A Minor Adjustment to the “For You” Algorithm Can Rapidly Foster Political Polarization.

Studies indicate that altering the tone of posts on X can escalate political polarization within just a week, a shift that traditionally would have taken about three years.

An innovative study examining the impact of Elon Musk’s social media platforms on political polarization discovered that even minor increases in posts featuring anti-democratic sentiments or partisan aggression led to a marked rise in negative sentiments toward the opposing political faction among Democrats and Republicans.


The level of division, termed “emotional polarization,” reached in just one week due to the modifications made to the feeds of a specific number of X users equated to what would typically take an average of three years from 1978 to 2020.

Most of the over 1,000 participants in the experiment during the 2024 U.S. presidential election remained unaware of the changes in the tone of their feeds.

The campaign featured divisive viral content on X, including a fake image of Kamala Harris with Jeffrey Epstein and an AI-generated depiction from an image Musk posted showing Harris as a communist dictator, which garnered 84 million views.

Researchers observed that consistent exposure to posts reflecting anti-democratic views or partisan animosity significantly affected users’ feelings towards polarization, inducing heightened emotions of sadness and anger.

Musk acquired Twitter in 2022, rebranded it as X, and introduced a “for you” feed that presented content aimed at maximizing user engagement rather than just displaying posts from accounts that users actively follow.

The finding that increasing anti-democratic content heightens hostility towards political adversaries underscores the “power of algorithms,” noted Martin Savesky, an assistant professor at the University of Washington’s School of Information and a co-author of the study alongside colleagues from Stanford University, Johns Hopkins University, and Northeastern University. This research is published in Science magazine.

“While the adjustments in users’ feeds were subtle, they reported marked changes in their sentiments toward others,” explained Tiziano Picardi, an assistant professor in the Johns Hopkins University School of Computer Science and co-author of the study. “These shifts align with approximately three years of polarization trends seen in the U.S.”

The study also indicated that even slight alterations in users’ feed content could substantially diminish political hostility between Republicans and Democrats, implying that X could foster political unity if Musk opts to implement such changes.

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“The intriguing aspect of these findings is that platforms can implement measures to mitigate polarization,” added Savesky. “This offers a new perspective for algorithm design.”

Mr. X was reached out for comment.

According to Pew Research, eight in ten American adults believe there’s an inability among Republicans and Democrats to agree on not only policies, but also on fundamental facts. Additionally, over half the British population perceives political differences as dangerously divisive, as revealed by a recent Ipsos poll.

The evolution of political polarization caused by exposure to posts on X was evaluated using an innovative methodology. Initially, researchers utilized AI to analyze posts in X’s “for you” feed in real time. The findings indicated that some groups were exposed to more divisive content while others faced less, demonstrating X’s predominant influence. Divisive posts included support for undemocratic practices, partisan violence, a lack of bipartisan consensus, and skewed interpretations of politicized facts.

After a week of reading these subtly modified feeds, researchers prompted users to evaluate their political opponents’ warmth or coldness, favorability or unfavorability. Changes in “emotional deflection” were rated at two degrees or higher on a scale from 0 to 100 on a “feeling thermometer.” This level of increase in polarization matched the typical trend observed in the U.S. over the past four decades leading to 2020. Conversely, reducing posts with anti-democratic views and partisan hostility led to a corresponding decline in political polarization.

Social media platforms have long faced criticism for amplifying divisive content to boost user engagement and thereby increase advertising revenue. Nevertheless, the study revealed that when divisive posts were deprioritized, users tended to like and share more frequently, despite a slight decrease in overall engagement in terms of time spent on the platform and posts viewed.

“The effectiveness of this approach illustrates its potential for integration into social media AI, aimed at mitigating detrimental personal and societal impacts,” the authors argue. “Simultaneously, our engagement analysis indicates a notable trade-off; implementing such measures could decrease short-term engagement levels, posing challenges to engagement-driven business models, supporting the idea that content that elicits strong reactions tends to generate more engagement.”

