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Wednesday, November 20, 2024

Op-Ed: Maybe polarizing social media was an even dumber idea than it looks

By Paul Wallis
November 20, 2024
DIGITAL JOURNAL

Elon Musk's X. — © AFP

The hordes of people leaving X are a sort of statistical obituary to years of propaganda. X is in big trouble, mainly because of its policies and algorithms and a bizarre relationship with infuriated advertisers.

Like most of American media, X instantly demoted itself to half of its own market share with its politics. It also became a servant, like FOX, to one side only. That’s not working out too well.

You’ll also notice from media coverage that nobody’s questioning the self-decapitation and disembowelment of X. The other glaring problem is that somehow this situation is now seen as normal.

It isn’t normal. People and advertisers are voting with their dollars and clicks.

Disgruntled X users are now heading to Bluesky in vast numbers. Millions of people have basically abandoned X. Bluesky looks a bit like early Twitter. Seems quite OK as an environment. I haven’t seen a rabid lunatic yet.

The new and huge problem is the quality of information vs communication. This is now an abyss of opposing information.

Unless there’s some middle ground, and the medium isn’t hopelessly biased, social media has just machinegunned itself in the foot. Politics is not the sole interest of the world. Other things happen, too, y’know.

That’s where audience loss is likely to be fatal. What if you don’t want to read about The Adventures of Donny and Elon in Disneyland?

What if you want a broad and useful mix of your own interests, instead?

The sole and whole purpose of social media is communication. Reducing your content range to such a narrow focus means you inevitably lose users.

Nor is the Chicken Little approach to information exactly popular. Nobody listens to raving lunatics if they don’t have to.

The possible exception to that theory is screen-fed America. Markets and media businesses take a long time to change course. This market doesn’t eat solid food anymore. The child-psychology is pretty obvious. These sources will probably simply continue to produce pablum.

The total stagnation of American mass media was one thing. This social media situation is stagnation of real-time information as well. X has made itself useless to its users.

People obviously don’t like that. The move to Bluesky is self-defense. The social media market can blame itself for a newcomer just walking off with its customers.

Let’s talk “dumb”.

Billions of dollars of investment are now evaporating in a festering social media environment and those billions aren’t coming back.

The World’s Richest Sudden Instant Fan Boy doesn’t have the excuse of being geriatric or illiterate. He should have enough metrics to see the cliff coming.

The big money markets in the US are all blue. The black holes are all red, with the possible exception of Texas. Ignore those big blue markets at your peril. Lose those markets and you’re doing hillbilly scale dollars. These much smaller markets can’t deliver the same value. Advertisers and marketers know that.

The rest of the world is also reacting very negatively to the toxicity of social media. The hubris and hype are all American-generated. The rest of the world can easily ignore most of this garbage.

What if reality gets involved in this mess? Economic risks and social disintegration are circling like buzzards over America in huge numbers with dollar signs on them. All types of media should be building financial fallout shelters about now. Markets can evaporate overnight.

No amount of fake news hysteria and self-congratulation can make an impression on that situation. You need “Make America Solvent Again” to do that, and it looks like that’s not happening for the next four years.

How would you read a commercial market that is basically suicidal? Would you focus on customer retention in the afterlife? You might have to do that.

Social media needs a functional market to exist at all. If the money’s pulling out, the message couldn’t be clearer.

__________________________________________________
Disclaimer

The opinions expressed in this Op-Ed are those of the author. They do not purport to reflect the opinions or views of the Digital Journal or its members.


Social media users probably won’t read beyond this headline, researchers say



A new study of 35 million news links circulated on Facebook reports that more than 75% of the time they were shared without the link being clicked upon and read



Penn State




UNIVERSITY PARK, Pa. — Congratulations. Reading this far into the story is a feat not many will accomplish, especially if shared on Facebook, according to a team led by Penn State researchers. In an analysis of more than 35 million public posts containing links that were shared extensively on the social media platform between 2017 and 2020, the researchers found that around 75% of the shares were made without the posters clicking the link first. Of these, political content from both ends of the spectrum was shared without clicking more often than politically neutral content.

The findings, which the researchers said suggest that social media users tend to merely read headlines and blurbs rather than fully engage with core content, appeared today (Nov. 19) in Nature Human Behavior. While the data were limited to Facebook, the researchers said the findings could likely map to other social media platforms and help explain why misinformation can spread so quickly online.

“It was a big surprise to find out that more than 75% of the time, the links shared on Facebook were shared without the user clicking through first,” said corresponding author S. Shyam Sundar, Evan Pugh University Professor and the James P. Jimirro Professor of Media Effects at Penn State. “I had assumed that if someone shared something, they read and thought about it, that they’re supporting or even championing the content. You might expect that maybe a few people would occasionally share content without thinking it through, but for most shares to be like this? That was a surprising, very scary finding.”

