Catch up on stories from the past week (and beyond) at the Slashdot story archive

 



Forgot your password?
typodupeerror
×
Science

Room-Temperature Superconductivity Study Retracted (science.org) 46

An anonymous reader quotes a report from Science Magazine: In 2020, Ranga Dias, a physicist at the University of Rochester, and his colleagues published a sensational result in Nature, featured on its cover. They claimed to have discovered a room-temperature superconductor: a material in which electric current flows frictionlessly without any need for special cooling systems. Although it was just a speck of carbon, sulfur, and hydrogen forged under extreme pressures, the hope was that someday the material would lead to variants that would enable lossless electricity grids and inexpensive magnets for MRI machines, maglev railways, atom smashers, and fusion reactors. Faith in the result is now evaporating. On Monday Nature retracted the study, citing data issues other scientists have raised over the past 2 years that have undermined confidence in one of two key signs of superconductivity Dias's team had claimed. "There have been a lot of questions about this result for a while," says James Hamlin, an experimental condensed matter physicist at the University of Florida. But Jorge Hirsch, a theoretical physicist at the University of California, San Diego (UCSD), and longtime critic of the study, says the retraction does not go far enough. He believes it glosses over what he says is evidence of scientific misconduct. "I think this is a real problem," he says. "You cannot leave it as, 'Oh, it's a difference of opinion.'"

The retraction was unusual in that Nature editors took the step over the objection of all nine authors of the paper. "We stand by our work, and it's been verified experimentally and theoretically," Dias says. Ashkan Salamat, a physicist at the University of Nevada, Las Vegas, and another senior member of the collaboration, points out the retraction does not question the drop in electric resistance -- the most important part of any superconductivity claim. He adds, "We're confused and disappointed in the decision-making by the Nature editorial board." The retraction comes even as excitement builds for the class of superconducting materials called hydrides, which includes the carbonaceous sulfur hydride (CSH) developed by Dias's team. Under pressures greater than at the center of the Earth, hydrogen is thought to behave like a superconducting metal. Adding other elements to the hydrogen -- creating a hydride structure -- can increase the "chemical pressure," reducing the need for external pressure and making superconductivity reachable in small laboratory vises called diamond anvil cells. As Lilia Boeri, a theoretical physicist at the Sapienza University of Rome, puts it, "These hydrides are a sort of realization of metallic hydrogen at slightly lower pressure."

In 2015, Mikhail Eremets, an experimental physicist at the Max Planck Institute for Chemistry, and colleagues reported the first superconducting hydride: a mix of hydrogen and sulfur that, under enormous pressures, exhibited a sharp drop in electrical resistance at a critical temperature (Tc) of 203 K (-70C). That was nowhere near room temperature, but warmer than the Tc for most superconducting materials. Some theorists thought adding a third element to the mix would give researchers a new variable to play with, enabling them to get closer to ambient pressures -- or room temperatures. For the 2020 Nature paper, Dias and colleagues added carbon, crushed the mix in a diamond anvil cell, and heated it with a laser to create a new substance. They reported that tests showed a sharp drop in resistance at a Tc of 288 K (15C) -- roughly room temperature -- and a pressure of 267 gigapascals, about 75% of the pressure at the center of the Earth. But in a field that has seen many superconducting claims come and go, a drop in resistance alone is not considered sufficient. The gold standard is to provide evidence of another key attribute of superconductors: their ability to expel an applied magnetic field when they cross Tc and become superconducting. Measuring that effect in a diamond anvil cell is impractical, so experimentalists working with hydrides often measure a related quantity called "magnetic susceptibility." Even then they must contend with tiny wires and samples, immense pressures, and a background magnetic signal from metallic gaskets and other experimental components. "It's like you're trying to see a star when the Sun is out," Hamlin says.
"The study's magnetic susceptibility data were what led to the retraction," reports Science. "The team members reported that a susceptibility signal emerged after they had subtracted a background signal, but they did not include raw data. The omission frustrated critics, who also complained that the team relied on a 'user-defined' background -- an assumed background rather than a measured one. But Salamat says relying on a user-defined background is customary in high-pressure physics because the background is so hard to measure experimentally."

Dias and Salamat posted a paper to arXiv in 2021 containing the raw susceptibility data and purported to explain how the background was subtracted, but it "raised more questions than it answered," says Brad Ramshaw, a quantum materials physicist at Cornell University. "The process of going from the raw data to the published data was incredibly opaque."

Hirsch accused the data of being "fabricated," noting suspicious similarities to data in a 2009 paper on superconductivity in europium under high pressures. It too was later retracted.
This discussion has been archived. No new comments can be posted.

