11 ms·

One of the authors in a related paper[1] is Hyun-Tak Kim. He has many publications in peer-reviewed journals[2]. One even has > 1500 citations[3]. I can't tell

One of the authors in a related paper[1] is Hyun-Tak Kim. He has many publications in peer-reviewed journals[2]. One even has > 1500 citations[3]. I can't tell if there is a catch anywhere, this seems pretty legitimate. Also, unlike some previous claims that required sophisticated setup to reproduce, this seems dead simple. I think we will hear from other researchers very soon. 1. Superconductor Pb10-xCux(PO4)6O showing levitation at room temperature and atmospheric pressure and mechanism: https://arxiv.org/pdf/2307.12037.pdf https://arxiv.org/pdf/2307.12037.pdf 2. Google Scholar: https://scholar.google.com/citations?user=_P8mux4AAAAJ&hl=en https://scholar.google.com/citations?user=_P8mux4AAAAJ&hl=en 3. Mott transition in VO2 revealed by infrared spectroscopy and nano-imaging: https://scholar.google.com/citations?view_op=view_citation&hl=en&user=_P8mux4AAAAJ&citation_for_view=_P8mux4AAAAJ:u5HHmVD_uO8C https://scholar.google.com/citations?view_op=view_citation&h...

PaulHoule 3y ago
Unlike those guys in Rochester, this seems to be a good experiment that is testing many of the signs of superconductivity.
- amluto 3y ago
  The actual picture of (poor) levitation in the paper you linked is pretty compelling. This isn’t a complex, noisy measurement showing something that’s related to superconductivity — this is a magnet and a supposed superconductor repelling each other. As far as I know, that’s possible with permanent magnets (and it would be weird, but not impossible, if the group instead synthesized a novel ferromagnet and didn’t notice), electrets (seems pretty unlikely here), very extreme amounts of static charge (again, seems unlikely), and actual superconductivity (would be awesome). Random bits of cooked oxides, ceramics, and such don’t float on a magnet.
  - scarmig 3y ago
    Their other data doesn't line up with ferromagnetism, though. It's either the real thing or a big fraud. Guess we'll find out soon enough. ETA: the video referenced is apparently available at https://www.youtube.com/watch?v=EtVjGWpbE7k https://www.youtube.com/watch?v=EtVjGWpbE7k . Interestingly, posted on Feb 26, 2023.
    - marcosdumay 3y ago
      Yeah, that thing does really want to stay in a constant level on the magnetic field. That would dispel every other explanation on the GP, as it's not simply being repelled or attracted.
      - Baeocystin 3y ago
        I found that video very compelling. If it was eddy current, the float standoff distance would have decayed. It sure looked to me like there was no decay at all, and wow! if true.
        oefnak 3y ago
        What is float standoff distance?
        Baeocystin 3y ago
        Eddy currents can be induced in non-superconducting materials that make it look like levitation, but the catch is that there has to be relative motion between the magnet and the object 'levitating' to generate the currents in the first place. I've linked to a relevant example in a Veritasium video here: https://youtu.be/g0amdIcZt5I?t=543 https://youtu.be/g0amdIcZt5I?t=543 But in this sample video, the standoff distance doesn't appear to be slowly dropping at all, which would rule out eddy currents as a source of the behavior. If you continue watching the linked video to 13:27, he talks about how and why superconductors levitate.
    - deleted 3y ago
      [deleted]
    - mildchalupa 3y ago
      Electromagnetic solenoid designer here... Copper and a magnet can certainly interact. Drop a magnet through a copper pipe and the eddy currents will induce a field that's opposed to the magnet causing a damping effect. Maybe something like this is going on where movement of the magnetic field is inducing an opposed magnetic field in the copper, and thus interacting. Anyhow it will be interesting. if It can generate a field of 1.5-2 Tesla you could have more efficient solenoids and probably motors.