Access to the Facebook data was granted via Social Science One, a research consortium hosted by Harvard University’s Institute for Quantitative Social Science focused on obtaining and sharing social and behavioral data responsibly and ethically. The data were provided in collaboration with Meta, Facebook’s parent company, and included user demographics and behaviors, such as a “political page affinity score.” This score was determined by external researchers identifying the pages users follow — like the accounts of media outlets and political figures. The researchers used the political page affinity score to assign users to one of five groups — very liberal, liberal, neutral, conservative and very conservative.

To determine the political content of shared links, the researchers in this study used machine learning, a form of artificial intelligence, to identify and classify political terms in the link content. They scored the content on a similar five-point political affinity scale, from very liberal to very conservative, based on how many times each affinity group shared the link.

"We created this new variable of political affinity of content based on 35 million Facebook posts during election season across four years. This is a meaningful period to understand macro-level patterns behind social media news sharing,” said co-author Eugene Cho Snyder, assistant professor of humanities and social sciences at New Jersey Institute of Technology

The team validated the political affinity of news domains, such as CNN or Fox, based on the media bias chart produced by AllSides, an independent company focused on helping people understand the biases of news content, and a ratings system developed by researchers at Northeastern University.

With these rating systems, the team manually sorted 8,000 links, first identifying them as political or non-political content. Then the researchers used this dataset to train an algorithm that assessed 35 million links shared more than 100 times on Facebook by users in the United States.

“A pattern emerged that was confirmed at the level of individual links,” Snyder said. “The closer the political alignment of the content to the user — both liberal and conservative — the more it was shared without clicks. … They are simply forwarding things that seem on the surface to agree with their political ideology, not realizing that they may sometimes be sharing false information.”

The findings support the theory that many users superficially read news stories based just on headlines and blurbs, Sundar said, explaining that Meta also provided data from its third-party fact-checking service — which identified that 2,969 of the shared URLs linked to false content.

The researchers found that these links were shared over 41 million times, without being clicked. Of these, 76.94% came from conservative users and 14.25% from liberal users. The researchers explained that the vast majority — up to 82% — of the links to false information in the dataset originated from conservative news domains.

To cut down on sharing without clicking, Sundar said that social media platforms could introduce “friction” to slow the share, such as requiring people to acknowledge that they have read the full content prior to sharing.

“Superficial processing of headlines and blurbs can be dangerous if false data are being shared and not investigated,” Sundar said, explaining that social media users may feel that content has already been vetted by those in their network sharing it, but this work shows that is unlikely. “If platforms implement a warning that the content might be false and make users acknowledge the danger in doing so, that might help people think before sharing.”

This wouldn’t stop intentional misinformation campaigns, Sundar said, and individuals still have a responsibility to vet the content they share.

“Disinformation or misinformation campaigns aim to sow the seeds of doubt or dissent in a democracy — the scope of these efforts came to light in the 2016 and 2020 elections,” Sundar said. “If people are sharing without clicking, they’re potentially playing into the disinformation and unwittingly contributing to these campaigns staged by hostile adversaries attempting to sow division and distrust.”

So, why do people share without clicking in the first place?

“The reason this happens may be because people are just bombarded with information and are not stopping to think through it,” Sundar said. “In such an environment, misinformation has more of a chance of going viral. Hopefully, people will learn from our study and become more media literate, digitally savvy and, ultimately, more aware of what they are sharing.”

Other collaborators on this paper include Junjun Yin and Guangqing Chi, Penn State; Mengqi Liao, University of Georgia; and Jinping Wang, University of Florida.

The Social Science Research Council, New York, supported this research.

 SPACE/COSMOS

SpaceX launches Starship but fails to repeat booster catch as Trump, Musk look on


SpaceX launched its Starship megarocket Tuesday, attended by President-elect Donald Trump and allies. The Super Heavy booster splashed into the Gulf of Mexico, missing the "chopstick" tower catch. SpaceX cited technical issues, overshadowing the event despite Trump's praise of the engineering feat during his victory speech.



Issued on: 20/11/2024 -
By: NEWS WIRES
Video by: Fraser JACKSON

01:47
The first stage of SpaceX's Starship rocket after landing off the coast of Texas during a test flight on November 19, 2024.
 © Chandan Khanna, AFP


SpaceX flew its latest test flight of its Starship megarocket on Tuesday, with President-elect Donald Trump joining Elon Musk to witness the spectacle firsthand in the latest sign of their ever closer ties.

But the Republican leader was deprived of the chance to see the descending first stage caught in the launch tower's "chopstick" arms, an engineering marvel demonstrated by the company last month and one he personally lauded during his election victory speech.

Instead, the massive Super Heavy booster made a more subdued splashdown in the Gulf of Mexico.

Company representatives cited unmet technical criteria, dampening the triumph of an event attended by an array of Trump-world figures.


Space X founder and CEO Musk has been a constant presence at Trump's side since the incoming president's election victory, joining him at a meeting with Argentina's President Javier Milei and even at a UFC bout.

