Tuesday, March 14, 2023

Evidence of near-ambient superconductivity in a N-doped lutetium hydride

Nature

The absence of electrical resistance exhibited by superconducting materials would have enormous potential for applications if it existed at ambient temperature and pressure conditions. Despite decades of intense research efforts, such a state has yet to be realized.

Here we report evidence of superconductivity on a nitrogen-doped lutetium hydride with a maximum Tc of 294 K at 10 kbar, that is, superconductivity at room temperature and near-ambient pressures. [Superconductivity was verified via] temperature-dependent resistance with and without an applied magnetic field, the magnetization (M) versus magnetic field (H) curve, a.c. and d.c. magnetic susceptibility, as well as heat-capacity measurements.

The Independent:  

Scientists have discovered a new material that could be set to change the entire world. Researchers say they have created a superconducting material that works at both a temperature and a pressure low enough to actually use it in practical situations.

Professor Dias and the team made the material by taking a rare earth metal named lutetium and mixed it with hydrogen and a small part of nitrogen. They were then left to react for two or three days, at high temperatures.

To work, the material still requires being heated to 20.5 degrees Celsius and compressed to about 145,000 psi. But that is vastly less intense than other, similar materials – including those announced in 2020 by Professor Dias that brought excitement and scepticism from scientists.

Wall Street Journal:

U.S. scientists say they have produced the first commercially accessible material that eliminates the loss of energy as electricity moves along a wire, a breakthrough that could mean longer-lasting batteries, more-efficient power grids and improved high-speed trains.

New York Times

The new superconductor consists of lutetium, a rare earth metal, and hydrogen with a little bit of nitrogen mixed in. It needs to be compressed to a pressure of 145,000 pounds per square inch before it gains its superconducting prowess...But it is also less than one one-hundredth of what the 2020 result required, which was akin to the crushing forces found several thousand miles deep within the Earth. 

“This is the start of the new type of material that is useful for practical applications,” Ranga P. Dias, a professor of mechanical engineering and physics at the University of Rochester in New York, said to a room packed full of scientists on Tuesday at a meeting of the American Physical Society in Las Vegas.

In the paper, the researchers reported that the pink crystals exhibited key properties of superconductors, like zero resistance, at temperatures up to 70 degrees Fahrenheit.

“I’m cautiously optimistic,” said Timothy Strobel, a scientist at the Carnegie Institution for Science in Washington who was not involved in Dr. Dias’s study. “The data in the paper, it looks great.”

This is a very exciting and potentially game-changing result. The hunt for a room-temperature superconductor has been frantic and long-lasting, due to properties that would enable them to revolutionize many aspects of modern technology. For its part, the paper is detailed and seems to have taken great care to demonstrate superconductivity via multiple channels. There is some controversy surrounding the results, which can be separated into two categories:

  1. Concerns about the validity of the results. Are they reproducible, or was this a fluke event? Is the new material really stable enough at STP to be viable?
  2. Ethical concerns about the results. The particular research group that put out this astonishing result has had a fraught past, with retracted papers and extended drama over previous results in a similar vein. Additionally, arguably the largest fraudulent scandal in scientific history (the infamous Schön scandal) was focused on this subfield, which tends to attract grandiose and wild claims.
For such a claim, one might expect jubilation and animated questions, but the audience’s response was hesitant—a few people politely asked technical questions, such as how well Dias’ team could control the amount of nitrogen in the sample. There was no whooping or cheering. The audience had been here before.

In 2020, Dias’ team announced in a paper in Nature that they had created a material, carbonaceous sulfur hydride, that superconducted at 287 K and 267 GPa. Researchers and news outlets lauded the finding, but the paper was retracted two years later after outside researchers found oddities in the results.

Another part of that wariness arises because, to date, no one has independently reproduced Dias’ team’s results. This lack of verification was raised by Jorge Hirsch of the University of California, San Diego, in the last talk of the session in which Dias and his team spoke. 

Quanta

While the announcement has been greeted with enthusiasm by some scientists, others are far more cautious, pointing to the research group’s controversial history of alleged research malfeasance. (Dias strongly denies the accusations.) 

But incidents involving the team’s previous work — including but not limited to a near-room-temperature superconductivity claim published in Nature in 2020 and retracted late last year — have cast a shadow across today’s announcement. “It’s hard to not wonder if some of the same problems that have gone unaddressed in previous work also exist in the new work,” Hamlin said. 

“There is a lot of evidence for superconductivity here if you take it at face value,” said Jorge Hirsch, a physicist at the University of California, San Diego. “But I do not believe any of what these authors say. I am not sold at all.”

Hirsch said his mistrust stems from a long history of allegations of research malfeasance made against previous and current members of the group, many of which he has pressed. Most recently, in 2020 Dias and his co-authors published a study of a carbonaceous sulfur hydride...Almost immediately, a handful of experts spotted unusual patterns in the data used to verify the material’s response to magnetic fields. When [they] released their raw data a year later in the form of a 149-page document, they detailed an unusual and complicated method for eliminating background magnetic interference — one they said was necessary for them to detect the tiny magnetic field rejected by the small sample. This method was inconsistent with how they’d described the procedure in the original paper, which led Nature to issue a retraction last September. 

