SoylentNews

noep writes:

https://www.psi.ch/en/science/scientific-highlights/altermagnetism-proves-its-place-on-the-magnetic-family-tree

There is now a new addition to the magnetic family: thanks to experiments at the Swiss Light Source SLS, researchers have proved the existence of altermagnetism:

Altermagnets have a special combination of the arrangement of spins and crystal symmetries. The spins alternate, as in antiferromagnets, resulting in no net magnetisation. Yet, rather than simply cancelling out, the symmetries give an electronic band structure with strong spin polarization that flips in direction as you pass through the material's energy bands -- hence the name altermagnets. This results in highly useful properties more resemblant of ferromagnets, as well as some completely new properties.

Spintronics has promised to revolutionise IT. Typically, ferromagnets have been used as they offer highly desirable, strong, spin-dependent physical phenomena. Yet the macroscopic net magnetisation that is useful in so many other applications poses practical limitations on the scalability of these devices as it causes crosstalk between bits. Instead, Antiferromagnets have been investigated for spintronics, as they have no net magnetisation and thus offer ultra-scalability and energy efficiency. However, the strong spin-dependent effects are lacking, again hindering their practical applicability.

Enter altermagnets with the best of both: zero net magnetisation together with the coveted strong spin-dependent phenomena typically found in ferromagnets -- merits that were regarded as principally incompatible.

The researchers believe that this new fundamental discovery in magnetism will enrich our understanding of condensed-matter physics, with impact across diverse areas of research and technology. As well as its advantages to the developing field of spintronics, it also offers a promising platform for exploring unconventional superconductivity, through new insights into superconducting states that can arise in different magnetic materials.

"Altermagnetism is actually not something hugely complicated. It is something entirely fundamental that was in front of our eyes for decades without noticing it," says Jungwirth. "And it is not something that exists only in a few obscure materials. It exists in many crystals that people simply had in their drawers. In that sense, now that we have brought it to light, many people around the world will be able to work on it, giving the potential for a broad impact."

Original Publications: Altermagnetic Lifting of Kramers spin degeneracy (J. Krempaský, L. Šmejkal, S. W. D'Souza, M. Hajlaoui, G. Springholz, K. Uhlířová, F. Alarab, P. C. Constantinou, V. Strokov, D. Usanov, W. R. Pudelko, R. González-Hernández, A. Birk Hellenes, Z. Jansa, H. Reichlová, Z. Šobáň, R. D. Gonzalez Betancourt, P. Wadley, J. Sinova, D. Kriegner, J. Minár, J. H. Dil, T. Jungwirth) Nature, 14 February 2024

DOI: 10.1038/s41586-023-06907-7

Original Submission

hubie writes:

Quitting smoking at any age brings big health benefits, fast: study:

People who quit smoking see major gains in life expectancy after just a few years, according to a new study by University of Toronto researchers at Unity Health Toronto.

The study, published in NEJM Evidence, shows that smokers who quit smoking before age 40 can expect to live almost as long as those who never smoked. Those who quit at any age return close to never-smoker survival 10 years after quitting, and about half that benefit occurs within just three years.

[...] Former smokers lowered their risk of death to 1.3-fold (or 30 per cent higher) compared to never smokers. Stopping smoking at any age was associated with longer survival, and even those who quit for less than three years gained up to six years in life expectancy.

"Many people think it's too late to quit smoking, especially in middle age," said Jha. "But these results counter that line of thought. It's never too late, the impact is fast and you can reduce risk across major diseases, meaning a longer and better quality of life."

The researchers found that quitting smoking reduced the risk of dying from vascular disease and cancer, in particular. Former smokers also reduced their risk of death from respiratory disease, but slightly less so, likely due to residual lung damage.

Journal Reference:
Eo Rin Cho, Ilene K. Brill, Inger T. Gram, et al., Smoking Cessation and Short- and Longer-Term Mortality, NEJM Evidence, 2024. https://doi.org/10.1056/EVIDoa2300272

Original Submission

taylorvich writes:

https://newatlas.com/energy/geologic-hydrogen-gold-rush/

There's enough natural hydrogen trapped underground to meet all projected demands for hundreds of years. An unpublished report by the US Geological Survey identifies it as a new primary resource, and fires the starter pistol on a new gold rush.

