Category: 7. Science

Twenty years ago, cognitive psychologist Elizabeth Spelke took a strong position in an ongoing public debate.

“There are no differences in overall intrinsic aptitude for science and mathematics among women and men,” the researcher declared.

A new paper in the journal Nature, written by Spelke and a team of European researchers, provides what she called “an even stronger basis for that argument.” 

A French government testing initiative launched in 2018 provided data on the math skills of more than 2.5 million schoolchildren over five years. Analyses showed virtually no gender differences at the start of first grade, when students begin formal math education. However, a gap favoring boys opened after just four months — and kept growing through higher grades.

The results support previous research findings based on far smaller sample sizes in the U.S. “The headline conclusion is that the gender gap emerges when systematic instruction in mathematics begins,” summarized Spelke, the Marshall L. Berkman Professor of Psychology.

Back in 2005, her position was informed by decades of work studying sensitivity to numbers and geometry in the youngest members of human society. 

“My argument was, ‘OK, if there really were biological differences, maybe we would see them in the infancy period,’” recalled Spelke, who laid out her evidence in a critical review for the journal American Psychologist that year. 

“We were always reporting on the gender composition of our studies, as well as the relative performance of boys and girls,” Spelke continued. “But we were never finding any differences favoring either gender over the other.”

The possibility remained that differences in skill or even motivation surface later in the lifecycle.

“The fact that there are no differences in infants could be because the abilities that show gender effects actually emerge during preschool,” Spelke said.

Recent years have found the psychologist applying her research on early counting and numeral-recognition skills via educational interventions, all analyzed and refined through randomized control experiments.

One of the world’s most influential researchers on early learning, Spelke recently partnered with Esther Duflo, an MIT economics professor and Nobel laureate, to advise the Delhi office of the nonprofit Abdul Latif Jameel Poverty Action Lab (J-PAL). The group is working with the governments of four separate Indian states to develop and test math curricula for preschoolers, kindergartners, and first-graders. 

Alongside her longtime collaborator, the cognitive neuroscientist Stanislas Dehaene, Spelke also serves as an adviser on the French Ministry of Education’s Scientific Council. The nationwide EvalAide language and math assessment was introduced with the council’s help in 2018. The project’s goal, Spelke explained, is establishing a baseline measure of every French child’s grasp of basic numeracy and literacy skills, while supporting the ministry in its commitment to implementing an evidence-based education for all French schoolchildren.

Spelke co-authored the Nature paper with Dehaene and eight other researchers, all based in France. Specifically analyzed were four consecutive cohorts of mostly 5- and 6-year-olds entering school between 2018 and 2021. 

As in many countries, French girls tested slightly ahead of French boys on language as they started first grade in the fall. But the gender gap was close to null when it came to math. 

“That definitely connects to the earlier issue of whether there’s a biological basis for these differences,” Spelke argued.

French first-graders were then reassessed after four months of school, when a small but significant math gap had emerged favoring boys. The effect quadrupled by the beginning of second grade, when schoolchildren were tested yet again.

“It was even bigger in fourth grade,” said Spelke, noting that French children are now assessed at the start of even-number grades. “And in sixth grade it was bigger still.”

For comparison, EvalAide results show the literacy gender gap was reduced by the first year’s four-month mark and changed far less as students progressed to higher grade levels.

Why would a gender gap widen on math specifically as students accumulated more time in school? According to Spelke, the paper provides “only negative answers” concerning ideas about innate sex differences and social bias.  

“If there was really a pervasive social bias, and the parents were susceptible to it,” she said, “we would expect boys to be more oriented toward spatial and numerical tasks when they first got to school.” 

Delving further into the data yielded more results that caught the researchers’ interest. For starters, Spelke’s co-authors could disaggregate the findings by month of birth, with the oldest French first-graders turning 7 in January — nearly a year before their youngest classmates. The math gap was found to correlate not with age, but with the number of months spent in school. 

Another noteworthy result concerned the COVID-19 pandemic, which wiped out the last 2.5 months of first grade for children who enrolled in fall 2019. “With less time in school, the amount of the gender gap grew by less than it did in the other years where there wasn’t a long school closure,” Spelke said.

The 2019 cohort yielded one more striking result. Earlier that year, French schoolkids had placed at the very bottom of 23 European countries on the quadrennial Trends in International Mathematics and Science Study. That sparked a national conversation: How could France, birthplace of the great René Descartes, be trailing its peers in mathematics?