Room-Temperature Superconductivity Study Retracted

Comments Filter:
  • by thesjaakspoiler ( 4782965 ) on Tuesday September 27, 2022 @11:15PM (#62919751)

    now that is something I can replicate in my attic and apply to my Apple II computer in order to have it outperform my Mac M2. =/

  • Reality check (Score:5, Interesting)

    by Luckyo ( 1726890 ) on Tuesday September 27, 2022 @11:18PM (#62919763)

    This silliness has sadly become a norm in superconductivity research. Instead of trying to discover something that would be useful, we're stuck with "my diamond anvil is better than yours" idiocy.

    For those not the know, we learned how to manufacture what is essentially a kind of an anvil that can put a very small object under extreme pressure in laboratory conditions. One of the things that extreme pressure does is raise temperature at which certain group of materials can become superconductive. And "advances" in this field have been advances in diamond anvils. As they became able to generate more and more pressure, researchers could raise the temperature more and more while retaining superconductivity.

    This is utterly pointless for practical applications, because there are no practical applications where we would maintain such pressures. This is literally a pointless dick measuring contest masquerading as useful scientific experimentation to get grants.

    • Re:Reality check (Score:5, Informative)

      by slack_justyb ( 862874 ) on Tuesday September 27, 2022 @11:59PM (#62919825)

      This is utterly pointless for practical applications, because there are no practical applications where we would maintain such pressures

      I believe the thing they are looking at is if some materials display metastability [wikipedia.org]. This point or pointlessness of that search I leave open to debate, but I do believe that the excuse on paper is a bit more than dick waving.

    • This is utterly pointless for practical applications, because there are no practical applications where we would maintain such pressures. This is literally a pointless dick measuring contest masquerading as useful scientific experimentation to get grants.

      I wouldn't be so sure about that, maybe they can apply string theory to this to create a quantum supercomputer?

    • by Roger W Moore ( 538166 ) on Wednesday September 28, 2022 @02:40AM (#62920049) Journal

      One of the things that extreme pressure does is raise temperature at which certain group of materials can become superconductive.

      No, it does not - the whole point of this controversy is that this claim of superconductivity has not been proven. Even worse, there seems to be some compelling evidence that the data used to make the claim in the first place were fabricated. The fact that Nature is retracting the paper over the objections of the authors lends a lot of credibility to that.

      This is why things like this have to be taken seriously. You, and doubtless many others, have started to think that high-pressure superconductivity in hydrides is a real thing and yet, as I understand it from a colleague who is a close collaborator of Hirsch, there are many reasons to doubt that, whatever they are seeing is superconductivity. Indeed, the Meisner effect - the smoking gun of superconductivity - still has not shown to happen for these materials.

      While superconductivity is not my area of expertise, in my own field of particle physics when you get a significant group of people objecting to and disagreeing with a result then it is usually a sure sign that someone screwed up the result somehow. When there are disagreements about something new that's real you do not tend to get paper retractions and everyone in the debate tends to be less certain and confrontational since the side that came up with the new result believes it is real and so is open to answering questions and doubts about it from the side that ha doubts (indeed those who found the result often have some doubts of their own!).

      • by HiThere ( 15173 ) <charleshixsn@@@earthlink...net> on Wednesday September 28, 2022 @08:49AM (#62920757)

        Well, what a lot of those people seem to be objecting to is that the raw data was hidden. This seems, to me, to be a reasonable objection, but it's not proof that they were lying, just that they shouldn't be believed.

        • I understand that some of the raw data was released by one of the authors on the paper and that it was an analysis of this data that showed signs of deliberate tampering. However, I have not seen the data myself nor do I know what the evidence of tampering was - but the people making these claims are people who I do not believe would make such claims without some pretty damning evidence to back them up.
  • Whatever temperature a room is at is "room temperature".

    • by Anonymous Coward
      not in science it isn't. while it isn't an exact number the current accepted range is 20-24c, though historically the lower limit was more towards 16.
    • Which is fine since, presumably, you'd want "room temperature" superconductors to actually be viable at a great range of temperatures that rooms can be in (and even outside environments) to be useful.
    • Re:Just noting ... (Score:4, Informative)

      by test321 ( 8891681 ) on Wednesday September 28, 2022 @03:00AM (#62920063)

      The (retracted) paper https://www.nature.com/article... [nature.com] says "a maximum superconducting transition temperature of 287.7 ± 1.2 kelvin (about 15 degrees Celsius)". A range of definitions coexist from 0 C to 25 C https://en.wikipedia.org/wiki/... [wikipedia.org] In physics paper one would use 298 K (the temperature for which the nominal value of thermodynamical quantities are found in tables, such as heat capacity, free enthalpy, etc.), in chemistry 20 C (the temperature at which the glassware are calibrated for volume), or 0 C in studies dealing with gases (the temperature at which the molar volume of ideal gas is calculated).