  - colechristensen 3y ago
    >As far as I know, that’s possible with permanent magnets (and it would be weird, but not impossible, if the group instead synthesized a novel ferromagnet and didn’t notice) As far as I know a stable arrangement of permanent magnets levitating is impossible without a baring surface to keep them aligned. (i.e. free floating levitation is not possible without active control)
    - floxy 3y ago
      Just so everyone is on the same page, static passive diamagnetic levitation is possible with materials like pyrolytic graphite. https://en.wikipedia.org/wiki/Diamagnetism https://en.wikipedia.org/wiki/Diamagnetism https://www.kjmagnetics.com/blog.asp?p=diamagnetic-levitation https://www.kjmagnetics.com/blog.asp?p=diamagnetic-levitatio... ...and superconductors are usually perfectly diamagnetic.
      - colechristensen 3y ago
        Every substance is one of * ferromagnetic - attracted to one pole of a magnet but not the other (in a given orientation), this is what everybody thinks of when they think of "magnets" * paramagnetic - attracted to both poles, i.e. stuff that sticks to magnets * diamagnetic - repelled by both poles, except in superconductors, this effect is very weak compared to the forces experienced involving ferro-ferro or fero-paramagnetic materials. There isn't another category, everything fits in to one of those buckets. Saying >Just so everyone is on the same page, static passive diamagnetic levitation is possible with materials like pyrolytic graphite. is a bit deceptive, as what people know as "magnetic" materials are ferromagnetic.
        CMScientist 3y ago
        You literally missed the most common magnetic phase - antiferromagnetism
    - jacquesm 3y ago
      That's not quite true. There is a Halbach array with a bunch of compensation coils that will nicely center as long as it is moving, no active control or bearing required. https://www.sciencedirect.com/science/article/abs/pii/S0304885311001181 https://www.sciencedirect.com/science/article/abs/pii/S03048... And many others besides. Halbach arrays are fascinating.
  - PlasmonOwl 3y ago
    I would say that this type of levitation where it sort of half levitates is quite common. I taught YBaCuO superconductor experiments for a few years. That Meisner effect would get full marks in my institution!
  - whatshisface 3y ago
    Believe it or not, the levitation effect can be found in non-superconducting materials with a high diamagnetic constant such as pyrolytic carbon. Induced magnetic fields are created by "effective currents," which can occur in zero-resistance systems that are not called superconductors (because they can't conduct across a significant distance, only around a tiny loop) like molecular or atomic orbitals. https://en.wikipedia.org/wiki/Pyrolytic_carbon https://en.wikipedia.org/wiki/Pyrolytic_carbon
    - howmayiannoyyou 3y ago
      Diamagnetism was my first reaction when I saw lead, and the addition of copper makes me think eddy current reactivity.
      - rozab 3y ago
        ...and this is Eddy's sofa, is it?
coolspot 3y ago
> Superconductor Pb10-xCux(PO4)6O showing levitation at room temperature and atmospheric pressure Is it late April Fools joke? It can’t be true. Edit: I am not surprised it levitates. I am astonished by how much it will reshape our world if it is real room-temp and ambient-pressure superconductor. Also is easy to produce. Just too good to be true.
- distortedsignal 3y ago
  All of those elements are so common - this should be easy to test. We'll see.
