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Maybe a cautionary reminder to not listen to random influencers on Twitter. The expert community was really silent and reserved from the beginning as they've se

Maybe a cautionary reminder to not listen to random influencers on Twitter. The expert community was really silent and reserved from the beginning as they've seen such wonder materials many times. Having worked in that field for many years I'm personally skeptical that there ever will be an ambient-pressure, room-temperature superconductor. The band structure and interactions that need to be present in the material are just one requirement for superconductivity, the other is that the ground state can actually form and won't be destroyed by thermal noise. However, the strong electron-phonon interaction required for (classical) superconductivity also makes the system susceptible to thermal noise, and in my opinion the thermal noise level at 290 K is just too much even for an ideal superconducting material.

mkagenius 3y ago
Yes, I only listen to people with handle like "ThePhysicist" or "theMaterialPhyisicist" at hackernews.
- jldugger 3y ago
  I think the point is you can probably ignore everyone who isn't giving a Nobel acceptance speech.
  - ElFitz 3y ago
    That’s why I personally only listen to the opinions of people with handles like "Planck54", "The1965PhysicsNobel" or "EconNobel94" on hackernews. Sorry, I couldn’t resist. N.B. I also tried to find some noteworthy Fields medal winner, but refrained since it appears I don’t know any of them, and that the committee’s choices and motivations have been subject to controversy [0]. [0]: https://www.science.org/content/article/fields-medal-was-never-meant-greatest-mathematical-genius https://www.science.org/content/article/fields-medal-was-nev...
    - jacquesm 3y ago
      Sure, but every now and then people get into an argument with a Putnam prize winner or the inventor of some Internet Protocol details and find themselves caught out...
      - JacobAldridge 3y ago
        I would bet picodollars that rarely happens here…
        jeltz 3y ago
        It happens more often than you think. For example it has happened a bunch of times that people have argued against PostgreSQL core developers about the internals of PostgreSQL. I know most of their usernames so it is always a great laugh for me.
        jacquesm 3y ago
        I think you missed the GPs subtle point.
        jacquesm 3y ago
        Hehe. Nice one.
- hliyan 3y ago
  [flagged]
  - ThePhysicist 3y ago
    FWIW I prefer to not use my real name in discussion threads here, although it is linked in my bio. So if you don't mind please remove it, thanks :)
    - hliyan 3y ago
      Apologies, by the time I saw this, the edit button had been disabled. Please feel free to flag the message so that dang can remove it.
whimsicalism 3y ago
But the high temp cup rate superconductors don’t follow classical landau theory afaik
moonchrome 3y ago
I don't see anything bad with this hype cycle : - these guys thought they found something - turns out it probably wasn't superconductors but it's an still interesting finding - there was no fraud and something new was discovered - material science got a bit more mainstream exposure I'd rather see that than another crypto or AI hype cycle
- exmadscientist 3y ago
  No, it really wasn't that bad. The annoying part, at least for me as someone who, uh, I guess used to go to a lot of colloquia on this stuff?, is the part you left out: people pre-judged the outcome (of all three phenomena you mention!) and then got really, really cranky with anyone who dared challenge their position. If you (generic rhetorical you) want to believe that LK99 is going to superconduct, or that Bitcoin is going to the moon, or that AGI is coming next week, that's great. Really, it is! And you're allowed to talk about it, and put your money where your mouth is, and all that. What you're not allowed to do is get mad at people who respectfully disagree with you and point out why your dumb arguments are dumb. And you really, really, really need to pay attention, and not get more hostile, when your position starts to get falsified, as is/was helpfully possible for LK99 (but not so much those others). Do not hold fast to false things. I understand that this is difficult when the people taking the other side are being equally awful, but such is life. We need to rise above, not get dragged down, lest everything fall into the same cesspools as contemporary politics.
  - netheril96 3y ago
    > really cranky with anyone who dared challenge their position. You could profit from those people, if you are confident in your position, by shorting some of the stocks that shoot up from people's pre-judgments on this matter.
    - jeltz 3y ago
      Usually not because as the saying goes: the market can stay irrational longer than you can stay solvent. Most people simply cannot afford to make those bets against the market.
killerstorm 3y ago
Can you explain how 300K is fundamentally different from 90K? 90K is 20 times above temperature of liquid helium. Is there some law of physics which says that you can go 20x the temperature of liquid helium but not 60x?
- djtango 3y ago
  Fwiw 77K is sufficiently cold that wild N2 gas molecules with pretty weak interactions are willing to play nicely with each other and condense...
- ThePhysicist 3y ago
  It's the relative energy scales in the system that matter. You can e.g. compare the superconducting energy gap to a temperature, for Niobium the gap is around 2.3 meV which corresponds to about 27 K. For high Tc superconductors the story is a bit more complicated but their pseudo gap is 5-8 times higher, hence around 150-200 K. Niobium has a Tc of 10 K, high Tc superconductors (unpressurized) at most 150 K. What's safe to say is that if the temperature becomes significantly higher than the energy gap the superconducting state will be lost as there's thermal tunneling out of the state and it becomes thermodynamically "unfavorable" (this simplifies things). Now there's no reason that we couldn't find a system with a larger energy gap but that gap itself is defined by other properties in the system that have constraints on their own. Fundamentally there's no reason that there couldn't be a system that fulfills all these constraints at room temperature, but there isn't a reason why there should be such a system either. Then again there might be different superconductivity mechanisms that we don't know about yet and that we could exploit, but I think it's not very likely that we'll find a regular material system with these properties because there are not that many crystal lattices to choose from and we've been looking for more than 50 years.
sheepscreek 3y ago
I think how people define superconductivity varies greatly in discussions. Wouldn’t be the worst thing if we concentrated our efforts on proving zero resistance first. IMO, a “super conductor” should only be characterized as a material with zero resistance under certain conditions. Everything else should not be a requirement, but more like a side-effect that had been observed to go along (such as diamagnetism through Meisner effect). Hopefully that will destigmatize future research efforts in both directions, namely towards finding zero resistance materials and those exhibiting diamagnetism. The worst thing we can do to science is going on a witch hunt. Curiosity powers this discipline. We don’t need for encourage all crazy theories but discouraging that line of thinking entirely will lead to fewer new discoveries. Fear driven science isn’t science at all.