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Source: www.theguardian.com

EHT Reveals Changing Polarization Patterns in Black Holes of Messier 87

Recent Observations of the M87* Black Hole by the Event Horizon Telescope (EHT) – Eight Ground-Based Radio Telescopes (ALMA, APEX, Iram 30 m Telescope, James Clerk Maxwell Telescope, Lage Millimeter Telescope Alfonso Serrano, Submillimeter Array Telescope) – Unveil a dynamic environment with varying polarization patterns near black holes.



The EHT images show that the magnetic field of M87* spiraled in one direction in 2017, settled in 2018, and reversed direction in 2021. Image credit: EHT collaboration.

Messier 87 is a vast elliptical galaxy situated approximately 53 million light-years away in the Virgo constellation.

This galaxy, also known as M87, houses the M87*, an ultra-massive black hole with a mass exceeding 6 billion solar masses.

In 2017, the EHT Collaboration detected a helical polarization pattern, indicating large-scale twisted magnetic structures, confirming long-held hypotheses about black hole interactions and their surrounding environments.

However, by 2018, the polarization nearly vanished. In 2021, a faint remnant began to spiral in the opposite direction.

Astrophysicists are now grappling with the pivotal question: Why?

“Black holes hold mysteries tightly, yet we continue to seek answers from their grasp,” stated Professor Avery Broderick, an astrophysicist at the University of Waterloo and the Perimeter Institute.

“Our team at Waterloo is reconstructing images from EHT data and determining what we can confidently assert—distinguishing between realistic findings and potential instrumental artifacts.”

“We are at the forefront of deciphering how EHT images, particularly their evolution, can unveil astrophysical dramas unfolding in the most extreme gravitational conditions.”

Each year, EHT collaborations revisit M87*, capturing fleeting moments that reveal its ongoing evolution, providing deeper insights into its well-guarded secrets.

“What’s intriguing is that the ring sizes have remained consistent over the years, validating the shadows of black holes predicted by Einstein’s theory, while the polarization patterns change dramatically,” remarked Dr. Paul Thierde, an astronomer at the Harvard & Smithsonian Center for Astrophysics.

“This indicates that the magnetized plasma swirling near the event horizon is not static but dynamic and complex, challenging theoretical models.”

The stability of M87*’s shadow serves as evidence that “black holes have no hair,” implying that a black hole is a simple geometric entity defined exclusively by mass, spin, or charge.

“This simplicity makes it an intriguing object of study within gravity, allowing for precise predictions. Other astrophysical phenomena seem secondary,” elaborated Professor Broderick.

“However, the surrounding environment can exhibit ‘hair,’ with magnetic fields being notable examples.”

“We have long understood what types of magnetic structures could exist, but now we believe there’s a rich diversity of configurations that can change rapidly, similar to human hairstyles.”

“These findings illustrate how EHT is maturing into a full-fledged scientific observatory that not only produces unprecedented images but also fosters a continuous and coherent understanding of black hole physics.”

“Each new observational campaign broadens our understanding, from the dynamics of plasma and magnetic fields to the role of black holes in the evolution of cosmic structures.”

“This is a concrete demonstration of the extraordinary scientific potential of this infrastructure.”

The survey results will be published in the journal Astronomy and Astrophysics.

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Kazunori Akiyama et al. (Event Horizon Telescope Collaboration). 2025. 2017-2021 Horizon scale variation of M87* from EHT observations. A&A in press; doi: 10.1051/0004-6361/202555855

Source: www.sci.news

IXPE Measures X-Ray Polarization from Magnetic Explosions

A magnetor is a type of neutron star that boasts an extraordinarily strong magnetic field, approximately one times stronger than Earth’s magnetic field. These colossal magnetic fields are believed to be generated when rapidly rotating neutron stars are birthed from the collapse of a giant star’s core. Magnetars emit brilliant X-rays and display erratic patterns of activity, with bursts and flares releasing millions of times more energy than the Sun emits in just one second. Polarization measurements offer insights into magnetic fields and surface characteristics. This was the focus of astronomers using the NASA Imaging X-ray Polarization Explorer (IXPE) to study 1E 1841-045, a magnetor located within Supernova Remnant (SNR) KES 73, situated nearly 28,000 light years from Earth. The findings are published in the Astrophysics Journal Letter.