Trump's decision to travel to Musk's home turf was the latest sign of the burgeoning bond between the billionaire duo, which has raised questions over possible conflicts of interests given SpaceX's lucrative contracts with NASA and the Pentagon.

Watch more  Spectacular landing: SpaceX catches giant Starship booster with mechanical arms

Flying in from his Mar-a-Lago home, Trump greeted Musk warmly on Tuesday afternoon, sporting a red MAGA hat as the pair headed off to watch from the control tower of the company's Starbase in Boca Chica, Texas, where Starship blasted off at 4:00 pm (2200 GMT).

Tuesday's launch marked the quickest turnaround between test flights for the world's most powerful rocket, a gleaming, 400-foot-tall (121-meter) stainless steel colossus central to Musk's ambition of colonising Mars and making humanity a multiplanetary species.

Musk aims to launch the first uncrewed missions to the Red Planet as early as 2026, coinciding with the next "Mars transfer window" -- a period when the journey between Earth and Mars is at its shortest.

NASA is also counting on a specialised version of Starship to ferry astronauts to the lunar surface later this decade under its Artemis program.
Stuffed banana

Flight six of Starship was seen as a test of whether SpaceX's first booster catch was pure precision or relied on a stroke of luck after Musk -- perhaps inadvertently -- disclosed how close the last flight came to disaster.

In a clip posted to X showcasing his gaming chops in "Diablo IV," sharp-eared fans caught an employee briefing him that the Super Heavy booster was "one second away" from a system failure that could have spelled catastrophe.

Starship's upper stage meanwhile made a partial orbit of Earth, reentered the atmosphere and splashed down in the Indian Ocean around an hour and five minutes after launch.

SpaceX employees erupted in cheers during a live feed watched by nearly nine million viewers, as the upper stage executed a near-vertical daylight splashdown off Australia's northwest coast, sending up a towering plume of water vapor before tipping over.

Key milestones included reigniting Starship's Raptor engines for the first time in space and trialing new heat shield materials. The flight also carried Starship's first ever payload -- a stuffed banana -- and served as a swan song for the current generation of Starship prototypes.

With twice the thrust of the Saturn V rockets that powered Apollo missions, Starship is the most powerful rocket ever built.

Musk has already teased that its successor, Starship V3, will be "3X more powerful" and could take flight in about a year.

The flight comes as Musk is riding high on Trump's November 5 White House win, having campaigned extensively for the returning Republican leader, as well as donating staggering sums from his own fortune to the cause.

His loyalty has paid off. Musk has been tapped to co-lead a new "Department of Government Efficiency" -- or DOGE, a cheeky nod to the meme-based cryptocurrency Musk loves to promote.

That in turn has led to concerns Musk could engage in "self-dealing" as the CEO is poised to straddle the line between government insider and corporate titan.

(AFP)


Unlocking the secrets of the first quasars: how they defy the laws of physics to grow



Istituto Nazionale di Astrofisica
An accreting supermassive black hole 

image: 

AI-generated representation of an accreting supermassive black hole, surrounded by gas spiralling toward it along the equatorial plane (the accretion disk) and emitting powerful winds of matter as it falls in. This representation is based on a NASA's artist's concept that illustrates a supermassive black hole with millions to billions times the mass of our sun.

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Credit: Credits: Emanuela Tortosa




In the article published today in the Astronomy & Astrophysics journal, new evidence suggests how supermassive black holes, with masses of several billion times that of our Sun, formed so rapidly in less than a billion years after the Big Bang. The study, led by researchers of the National Institute for Astrophysics (INAF), analyses a sample of 21 quasars, among the most distant ever discovered, observed in the X-rays band by the XMM-Newton and Chandra space telescopes. The results suggest that the supermassive black holes at the centre of these titanic quasars, the first formed during the cosmic dawn, may have reached their extraordinary masses through very rapid and intense accretion, thus providing a plausible explanation for their existence in the early stages of the Universe.

Quasars are active galaxies powered by the central supermassive black holes (known as active galactic nuclei), which emit an enormous amount of energy as they attract matter. They are extremely luminous and distant from us. In particular, the quasars examined in this study are among the most distant objects ever observed, dating back to a time when the Universe was less than a billion years old.

In this work, the analysis of X-ray emissions from these objects revealed an entirely unexpected behaviour of the supermassive black holes at their centres: a connection emerged between the shape of the X-ray emission and the speed of the winds of matter ejected by the quasars. This relationship links the wind speed, which can reach thousands of kilometres per second, to the temperature of the gas in the corona, the region that emits X-rays closest to the black hole. Thus, the corona turned out to be connected to the powerful accretion mechanisms of the black hole itself. Quasars with low-energy X-ray emission, and thus a lower temperature in the corona, show faster winds. This indicates a highly rapid growth phase that exceeds a physical limit for the accretion of matter called the Eddington limit, which is why this phase is called "super-Eddington." Conversely, quasars with higher-energy X-ray emissions tend to exhibit slower winds.