  - stu255 3y ago
    Any news yet? You could almost make this stuff in a pizza oven.
    - distortedsignal 3y ago
      I would guess that it'll take a month or two to repro the procedure. The paper was uploaded in the last week, so we're still probably a few weeks out on peer review.
- zenexer 3y ago
  Superconductors will typically levitate if placed above a magnet, and vice versa. Magnets are weird--superconductors even more so. I assume that's what they were referring to? Edit: Judging by Fig 4, which has a large object conspicuously labeled "magnet", that's probably what they're referring to.
  - amluto 3y ago
    This whole experiment is quite reminiscent of an experiment I did in high school. We synthesized a high temperature superconductor (IIRC it was YBCO) by grinding some powders together with a mortal and pestle and baking the result. And we stuck it in a little cup of LN2 and floated a magnet on it. It really works! This group used somewhat nastier powders, they had to cook parts of it in a vacuum, and they floated the result on a magnet instead of vice versa. And it only floated a bit. But they did it without any cooling!
deleted 3y ago
[deleted]
xxpor 3y ago
One catch would be the use of lead would restrict the use cases fairly heavily
- phatskat 3y ago
  > fairly heavily Not being in sciences I can’t tell if this sentence is legit or you just got a good joke in there
- JumpCrisscross 3y ago
  > the use of lead would restrict the use cases Most people aren't licking the insides of their computer processors, fusion reactors, radio telescopes and MRIs.
  - amatecha 3y ago
    It's more about producing toxic waste and contaminating the environment - no one's licking the solder joints in their electronics either, but you still have to use lead-free solder. For instance in EU, https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A02011L0065-20230301#B-1 https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A... Canada, https://www.canada.ca/en/health-canada/services/environmental-workplace-health/environmental-contaminants/lead/lead-information-package-some-commonly-asked-questions-about-lead-human-health.html https://www.canada.ca/en/health-canada/services/environmenta... USA, https://www.epa.gov/lead/learn-about-lead https://www.epa.gov/lead/learn-about-lead
    - JumpCrisscross 3y ago
      > more about producing toxic waste Compared to refining traditional conductors and recycling/disposing of used electronics? > you still have to use lead-free solder One, fumes. Two, people touch their solder and then grab a cookie. We're premature. The results need to be proven. But the benefits of RTP superconductors is mindblowingly high enough that risks from lead contamination (far from a novel problem, I might add) can be safely ignored.
johncalvinyoung 3y ago
Found another earlier paper on LK-99, published in Journal of the Korean Crystal Growth and Crystal Technology in April '23. I don't read Korean though so didn't get a lot out of it. http://journal.kci.go.kr/jkcgct/archive/articleView?artiId=ART002955269 http://journal.kci.go.kr/jkcgct/archive/articleView?artiId=A...
deleted 3y ago
[deleted]
PBnFlash 3y ago
Okay I can believe super conductivity, but having LK-99 a registered trademark already is where I draw the line.
- kuschku 3y ago
  Considering they've published dozens of papers on these experiments over the past months, it doesn't sound too unusual so far.
- carlintveld 3y ago
  Is it even possible to have super conduction at room temperature? I always thought it was highly associated with cold temperatures.
  - smolder 3y ago
    Until and unless this story gets proven true, it's unknown. We can't reliably predict what materials will have what properties.
- Quiark 3y ago
  True, I would prefer "unobtanium"