The "black gold" oil rush in the US started in 1859, when one Edwin Drake drove a stake into the Pennsylvania soil and oil started flowing out. The gold hydrogen rush may have a similar moment to point back to; in 1987, as one Mamadou Ngulo Konaré tells the story, well diggers gave up on a 108-m (354-ft) deep dry borehole, but he and other villagers in Bourakébougou, Mali, noticed that wind was blowing out of it. When one of the drillers looked in, smoking a cigarette, it blew up in his face, causing severe burns as well as a huge fire.

That fire, as Science quoted Konaré, burned "like blue sparking water, and did not have black smoke pollution. The color of the fire at night was like shining gold." It took weeks to put the fire out and plug the hole, but subsequent analysis showed the gas coming out was 98% pure hydrogen. Celebratory mangos were served. Some years later, a little 30 kW Ford generator was hooked up, and Bourakébougou became the first village in the world to enjoy the benefits of clean, naturally occuring hydrogen as a green energy source.
...
Either way, the situation has now changed, big time. Geoffrey Ellis, of the US Geological Survey, has been investigating the global potential of geo-locked "gold" hydrogen as a new primary resource. In a Denver meeting of the American Association for the Advancement of Science, he previewed the results of an as-yet unpublished study, according to the Financial Times.

In short, there are as many as 5.5 trillion tons of hydrogen in underground reservoirs worldwide. It may have been generated by the interaction of certain iron-rich minerals with subterranean water. In some cases, it may be mixed in with other gases such as methane, from which it would need to be separated. But it's there, in such extraordinary quantities that analysts are expecting a gold hydrogen rush at a global scale.

upstart writes:

Users are even more likely to stick with Google due to one change, says Yelp:

To comply with looming rules that ban tech giants from favoring their own services, Google has been testing new look search results for flights, trains, hotels, restaurants, and products in Europe. The EU's Digital Markets Act is supposed to help smaller companies get more traffic from Google, but reviews service Yelp says that when it tested Google's design tweaks with consumers it had the opposite effect—making people less likely to click through to Yelp or another Google competitor.

The results, which Yelp shared with European regulators in December and WIRED this month, put some numerical backing behind complaints from Google rivals in travel, shopping, and hospitality that its efforts to comply with the DMA are insufficient—and potentially more harmful than the status quo. Yelp and thousands of others have been demanding that the EU hold a firm line against the giant companies including Apple and Amazon that are subject to what's widely considered the world's strictest antitrust law, violations of which can draw fines of up to 10 percent of global annual sales.

"All the gatekeepers are trying to hold on as long as possible to the status quo and make the new world unattractive," says Richard Stables, CEO of shopping comparison site Kelkoo, which is unhappy with how Google has tweaked shopping results to comply with the DMA. "That's really the game plan."

Google spokesperson Rory O'Donoghue says the more than 20 changes made to search in response to the DMA are providing more opportunities for services such as Yelp to show up in results. "To suggest otherwise is plain wrong," he says. Overall, Google's tests of various DMA-inspired designs show clicks to review and comparison websites are up, O'Donoghue says—at the cost of users losing shortcuts to Google tools and individual businesses like airlines and restaurants facing a drop in visits from Google search. "We've been seeking feedback from a range of stakeholders over many months as we try to balance the needs of different types of websites while complying with the law," he says.

Google, which generates 30 percent of its sales from Europe, the Middle East, and Africa, views the DMA as disrespecting its expertise in what users want. Critics such as Yelp argue that Google sometimes siphons users away from the more reliable content they offer. Yelp competes with Google for advertisers but generated less than 1 percent of its record sales of $1.3 billion last year from outside the US. An increase in European traffic could significantly boost its business.

Original Submission

upstart writes:

Facial-recognition data is typically used to prompt more vending machine sales:

Canada-based University of Waterloo is racing to remove M&M-branded smart vending machines from campus after outraged students discovered the machines were covertly collecting facial-recognition data without their consent.