In May 2019, the French Education Ministry, with the support of its Scientific Council, called for the introduction of more math curriculum during kindergarten. For the first time, an ever-so-slight gender math gap appeared that fall for those entering first grade. It hadn’t been there in 2018 but remained detectable in results from the 2020 and 2021 cohorts.

The overall results, the most conclusive to date, suggest it’s time to shelve explanations based on biology or bias. Instead, it appears there’s something about early math instruction that produces gender disparities. 

“We still don’t know what that is exactly,” said Spelke, who plans to spend much of her 2025-26 sabbatical year in France. “But now we have a chance to find out by randomized evaluations of changes to the curriculum.”

An astrophotographer has captured a stunning shot of a powerful solar flare photobombing the International Space Station (ISS) as the human-inhabited spacecraft appeared to zoom across the surface of our home star.

Andrew McCarthy (aka Cosmic Background) snapped the incredible image on June 15 from a spot in the Sonoran Desert in Arizona. He was initially planning to photograph a standard “transit” photo of the ISS passing directly between Earth and the sun. However, as McCarthy was setting up his camera, he noticed that one sunspot — dubbed AR4114 — had begun to “flare to life,” he told Live Science.

Scientists with NASA’s Lucy mission are finally wrapping up the process of refining the data gathered by the spacecraft’s April 20 encounter with Donaldjohanson, an asteroid in our solar system’s main asteroid belt. And it’s, uh, as peanut-shaped as we first saw it. 

Earlier this year, Lucy’s Long Range Reconnaissance Imager snapped an image of Donaldjohansson while quickly swooping past it, at a distance of about 600 miles (960 kilometers), with the smallest visible features measuring around 130 feet (40 meters) across—an impressive close-up, considering the overall scale of anything we observe in space. 

Regrettably, the Sun’s position behind Lucy reduced the contrast of the asteroid’s smaller details. But the close visit is invaluable nevertheless, as it’s allowing scientists to carefully comb over the details of its surface after adjusting for the brightness. 

“Asteroid Donaldjohanson has strikingly complicated geology,” said Hal Levison, Lucy’s principal investigator, in an earlier press release about the asteroid. Donaldjohansson likely got its lumpy shape from a cosmic collision between two smaller objects around 150 million years ago. It’s a relatively common shape among smaller asteroids in the solar system, so what we learn from Donaldjohanson could inform our understanding of many other cosmic objects. 

“As we study the complex structures in detail, they will reveal important information about the building blocks and collisional processes that formed the planets in our Solar System,” Levison added in the same release. 

Donaldjohansson is not the main objective of the Lucy mission, whose itinerary is set for the eight Trojan asteroids that share Jupiter’s orbit around the Sun. Still, Lucy’s Donaldjohanson encounter—and the November 2023 flyby of asteroid Dinkinesh—is an excellent “dress rehearsal” for Lucy as it continues its journey toward the cooler, outer regions of the solar system, according to NASA’s Erin Morton in a statement earlier this week. 

Lucy’s next milestone is set to occur in August 2027, when the spacecraft will finally start to explore the Jupiter Trojan asteroids in earnest—starting with Eurybates, a carbonaceous asteroid so big that it has its own satellite, Queta.

Since the discovery of the first exoplanet orbiting a Sun-like star, the confirmation of nearly 6000 exoplanets to date – and their diversity – has revolutionized our knowledge of planetary systems in the past three decades.

Nevertheless, the majority of these planets are around mature stars (≳1 Gyr), where the planet birth environments have already dissipated. Indeed, we have only confirmed 2 forming planets (i.e., protoplanets; ≲10 Myr) residing in one single system. In comparison, we have imaged over 200 protoplanetary disks in the past decade, with many of them hosting substructures such as spirals and gaps which suggest the existence of protoplanets.

To understand the early stages of planet formation, the Habitable Worlds Observatory (HWO) – with its high-contrast imaging and integral field spectroscopy capabilities – presents a unique opportunity to explore the demographics of the natal stages of planet formation and their birth environments.

We propose to image protoplanets within substructured protoplanetary disks using HWO via direct imaging, and characterize them (i.e., protoplanets, protoplanetary disks, circumplanetary disks) using integral field spectroscopy and spectropolarimetry. This effort will dramatically extend current population of protoplanets, probing and characterizing over 200 protoplanets.

