Superconductivity fight
- shpalman
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Superconductivity fight
Preprint server removes ‘inflammatory’ papers in superconductor controversy
This is about that business of high-pressure room-temperature superconductors (i.e. "we got them to work at room temperature we only need a huge pressure to do it") as opposed to normal-'pressure low-temperature superconductors (i.e. "we got them to work at normal pressure we only need a low temperature to do it"). The low temperature is probably easier but yeah, room-temperature superconductors, if you believe the results, which there are obviously some who don't.
This is about that business of high-pressure room-temperature superconductors (i.e. "we got them to work at room temperature we only need a huge pressure to do it") as opposed to normal-'pressure low-temperature superconductors (i.e. "we got them to work at normal pressure we only need a low temperature to do it"). The low temperature is probably easier but yeah, room-temperature superconductors, if you believe the results, which there are obviously some who don't.
having that swing is a necessary but not sufficient condition for it meaning a thing
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Re: Superconductivity fight
The temperature of superconductivity was a hot topic back in the 90’s when I was learning about it. Terrible straight-line extrapolation from essentially 2 groups of data points to show how it was all but inevitable that we would get room temperature superconductivity sometime soon. Motivated reasoning in abundance.shpalman wrote: ↑Thu Mar 17, 2022 9:00 amPreprint server removes ‘inflammatory’ papers in superconductor controversy
This is about that business of high-pressure room-temperature superconductors (i.e. "we got them to work at room temperature we only need a huge pressure to do it") as opposed to normal-'pressure low-temperature superconductors (i.e. "we got them to work at normal pressure we only need a low temperature to do it"). The low temperature is probably easier but yeah, room-temperature superconductors, if you believe the results, which there are obviously some who don't.
where once I used to scintillate
now I sin till ten past three
now I sin till ten past three
- shpalman
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Re: Superconductivity fight
Our lecturer had just written a textbook on superconductivity in which he wrote that he'd left the chapter on high-Tc until last in the hope that someone would have figured out how it worked by the time he got around to it. That was also back in the 90's.Grumble wrote: ↑Thu Mar 17, 2022 4:17 pmThe temperature of superconductivity was a hot topic back in the 90’s when I was learning about it. Terrible straight-line extrapolation from essentially 2 groups of data points to show how it was all but inevitable that we would get room temperature superconductivity sometime soon. Motivated reasoning in abundance.shpalman wrote: ↑Thu Mar 17, 2022 9:00 amPreprint server removes ‘inflammatory’ papers in superconductor controversy
This is about that business of high-pressure room-temperature superconductors (i.e. "we got them to work at room temperature we only need a huge pressure to do it") as opposed to normal-'pressure low-temperature superconductors (i.e. "we got them to work at normal pressure we only need a low temperature to do it"). The low temperature is probably easier but yeah, room-temperature superconductors, if you believe the results, which there are obviously some who don't.
having that swing is a necessary but not sufficient condition for it meaning a thing
@shpalman@mastodon.me.uk
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Re: Superconductivity fight
Really high temperature superconductivity would be fantastic for fusion power...shpalman wrote: ↑Thu Mar 17, 2022 4:21 pmOur lecturer had just written a textbook on superconductivity in which he wrote that he'd left the chapter on high-Tc until last in the hope that someone would have figured out how it worked by the time he got around to it. That was also back in the 90's.Grumble wrote: ↑Thu Mar 17, 2022 4:17 pmThe temperature of superconductivity was a hot topic back in the 90’s when I was learning about it. Terrible straight-line extrapolation from essentially 2 groups of data points to show how it was all but inevitable that we would get room temperature superconductivity sometime soon. Motivated reasoning in abundance.shpalman wrote: ↑Thu Mar 17, 2022 9:00 amPreprint server removes ‘inflammatory’ papers in superconductor controversy
This is about that business of high-pressure room-temperature superconductors (i.e. "we got them to work at room temperature we only need a huge pressure to do it") as opposed to normal-'pressure low-temperature superconductors (i.e. "we got them to work at normal pressure we only need a low temperature to do it"). The low temperature is probably easier but yeah, room-temperature superconductors, if you believe the results, which there are obviously some who don't.