"Our work suggests that the supermassive black holes at the centre of the first quasars formed within the first billion years of the Universe's life may have actually increased their mass very rapidly, challenging the limits of physics," says Alessia Tortosa, lead author of the study and researcher at INAF in Rome. "The discovery of this connection between X-ray emission and winds is crucial for understanding how such large black holes could have formed in such a short time, thus providing a concrete clue to solve one of the greatest mysteries of modern astrophysics."

The result was achieved mainly by analysing data collected with the XMM-Newton space telescope of the European Space Agency (ESA), which allowed for approximately 700 hours of observations of the quasars. Most of the data, collected between 2021 and 2023 as part of the Multi-Year XMM-Newton Heritage Programme, under the direction of Luca Zappacosta, a researcher at INAF in Rome, is part of the HYPERION project, which aims at studying hyperluminous quasars during the cosmic dawn of the Universe. The extensive observation campaign was led by a team of Italian scientists and received crucial support from INAF, which funded the program, thereby supporting cutting-edge research on the evolutionary dynamics of the early structures of the Universe.

"In the HYPERION program, we focused on two key factors: on one hand, the careful selection of quasars to observe, choosing the titans, meaning those that had accumulated as much mass as possible, and on the other hand, the in-depth study of their properties in X-rays, something never attempted before on such a large number of objects from the cosmic dawn," says Luca Zappacosta, a researcher at INAF in Rome. We hit the jackpot! The results we're getting are genuinely unexpected, and they all point to a super-Eddington growth mechanism of the black holes."

This study provides important insights for future X-ray missions, such as ATHENA (ESA), AXIS, and Lynx (NASA), which are scheduled for launch between 2030 and 2040. In fact, the results obtained will be useful for refining the next-generation observational instruments and for defining better strategies for investigating black holes and active galactic nuclei in X-rays at more distant cosmic epochs. These are key elements for understanding the formation of the first galactic structures in the primordial Universe.

Related journal article: HYPERION. Shedding light on the first luminous quasars: A correlation between UV disc winds and X-ray continuum”, di Tortosa A. et al. 2024, Astronomy & Astrophysics.

Tuesday, November 19, 2024

Hundreds of 19th-century skulls collected in the name of medical science tell a story

The Conversation
November 18, 2024

Human Skull (AFP)

When I started my research on the Samuel George Morton Cranial Collection, a librarian leaned over my laptop one day to share some lore. “Legend has it,” she said, “John James Audubon really collected the skulls Morton claimed as his own.” Her voice was lowered so as not to disturb the other scholars in the hushed archive.

As my work progressed, I uncovered no evidence to substantiate her whispered claim. Audubon had collected human skulls, several of which he then passed on to Morton. But birds and ornithology remained Audubon’s passion.

Nevertheless, the librarian’s offhanded comment has proven useful – a touchstone of sorts that continues to remind me of the controversy and confusion long surrounding the Morton Collection.

Morton was a physician and naturalist who lived in Philadelphia from 1799 until the end of his life in 1851. A lecture he delivered to aspiring doctors at the Philadelphia Association for Medical Instruction outlined the reasons for his cranial compulsion:
“I commenced the study of Ethnology in 1830; in which year, having occasion to deliver an introductory lecture on Anatomy, it occurred to me to illustrate the difference in the form of the skull as seen in the five great races of men … When I sought the materials for my proposed lecture, I found to my surprise that they could be neither bought nor borrowed.”

He would go on to acquire almost 1,000 human skulls.

Morton used these skulls to advance an understanding of racial differences as natural, easily categorizable and able to be ranked. Big-brained “Caucasians,” he argued in the 1839 publication “Crania Americana,” were far superior to small-skulled American Indians and even smaller-skulled Black Africans. Many subsequent scholars have since thoroughly debunked his ideas.

Certainly, condemnation of Morton as a scientific racist is warranted. But I find this take represents the man as a caricature, his conclusions as foregone. It provides little insight into his life and the complicated, interesting times in which he lived, as I detail in my book “Becoming Object: The Sociopolitics of the Samuel George Morton Cranial Collection.”

My research demonstrates that studies of skulls and diseases undertaken by Morton and his medical and scientific colleagues contributed to an understanding of U.S. citizenship that valued whiteness, Christianity and heroic masculinity defined by violence. It is an exclusionary idea of what it means to be American that persists today.

Yet, at the same time, the collection is an unintended testament to the diversity of the U.S. population during a tumultuous moment in the nation’s history.


Samuel Morton wasn’t a lone voice on the fringe of medicine. 'Memoir of the life and scientific labors of Samuel George Morton' by Henry S. Patterson, CC BY


Men of science and medicine

As a bioarchaeologist who has studied the Morton Collection for many years, I have sought to better understand the social, political and ideological circumstances that led to its creation. From my work – analyzing archival sources including letters, laws, maps and medical treatises, as well as the skulls themselves – I’ve learned that, over a lifetime, Morton fostered a professional network that had far-reaching tentacles.