Hirsch and other physicists allege that the misconduct goes beyond a misleading mix-up regarding the magnetic background. In September, [they] published a claim that what Dias and Salamat had released as raw CSH data was actually derived from the published data. “[We] proved basically mathematically that the raw data are not measured in the laboratory; they are fabricated,” Hirsch said. Hamlin independently released a preprint last October claiming that the electrical resistivity data also appeared to have been processed in an undisclosed manner — a new allegation atop the issue that led to the 2022 retraction.     

Yet the CSH paper isn’t the only related work under fire. One co-author of the CSH paper, Mathew Debessai, was the first author on a 2009 study claiming superconductivity in a third material, europium, which was later retracted for presenting altered data...Others have also argued that some of the data in another of Dias’ recent papers was duplicated from data taken while the team was studying a completely different substance.

Here is a figure summarizing the data believed to be duplicated. The zoom-ins to below the 120 K range look remarkably similar. 

PubPeer


Figure 2: Comparison of data on GeS and corresponding data purportedly measured on MnS... However, if we restrict our view to only the data below 120 K (right panels), we find that the data are essentially identical, within the precision of the extraction process. No transformations have been applied to the data. 

Considering only the data below 120 K, there is essentially perfect agreement of the shapes of three different pairs of curves within the limitations of the digitization methods. It can not be reasonably concluded that this could occur by coincidence across three different data sets appearing in two different figures. Can the authors please check if an error led to the GeSe data being used in the MnS paper? 

A big problem with confirming their results is that it can be challenging to ensure a recipe is followed exactly. Confirmation could be provided if Dias and his team shared the actual material, but they are unwilling to do so for proprietary reasons.

Science:

To solve the riddle, the U of R team “should do everything they can to help other groups reproduce it,” says Mikhail Eremets, a physicist at the Max Planck Institute for Chemistry, whose team discovered the first hydride superconductor in 2015 but failed to replicate the CSH results. “If they will not it will be a disaster.” But this level of cooperation doesn’t appear to be in the cards. Dias says Unearthly Materials, a company he and Salamat founded, is trying to commercialize the new hydride. “We are not going to distribute this material considering the proprietary nature of our process and the intellectual property rights that exist,” Dias said via email.

Other physicists aren’t pleased. “It’s a completely unscientific behavior,” Boeri says. Hamlin says he won’t commit a student to replicating the work unless the U of R group shares samples and raw data. Salamat says the raw data are available online. As for sharing samples, the paper provides a detailed recipe, he says. “People can go ahead and make it for themselves.” [emphasis added]

It's quite disappointing that they are unwilling to share the actual material, as that would silence most if not all of the controversy and let the discovery gain the prominence it deserves. Personally, I don't understand the difference between sharing the material for verification purposes versus sharing a detailed recipe that will allow for exact reproduction. This would be concerning regardless of the past history of the group. We've also seen this exact response from this group before: in 2020, when their last claimed room-temperature superconductor fell apart. It took a bit of digging, but I found Hirsch's original pre-print "Anatomy of a Probable Scientific Fraud". In it, he attaches emails he sent to Dias' team asking for access to their raw data, in order to help verify their results. 

UCSD:

It is also relevant to this story that independently Dr. Evgueni F. Talantsev had requested resistivity raw data as well as a a time track record for each measurement from Dias directly and through Nature editor Dr. Luke Fleet on October 21, 2020 [25] and again directly and through Nature editor Dr. Roedel on or about November 10. On November 16, Dias responded:

Dear Dr. Talantsev, We acknowledge your request for data relating to our recent Nature article entitled “Room temperature Superconductivity on carbonaceous sulfur hydrides”. We have discussed the request with counsel and unfortunately, we are not able to provide you with the data for a number of reasons, including the following. The data may contain patentable inventions for which patent applications have not been updated or filed. We have been advised that disclosure of the data may impair our ability to file patent applications in the future. We cannot anticipate when we may have the authorization to share the data. Regards, Ranga

This is the same justification they are using today to deny other researchers access to the material, for verification. As a reminder, the "patentable inventions" they used to justify the lack of transparency ended up falling through, as even their own analysis was unable to reproduce them:

New York Times:

A preprint redoing measurements of the carbon-sulfur-hydrogen material from the retracted 2020 paper is now circulating, but even that raises questions. “They’re significantly different from the original measurements,” Dr. Strobel said. “One could argue they haven’t even reproduced results themselves.”

Scientific American:

Hamlin went on to analyze a paper that Dias and Salamat published in Physical Review Letters (PRL) in 2021 in which they and their colleagues measured another hydride called manganese sulfide. Hamlin noted similarities between the electrical resistance data in the 2021 paper and those in Dias’s 2013 Ph.D. thesis, which had involved a completely different superconducting material. He shared these concerns with the journal and the paper’s authors. Salamat has since responded, suggesting that even though the two data sets may appear similar, the resemblance is not indicative of copied data. “We’ve shown that if you just overlay other people’s data qualitatively, a lot of things look the same,” he says. “This is a very unfair approach.”