mkagenius 3y ago

Yes, I only listen to people with handle like "ThePhysicist" or "theMaterialPhyisicist" at hackernews.

jldugger 3y ago
I think the point is you can probably ignore everyone who isn't giving a Nobel acceptance speech.
- ElFitz 3y ago
  That’s why I personally only listen to the opinions of people with handles like "Planck54", "The1965PhysicsNobel" or "EconNobel94" on hackernews. Sorry, I couldn’t resist. N.B. I also tried to find some noteworthy Fields medal winner, but refrained since it appears I don’t know any of them, and that the committee’s choices and motivations have been subject to controversy [0]. [0]: https://www.science.org/content/article/fields-medal-was-never-meant-greatest-mathematical-genius https://www.science.org/content/article/fields-medal-was-nev...
  - jacquesm 3y ago
    Sure, but every now and then people get into an argument with a Putnam prize winner or the inventor of some Internet Protocol details and find themselves caught out...
    - JacobAldridge 3y ago
      I would bet picodollars that rarely happens here…
      - jeltz 3y ago
        It happens more often than you think. For example it has happened a bunch of times that people have argued against PostgreSQL core developers about the internals of PostgreSQL. I know most of their usernames so it is always a great laugh for me.
        jacquesm 3y ago
        I think you missed the GPs subtle point.
      - jacquesm 3y ago
        Hehe. Nice one.
hliyan 3y ago
[flagged]
- ThePhysicist 3y ago
  FWIW I prefer to not use my real name in discussion threads here, although it is linked in my bio. So if you don't mind please remove it, thanks :)
  - hliyan 3y ago
    Apologies, by the time I saw this, the edit button had been disabled. Please feel free to flag the message so that dang can remove it.