The scandal started when a student using the alias SquidKid47 posted an image on Reddit showing a campus vending machine error message, "Invenda.Vending.FacialRecognitionApp.exe," displayed after the machine failed to launch a facial recognition application that nobody expected to be part of the process of using a vending machine.

"Hey, so why do the stupid M&M machines have facial recognition?" SquidKid47 pondered.

The Reddit post sparked an investigation from a fourth-year student named River Stanley, who was writing for a university publication called MathNEWS.

Stanley sounded alarm after consulting Invenda sales brochures that promised "the machines are capable of sending estimated ages and genders" of every person who used the machines without ever requesting consent.

[...] A University of Waterloo spokesperson, Rebecca Elming, eventually responded, confirming to CTV News that the school had asked to disable the vending machine software until the machines could be removed.

[...] Adaria Vending Services told MathNEWS that "what's most important to understand is that the machines do not take or store any photos or images, and an individual person cannot be identified using the technology in the machines. The technology acts as a motion sensor that detects faces, so the machine knows when to activate the purchasing interface—never taking or storing images of customers."

According to Adaria and Invenda, students shouldn't worry about data privacy because the vending machines are "fully compliant" with the world's toughest data privacy law, the European Union's General Data Protection Regulation (GDPR).

Freeman writes:

https://arstechnica.com/information-technology/2024/02/i-just-dont-see-how-we-survive-tyler-perry-issues-hollywood-warning-over-ai-video-tech/

In an interview with The Hollywood Reporter published Thursday, filmmaker Tyler Perry spoke about his concerns related to the impact of AI video synthesis on entertainment industry jobs. In particular, he revealed that he has suspended a planned $800 million expansion of his production studio after seeing what OpenAI's recently announced AI video generator Sora can do.

"I have been watching AI very closely," Perry said in the interview. "I was in the middle of, and have been planning for the last four years... an $800 million expansion at the studio, which would've increased the backlot a tremendous size—we were adding 12 more soundstages. All of that is currently and indefinitely on hold because of Sora and what I'm seeing. I had gotten word over the last year or so that this was coming, but I had no idea until I saw recently the demonstrations of what it's able to do. It's shocking to me."

[...] "It makes me worry so much about all of the people in the business," he told The Hollywood Reporter. "Because as I was looking at it, I immediately started thinking of everyone in the industry who would be affected by this, including actors and grip and electric and transportation and sound and editors, and looking at this, I'm thinking this will touch every corner of our industry."

You can read the full interview at The Hollywood Reporter

[...] Perry also looks beyond Hollywood and says that it's not just filmmaking that needs to be on alert, and he calls for government action to help retain human employment in the age of AI. "If you look at it across the world, how it's changing so quickly, I'm hoping that there's a whole government approach to help everyone be able to sustain."

Previously on SoylentNews:
OpenAI Teases a New Generative Video Model Called Sora - 20240222

upstart writes:

Twitter security staff kept firm in compliance by disobeying Musk, FTC says:

Twitter employees prevented Elon Musk from violating the company's privacy settlement with the US government, according to Federal Trade Commission Chair Lina Khan.

After Musk bought Twitter in late 2022, he gave Bari Weiss and other journalists access to company documents in the so-called "Twitter Files" incident. The access given to outside individuals raised concerns that Twitter (which is currently named X) violated a 2022 settlement with the FTC, which has requirements designed to prevent repeats of previous security failures.

Some of Twitter's top privacy and security executives also resigned shortly after Musk's purchase, citing concerns that Musk's rapid changes could cause violations of the settlement.

FTC staff deposed former Twitter employees and "learned that the access provided to the third-party individuals turned out to be more limited than the individuals' tweets and other public reporting had indicated," Khan wrote in a letter sent today to US Rep. Jim Jordan (R-Ohio). Khan's letter said the access was limited because employees refused to comply with Musk's demands:

The deposition testimony revealed that in early December 2022, Elon Musk had reportedly directed staff to grant an outside third-party individual "full access to everything at Twitter... No limits at all." Consistent with Musk's direction, the individual was initially assigned a company laptop and internal account, with the intent that the third-party individual be given "elevated privileges" beyond what an average company employee might have.