He had plenty of help amassing the collection of skulls that bears his name.

The physician connected with medical colleagues – many of whom, like him, received degrees from the University of Pennsylvania – gentleman planters, enslavers, naturalists, amateur paleontologists, foreign diplomats and military officers. Occupational differences aside, they were mostly white, Christian men of some financial means.

Their interactions took place during a pivotal moment in American history, the interlude between the nation’s revolutionary consolidation and its violent civil unraveling.

Throughout this stretch of time, Morton and his colleagues catalyzed biomedical interventions and scientific standards to more effectively treat patients. They set in motion public health initiatives during epidemics. They established hospitals and medical schools. And they did so in the service of the nation.

Not all lives were seen as worthy of these men’s care, however. Men of science and medicine may have fostered life for many, but they also let others die. In “Becoming Object,” I track how they represented certain populations as biologically inferior; diseases were tied to nonwhite people, female anatomy was pathologized, and poverty was presumed inherited.

From person to specimen

Such representations made it easier for Morton and his colleagues to regulate these groups’ bodies, rationalize their deaths and collect their skulls with casual cruelty from almshouse dissecting tables, looted cemeteries and body-strewn battlefields. That is, a sizable portion of the skulls in Morton’s collections were not culled from ancient graves but belonged to those of the recently alive.

It is no coincidence that Morton began his scientific research in earnest the same year Andrew Jackson signed the Indian Removal Act of 1830. Men of science and medicine benefited from the expansionist policies, violent martial conflicts and Native displacement that underpinned Manifest Destiny.


A drawing from Morton’s book of the skull of a Seminole man killed by American troops. A bullet hole is visible on the left side of the man’s head. 'Crania Americana' by Samuel George Morton, CC BY


The collection reveals these acts of nation-building as necropolitical strategies – techniques used by sovereign powers to destroy or erase certain, often already vulnerable, populations from the national consciousness. These skulls attest to precarious existences, untimely deaths and trauma experienced from cradle to beyond the grave.

In the specific case of Native Americans, skeletal analysis testifies to the violent effects of U.S. military campaigns and forced removal. Native skulls that Morton labeled “warriors” have evidence of unhealed fractures and gunshot wounds. Children’s skulls bear the marks of compromised health; such pathology and their young ages at death are evidence of long-standing malnutrition, poverty and deprivation or stress.


To effectively transform subjects into objects – human beings into specimens – collected crania were ensconced in the institutional spaces of medical school lecture halls and museum storage cabinets.

There, Morton first numbered them sequentially. These numbers along with information about race, sex, age, “idiocy” or “criminality,” cranial capacity and provenance were inked on skulls and written in catalogs. Very rarely was the person’s name recorded. If used as teaching tools, Morton drilled holes to hang the skulls for display and notated them with the names of skeletal elements and features.

As dehumanizing as this process was, the Morton Collection does contain evidence of resilience and heterogeneous lives. There are traces of people with mixed-race backgrounds such as Black Indians. Several people may have also bent gender to navigate dire conditions or in keeping with social norms, such as native Beloved Women, who were active in warfare and political life.



In contrast to those whose skulls ended up in his collection, Samuel Morton’s own grave was memorialized with a monument. Pamela L. Geller


What these bones mean today


As anthropologists now recognize, it is through the repatriation of the remains of the people in the Morton Collection to their descendants, among other types of reparations, that current practitioners may begin to atone for the sins of intellectual forebears. Indeed, all institutions housing legacy collections must contend with this issue.

There are other, valuable lessons – about diversity and suffering – that the Morton Collection has to impart in today’s interesting times.

The collection demonstrates that the American body politic has always been a diverse one, despite efforts of erasure by men like Morton and his colleagues. Piecing together the stories of past, disenfranchised lives – and acknowledging the silences that have made it difficult to flesh them out – counters past white nationalism and xenophobia and their current resurgence.

The collection, I believe, also urges the repudiation of violence, casual cruelty and opportunism as admirable attributes of masculinity. Valorizing men who embody these qualities has never served America well. Particularly in the mid-1800s, when Morton amassed skulls, it led to a nation divided and hardened to suffering, an unfathomable death count and the increasing fragility of democracy.

Pamela L. Geller, Associate Professor of Anthropology, University of Miami

This article is republished from The Conversation under a Creative Commons license. Read the original article.
SPACE / COSMOS

Egg-shaped galaxies may be aligned to the black holes at their hearts, astronomers find


The Conversation
November 18, 2024

The active galaxy Centaurus A, with jets emanating from the central black hole. ESO/WFI (Optical); MPIfR/ESO/APEX/A.Weiss et al. (Submillimetre); NASA/CXC/CfA/R.Kraft et al. (X-ray), CC BY

Black holes don’t have many identifying features. They come in one color (black) and one shape (spherical).

