Daily Archives: January 15, 2023

Contrails Cause 57% of a Plane’s Climate Impact. Can That Be Changed?

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Contrails — the wispy ice clouds trailing behind flying jets — “are surprisingly bad for the environment,” reports CNN: A study that looked at aviation’s contribution to climate change between 2000 and 2018 concluded that contrails create 57% of the sector’s warming impact, significantly more than the CO2 emissions from burning fuel. They do so by trapping heat that would otherwise be released into space.

And yet, the problem may have an apparently straightforward solution. Contrails — short for condensation trails, which form when water vapor condenses into ice crystals around the small particles emitted by jet engines — require cold and humid atmospheric conditions, and don’t always stay around for long. Researchers say that by targeting specific flights that have a high chance of producing contrails, and varying their flight path ever so slightly, much of the damage could be prevented.

Adam Durant, a volcanologist and entrepreneur based in the UK, is aiming to do just that. “We could, in theory, solve this problem for aviation within one or two years,” he says…. Of contrails’ climate impact, “80 or 90% is coming from only maybe five to 10% of all flights,” says Durant. “Simply redirecting a small proportion of flights can actually save the majority of the contrail climate impact….”

In 2021, scientists calculated that addressing the contrail problem would cost under $1 billion a year, but provide benefits worth more than 1,000 times as much. And a study from Imperial College London showed that diverting just 1.7% of flights could reduce the climate damage of contrails by as much as 59%.
Durant’s company Satavia is now testing its technology with two airlines and “actively looking for more airlines in 2023 to work with, as we start scaling up the service that we offer.”

Truly addressing the issue may require some changes to air traffic rules, Durant says — but he’s not the only one working on the issue. There’s also the task force of a non-profit energy think tank that includes six airlines, plus researchers and academics. “We could seriously reduce, say, 50% of the industry’s contrails impact by 2030,” Durant tells CNN. “That’s totally attainable, because we can do it with software and analytics.”

Source: Contrails Cause 57% of a Plane’s Climate Impact. Can That Be Changed? – Slashdot

Meta sues surveillance company for allegedly scraping more than 600,000 accounts – pots and kettles

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Meta has filed a lawsuit against Voyager Labs, which it has accused of creating tens of thousands of fake accounts to scrape data from more than 600,000 Facebook users’ profiles. It says the surveillance company pulled information such as posts, likes, friend lists, photos, and comments, along with other details from groups and pages. Meta claims that Voyager masked its activity using its Surveillance Software, and that the company has also scraped data from Instagram, Twitter, YouTube, LinkedIn and Telegram to sell and license for profit.

In the complaint, which was obtained by Gizmodo, Meta has asked a judge to permanently ban Voyager from Facebook and Instagram. “As a direct result of Defendant’s unlawful actions, Meta has suffered and continues to suffer irreparable harm for which there is no adequate remedy at law, and which will continue unless Defendant’s actions are enjoined,” the filing reads. Meta said Voyager’s actions have caused it “to incur damages, including investigative costs, in an amount to be proven at trial.”

Meta claims that Voyager scraped data from accounts belonging to “employees of non-profit organizations, universities, news media organizations, healthcare facilities, the armed forces of the United States, and local, state, and federal government agencies, as well as full-time parents, retirees, and union members.” The company noted in a blog post it disabled accounts linked to Voyager and that filed the suit to enforce its terms and policies.

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In 2021, The Guardian reported that the Los Angeles Police Department had tested Voyager’s social media surveillance tools in 2019. The company is said to have told the department that police could use the software to track the accounts of a suspect’s friends on social media, and that the system could predict crimes before they took place by making assumptions about a person’s activity.

According to The Guardian, Voyager has suggested factors like Instagram usernames denoting Arab pride or tweeting about Islam could indicate someone is leaning toward extremism. Other companies, such as Palantir, have worked on predictive policing tech. Critics such as the Electronic Frontier Foundation claim that tech can’t predict crime and that algorithms merely perpetuate existing biases.