![Wink ;)](./images/smilies/icon_e_wink.gif)
- shpalman
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Re: Superconductivity fight
“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.”
Evidence of near-ambient superconductivity in a N-doped lutetium hydride
Evidence of near-ambient superconductivity in a N-doped lutetium hydride
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.
having that swing is a necessary but not sufficient condition for it meaning a thing
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Re: Superconductivity fight
I mean calling 10kbar “near ambient” is a very relative term. This kind of thing should be replicable so I shall reserve judgement. I hope it’s true.
where once I used to scintillate
now I sin till ten past three
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Re: Superconductivity fight
Given that their previous paper at even higher pressures was retracted due to major issues, I'm not paying much attention to this.
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Re: Superconductivity fight
More on those major issues from a freelance science writer based in New York who had no communication about this story with his father the Managing Editor of Phys. Rev. Lett..
I'm paying attention to this to see how it turns out to be faked/wrong this time... It's a much more accessible pressure but they can always claim that the other groups haven't made the material properly when they fail to replicate, while never letting anyone else have their "working" samples for spurious IP reasons.
It's a different kind of "pressure" but we regularly make samples with about 1 GPa of biaxial elastic stress in them.
I'm paying attention to this to see how it turns out to be faked/wrong this time... It's a much more accessible pressure but they can always claim that the other groups haven't made the material properly when they fail to replicate, while never letting anyone else have their "working" samples for spurious IP reasons.
It's a different kind of "pressure" but we regularly make samples with about 1 GPa of biaxial elastic stress in them.
having that swing is a necessary but not sufficient condition for it meaning a thing
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Re: Superconductivity fight
There's already an arxiv paper from one Chinese team showing that they failed to replicate it.
Re: Superconductivity fight
Side note from this, I wonder if there’s a region of Jupiter where temperatures and pressures are in the right region to have superconducting hydrogen, and if so would we be able to detect it?
where once I used to scintillate
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Re: Superconductivity fight
having that swing is a necessary but not sufficient condition for it meaning a thing
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Re: Superconductivity fight
Yeah, I think so. In that they couldn't get above 71K or below 161 GPashpalman wrote: ↑Sat Mar 11, 2023 1:59 pmThis? Superconductivity above 70 K experimentally discovered in lutetium polyhydride
Re: Superconductivity fight
I'm now imagining using this to carry the electricity from my cold fusion rig
Have you considered stupidity as an explanation
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Re: Superconductivity fight
... we identify a notable temperature-induced resistance anomaly of structural and/or electronic origin in LuHxNy, which is most pronounced in the pink phase and may have been erroneously interpreted as a sign of superconducting transition...
A few tweets regarding whether Nature can be trusted anymore in reply to that tweet from the coauthor of the retracted Majorana Nature paper...
A few tweets regarding whether Nature can be trusted anymore in reply to that tweet from the coauthor of the retracted Majorana Nature paper...
having that swing is a necessary but not sufficient condition for it meaning a thing
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Re: Superconductivity fight
I've never really trusted Nature. It only takes the most surprising and potentially significant results in any particular field, and passes them through an non field-expert editorial team, who have to find good reviewers for that paper. That makes the likelihood of any particular paper being shown to be wrong much higher than a boring paper in a boring field specific journal, whether that's due to malfeasance, researcher or reviewer incompetence or just bad luck.shpalman wrote: ↑Tue Apr 04, 2023 8:17 am... we identify a notable temperature-induced resistance anomaly of structural and/or electronic origin in LuHxNy, which is most pronounced in the pink phase and may have been erroneously interpreted as a sign of superconducting transition...
A few tweets regarding whether Nature can be trusted anymore in reply to that tweet from the coauthor of the retracted Majorana Nature paper...