The main difference between black holes is mass: some weigh about as much as a star like our Sun, while others weigh around a million times more. Stellar-mass black holes can be found anywhere in a galaxy, but the really big ones (known as supermassive black holes) are found in the cores of galaxies.

These supermassive behemoths are still quite tiny when seen in cosmic perspective, typically containing only around 1% of their host galaxy’s mass and extending only to a millionth of its width

However, as we have just discovered, there is a surprising link between what goes on near the black hole and the shape of the entire galaxy that surrounds it. Our results are published in Nature Astronomy.

When black holes light up

Supermassive black holes are fairly rare. Our Milky Way galaxy has one at its centre (named Sagittarius A*), and many other galaxies also seem to host a single supermassive black hole at their core.


Under the right circumstances, dust and gas falling into these galactic cores can form a disk of hot material around the black hole. This “accretion disk” in turn generates a super-heated jet of charged particles that are ejected from the black hole at mind-boggling velocities, close to the speed of light.

When a supermassive black hole lights up like this, we call it a quasar.

How to watch a quasar

To get a good look at quasar jets, astronomers often use radio telescopes. In fact, we sometimes combine observations from multiple radio telescopes located in different parts of the world.

Using a technique called very long baseline interferometry, we can in effect make a single telescope the size of the entire Earth. This massive eye is much better at resolving fine detail than any individual telescope.

As a result, we can not only see objects and structures much smaller than we can with the naked eye, we can do better than the James Webb Space Telescope.



Black holes are millions of times smaller than galaxies, yet make jets that are pointed in the same direction as the entire galaxy. Optical image: NASA, ESA, R.M. Crockett (University of Oxford, U.K.), S. Kaviraj (Imperial College London and University of Oxford, U.K.), J. Silk (University of Oxford), M. Mutchler (Space Telescope Science Institute, Baltimore, USA), R. O'Connell (University of Virginia, Charlottesville, USA), and the WFC3 Scientific Oversight Committee. Top right: MOJAVE Collaboration, NRAO/NSF. Bottom right: Event Horizon Telescope / ESO (same as before) CC BY-SA

This is the technique that was used to make the first “black hole image” in 2019, showing the halo of light generated around the supermassive black hole hosted by the galaxy M87.


Quasar jets that can be detected using very long baseline interferometry can be millions of light years long and are almost always found in elliptical galaxies. Using very long baseline interferometry, we can observe them all the way down to a few light years or so from their black hole of origin.

The direction of the jet near its source tells us about the orientation of the accretion disk, and so potentially the properties of the black hole itself.


Connection to the host galaxy


What about the host galaxies? A galaxy is a three-dimensional object, formed of hundreds of billions of stars.

But it appears to us (observed in optical or infrared) in projection, either as an ellipse or a spiral. We can measure the shape of these galaxies, tracing the profile of starlight, and measure the long axis and short axis of the two-dimensional shape.

In our paper, we compared the direction of quasar jets with the direction of this shorter axis of the galaxy ellipse, and found that they tend to be pointing in the same direction. This alignment is more statistically significant than you would expect if they were both randomly oriented.

This is surprising, as the black hole is so small (the jets we measure are only a few light years in length) compared to the host galaxy (which can be hundreds of thousands or even millions of light years across).

It is surprising that such a relatively small object can affect, or be affected by, the environment on such large scales. We might expect to see a correlation between the jet and the local environment, but not with the whole galaxy.
How galaxies form

Does this have something to say about the way galaxies form?


Spiral galaxies are perhaps the most famous kind of galaxy, but sometimes they collide with other spirals and form elliptical galaxies. We see these three-dimensional egg-shaped blobs as two-dimensional ellipses on the sky.

The merger process triggers quasar activity in ways we don’t fully understand. As a result, almost all quasar jets that can be detected using very long baseline interferometry are hosted in elliptical galaxies.

The exact interpretation of our results remains mysterious, but is important in the context of the recent James Webb Space Telescope discovery of highly massive quasars (with massive black holes), which have formed much earlier in the universe than expected. Clearly, our understanding of how galaxies form and how black holes influence that needs to be updated.


David Parkinson, Research Scientist in Astrophysics, The University of Queensland and Jeffrey Hodgson, Assistant Professor in Astrophysics, Sejong University

This article is republished from The Conversation under a Creative Commons license. Read the original article.


AnalySwift receives NASA STTR contract to transform spacecraft infrastructure for secondary uses during long-duration missions



Company and Purdue will develop composite heater layer and better engineering tools for composites



Purdue University

Kawai Kwok, Purdue University and AnalySwift, NASA STTR contract, reassembly 

image: 

Kawai Kwok, an associate professor in Purdue University’s School of Aeronautics and Astronautics, will be the primary investigator on a project with commercial software provider AnalySwift LLC. NASA has awarded AnalySwift a $156,424 Phase I Small Business Technology Transfer contract for the research.