Impressions of Magneter artists. Image credit: NASA’s Goddard Space Flight Center/S. Wesinger.

Magnetors represent a category of young neutron stars. They are the remnants of giant stars that collapsed in on themselves at the end of their life cycles, resembling the mass of the Sun but compressed into a city-sized volume.

Neutron stars exemplify some of the most extreme physical conditions in the observable universe, offering a unique chance to investigate states that cannot be replicated in terrestrial laboratories.

The 1E 1841-045 magnetor was observed in an explosive state on August 21, 2024, by NASA’s Swift, Fermi, and other advanced telescopes.

The IXPE team has permitted several requests to pause scheduled observations of the telescope multiple times each year, redirecting focus to unique and unexpected celestial phenomena.

When 1E 1841-045 transitioned into this bright active phase, scientists chose to direct IXPE to capture the first polarization measurements of the magnetor’s flare.

Magnetors possess magnetic fields thousands of times stronger than most neutron stars, hosting the most powerful magnetic fields among known cosmic entities.

These extreme magnetic field fluctuations can lead to the emission of X-ray energies up to 1,000 times greater than usual for several weeks.

This heightened state is referred to as explosive activity, though the underlying mechanisms remain poorly understood.

IXPE’s X-ray polarization measurements may help unveil the mysteries behind these phenomena.

Polarized light carries information about the direction and orientation of emitted X-ray waves. A higher degree of polarization indicates that the X-ray waves are moving in harmony, akin to a tightly choreographed dance.

Studying the polarization characteristics of magnetors provides clues regarding the energy processes associated with observed photons and the direction and configuration of the magnetor’s magnetic field.

This diagram illustrates the IXPE measurements of X-ray polarized light emitted by 1E 1841-045. Image credit: Michela Rigoselli / Italian National Institute of Astrophysics.

IXPE results, supported by NASA’s Nustar and other telescope observations, indicate that X-ray emissions from 1E 1841-045 exhibit increased polarization at higher energy levels while maintaining a consistent emission direction.

This significant contribution to the high degree of polarization is attributed to the hard X-ray tail of 1E 1841-045, a highly energetic component of the magnetosphere responsible for the highest photon energies detected by IXPE.

Hard X-rays refer to X-rays characterized by shorter wavelengths and greater energy than soft X-rays.

While prevalent in magnetars, the processes that facilitate the generation of these high-energy X-ray photons remain largely enigmatic.

Despite several proposed theories explaining this emission, the high polarization associated with these hard X-rays currently offers additional clues to their origins.

“This unique observation enhances existing models that aim to explain magnetic hard X-ray emissions by elucidating the extensive synchronization seen among these hard X-ray photons,” remarked a student from George Washington University. First paper.

“This effectively demonstrates the power of polarization measurements in refining our understanding of the physics within a magnetar’s extreme environment.”

“It would be fascinating to observe 1E 1841-045 as it returns to its stable baseline state and to track the evolution of polarization,” added Dr. Michela Rigoselli, an astronomer at the National Institute of Astrophysics in Italy. Second paper.

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Rachel Stewart et al. 2025. X-ray polarization of Magnetor 1E 1841-045. apjl 985, L35; doi: 10.3847/2041-8213/adbffa

Michela Rigoselli et al. 2025. IXPE detection of highly polarized X-rays from Magnetor 1E 1841-045. apjl 985, L34; doi: 10.3847/2041-8213/adbffb

Source: www.sci.news