  • Whack-a-mole (Score:5, Insightful)

    by The Evil Atheist ( 2484676 ) on Wednesday September 28, 2022 @01:44AM (#62919955)
    Unless retractions play a role in changing the culture of universities and other research institutions as publish-or-die, we'll just be playing whack-a-mole, but with infinite holes and infinite moles.

    It's time people stopped measuring publication output and switch to measuring replications and retractions. Institutions should be publicly shamed for low replications (both of their own research and for replicating others' research), and high retractions.
    • by gweihir ( 88907 )

      Yep. The whole system is fundamentally broken. And "high quality" venues are anything but. As the story shows, you can even fake out "Nature". Also, we need a culture of publishing negative results. These are often far more valuable anyways.

  • Generally the concept of a scientific study has criteria it employs.

    These FRAUDS are no different than cold fusion geniuses Pons and Fleischman.
    They gamed the system. They lied, cheated, and abused the trust of real science practitioners.

    May they all die painfully.. There's no cold fusion. There's no room temperature superconductivity.
    There are certainly pieces of shit fake scientists who lie, cheat, and steal, hoping to get rich quickly,
    and I do hope they die quickly.

  • by backslashdot ( 95548 ) on Wednesday September 28, 2022 @02:29AM (#62920031)

    Reposting from AC potty mouthed comment above https://science.slashdot.org/c... [slashdot.org] : "This guy keeps making claims and losing the data, yet somehow gets published in top journals. Before this, it was "metallic hydrogen" that they swear to God, scout's honor, claim they had .. but lost and now can't replicate. Now with this claim too, they aren't providing enough data for anyone else to reproduce or validate the claims .. yet it gets published in top journals. WTF? It's not only him btw, I have been noticing this a lot with others publications too. If you can't provide the data that lets others duplicate your experiment fuck off, don't publish."

    That claim does not seem to be retracted.

  • by poptopdrop ( 6713596 ) on Wednesday September 28, 2022 @03:31AM (#62920079)

    Worth pointing out that that Nature retracted this for them.

        "The retraction was unusual in that Nature editors took the step over the objection of all nine authors of the paper."

    The authors are still standing behind their lies.
    It's time for misconduct trials.

  • ...the 'room' had a temperature of 0 Kelvin?

  • Apparently, there's new physics that we don't know about. https://patents.google.com/pat... [google.com]
    It must be real if the US Navy is involved.

    • by Retired Chemist ( 5039029 ) on Wednesday September 28, 2022 @08:20AM (#62920659)
      You can patent nearly anything in the US as long as it is "novel". No one actually checks that your claims are real and that the object you are claiming does what you say it does. All the patent examiner does is do a key word search and if no "prior art" is found, you get the patent. Since the examiner usually knows nothing about the field in question, there idea of what is prior art is usually poor anyway.
    • Honestly it seems like somone in the navy got close enough to get between the "I figured out how to make it" and "If somone finds he, make sure they know we made it". Its not describing the material, make up or anything AT ALL. Its basically describing how to use/keep it superconductive for some unknown practical application. But again you can patent anything if you give enough sources to say it "might" be possible.
  • What we need is... (Score:4, Interesting)

    by ebrandsberg ( 75344 ) on Wednesday September 28, 2022 @09:58AM (#62921019)

    The Journal of Reproducible Results. Just a journal of reproduced research to help document research that has been reproduced, and to improve the ability of researchers to publish when all they are doing is reproducing previous tests. Likewise, there should be a "journal of negative results" to document when a hypothesis did NOT prove out, as negative results can be just as useful as positive results.

    • Several top academic conferences now have awards or labels for the submission of "artifacts" that allow results in the paper to be reproduced or at least independently analyzed. Artifact submission is not yet required at any conference, but the movement is starting to gain some steam. This is a step in the right direction. However, a corresponding problem is the review process. Even in top conferences, the reviewers are all ostensibly experts but some only perform cursory reviews. Artifact review requi

  • In Soviet Russia they used to say "V Pravdi nyet izvestia, i v Isvestyi nyet pravda" or something like that. In this case, it illustrates that in Nature there isn't always that much science, and I would add that in Science there isn't always that much real about nature.

    Both of these publications are big splash PR machines, and their review processes have been flawed for a long time.

  • I remember stumbling across the original of this article while I was learning because I was researching a similar issue from conductivity myself. I had to do a report on my findings but since it turned out to be a fake I had to redo everything in a short time and failing that I even used the service https://essays.edubirdie.com/report-writing-services [edubirdie.com] for such moments. Too bad it turned out to be a lie which I bought and wasted a lot of time for nothing.

If money can't buy happiness, I guess you'll just have to rent it.

Working...