PaulHoule 3y ago

Unlike those guys in Rochester, this seems to be a good experiment that is testing many of the signs of superconductivity.

amluto 3y ago
The actual picture of (poor) levitation in the paper you linked is pretty compelling. This isn’t a complex, noisy measurement showing something that’s related to superconductivity — this is a magnet and a supposed superconductor repelling each other. As far as I know, that’s possible with permanent magnets (and it would be weird, but not impossible, if the group instead synthesized a novel ferromagnet and didn’t notice), electrets (seems pretty unlikely here), very extreme amounts of static charge (again, seems unlikely), and actual superconductivity (would be awesome). Random bits of cooked oxides, ceramics, and such don’t float on a magnet.
- scarmig 3y ago
  Their other data doesn't line up with ferromagnetism, though. It's either the real thing or a big fraud. Guess we'll find out soon enough. ETA: the video referenced is apparently available at https://www.youtube.com/watch?v=EtVjGWpbE7k https://www.youtube.com/watch?v=EtVjGWpbE7k . Interestingly, posted on Feb 26, 2023.
  - marcosdumay 3y ago
    Yeah, that thing does really want to stay in a constant level on the magnetic field. That would dispel every other explanation on the GP, as it's not simply being repelled or attracted.
    - Baeocystin 3y ago
      I found that video very compelling. If it was eddy current, the float standoff distance would have decayed. It sure looked to me like there was no decay at all, and wow! if true.
      - oefnak 3y ago
        What is float standoff distance?
        Baeocystin 3y ago
        Eddy currents can be induced in non-superconducting materials that make it look like levitation, but the catch is that there has to be relative motion between the magnet and the object 'levitating' to generate the currents in the first place. I've linked to a relevant example in a Veritasium video here: https://youtu.be/g0amdIcZt5I?t=543 https://youtu.be/g0amdIcZt5I?t=543 But in this sample video, the standoff distance doesn't appear to be slowly dropping at all, which would rule out eddy currents as a source of the behavior. If you continue watching the linked video to 13:27, he talks about how and why superconductors levitate.
  - deleted 3y ago
    [deleted]
  - mildchalupa 3y ago
    Electromagnetic solenoid designer here... Copper and a magnet can certainly interact. Drop a magnet through a copper pipe and the eddy currents will induce a field that's opposed to the magnet causing a damping effect. Maybe something like this is going on where movement of the magnetic field is inducing an opposed magnetic field in the copper, and thus interacting. Anyhow it will be interesting. if It can generate a field of 1.5-2 Tesla you could have more efficient solenoids and probably motors.
- colechristensen 3y ago
  >As far as I know, that’s possible with permanent magnets (and it would be weird, but not impossible, if the group instead synthesized a novel ferromagnet and didn’t notice) As far as I know a stable arrangement of permanent magnets levitating is impossible without a baring surface to keep them aligned. (i.e. free floating levitation is not possible without active control)
  - floxy 3y ago
    Just so everyone is on the same page, static passive diamagnetic levitation is possible with materials like pyrolytic graphite. https://en.wikipedia.org/wiki/Diamagnetism https://en.wikipedia.org/wiki/Diamagnetism https://www.kjmagnetics.com/blog.asp?p=diamagnetic-levitation https://www.kjmagnetics.com/blog.asp?p=diamagnetic-levitatio... ...and superconductors are usually perfectly diamagnetic.
    - colechristensen 3y ago
      Every substance is one of * ferromagnetic - attracted to one pole of a magnet but not the other (in a given orientation), this is what everybody thinks of when they think of "magnets" * paramagnetic - attracted to both poles, i.e. stuff that sticks to magnets * diamagnetic - repelled by both poles, except in superconductors, this effect is very weak compared to the forces experienced involving ferro-ferro or fero-paramagnetic materials. There isn't another category, everything fits in to one of those buckets. Saying >Just so everyone is on the same page, static passive diamagnetic levitation is possible with materials like pyrolytic graphite. is a bit deceptive, as what people know as "magnetic" materials are ferromagnetic.
      - CMScientist 3y ago
        You literally missed the most common magnetic phase - antiferromagnetism
  - jacquesm 3y ago
    That's not quite true. There is a Halbach array with a bunch of compensation coils that will nicely center as long as it is moving, no active control or bearing required. https://www.sciencedirect.com/science/article/abs/pii/S0304885311001181 https://www.sciencedirect.com/science/article/abs/pii/S03048... And many others besides. Halbach arrays are fascinating.
- PlasmonOwl 3y ago
  I would say that this type of levitation where it sort of half levitates is quite common. I taught YBaCuO superconductor experiments for a few years. That Meisner effect would get full marks in my institution!
- whatshisface 3y ago
  Believe it or not, the levitation effect can be found in non-superconducting materials with a high diamagnetic constant such as pyrolytic carbon. Induced magnetic fields are created by "effective currents," which can occur in zero-resistance systems that are not called superconductors (because they can't conduct across a significant distance, only around a tiny loop) like molecular or atomic orbitals. https://en.wikipedia.org/wiki/Pyrolytic_carbon https://en.wikipedia.org/wiki/Pyrolytic_carbon
  - howmayiannoyyou 3y ago
    Diamagnetism was my first reaction when I saw lead, and the addition of copper makes me think eddy current reactivity.
    - rozab 3y ago
      ...and this is Eddy's sofa, is it?