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Credit: (Purdue University photo/Alan Cesar)




WEST LAFAYETTE, Ind. — AnalySwift LLC, a Purdue University-affiliated company, has received a Phase I STTR (Small Business Technology Transfer) contract from NASA worth $156,424.

Allan Wood, AnalySwift president and CEO, said the contract will fund two advancements: processes and hardware to disassemble spacecraft components and reassemble them for a secondary use, and software for multiphysics simulation and analysis of the involved thermoplastics.

Kawai Kwok, associate professor in Purdue’s School of Aeronautics and Astronautics, is the principal investigator.

Wood said long-duration crewed missions to the moon, Mars and beyond require infrastructure, such as trusses, to be constructed sustainably on these surfaces. But there are immense logistical challenges in transporting heavy and large payloads to space.

“The AnalySwift project proposes a novel method of disassembling and reassembling thermoplastic composite joints in space,” he said. “Our proposed method enables reconfiguration of truss structures in space, transitioning away from the current one-time use model to a scalable and sustainable approach.”

Kwok said spacecraft components could be quickly and easily repurposed into vastly different geometries.

“For example, a lunar lander support truss could become a vertical solar array support truss,” he said. “There are other applications, depending on mission needs using the same set of structural elements and innovative multiphysics modeling.”

Contract deliverables

Kwok said AnalySwift will develop a composite heater layer for the trusses and other infrastructure; it will be embedded with nanostructured carbon fillers. The layer will be made from the same thermoplastic matrix as the adhered composite parts. The layer will bring the matrix to the processing temperature for interface debonding by mechanical forces.

“Lightweight conductive nanocarbon thin films will be encapsulated inside semicrystalline thermoplastics such as PEEK (polyether ether ketone),” he said. “The disassembled struts and joints will be reassembled to the repurposed configuration via resistance welding using the same or additional heaters. The proposed in situ heating and reassembly method enables spacecraft components to be reutilized, which greatly reduces the logistical footprint to deliver technologies to space.”

Liang Zhang, senior research scientist at AnalySwift, said the company also will develop better engineering tools for composites, enabling reliable multiphysics simulation of their technique to repurpose lightweight structures made from thermoplastics.

“Theoretical and computational developments will include a new software tool or module, Thermoplastic Composites Multiphysics,” he said. “This multiphysics modeling framework will simulate the debonding and bonding processes of thermoplastic composite joint-strut interfaces using embedded carbon nanoheaters.”

Kwok said the framework has broader applications for thermoplastics.

“Advancements include developing multiphysics models and data for electrical heating and welding, including establishing relations between bonding strength and the process conditions of temperature, pressure and time,” he said. “More specifically, the disassembly and assembly processes of a nanocomposite is simulated using a third-party commercial finite element code with user subroutines defining the governing behavior of the material system.”

Zhang said AnalySwift’s multiphysics simulation tool will determine force, pressure and temperature histories during assembly and disassembly processes.

“More specifically, it will incrementally solve the constitutive relations as an initial value problem, extract temperature distributions at specific time points, and calculate the time and power required for completion,” he said.

Non-space applications

Wood said the processes and hardware advancements for disassembly and reassembly are more applicable to space applications, but the software has other potential uses.

“It can be particularly useful where simulation tools can improve utilization possibilities for high-performance thermoplastics,” he said. “Additional applications can be likely for aerospace, defense, automotive, marine, energy, electronics, sporting goods and medical devices. Applications also extend beyond simulation and into repair for thermoplastics.”

About AnalySwift

AnalySwift LLC is a provider of composite simulation software, which enables an unprecedented combination of efficiency and accuracy, including multiphysics structural and micromechanics modeling. Drawing on cutting-edge university technology, AnalySwift’s powerful solutions save orders of magnitude in computing time without a loss of accuracy so users can consider more design options and arrive at the best solution more quickly. The technologies deliver the accuracy of detailed 3D finite element analysis at the efficiency of simple engineering models. SwiftComp was developed at Purdue University and licensed from the Purdue Research Foundation. Contact AnalySwift at info@analyswift.com.

About Purdue Innovates Office of Technology Commercialization

The Purdue Innovates Office of Technology Commercialization operates one of the most comprehensive technology transfer programs among leading research universities in the U.S. Services provided by this office support the economic development initiatives of Purdue University and benefit the university’s academic activities through commercializing, licensing and protecting Purdue intellectual property. In fiscal year 2024, the office reported 145 deals finalized with 224 technologies signed, 466 invention disclosures received, and 290 U.S. and international patents received. The office is managed by the Purdue Research Foundation, a private, nonprofit foundation created to advance the mission of Purdue University. Contact otcip@prf.org for more information.