However, based on a concern that such an arrangement would risk exposing nonpublic user information in potential violation of the FTC's Order, longtime information security employees at Twitter intervened and implemented safeguards to mitigate the risks. Ultimately the third-party individuals did not receive direct access to Twitter's systems, but instead worked with other company employees who accessed the systems on the individuals' behalf.

Jordan is chair of the House Judiciary Committee and has criticized the investigation, claiming that "the FTC harassed Twitter in the wake of Mr. Musk's acquisition." Khan's letter to Jordan today argues that the FTC investigation was justified.

"The FTC's investigation confirmed that staff was right to be concerned, given that Twitter's new CEO had directed employees to take actions that would have violated the FTC's Order," Khan wrote. "Once staff learned that the FTC's Order had worked to ensure that Twitter employees took appropriate measures to protect consumers' private information, compliance staff made no further inquiries to Twitter or anyone else concerning this issue."

Khan also wrote that deep staff cuts following the Musk acquisition, and resignations of Twitter's top privacy and compliance officials, meant that "there was no one left at the company responsible for interpreting and modifying data policies and practices to ensure Twitter was complying with the FTC's Order to safeguard Americans' personal data." The letter continued:

Original Submission

upstart writes:

Signal now lets you keep your phone number private with the launch of usernames:

Signal is launching usernames, the company announced today. Up until now, you have had to give someone your phone number to chat with them on Signal. Now you can create a unique username that you can use instead. Usernames are currently launching in beta and will be rolling out to all users in the coming weeks. Signal still requires a phone number when registering for the app.

As end-to-end encrypted messaging apps go, Signal stands apart as one with the strongest security and privacy features. By allowing users to now keep their phone numbers private, Signal is closing one of the few loopholes that could allow hacker's access to a victim's messages — where hackers hijack the phone number at the phone carrier level used to register with Signal.

Usernames in Signal do not function like usernames on social media platforms, the company says. For example, Signal usernames are not logins or handles that you'll be known by in the app. Instead, they're just a quick way to connect with someone on the app without sharing your phone number.

If you create a username, your profile name will still display whatever you set it to, and won't show your username. People you message on the app also can't see or find your username unless you have shared it with them. If someone wants to talk to you on the app, they will need to know your exact username because Signal doesn't provide a searchable directory of usernames like X and Instagram do. Or, you have the option to generate a QR code or link that directs people to your username.

Once you create a username, your phone number will no longer be visible in Signal to anyone running the latest version of the app if they don't already have it saved in their contacts. When you message people either directly or in group chats, your phone number won't show up, as users will only see your profile name and image. However, if you still want people to see your phone number when you message them, you can change the default setting in your "Phone Number" settings.

To create a username, go into your "Profile" settings. From there, choose a unique username that has two or more numbers at the end of it. You can change your username as often as you want, and you also have the choice to delete your username altogether if you don't want one anymore. The company says it created usernames to be easily changeable so that you can choose to make a specific username for things like a conference or a group trip, and then change it once it's over.

To start chatting with someone via their username, you need to open the "New Chat" screen in the app and type in their username.

Signal is also introducing a new privacy setting that will let you control who can find you on the app with your phone number. Up until now, anyone who had your phone number, whether they got it on social media or a business card, has been able to find you on Signal. Now you can restrict this by going into your settings and navigating to the "Who can find me by my number" setting and selecting "Nobody."

If you select the "Everybody" option, this means that anyone who has your phone number can type it into Signal and send you a message request, which you can of course reject or block.

hubie writes:

With skull parts that click together like puzzle pieces and a large central tooth, the real-life sandworm is stranger than fiction:

Amphisbaenians are strange creatures. Like worms with vertebrae, scales, a large central tooth and sometimes small forearms, these reptiles live underground, burrowing tunnels and preying on just about anything they encounter, not unlike a miniature version of the monstrous sandworms from "Dune."