By expanding the number of protoplanets by two orders of magnitude, these observations will test and refine planet formation theory and planet-disk interaction theory, and further motivate planet migration studies together with existing mature planets. The results will offer critical insight into planetary system formation and evolution, and help understand the origin of our own Solar System.

Bin B. Ren

Comments: 9 pages, 3 figures, 2 tables. HWO Science Case #SCDD-SSiC-8 for HWO25 proceedings
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2506.24129 [astro-ph.IM] (or arXiv:2506.24129v1 [astro-ph.IM] for this version)
https://doi.org/10.48550/arXiv.2506.24129
Focus to learn more
Submission history
From: Bin Ren Dr.
[v1] Mon, 30 Jun 2025 17:59:59 UTC (1,388 KB)
https://arxiv.org/abs/2506.24129
Astrobiology,

Extremophilic bacteria from extreme environments, such as the Atacama Desert, Salar de Huasco, and Antarctica, exhibit adaptations to intense UV radiation. In this study, we investigated the genomic and structural mechanisms underlying UV resistance in three bacterial isolates identified as Bacillus velezensis PQ169, Pseudoalteromonas sp. AMH3-8, and Rugamonas violacea T1-13.

Through integrative genomic analyses, we identified key genes involved in DNA-repair systems, pigment production, and spore formation. Phylogenetic analyses of aminoacidic sequences of the nucleotide excision repair (NER) system revealed conserved evolutionary patterns, indicating their essential role across diverse bacterial taxa.

Structural modeling of photolyases from Pseudoalteromonas sp. AMH3-8 and R. violacea T1-13 provided further insights into protein function and interactions critical for DNA repair and UV resistance. Additionally, the presence of a complete violacein operon in R. violacea T1-13 underscores pigment biosynthesis as a crucial protective mechanism.

In B. velezensis PQ169, we identified the complete set of genes responsible for sporulation, suggesting that sporulation may represent a key protective strategy employed by this bacterium in response to environmental stress.

Our comprehensive approach underscores the complexity and diversity of microbial adaptations to UV stress, offering potential biotechnological applications and advancing our understanding of microbial resilience in extreme conditions.

Phylogenetic tree based on the amino acid sequences of UvrA, UvrB, and UvrC proteins (NER system). Multiple sequence alignment was performed using MUSCLE on the Phylogeny.fr platform, followed by tree construction with PhyML and visualization using TreeDyn. The resulting tree was further arranged and refined using the Interactive Tree of Life (iTOL v7) tool. The maximum likelihood method was employed with 1000 bootstrap replicates, where the node sizes reflect the level of bootstrap support. Each label includes the gene name, the bacterial species, and the corresponding NCBI accession number. Three environmental strains are highlighted: Bacillus velezensis PQ-169 (green), Pseudoalteromonas sp. AMH3-8 (yellow), and Rugamonas violacea T1-13 (purple). These strains, along with other extremophilic, UV-resistant, and pathogenic bacteria, were included to compare UvrA (red clade), UvrB (blue clade), and UvrC (green clade) variations under extreme environmental conditions. — Int J Mol Sci via PubMed

Isolation sites, genomic assembly characteristics, and ANI-based taxonomic assignment of three extremophilic bacterial isolates. (a–c) Representative sampling sites of bacterial isolates: (a) Atacama Desert, (b) Salar de Huasco, and (c) Antarctic soil. (d–f) Circular genome representations illustrating variability in genome size, contiguity, and genetic content: (d) Bacillus velezensis PQ169 (76 contigs, 4.18 Mb), (e) Pseudoalteromonas sp. AMH3-8 (single contig, 4.74 Mb), and (f) Rugamonas violacea T1-13 (171 contigs, 6.85 Mb). Rings (outer to inner) represent predicted CDSs, RNA genes (rRNA, tRNA, and tmRNA), GC content, and GC skew. (g–i) Heatmaps depicting average nucleotide identity based on MUMmer (ANIm) analysis between each isolate and closely related reference strains, supporting definitive taxonomic assignment: (g) Bacillus velezensis PQ169, (h) Pseudoalteromonas sp. AMH3-8, and (i) Rugamonas violacea T1-13. Color gradients indicate similarity percentages, with red color representing higher ANI values, and blue lower values. — Int J Mol Sci via PubMed

astrobiology, genomics, extremophiles,