This did not satisfy at least one of Salamat’s co-authors on the PRL paper: Simon A. J. Kimber, a former researcher, was disturbed to hear about the potential problem with the data and agrees with Hamlin’s conclusions. “I’ve been at this game for a long time, and I couldn’t think of a single reasonable explanation as to why those data sets should overlap like that,” he says. “I replied to everybody, to PRL’s editors, and said, ‘I think this should be retracted. I can’t think of any logical reason why this should be—retract, retract, retract.’” 

New York Times:

However, the “if” part of that sentiment swirls around Dr. Dias, who has been dogged by doubts and criticism, and even accusations by a few scientists that he has fabricated some of his data. The results of the 2020 Nature paper have yet to be reproduced by other research groups, and critics say that Dr. Dias has been slow to let others examine his data or perform independent analyses of his superconductors.

The editors of Nature retracted the earlier paper last year over the objections of Dr. Dias and the other authors.

“I’ve lost some trust in what’s coming from that group,” said James Hamlin, a professor of physics at the University of Florida.

Dr. Dias’s main antagonist is Jorge Hirsch, a theoretical physicist at the University of California, San Diego...The plot in the paper seemed too neat, and the scientists did not explain how they had subtracted out background effects in the plot. When Dr. Dias released the underlying raw data, Dr. Hirsch said, his analysis indicated that it had been generated by a mathematical formula and could not be actually measured in an experiment. 

I found this passage later in the article interesting (though admittedly not particularly relevant):

Dr. Hamlin was also disturbed when he found that several passages from his doctoral thesis, written in 2007, had appeared, word for word, in Dr. Dias’s dissertation...Of the copying of text from Dr. Hamlin’s doctoral thesis, Dr. Dias said he should have included citations. “It was my mistake,” Dr. Dias said.

Generally scientific writing is paraphrased for citation, not copied exactly. Even self-plagiarism is extremely discouraged, so I can't imagine any train of thought that would lead to actually copying someone else's work word-for-word in an original thesis. A citation arguably wouldn't have made that okay.

It is important to note that while Hirsch is not the only scientist to point out issues with the results (past and present) from Dias' team, he may have a bias as Dias' results would support a theory that he is somewhat infamous for opposing:

Science:

Ranga Dias, an applied physicist at the University of Rochester, who with his colleagues made the room-temperature superconductivity claim, rejects Hirsch’s allegations. He asserts that Hirsch isn’t an expert in high-pressure physics and that he has a history of claiming that the Nobel Prize–winning “BCS theory” underlying superconductivity is incorrect. Dias says Hirsch relentlessly badgers superconductivity researchers. “Hirsch is a troll,” Dias says. “We are not going to feed this troll” by providing the data. 

Dias and others say they don’t trust Hirsch to appraise the data fairly. “Unfortunately, sometimes he is not objective,” says Vasily Minkov, a chemist at the Max Planck Institute for Chemistry who synthesizes hydride superconductors and says Hirsch has cherry-picked data from the Max Planck experiments for his critiques.

This back-and-forth has resulted in moderation as the claims from each about the other have grown less and less professional.

Science:  

A debate over claims of room temperature superconductivity has now boiled over into the realm of scientific publishing. Administrators of arXiv, the widely used physics preprint server, recently removed or refused to post several papers from the opposing sides, saying their manuscripts include inflammatory content and unprofessional language. ArXiv has also banned one of the authors, Jorge Hirsch, a theoretical physicist at the University of California, San Diego (UCSD), from posting papers for 6 months.

While Hirsch may have been somewhat abrasive (Daniel Arovas amusingly referred to the exchange as "distasteful accusations") he was far from the only person who shared the concerns--including some of the authors of the 2020 paper.

One of [the 2009] study’s authors, James Hamlin, a physicist now at the University of Florida, who participated in the europium study as a graduate student, recently determined, he says, that “there are alterations to the data.” The study’s senior author, James Schilling, an emeritus physicist at Washington University in St. Louis, says he shares that concern. Now, some of the co-authors are redoing the measurements, and if they don’t hold up, the team will retract the [2020] paper, Hamlin says. 

The paper was eventually retracted. 

Science:

Given the questions, several scientists say Dias should make his data public. “I am unhappy that Dias is supposedly not cooperating with researchers who are questioning his data,” says Marvin Cohen, a theoretical physicist at UC Berkeley. Schilling is blunt: “I told Dias to give [Hirsch] the raw data, for heaven’s sake.”

In his email [responding to Hirsch's request for the raw data], Dias wrote, “Given that you have an active comment on our work, we consider such a request would not be reasonable.” Frustrated, Hirsch requested the data from Nature and the National Science Foundation (NSF), which funded the work. On 30 August, Nature appended an editor’s note to Dias’s paper saying: “The editors of Nature have been alerted to undeclared access restrictions relating to the data behind this paper. We are working with the authors to correct the data availability statement.” NSF and the University of Rochester both tell Science they cannot comment on possible investigative matters.

A theoretical analysis on the theoretical feasibility of superconductivity in lutetium hydride was published. The results add an interesting dimension to the controversy.