Even though they're found around much of the world, little is known about how amphisbaenians behave in the wild because they cannot be observed while in their natural habitat under sand and soil. But thanks to two papers published in the March issue of The Anatomical Record, new light is being shed on these animals and their specialized anatomy.

[...] "You could fit three skulls of the Zygaspis quadrifrons on the nail of my pinky. We can now look at these really small vertebrate organisms in a measure of detail that we never had before," Bell said.

[...] "They wriggle around and try to escape and move in ways that worms just aren't able to. These are much more like little snakes in the way that they move and interact. It's just surprising for something that's so tiny. You just don't expect that behavior," Lewis said.

Some of the most striking imagery to come from these CT scans highlights sutures within the skull: deep, thin waves that "grab" on to each other, Lewis described. The images also render in exquisite details the amphisbaenians' strange singular central tooth, which interlocks with two bottom teeth.

"Combined with the powerful jaw muscles in amphisbaenians, it gives them a ferocious bite for an animal of their size. They can bite and tear out pieces of their prey," Bell said.

Journal References:
    Antonio Meza, Christopher J. Bell, Juan D. Daza, et al., Variation in the cranial osteology of the amphisbaenian genus Zygaspis based on high-resolution x-ray computed tomography, The Anatomical Record, First Published: 17 October 2023 https://doi.org/10.1002/ar.25321
    Christopher J. Bell, Cristhian Cadena, Antonio Meza, et al., Cranial anatomy of the "round-headed" Amphisbaenian Zygaspis quadrifrons (Squamata, Amphisbaenia) based on high-resolution x-ray computed tomography, The Anatomical Record, First Published: 17 October 2023 https://doi.org/10.1002/ar.25321

Original Submission

mendax writes:

Ars has a story containing tips and tricks for making Microsoft leave you alone while you use your PC in Windows 11. To wit:

I've written before about my nostalgia for the Windows XP- or Windows 7-era "clean install," when you could substantially improve any given pre-made PC merely by taking an official direct-from-Microsoft Windows install disk and blowing away the factory install, ridding yourself of 60-day antivirus trials, WildTangent games, outdated drivers, and whatever other software your PC maker threw on it to help subsidize its cost.

You can still do that with Windows 11—in fact, it's considerably easier than it was in those '00s versions of Windows, with multiple official Microsoft-sanctioned ways to download and create an install disk, something you used to need to acquire on your own. But the resulting Windows installation is a lot less "clean" than it used to be, given the continual creep of new Microsoft apps and services into more and more parts of the core Windows experience. [...]

[T]his [article] is not a guide about creating a minimally stripped-down, telemetry-free version of Windows that removes anything other than what Microsoft allows you to remove ... but [one that demonstrates how to] remov[e] built-in Windows components can cause unexpected compatibility and security problems...."

I am a long-time macOS user, and willingly pay the hefty Apple "tax" to use it because macOS behaves itself, but I am forced to use Windows 11 at work and I hate it for many of the reasons outlined in this article. Windows, like DOS before it decades ago, has become a boot-sector virus. Windows delenda est!

Original Submission

taylorvich writes:

https://newatlas.com/science/adhd-evolutionary-benefits-foraging-explore-exploit/

While current diagnostic definitions of attention-deficit hyperactivity disorder (ADHD) are relatively new, the general condition has been identified by clinicians under a variety of names for centuries. Recent genetic studies have revealed the condition to be highly heritable, meaning the majority of those with the condition have genetically inherited it from their parents.

Depending on diagnostic criteria, anywhere from two to 16% of children can be classified as having ADHD. In fact, increasing rates of diagnosis over recent years have led to some clinicians arguing the condition is overdiagnosed.

What is relatively clear, however, is that the behavioural characteristics that underpin ADHD have been genetically present in human populations for potentially quite a long time. And that has led some researchers to wonder what the condition's evolutionary benefits could be.