Data scraping is an issue that Meta has to take seriously. In 2021, it sued an individual for allegedly scraping data on more than 178 million users. Last November, the Irish Data Protection Commission fined the company €265 million ($277 million) for failing to stop bad actors from obtaining millions of people’s phone numbers and other data, which were published elsewhere online. The regulator said Meta failed to comply with GDPR data protection rules.

Source: Meta sues surveillance company for allegedly scraping more than 600,000 accounts | Engadget

YouTube may fix controversial policy to demonetize videos with swearing – wait why can’t you swear on YouTube? US prudish sensibilities suck ass

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YouTube is rethinking its approach to colorful language after an uproar. In a statement to The Verge, the Google brand says it’s “making some adjustments” to a profanity policy it unveiled in November after receiving blowback from creators. The rule limits or removes ads on videos where someone swears within the first 15 seconds or has “focal usage” of rude words throughout, and is guaranteed to completely demonetize a clip if swearing either occurs in the first seven seconds or dominates the content.

While that policy wouldn’t necessarily be an issue by itself, YouTube has been applying the criteria to videos uploaded before the new rule took effect. As Kotaku explains, YouTube has demonetized old videos for channels like RTGame. Producers haven’t had success appealing these decisions, and the company won’t let users edit these videos to pass muster.

Communication has also been a problem. YouTube doesn’t usually tell violators exactly what they did wrong, and creators tend to only learn about the updated policy after the service demonetizes their work. There are also concerns about inconsistency. Some videos are flagged while others aren’t, and a remonetized video might lose that income a day later. Even ProZD’s initial video criticizing the policy, which was designed to honor the rules, lost ad revenue after two days.

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Source: YouTube may fix controversial policy to demonetize videos with swearing

Posted in Art

AI discovers new nanostructures, reduces experiment time from months to hours

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Scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory have successfully demonstrated that autonomous methods can discover new materials. The artificial intelligence (AI)-driven technique led to the discovery of three new nanostructures, including a first-of-its-kind nanoscale “ladder.” The research was published today in Science Advances..

The newly discovered structures were formed by a process called , in which a material’s molecules organize themselves into unique patterns. Scientists at Brookhaven’s Center for Functional Nanomaterials (CFN) are experts at directing the self-assembly process, creating templates for materials to form desirable arrangements for applications in microelectronics, catalysis, and more. Their discovery of the nanoscale ladder and other new structures further widens the scope of self-assembly’s applications.

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“gpCAM is a flexible algorithm and software for autonomous experimentation,” said Berkeley Lab scientist and co-author Marcus Noack. “It was used particularly ingeniously in this study to autonomously explore different features of the model.”

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“An old school way of doing material science is to synthesize a sample, measure it, learn from it, and then go back and make a different sample and keep iterating that process,” Yager said. “Instead, we made a sample that has a gradient of every parameter we’re interested in. That single sample is thus a vast collection of many distinct material structures.”

Then, the team brought the sample to NSLS-II, which generates ultrabright X-rays for studying the structure of materials.

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“One of the SMI beamline’s strengths is its ability to focus the X-ray beam on the sample down to microns,” said NSLS-II scientist and co-author Masa Fukuto. “By analyzing how these microbeam X-rays get scattered by the material, we learn about the material’s local structure at the illuminated spot. Measurements at many different spots can then reveal how the local structure varies across the gradient sample. In this work, we let the AI algorithm pick, on the fly, which spot to measure next to maximize the value of each measurement.”

As the sample was measured at the SMI beamline, the algorithm, without human intervention, created of model of the material’s numerous and diverse set of structures. The model updated itself with each subsequent X-ray measurement, making every measurement more insightful and accurate.

The Soft Matter Interfaces (SMI) beamline at the National Synchrotron Light Source II. Credit: Brookhaven National Laboratory

In a matter of hours, the algorithm had identified three key areas in the complex sample for the CFN researchers to study more closely. They used the CFN electron microscopy facility to image those key areas in exquisite detail, uncovering the rails and rungs of a nanoscale ladder, among other novel features.