About Purdue University

Purdue University is a public research institution demonstrating excellence at scale. Ranked among top 10 public universities and with two colleges in the top four in the United States, Purdue discovers and disseminates knowledge with a quality and at a scale second to none. More than 105,000 students study at Purdue across modalities and locations, including nearly 50,000 in person on the West Lafayette campus. Committed to affordability and accessibility, Purdue’s main campus has frozen tuition 13 years in a row. See how Purdue never stops in the persistent pursuit of the next giant leap — including its first comprehensive urban campus in Indianapolis, the Mitch Daniels School of Business, Purdue Computes and the One Health initiative — at https://www.purdue.edu/president/strategic-initiatives.

Media contact: Steve Martin, sgmartin@prf.org


New idea may crack enigma of the Crab Nebula’s ‘zebra’ pattern



University of Kansas
Zebra-pattern pulsar 

image: 

Medvedev modeled wave diffraction off a circular reflecting region with radially varying index of refraction outside of it to better understand the Crab Nebula’s zebra pattern.

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Credit: Mikhail Medvedev




LAWRENCE — A theoretical astrophysicist from the University of Kansas may have solved a nearly two-decade-old mystery over the origins of an unusual "zebra" pattern seen in high-frequency radio pulses from the Crab Nebula.

His findings have just been published in Physical Review Letters (PRL), among the most prestigious physics journals.

The Crab Nebula features a neutron star at its center that has formed into a 12-mile-wide pulsar pinwheeling electromagnetic radiation across the cosmos.

“The emission, which resembles a lighthouse beam, repeatedly sweeps past Earth as the star rotates,” said lead author Mikhail Medvedev, professor of physics & astronomy at KU. “We observe this as a pulsed emission, usually with one or two pulses per rotation. The specific pulsar I’m discussing is known as the Crab Pulsar, located in the center of the Crab Nebula 6,000 light years away from us.”

The Crab Nebula is the remnant of a supernova that appeared in 1054.

“Historical records, including Chinese accounts, describe an unusually bright star appearing in the sky,” said the KU researcher.

But unlike any other known pulsar, Medvedev said the Crab Pulsar features a zebra pattern — unusual band spacing in the electromagnetic spectrum proportional to band frequencies, and other weird features like high polarization and stability.

“It’s very bright, across practically all wave bands,” he said. “This is the only object we know of that produces the zebra pattern, and it only appears in a single emission component from the Crab Pulsar. The main pulse is a broadband pulse, typical of most pulsars, with other broadband components common to neutron stars. However, the high-frequency interpulse is unique, ranging between 5 and 30 gigahertz — frequencies similar to those in a microwave oven.”

Since this pattern was discovered in a 2007 paper, the KU researcher said the pattern had proved “baffling” for investigators.

“Researchers proposed various emission mechanisms, but none have convincingly explained the observed patterns,” he said.

Using data from the Crab Pulsar, Medvedev established a method using wave optics to gauge the density of the pulsar’s plasma – the “gas” of charged particles (electrons and positrons) — using a fringe pattern found in the electromagnetic pulses.

“If you have a screen and an electromagnetic wave passes by, the wave doesn’t propagate straight through,” Medvedev said. “In geometrical optics, shadows cast by obstacles would extend indefinitely — if you’re in the shadow, there’s no light; outside of it, you see light. But wave optics introduces a different behavior — waves bend around obstacles and interfere with each other, creating a sequence of bright and dim fringes due to constructive and destructive interference.”

This well-known fringe pattern phenomenon is caused by consistent constructive interference but has different characteristics when radio waves propagate around a neutron star.

“A typical diffraction pattern would produce evenly spaced fringes if we just had a neutron star as a shield,” the KU researcher said. “But here, the neutron star’s magnetic field generates charged particles constituting a dense plasma, which varies with distance from the star. As a radio wave propagates through the plasma, it passes through dilute areas but is reflected by dense plasma. This reflection varies by frequency: Low frequencies reflect at large radii, casting a bigger shadow, while high frequencies create smaller shadows, resulting in different fringe spacing.”

In this way, Medvedev determined the Crab Pulsar’s plasma matter causes diffraction in the electromagnetic pulses responsible for the neutron star’s singular zebra pattern.

“This model is the first one capable of measuring those parameters,” Medvedev said. “By analyzing the fringes, we can deduce the density and distribution of plasma in the magnetosphere. It's incredible because these observations allow us to convert fringe measurements into a density distribution of the plasma, essentially creating an image or performing tomography of the neutron star's magnetosphere.”

Next, Medvedev said his theory can be tested with collection of more data from the Crab Pulsar and fine-tuned by factoring in its powerful and strange gravitational and polarization effects. The new understanding of how a plasma matter alters a pulsar’s signal will change how astrophysicists understand other pulsars.

“The Crab Pulsar is somewhat unique — it’s relatively young by astronomical standards, only about a thousand years old, and highly energetic,” he said. “But it’s not alone; we know of hundreds of pulsars, with over a dozen that are also young. Known binary pulsars, which were used to test Einstein’s general relativity theory, can also be explored with the proposed method. This research can indeed broaden our understanding and observation techniques for pulsars, particularly young, energetic ones.”