Imagine you are part of a wandering tribe of early humans. Your group comes across a field full of one kind of fruit and everyone is faced with a big question. Do you settle in the field and exploit the fruit stocks until they are all gone, or do you quickly take what you can and continue to explore for more varied foods?

This exploit or explore trade-off is fundamental to the survival of all animals. At what point is the risk of staying in one place greater than the risk of moving on to find out what is over the next hill?

In the early 2000s a team of scientists set out to study the genetics of a unique tribe of people in Northern Kenya. Known as the Ariaal, this population has traditionally been incredibly nomadic. Some members of the Ariaal settled down in one place over the 20th century and adopted modern methods of agriculture while other tribe members continued to live as nomadic pastoralists.

The scientists compared the genetic and health differences between these two cohorts of Ariaal and discovered something incredibly interesting. Generally, all of the Ariaal people carried a unique genetic mutation, dubbed DRD4/7R. This genetic trait had previously been identified commonly in people with ADHD.

Gaaark writes:

OS/2 was a joint operating system project by IBM and Microsoft, which was intended for IBM's own Personal System/2 (PS/2) PCs. (If you've ever seen the old circular ports used by keyboards and mice on old PCs, those are also called PS/2 ports— because they're inherited from this.)

While OS/2 comes after the original IBM PC DOS and MS-DOS, we know today that the partnership between IBM and Microsoft would not last in that form. Microsoft eventually stopped working with IBM in 1992 when it dropped Windows 3.1, a direct competitor of the OS/2 software IBM paid it to make.

OS/2 was intended as a protected-mode successor of PC DOS targeting the Intel 80286 processor. Notably, basic system calls were modeled after MS-DOS calls; their names even started with "Dos" and it was possible to create "Family Mode" applications – text mode applications that could work on both systems. Because of this heritage, OS/2 shares similarities with Unix, Xenix, and Windows NT.

Up to $990 million per year was spent developing OS/2 and its replacement. OS/2 sales were largely concentrated in networked computing used by corporate professionals; however, by the early 1990s, it was overtaken by Microsoft Windows NT. While OS/2 was arguably technically superior to Microsoft Windows 95, OS/2 failed to develop much penetration in the mass market consumer and stand-alone desktop PC segments.

IBM discontinued its support for OS/2 on December 31, 2006. Since then, OS/2 has been developed, supported and sold by two different third-party vendors under license from IBM – first by Serenity Systems as eComStation since 2001, and later by Arca Noae LLC as ArcaOS since 2017.

If you're reading this before April 15, 2024, and wish to dig into OS/2 computing history, you're also advised to check out the Hobbes OS/2 Archive while it still exists. The Hobbes OS/2 Archive is the longest-lived host of OS/2 software, but the decades have finally caught up to it, and it's set to close in April.
      https://hobbes.nmsu.edu/

Submitter remembers buying OS/2 Warp ( https://en.wikipedia.org/wiki/OS/2 ) (although, not really sure which version) : The box I bought (if memory serves... which it doesn't Batman...) came with a CD and like 10 diskettes. I didn't have a CD drive at the time, so had to install from the many diskettes, which didn't always install failure free. Finally got it installed and tried it out some, but, again if memory serves, had so little hard-drive space that i couldn't install much else to fool with to test compatibility.

Then Windows Whatever came along (remember "Start me up" from the Rolling Stones?) and then finally found Linux and never looked back.

If only IBM had had better marketers....

Original Submission

DannyB writes:

Addicted to swiping right? Lawsuit claims Tinder and Hinge are designed to get users hooked.

A new lawsuit claims that dating apps Tinder and Hinge are designed to addict users and lock them into a perpetual loop.

If you're swiping on dating apps for hours, you're not alone — and a new lawsuit claims it's by design.

Dating apps such as Tinder and Hinge are intentionally addictive, a class-action lawsuit filed in federal court in California on Valentine's Day claims.

Hidden algorithms push users to stay on the apps and "gamify dating" — counterintuitive to the apps' intended purpose to help people find connections and form relationships, six plaintiffs contend in the lawsuit.