AIP:

Recently, room-temperature superconductivity has been reported in a nitrogen-doped lutetium hydride at near-ambient pressure [Dasenbrock-Gammon et al., Nature 615, 244 (2023)]. 

Here, we systematically study the phase diagram of Lu–N–H at 1 GPa using first-principles calculations, and we do not find any thermodynamically stable ternary compounds.

Our theoretical results show that the Tc values of N-doped LuH3 estimated using the Allen–Dynes-modified McMillan equation are much lower than room temperature.

The conclusion seems to be that, based on existing theory, it is not possible to form a stable combination of lutetium, nitrogen, and hydrogen. 

Notably, all predicted potential ternary compounds lie above the convex hull at 1 GPa. Thus, no ternary Lu–N–H compounds can remain thermodynamically stable at this pressure, which is consistent with the main results of Xie et al.26

And even if it were, it seems it would superconduct at far lower than room temperature, in line with existing experiments. 

Our simulations show that the lowest T_c is 4 K for LuH3 without doping. In addition, T_c increases with increasing N-doping concentration; thus, doping N atoms into LuH3 will increase T_c. However, the highest T_c in this VCA calculation is 22 K, obtained with 1% N-doping at 30 GPa, which is much lower than room temperature.

It's worth noting that 30 GPa is about 300 kbar, which is 30 times higher than the pressures reported in Dias et al. (2023). Further investigation is needed, but it seems theoretically unlikely to produce a material like the doped LuNH3 at the reported temperatures and pressures. Certainly even less likely for it to superconduct at room temperatures. This is based on existing theory, so the possibility remains that Dias et al. have discovered an exciting new effect that will require more advanced models to explain.

I've been posting occasional updates as I've followed this and other superconductor stories with great interest. This one took an interesting turn with a series of retractions from Nature.

Nature

RETRACTED ARTICLE: Room-temperature superconductivity in a carbonaceous sulfur hydride

The editors of Nature have been alerted to concerns regarding the manner in which the data in this paper have been processed and interpreted. Nature is working with the authors to investigate these concerns and establish what (if any) impact they will have on the paper’s results and conclusions. In the meantime, readers are advised to use caution when using results reported therein. 

This is their second retracted paper.

Nature News:

Nature has retracted a controversial paper claiming the discovery of a superconductor — a material that carries electrical currents with zero resistance — capable of operating at room temperature and relatively low pressure.

“They have expressed the view as researchers who contributed to the work that the published paper does not accurately reflect the provenance of the investigated materials, the experimental measurements undertaken and the data-processing protocols applied,” [the retraction report] says, adding that these co-authors “have concluded that these issues undermine the integrity of the published paper”.

“It is at this point hardly surprising that the team of Dias and Salamat has a third high-profile paper being retracted,” says Paul Canfield, a physicist at Iowa State University in Ames and at Ames National Laboratory. Many physicists had seen the Nature retraction as inevitable after the other two, and especially since The Wall Street Journal and Science reported in September that 8 of the 11 authors of the paper — including Salamat — had requested it in a letter to the journal.

One lab says it has partially reproduced Dias and Salamat’s results using a sample provided by the Rochester team. But many others, which tried creating their own samples and running tests, could not. And in the meantime, other causes for concern have arisen. An investigation launched by Physical Review Letters before it retracted its paper by Dias and Salamat found “apparent data fabrication”.

Science.org:

Facing a mutiny by his co-authors, Ranga Dias, the University of Rochester (U of R) physicist embroiled in controversy over his superconductivity research and allegations of scientific misconduct, is set to have a third paper retracted.

If the paper is retracted, it will follow retractions of two other superconducting claims from Dias’s teams: one last month from Physical Review Letters (PRL), and one in September 2022 of a different Nature paper.

In a 14 September email to the co-authors, Nature Senior Editor Tobias Rödel says a postpublication review revealed issues that are “mostly unaddressed.” Rödel added, “We are in absolute agreement with your request that the paper be retracted.”

Questions about the March paper’s results appeared online immediately after its publication. On 2 May, two researchers submitted an anonymous critique of the paper to Nature. These researchers disclosed their identities to Science: They are James Hamlin, a high-pressure experimentalist at the University of Florida, and Brad Ramshaw, an expert in superconductivity at Cornell University.

In their letter to Nature the co-authors allege they had raised concerns about the study prior to publication, but that Dias dismissed them. 

After seeing the postpublication review, the co-authors used their access to the raw data to corroborate Hamlin and Ramshaw’s concerns about the zero-resistance measurement. 

New York Times:

A prominent physics journal on Tuesday retracted a materials science paper that has garnered scrutiny.

The retracted paper did not involve superconductivity, but it added to accusations against Dr. Dias of research misconduct, including the fabrication and falsification of data. 

Nine of the 10 authors of the paper, which was published in Physical Review Letters, agreed to the retraction. Dr. Dias was the lone holdout, and he has maintained that the paper accurately portrays the research findings. However, he said on Tuesday that his collaborators, working in the laboratory of Ashkan Salamat, a professor of physics at the University of Nevada, Las Vegas, introduced errors when producing charts of the data using Adobe Illustrator, software not typically used to make scientific charts.