coolspot 3y ago

> Superconductor Pb10-xCux(PO4)6O showing levitation at room temperature and atmospheric pressure Is it late April Fools joke? It can’t be true. Edit: I am not surprised it levitates. I am astonished by how much it will reshape our world if it is real room-temp and ambient-pressure superconductor. Also is easy to produce. Just too good to be true.

distortedsignal 3y ago
All of those elements are so common - this should be easy to test. We'll see.
- stu255 3y ago
  Any news yet? You could almost make this stuff in a pizza oven.
  - distortedsignal 3y ago
    I would guess that it'll take a month or two to repro the procedure. The paper was uploaded in the last week, so we're still probably a few weeks out on peer review.
zenexer 3y ago
Superconductors will typically levitate if placed above a magnet, and vice versa. Magnets are weird--superconductors even more so. I assume that's what they were referring to? Edit: Judging by Fig 4, which has a large object conspicuously labeled "magnet", that's probably what they're referring to.
- amluto 3y ago
  This whole experiment is quite reminiscent of an experiment I did in high school. We synthesized a high temperature superconductor (IIRC it was YBCO) by grinding some powders together with a mortal and pestle and baking the result. And we stuck it in a little cup of LN2 and floated a magnet on it. It really works! This group used somewhat nastier powders, they had to cook parts of it in a vacuum, and they floated the result on a magnet instead of vice versa. And it only floated a bit. But they did it without any cooling!

deleted 3y ago

[deleted]

xxpor 3y ago

One catch would be the use of lead would restrict the use cases fairly heavily

phatskat 3y ago
> fairly heavily Not being in sciences I can’t tell if this sentence is legit or you just got a good joke in there
JumpCrisscross 3y ago
> the use of lead would restrict the use cases Most people aren't licking the insides of their computer processors, fusion reactors, radio telescopes and MRIs.
- amatecha 3y ago
  It's more about producing toxic waste and contaminating the environment - no one's licking the solder joints in their electronics either, but you still have to use lead-free solder. For instance in EU, https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A02011L0065-20230301#B-1 https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A... Canada, https://www.canada.ca/en/health-canada/services/environmental-workplace-health/environmental-contaminants/lead/lead-information-package-some-commonly-asked-questions-about-lead-human-health.html https://www.canada.ca/en/health-canada/services/environmenta... USA, https://www.epa.gov/lead/learn-about-lead https://www.epa.gov/lead/learn-about-lead
  - JumpCrisscross 3y ago
    > more about producing toxic waste Compared to refining traditional conductors and recycling/disposing of used electronics? > you still have to use lead-free solder One, fumes. Two, people touch their solder and then grab a cookie. We're premature. The results need to be proven. But the benefits of RTP superconductors is mindblowingly high enough that risks from lead contamination (far from a novel problem, I might add) can be safely ignored.

johncalvinyoung 3y ago

Found another earlier paper on LK-99, published in Journal of the Korean Crystal Growth and Crystal Technology in April '23. I don't read Korean though so didn't get a lot out of it. http://journal.kci.go.kr/jkcgct/archive/articleView?artiId=ART002955269 http://journal.kci.go.kr/jkcgct/archive/articleView?artiId=A...

deleted 3y ago

[deleted]

PBnFlash 3y ago

Okay I can believe super conductivity, but having LK-99 a registered trademark already is where I draw the line.

kuschku 3y ago
Considering they've published dozens of papers on these experiments over the past months, it doesn't sound too unusual so far.
carlintveld 3y ago
Is it even possible to have super conduction at room temperature? I always thought it was highly associated with cold temperatures.
- smolder 3y ago
  Until and unless this story gets proven true, it's unknown. We can't reliably predict what materials will have what properties.
Quiark 3y ago
True, I would prefer "unobtanium"