[....] "The lawsuit is a bit absurd, if I'm honest," psychologist and relationship coach Jo Hemmings told The Washington Post, adding that "responsibility lies in the hands of the user," not the apps or developers.

In the future someday people might venture outside and date actual humans in person.

Original Submission

upstart writes:

An accretion disk 7 light-years across powers an exceptionally bright galaxy:

Quasars initially confused astronomers when they were discovered. First identified as sources of radio-frequency radiation, later observations showed that the objects had optical counterparts that looked like stars. But the spectrum of these ostensible stars showed lots of emissions at wavelengths that didn't seem to correspond to any atoms we knew about.

Eventually, we figured out these were spectral lines of normal atoms but heavily redshifted by immense distances. This means that to appear like stars at these distances, these objects had to be brighter than an entire galaxy. Eventually, we discovered that quasars are the light produced by an actively feeding supermassive black hole at the center of a galaxy.

[...] J0529−4351 had been observed a number of times, but its nature wasn't recognized until a survey went hunting for quasars and recognized it was one. At the time of the 2023 paper that described the survey, the researchers behind it suggested that it had either been magnified through gravitational lensing, or it was the brightest quasar we've ever identified.

[...] So, how do you take an instance of an incredibly bright object and make it even brighter? The light from a quasar is produced by an accretion disk. While accretion disks can form around black holes with masses similar to stars, quasars require a supermassive black hole like the ones found at the center of galaxies. These disks are formed of material that has been captured by the gravity of the black hole and is in orbit before falling inward and crossing the event horizon. Light is created as the material is heated by collisions of its constituent particles and gives up gravitational energy as it falls inward.

Getting more light out of an accretion disk is pretty simple: You either put more material in it or make it bigger. But there's a limit to how much material you can cram into one. At some point, the accretion disk will produce so much radiation that it drives off any additional material that's falling inward, essentially choking off its own food supply. Called the Eddington limit, this sets ceilings on how bright an accretion disk can be and how quickly a black hole can grow.

Factors like the mass of the black hole and its spin help set the Eddington limit. Plus, the amount of material falling inward can drop below the Eddington limit, leading to a bit less light being produced. Trying various combinations of these factors and checking them against observational data, the researchers came up with several estimates for the properties of the supermassive black hole and its accretion disk.

upstart writes:

How Kybers and ratcheting are boosting the resiliency of Apple's messaging app:

iMessage is getting a major makeover that makes it among the two messaging apps most prepared to withstand the coming advent of quantum computing, largely at parity with Signal or arguably incrementally more hardened.

On Wednesday, Apple said messages sent through iMessage will now be protected by two forms of end-to-end encryption (E2EE), whereas before, it had only one. The encryption being added, known as PQ3, is an implementation of a new algorithm called Kyber that, unlike the algorithms iMessage has used until now, can't be broken with quantum computing. Apple isn't replacing the older quantum-vulnerable algorithm with PQ3—it's augmenting it. That means, for the encryption to be broken, an attacker will have to crack both.

The iMessage changes come five months after the Signal Foundation, maker of the Signal Protocol that encrypts messages sent by more than a billion people, updated the open standard so that it, too, is ready for post-quantum computing (PQC). Just like Apple, Signal added Kyber to X3DH, the algorithm it was using previously. Together, they're known as PQXDH.

iMessage and Signal provide end-to-end encryption, a protection that makes it impossible for anyone other than the sender and recipient of a message to read it in decrypted form. iMessage began offering E2EE with its rollout in 2011. Signal became available in 2014.

[...] Another important part of the iMessage upgrade is automatic key refreshing that happens behind the scenes. By changing the key regularly as messages pass back and forth, messengers become more resilient in the event of a compromise. When an adversary obtains a static key, all messages sent with it are subject to immediate decryption. Key refreshing in the same scenario limits what can be decrypted to only a single message or a small subset of messages.

Signal has always provided key refreshing through a signature innovation in the protocol known as ratcheting. Apple says its key refresh mechanism is modeled on ratcheting. To do this, Apple is replacing the elliptic-curve cryptography used since 2019 with Elliptic-curve Diffie-Hellman.