This took me pretty massively by surprise. I can only speak from my own personal experience, but nobody--I mean nobody--makes charts by hand anymore. We've had programmatic tools to ensure precision for literally decades. Most plots these days are done using scripts that access plotting libraries; for example, I make my plots in Python using matplotlib. I just can't understand what part of the process one would use Adobe Illustrator of all things for--I wish Dr. Dias had elaborated on this more. The problems identified were found in the background subtraction procedure and potentially claims of duplicated data; without commenting on the truth of these allegations, how could one "accidentally" do these things or something similar in Adobe Illustrator of all things? And why would this affect the raw data files that were shared with the investigators and coauthors, which ultimately were found to be flawed as well? 

Nature News:

As part of the investigation, co-author Ashkan Salamat, a physicist at the University of Nevada, Las Vegas, and a long-time collaborator of Dias, supplied what he claimed was raw data used to create figures in the PRL paper. But all four investigators found that the data Salamat provided did not match the figures in the paper.

Ignoring everything else, the raw data didn't match the figures. But Dr. Dias necessarily needs the figures to be correct if his superconductor is legitimate--the figures showed the proof. 

Science News:

A stunning claim of a room-temperature superconductor that grabbed headlines has fizzled. The paper was retracted November 7 from the journal Nature, making for a trio of high-profile retractions for physicist Ranga Dias of the University of Rochester.

The retraction is no surprise to the scientific community, many of whom had expressed hefty skepticism about Dias’ work, following the earlier retractions and many other researchers’ failures to reproduce Dias’ results. 

Compared to the previous retractions, “this is much more worrying,” Boeri says. “This is not just somebody who is doing some honest mistakes.”

Ranga Dias (via Twitter):

Meissner effect on N- doped Lutetium Hydride! 

[mic drop gif]

The Meissner effect is considered the definitive proof of superconductivity!

I look forward to the submission of that result. At the end of the day, everyone only benefits if Dr. Dias is correct and room-temperature superconductivity is achieved.

Photometry and spectroscopy of the Type Icn supernova 2021ckj: The diverse properties of the ejecta and circumstellar matter of Type Icn SNe

arXiv:

Spectral modeling of SN 2021ckj reveals that its composition is dominated by oxygen, carbon and iron group elements, and the photospheric velocity at peak is ~10000 km/s. From the light curve (LC) modeling applied to SNe 2021ckj, 2019hgp, and 2021csp, we find that the ejecta and CSM properties of Type Icn SNe are diverse.

The similarity of the emission components of these lines implies that the emitting regions of SNe 2021ckj and 2021csp have similar ionization states, and thus suggests that they have similar properties of the ejecta and CSM, which is inferred also from the LC modeling. Taking into account the difference in the strength of the absorption features, this heterogeneity may be attributed to viewing angle effects in otherwise common aspherical ejecta.


The core degenerate scenario for the type Ia supernova SN 2020eyj

arXiv:

We argue that the core degenerate (CD) scenario of type Ia supernovae (SNe Ia) can explain the compact helium-rich circumstellar material (CSM) of SN 2020eyj...We follow the evolution of two stellar models with initial masses of 5Mo and 7Mo to their asymptotic giant branch phase when they are supposed to engulf the WD companion. We find that there is a sufficiently massive CO core to merge with the WD in the frame of the CD scenario as well as a massive helium-rich layer, ~0.3-1Mo, to account for the helium-rich CSM of SN 2020eyj.

The motivation of our study is the new observations of SN 2020eyj, a SN Ia-CSM with a helium-rich CSM (Kool et al. 2022) and the need to consider all SN Ia scenarios when analysing observations, as the long list of recent papers that study different scenarios suggests.

Building on earlier papers that argue for the CD scenario for SNe Ia-CSM (section 2) we propose the CD scenario also for SN 2020eyj, but we consider a new channel that accounts for the helium-rich CSM (section 3).


Tuesday, March 7, 2023

LCO Data Confirm the Success of NASA’s DART Mission

Las Cumbres Observatory

The NASA Double Asteroid Redirection Test mission — the first test mission for NASA’s Planetary Defense Coordination Office — launched a spacecraft in November of 2021 with the aim to crash into the binary near-Earth asteroid system Didymos. 

LCO scientists Dr. Tim Lister, Dr. Joey Chatelain, and Dr. Edward Gomez are coauthors on this paper. Dr. Lister heads the LCO group studying Near-Earth Objects, which employed data taken from LCO 1-m telescopes in South Africa and Chile for analysis. The data from the LCO telescopes, along with two others in Chile and planetary radar observations from Goldstone, CA, were used to measure the new period of Dimorphos after the DART impact. 

Dr. Tim Lister is pleased that LCO played a vital role in the DART mission, “It’s been a great privilege to be involved with and contribute to such an important mission for planetary defense. Having LCO telescopes in both Chile and South Africa allowed us to compare with other telescopes in Chile and also capture parts of Dimorphos’s orbit that other telescopes couldn’t. LCO’s extensive telescope network in the Southern Hemisphere was important in being able to measure the period change so soon after the impact.”