From start to finish, the experiment ran about six hours. The researchers estimate they would have needed about a month to make this discovery using traditional methods.

“Autonomous methods can tremendously accelerate discovery,” Yager said. “It’s essentially ‘tightening’ the usual discovery loop of science, so that we cycle between hypotheses and measurements more quickly. Beyond just speed, however, autonomous methods increase the scope of what we can study, meaning we can tackle more challenging science problems.”

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“We are now deploying these methods to the broad community of users who come to CFN and NSLS-II to conduct experiments,” Yager said. “Anyone can work with us to accelerate the exploration of their materials research. We foresee this empowering a host of new discoveries in the coming years, including in national priority areas like clean energy and microelectronics.”

More information: Gregory S. Doerk et al, Autonomous discovery of emergent morphologies in directed self-assembly of block copolymer blends, Science Advances (2023). DOI: 10.1126/sciadv.add3687. www.science.org/doi/10.1126/sciadv.add3687

Source: Artificial intelligence discovers new nanostructures

A team of physicists devise a model that maps a star’s surprising orbit about a supermassive black hole

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Hundreds of millions of light-years away in a distant galaxy, a star orbiting a supermassive black hole is being violently ripped apart under the black hole’s immense gravitational pull. As the star is shredded, its remnants are transformed into a stream of debris that rains back down onto the black hole to form a very hot, very bright disk of material swirling around the black hole, called an accretion disc. This phenomenon—where a star is destroyed by a supermassive black hole and fuels a luminous accretion flare—is known as a tidal disruption event (TDE), and it is predicted that TDEs occur roughly once every 10,000 to 100,000 years in a given galaxy.

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TDEs are usually “once-and-done” because the extreme gravitational field of the SMBH destroys the star, meaning that the SMBH fades back into darkness following the accretion flare. In some instances, however, the high-density core of the star can survive the gravitational interaction with the SMBH, allowing it to orbit the black hole more than once. Researchers call this a repeating partial TDE.

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findings, published in Astrophysical Journal Letters, describe the capture of the star by a SMBH, the stripping of the material each time the star comes close to the black hole, and the delay between when the material is stripped and when it feeds the black hole again.

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Once bound to the SMBH, the star powering the emission from AT2018fyk has been repeatedly stripped of its outer envelope each time it passes through its point of closest approach with the black hole. The stripped outer layers of the star form the bright accretion disk, which researchers can study using X-Ray and Ultraviolet /Optical telescopes that observe light from distant galaxies.

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“Until now, the assumption has been that when we see the aftermath of a close encounter between a star and a , the outcome will be fatal for the star, that is, the star is completely destroyed,” he says. “But contrary to all other TDEs we know of, when we pointed our telescopes to the same location again several years later, we found that it had re-brightened again. This led us to propose that rather than being fatal, part of the star survived the initial encounter and returned to the same location to be stripped of material once more, explaining the re-brightening phase.”

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So how could a star survive its brush with death? It all comes down to a matter of proximity and trajectory. If the star collided head-on with the black hole and passed the event horizon—the threshold where the speed needed to escape the black hole surpasses the speed of light—the star would be consumed by the black hole. If the star passed very close to the black hole and crossed the so-called “tidal radius”—where the tidal force of the hole is stronger than the gravitational force that keeps the star together—it would be destroyed. In the model they have proposed, the star’s orbit reaches a point of closest approach that is just outside of the tidal radius, but doesn’t cross it completely: some of the material at the stellar surface is stripped by the black hole, but the material at its center remains intact.

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More information: T. Wevers et al, Live to Die Another Day: The Rebrightening of AT 2018fyk as a Repeating Partial Tidal Disruption Event, The Astrophysical Journal Letters (2023). DOI: 10.3847/2041-8213/ac9f36

Source: A team of physicists devise a model that maps a star’s surprising orbit about a supermassive black hole