whimsicalism 3y ago

But the high temp cup rate superconductors don’t follow classical landau theory afaik

moonchrome 3y ago

I don't see anything bad with this hype cycle : - these guys thought they found something - turns out it probably wasn't superconductors but it's an still interesting finding - there was no fraud and something new was discovered - material science got a bit more mainstream exposure I'd rather see that than another crypto or AI hype cycle

exmadscientist 3y ago
No, it really wasn't that bad. The annoying part, at least for me as someone who, uh, I guess used to go to a lot of colloquia on this stuff?, is the part you left out: people pre-judged the outcome (of all three phenomena you mention!) and then got really, really cranky with anyone who dared challenge their position. If you (generic rhetorical you) want to believe that LK99 is going to superconduct, or that Bitcoin is going to the moon, or that AGI is coming next week, that's great. Really, it is! And you're allowed to talk about it, and put your money where your mouth is, and all that. What you're not allowed to do is get mad at people who respectfully disagree with you and point out why your dumb arguments are dumb. And you really, really, really need to pay attention, and not get more hostile, when your position starts to get falsified, as is/was helpfully possible for LK99 (but not so much those others). Do not hold fast to false things. I understand that this is difficult when the people taking the other side are being equally awful, but such is life. We need to rise above, not get dragged down, lest everything fall into the same cesspools as contemporary politics.
- netheril96 3y ago
  > really cranky with anyone who dared challenge their position. You could profit from those people, if you are confident in your position, by shorting some of the stocks that shoot up from people's pre-judgments on this matter.
  - jeltz 3y ago
    Usually not because as the saying goes: the market can stay irrational longer than you can stay solvent. Most people simply cannot afford to make those bets against the market.

killerstorm 3y ago

Can you explain how 300K is fundamentally different from 90K? 90K is 20 times above temperature of liquid helium. Is there some law of physics which says that you can go 20x the temperature of liquid helium but not 60x?

djtango 3y ago
Fwiw 77K is sufficiently cold that wild N2 gas molecules with pretty weak interactions are willing to play nicely with each other and condense...
ThePhysicist 3y ago
It's the relative energy scales in the system that matter. You can e.g. compare the superconducting energy gap to a temperature, for Niobium the gap is around 2.3 meV which corresponds to about 27 K. For high Tc superconductors the story is a bit more complicated but their pseudo gap is 5-8 times higher, hence around 150-200 K. Niobium has a Tc of 10 K, high Tc superconductors (unpressurized) at most 150 K. What's safe to say is that if the temperature becomes significantly higher than the energy gap the superconducting state will be lost as there's thermal tunneling out of the state and it becomes thermodynamically "unfavorable" (this simplifies things). Now there's no reason that we couldn't find a system with a larger energy gap but that gap itself is defined by other properties in the system that have constraints on their own. Fundamentally there's no reason that there couldn't be a system that fulfills all these constraints at room temperature, but there isn't a reason why there should be such a system either. Then again there might be different superconductivity mechanisms that we don't know about yet and that we could exploit, but I think it's not very likely that we'll find a regular material system with these properties because there are not that many crystal lattices to choose from and we've been looking for more than 50 years.

sheepscreek 3y ago

I think how people define superconductivity varies greatly in discussions. Wouldn’t be the worst thing if we concentrated our efforts on proving zero resistance first. IMO, a “super conductor” should only be characterized as a material with zero resistance under certain conditions. Everything else should not be a requirement, but more like a side-effect that had been observed to go along (such as diamagnetism through Meisner effect). Hopefully that will destigmatize future research efforts in both directions, namely towards finding zero resistance materials and those exhibiting diamagnetism. The worst thing we can do to science is going on a witch hunt. Curiosity powers this discipline. We don’t need for encourage all crazy theories but discouraging that line of thinking entirely will lead to fewer new discoveries. Fear driven science isn’t science at all.