DART is a really exciting project--it's really fun to watch these results unfold from a front row seat. Tim, Edward and Joey are awesome scientists, and Tim's talks about DART are phenomenal. I had the privilege and misfortune of speaking following a DART talk he gave at our local Astronomy on Tap; very tough act to follow. 

BlackLotus UEFI bootkit: Myth confirmed

WeLiveSecurity

As already mentioned, the bootkit has been sold on underground forums since at least October 6th, 2022. At this point, we have not been able to identify, from our telemetry, the exact distribution channel used to deploy the bootkit to victims. The low number of BlackLotus samples we have been able to obtain, both from public sources and our telemetry, leads us to believe that not many threat actors have started using it yet.

The goal of the installer is clear – it’s responsible for disabling Windows security features such as BitLocker disk encryption and HVCI, and for deployment of multiple files, including the malicious bootkit, to the ESP. Once finished, it reboots the compromised machine to let the dropped files do their job – to make sure the self-signed UEFI bootkit will be silently executed on every system start, regardless of UEFI Secure Boot protection status.

ArsTechnica:

Researchers on Wednesday announced a major cybersecurity find—the world’s first-known instance of real-world malware that can hijack a computer’s boot process even when Secure Boot and other advanced protections are enabled and running on fully updated versions of Windows.

Because the UEFI is the first thing to run when a computer is turned on, it influences the OS, security apps, and all other software that follows. These traits make the UEFI the perfect place to launch malware. When successful, UEFI bootkits disable OS security mechanisms and ensure that a computer remains infected with stealthy malware that runs at the kernel mode or user mode, even after the operating system is reinstalled or a hard drive is replaced.

The ultimate takeaway is that UEFI bootkit BlackLotus is able to install itself on up-to-date systems using the latest Windows version with secure boot enabled.  

TheRegister:

Once BlackLotus exploits CVE-2022-21894 and turns off the system's security tools, it deploys a kernel driver and an HTTP downloader. The kernel driver, among other things, protects the bootkit files from removal, while the HTTP downloader communicates with the command-and-control server and executes payloads.

And while the researchers don't attribute the malware to a particular gang or nation-state group, they do note that the BlackLotus installers they analyzed won't proceed if the compromised computer is located in Armenia, Belarus, Kazakhstan, Moldova, Romania, Russia, and Ukraine.

This is a really tough sort of attack to protect against. If Microsoft deployed the trivial solution (simply flagging the vulnerable boot files as untrustworthy), it may brick every machine with an outdated UEFI. The exploit also uses BatonDrop, discovered by Wack0 back in August.

GitHub:

Windows Boot Applications allow the truncatememory setting to remove blocks of memory containing "persistent" ranges of serialised data from the memory map, leading to Secure Boot bypass. 

The attacker needs to ensure the serialised Secure Boot Policy is allocated above a known physical address.

This issue can be used to dump BitLocker keys (where Secure Boot is used for integrity validation). 

No known vulnerable boot application has been revoked yet. Revocation would cause all existing Windows installation/recovery media, and old backups, to fail to boot.

Sunday, March 5, 2023

James Webb captures an extremely distant triple-lensed supernova

ESA/Webb:

This observation from the NASA/ESA/CSA James Webb Space Telescope contains three different images of the same supernova-hosting galaxy, all of which were created by a colossal gravitational lens. In this case, the lens is the galaxy cluster RX J2129, located around 3.2 billion light-years from Earth in the constellation Aquarius. 

Astronomers discovered the supernova in the triply-lensed background galaxy using observations from the NASA/ESA Hubble Space Telescope, and they suspected that they had found a very distant Type Ia supernova.

SNe Type Ia function as standard candles, so if it really is Type Ia it could be used to determine a cosmic distance to RX J2129. However, I'm curious as to how they made this determination, as I didn't see any conclusive lightcurve or spectra associated with this find. No one has classified the supernova on TNS either. Update: apparently spectroscopy was obtained by NIRSpec but it's not clear if classification was possible.

Digital Trends:

The image features a huge galaxy cluster called RX J2129, located 3.2 billion light-years away, which is acting as a magnifying glass and bending light coming from more distant galaxies behind it. That’s what is causing the stretched-out shape of some of the galaxies toward the top right of the image.

CNET:

Not only does the galaxy appear three times, but it appears at different points in time. A supernova -- a bright exploding star -- is visible in the earliest version of the galaxy. The second and third images, from about 320 days and 1,000 days later, show that the supernova has faded away. An annotated version of the image points out these cool features: 


Mashable:

Astronomers are now adept at spotting the telltale effects of gravitational lensing, but that wasn't always the case. Four decades ago, the concentric arcs of light and stretched celestial objects could be downright confusing. In 1987, an enormous blue arc thought to be hundreds of trillions of miles long was first considered one of the largest objects ever detected in space. The arc was found near the galaxy cluster Abell 370, with another similar object near galaxy cluster 2242-02.

Saturday, March 4, 2023

Hyperauthorship: the publishing challenges for ‘big team’ science

Nature:

Then the COVID-19 pandemic broke that record, with 15,025 co-authors on a research paper examining the effect of SARS-CoV-2 vaccination on post-surgical COVID-19 infections and mortality.