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Re: Superconductivity fight
having that swing is a necessary but not sufficient condition for it meaning a thing
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Re: Superconductivity fight
having that swing is a necessary but not sufficient condition for it meaning a thing
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Re: Superconductivity fight
having that swing is a necessary but not sufficient condition for it meaning a thing
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Re: Superconductivity fight
shpalman wrote: ↑Wed Jul 26, 2023 6:12 amThe First Room-Temperature Ambient-Pressure Superconductor
Of course nobody actually believes it.
I think even my father would find a room temperature of > 127° a tad high. (Obviously, there's a specialist meaning of room temperature in fizziks.)room-temperature superconductor (Tc≥400 K, 127∘C)
Re: Superconductivity fight
The paper claims to show superconductivity at temperatures below 400K, including ambient. Tc is the upper temperature limit for superconducting effects.Brightonian wrote: ↑Wed Jul 26, 2023 10:23 amshpalman wrote: ↑Wed Jul 26, 2023 6:12 amThe First Room-Temperature Ambient-Pressure Superconductor
Of course nobody actually believes it.I think even my father would find a room temperature of > 127° a tad high. (Obviously, there's a specialist meaning of room temperature in fizziks.)room-temperature superconductor (Tc≥400 K, 127∘C)
Re: Superconductivity fight
The paper does include most, if not all, of the direct measurements of superconducting effects that I would expect to see in a proper discovery of a new superconducting material.
The claimed material is also the right kind of structure that might possibly show higher temperature superconductivity.
But obviously, any claim like this needs replication, either in measurements on additional samples produced by the group, or made independently.
The claimed material is also the right kind of structure that might possibly show higher temperature superconductivity.
But obviously, any claim like this needs replication, either in measurements on additional samples produced by the group, or made independently.
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Re: Superconductivity fight
I see, thanks.dyqik wrote: ↑Wed Jul 26, 2023 10:26 amThe paper claims to show superconductivity at temperatures below 400K, including ambient. Tc is the upper temperature limit for superconducting effects.Brightonian wrote: ↑Wed Jul 26, 2023 10:23 amshpalman wrote: ↑Wed Jul 26, 2023 6:12 amThe First Room-Temperature Ambient-Pressure Superconductor
Of course nobody actually believes it.I think even my father would find a room temperature of > 127° a tad high. (Obviously, there's a specialist meaning of room temperature in fizziks.)room-temperature superconductor (Tc≥400 K, 127∘C)
Re: Superconductivity fight
But as an ambient environment superconductor, replicating measurements should be easy. That makes it difficult to imagine getting away with a grift on this, while high pressure measurements are harder to replicate.dyqik wrote: ↑Wed Jul 26, 2023 10:29 amThe paper does include most, if not all, of the direct measurements of superconducting effects that I would expect to see in a proper discovery of a new superconducting material.
The claimed material is also the right kind of structure that might possibly show higher temperature superconductivity.
But obviously, any claim like this needs replication, either in measurements on additional samples produced by the group, or made independently.
ETA: which means it's either very interesting or a very stupid grift.
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Re: Superconductivity fight
What I think they mean is that they went up to 400 K and still hadn't seen the transition out of "superconductivity" which does strongly suggest to me that they're never in superconductivity in the first place.Brightonian wrote: ↑Wed Jul 26, 2023 10:23 amshpalman wrote: ↑Wed Jul 26, 2023 6:12 amThe First Room-Temperature Ambient-Pressure Superconductor
Of course nobody actually believes it.I think even my father would find a room temperature of > 127° a tad high. (Obviously, there's a specialist meaning of room temperature in fizziks.)room-temperature superconductor (Tc≥400 K, 127°C)
having that swing is a necessary but not sufficient condition for it meaning a thing
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Re: Superconductivity fight
Oh well if it's the same colour it must be a superconductor.LK-99 is a gray-black color, as shown in Figure 3(b). It is the superconductor with the same color as typical superconductors.
having that swing is a necessary but not sufficient condition for it meaning a thing
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