrum and we have the resources in the Utah Nanofab to actually make them,” said Menon, who directs the U’s Laboratory for Optical Nanotechnologies.
The key innovation lies in the microscopically small concentric rings that the researchers can pattern on the substrate. Unlike the ridges of FZPs, which are optimized for a single wavelength, the size and spacing of the flat lens’ indentations keep the diffracted wavelengths of light close enough together to produce a full-color, in-focus image.
“Simulating the performance of these lenses over a very large bandwidth, from visible to near-infrared, involved solving complex computational problems involving very large datasets,” Majumder said. “Once we optimized the design of the lens’ microstructures, the manufacturing process involved required very stringent process control and environmental stability.”
A large, flat, color-accurate lens could have massive implications across industries, but its most immediate application is in astronomy. The researchers demonstrated the capabilities of their flat lens with test images of the sun and moon.
“Our demonstration is a stepping stone towards creating very large aperture lightweight flat lenses with the capability of capturing full-color images for use in air-and-space-based telescopes,” Majumder said.
The concentric rings of microscopic indentations on the researchers’ flat lens are optimized to bring all wavelengths of light into focus at the same time.
Credit
Menon Lab, University of Utah
The study, “Color astrophotography with a 100 mm-diameter f/2 polymer flat lens,” appeared on Feb. 3 in Applied Physics Letters. This research was supported by the Defense Advanced Research Projects Agency, or DARPA, (FA8650-20-C-7020 P00001), the Office of Naval Research (N00014-22-1-2014), and NASA (NNL16AA05C). This content is solely the responsibility of the authors and does not necessarily represent the official views of these funding agencies. Monjurul Meem is now a process engineer at Intel.