The term ‘hyperauthorship’ is credited to information scientist Blaise Cronin7 at Indiana University in Bloomington, who used it in a 2001 publication to describe papers with 100 or more authors. But with the rise of large international and multi-institutional scientific collaborations — such as the ATLAS consortium behind the discovery of the Higgs boson — papers with hundreds, even thousands, of authors are becoming more common. There are many legitimate reasons for this shift, but it is raising questions — and concerns — about the nature of authorship and the impact that hyperauthorship has on the metrics of scientific achievement.

It’s a big change from the 1980s and is driven largely by an increase in international collaboration in science, says Jonathan Adams, chief scientist at the ISI and co-author of the report. 

These changes reflect the growing need for large research groups, spread across different types of institution and geographies, to answer complex questions. They also reflect a desire for more-inclusive authorship that recognizes researchers from backgrounds that might have been overlooked in the past.

But hyperauthorship creates challenges for researchers and for the journals that publish their work. Coordinating so many individual contributions across a multitude of institutions and nations is an enormous logistical feat. And hyperauthorship is raising philosophical questions about what it means to be an author of a research paper, and who has the right to — and need for — acknowledgement.

Overall a very interesting read into the phenomenon of high-authorship, high-impact papers.

Adams suggests that the number of authors on publications should be considered when looking at citation counts for institutions or nations, just as citation counts are normalized for year of publication and field. “We should be normalizing for the authorship, so you get a more representative citation indicator.” He says there’s even a case for leaving the largest of hyperauthored papers out of the citation process entirely. “If it’s CERN or one of the big telescopes, it’s like you’re either in the club or you’re not,” Adams says. “And then, what are we comparing you with?” [emphasis added]

I disagree with a lot of the conclusions of the article, but this opinion in particular I think could have a damaging effect. Much of my work is with a large collaboration (the Event Horizon Telescope Collaboration), so I have personal experience with this. Oftentimes, high-author papers are the only product researchers in the collaboration will have; anything they are working will get subsumed into these monster result papers. To torpedo these types of papers in a citation count will completely nullify years and years of research for many scientists working full time on these projects, dedicating their lives and careers to these results, with collaboration papers being their only scientific product. 

Another critical oversight this article makes is regarding collaborations (like the EHT) which have policies mandating full authorship. I spent the better part of 2 years working solely on a single paper which, when published, was determined to require full Collaboration authorship. This was a fair assessment, as the paper relied on the previous and ongoing work of large portion of the Collaboration and presented results that impacted and supported other major Collaboration work. I fully supported and advocated for this classification. However, the idea that the paper could simply be tossed in future citation counts purely because it has a giant author list is frankly terrible, given how important citation counts are becoming as a measure of productivity and impact. 

I know I am not alone in this situation--there are many, many early career scientists facing this exact problem. We work in large collaborations because many problems today are intractable without huge groups of people and data--something this article understands. However, the requirement of working in such a large collaborations is that most of your work goes into collaboration papers with everyone else's, and short-author-list papers are simply not as common--and certainly almost never as impactful. Especially for early-career scientists (particularly students), they may not be allowed to lead projects in these collaborations, meaning their only contributions will be recorded in the collaboration papers, if at all.

While altering citation counts to exclude high-authorship papers may weed out people who haven't contributed directly to the writing of a paper, it will be a harsh foot in the back of early-career scientists who rely on these projects and infrastructures to get their start in a world of large collaborations. 

Potential comet for 2024: C/2023 A3

MPEC:

Q.-Z. Ye reports cometary activity of an asteroidal NEOCP candidate (initially reported by ATLAS South Africa - M22 on Feb. 22 UT) in prediscovery images obtained by Palomar Mountain-ZTF (I41) on Dec 12, 2022 UT, noting a very condensed 2" coma and a straight 10" tail at position angle 230-250 deg. The object was independently discovered on Jan. 9 UT at Purple Mountain Observatory, XuYi Station (D29).

EarthSky:

At discovery, the comet was still 7.3 astronomical units (AU) from the sun, and shining at a dim magnitude 18.

Preliminary analysis of its trajectory suggests comet “A3” completes an orbit around the sun every 80,660 years. As of March 2023, the celestial visitor is currently between the orbits of Saturn and Jupiter. Although some specific facts and dates might be updated, currently it appears that closest approach to Earth should occur on October 13, 2024 at 05:38 UTC.

LiveScience:

As viewed from Earth, the comet may be as luminous as the brightest stars in the sky during its upcoming flyby, according to EarthSky. This is brighter than the green comet C/2022 E3 that just passed by Earth in January. That comet had a brightness of around magnitude +4.6, just visible to the naked eye. The new comet may have a brightness of magnitude 0.7, potentially peaking at magnitude -5, similar to Venus at its brightest(opens in new tab). (Lower numbers mean greater brightness on the stellar magnitude scale.) 

Much is yet unknown about C/2023 A3, including its size. Without more data, astronomers are still debating the comet's chances of survival. In a message chain for astronomers(opens in new tab), University of Pennsylvania postdoctoral researcher Qicheng Zhang(opens in new tab) summed up the situation, calling C/2023 A3 the most promising comet in years to provide naked-eye views but cautioning that these hopes could be dashed. "C/2023 A3's survival, while promising, is not guaranteed at this point," Zhang wrote.

I plan on following this comet closely! Excited to see what mass measurements come out, and it will be fun to try and photograph it.

Blender can now use AI to create images and effects from text descriptions

Stability.ai:

The Stability addon for Blender lets you use Stable Diffusion right inside your favorite 3D software. Generate textures, generate AI video from your renders, and more.

One of the most commonly used features of the addon is the ability to generate images from your existing renders. This is a great way to experiment with different styles or aesthetics in Blender without having to remodel your existing scene!


Engadget:

Stability AI has introduced a Stability for Blender tool that, as the name implies, brings Stable Diffusion's image creation tech to the open-source 3D tool. You can create AI-based textures, effects and animations, whether using source material from your renders or nothing more than a text description. 

Stability for Blender requires an API (programming interface) key and an internet connection, but it's free to use. It doesn't require any software dependencies or a dedicated GPU. 

Wednesday, March 1, 2023

Update to: Observational Evidence for Cosmological Coupling of Black Holes and its Implications for an Astrophysical Source of Dark Energy

Full post cataloging the reactions to this paper here.

PhysicsWorld:

The new theory hasn’t passed without controversy in physics circles, with many researchers unwilling to accept this cosmological coupling just yet.

“I can spot things that are troubling,” Universidad ECCI cosmologist Luz Ángela García tells Physics World. “Saying that their observation sets evidence for black holes being made out of dark energy seems like a long shot, in particular, because we cannot perform measurements ‘inside’ the black hole.”

García is also troubled by the fact that by linking dark energy to black holes, the team’s theory connects this force to the life cycle of stars, describing it as “very risky”. This is because when scientists consider the energy–matter content of the universe, black holes and thus dark energy in this model have already been accounted for in the 5% “ordinary matter” proportion of the energy–matter content of the universe.

Finally, García notes that the timeline of the universe leaves a gap of two billion years that the team’s theory struggles to fill.

“The peak of the number of black holes and quasars coincides with the peak of the star formation history approximately 10 billion years ago, and after that there’s a rapid decline in the number of these massive objects,” she explains. “On the other hand, the kickstart of the dark-energy domination occurs more or less eight billion years ago.”

This article has a quote from Dr. Farrah regarding the "controversy":

Farrah himself concurs that the mystery of dark energy is far from solved, acknowledging that while the two papers provide evidence of an astrophysical source for dark energy, their argument needs much more scrutiny.

“Dark energy remains a deeply mysterious phenomenon,” Farrah concludes. “I would say our papers raise the possibility of black holes as a source for dark energy and provide an ‘interesting hypothesis’, but at present, no more than that.”

I put "controversy" in quotes because while there is a lot of disagreement in the community about the validity of the theory, "controversy" has a very gross inappropriate drama-esque association with it. Fundamentally, nothing about the paper is inappropriate or "controversial" in this sense. Farrah and his team split the work into two distinct volumes; the first providing a solid report on an exciting data analysis, leaving 100% of the interpretation for the second volume. Do you notice how no one is casting much doubt on the first of the papers? It's because their actual data analysis is excellent; it's the interpretation scientists are disagreeing on. Farrah recognizes this himself in his quotes and interviews. Not only was it a smart thing to do (to avoid any "guilt by association" with the data analysis), it was also (in my opinion) a very responsible thing to do. The data are untainted by the interpretation, and the interpretation is not lent undue credibility by the solid data analysis.

Initial Flash and Spectral Formation of Type Ia Supernovae with An Envelope: Applications to Over-luminous SNe Ia

arXiv:

Over-luminous type Ia supernovae (SNe Ia) show peculiar observational features, for which an explosion of a super-massive white dwarf (WD) beyond the classical Chandrasekhar-limiting mass has been suggested, largely based on their high luminosities and slow light-curve evolution.

In the present work, we suggest a scenario that provides a unified solution to these peculiarities, through hydrodynamic and radiation transfer simulations together with analytical considerations; a C+O-rich envelope (~0.01 - 0.1 Msun) attached to an exploding WD. Strong C II lines are created within the shocked envelope.

The scenario thus can explain some of the key diverse observational properties by a different amount of the envelope, but additional factors are also required; we argue that the envelope is distributed in a disc-like structure, and also the ejecta properties, e.g., the mass of the WD, plays a key role.

Interestingly, the proposed scenario can also be tested for normal (non overluminous) SNe Ia:

Indeed, by combining the expected properties as summarized above, we can comprehensively test this scenario for SNe Ia with intensive observational coverage from the infant to late phases; the present work thus provides one strong motivation for the high-cadence survey and prompt follow-up observation for SNe Ia of various subclasses, especially nearby events that allow longterm monitoring toward the late phase.  

The predicted spectra are shown in Figure 4:



Thermal vacuum testing for the Europa Clipper

NASA (via YouTube ): We'll be back soon. The spacecraft is currently undergoing vacuum testing. I was a huge fan of the livestream for b...