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Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

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Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#321

Post by stcredzero »

obrix wrote: post #184
jacquesm wrote: post #94

Earlier quoted context omitted.

Even a 'very small resistance' would likely be prohibitive. Pure silver for instance is an excellent conductor, but when you're talking about the last little bits it's orders of magnitude difference between that and a superconductor, and those orders of magnitude difference in resistance translate into orders of magnitude more current. So even a small resistance would cause your MRI machine to have a resolution so lo…

MR imaging is possible with permanent magnets and resistive (copper wire wound) magnets at low field strengths, below 0.35T or so. Above that the heating of the magnet windings becomes excessive and it would be very difficult to maintain a stable enough field strength. Superconducting magnets are very nice as long as there is no quenching. The material used for conductors must be mechanically stable and perform consi…

The material used for conductors must be mechanically stable and perform consistently from one production batch to another. One reason why current high tc superconductors are not popular

I was going to ask: Why don't we use the current high temperature superconductors, and start building grid interconnects? I guess part of the answer lies in the cost that would be incurred because of the mechanical properties of the existing superconductors.

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#322

Post by dclowd9901 »

generalizations wrote: post #121
swagmoney1606 wrote: post #98

Earlier quoted context omitted.

We'll probably know for sure within the month!

Somewhat disappointed the russian twitter anon isn't included, since they seem to have made the first replication attempt that might have panned out.

Iris? That person comes off as completely unhinged. If their result is genuine, I’ll eat my curtain.

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#323

Post by stonemetal12 »

jcranmer wrote: post #74
tomohelix wrote: post #30

Summary of events so far: The claim: Room temp (~300K) superconductor exists and we got it! The replication attempts: The production method is so poorly documented only a fraction of the samples being made shows any interesting properties. And among those interesting ones, results varies. Very few, if any, attempt actually completely shows the entire spectrum of properties and behaviors of a true superconductor at ro…

> Worst case scenario, we got another class of high temp (warmer than liquid nitrogen but cold enough that applications are limited) superconductor but nothing revolutionary since at this point, it is pretty conclusive that there is something interesting with LK-99. I don't think that's the worst case scenario. The worst case scenario is that there is actually nothing interesting with LK-99, and everything we've seen…

I think it comes down to a lack of knowledge. I was pretty skeptical of the original claim, since RT has been a goal for a long time and no one has achieved it . So far all the repro attempts I have seen mention temps around 100K. I don't follow SC so 100k sounds "really cold" to me. It matches with my shallow understanding of SC "it is really cold". Maybe that is really warm in SC land. Either way there hasn't been a near freezing repro so I have grown more skeptical of the original claim.

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#324

Post by _ph_ »

Jyaif wrote: post #300
_ph_ wrote: post #212

Earlier quoted context omitted.

Yes, as others already said, superconductors are zero resistance. Which is easy to check if you have enough of the substance to run meaninful currents through it. There might be miniscule amounts of resistance for contacting and impurities, but the resistance doesn't grow e.g. with wire length. So how is this possible? The explanation is acutally reasonably easy, but requires the strangeness of quantum dynamics. One…

Fascinating. Let me get this straight: If you have a piece of phosphor, you can't heat it up with red light, regardless of the amount of red light you shine at it? If so, does the red light bounce off? Go straight through?

Yes, it will of course absorb or reflect the red light like any stone would, but to "charge" its luminiszence you need at least green light - blue works great. That is, why you never could charge your watch dial with incandescent light, but any white LED will work great because their light usually contains a lot of blue light. Fun fact: though it is calles "phosphorescence" all those colors don't contain any Phosphor, that Phosphor isn't phosphorescent :p An error in early naming.

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#325

Post by thehappypm »

Waterluvian wrote: post #45

I don’t understand the physics, but it feels like a truly zero resistance conductor would violate some law of thermodynamics or something. Is a superconductor truly zero impedence or just very very very low? Because I’m seeing a lot of these graphs with something like: “0.00001ohm” as the y-axis floor.

Ask yourself this question: Why does resistance occur at all? Why is it that electrons moving through a material cause them to heat up? What is actually happening to cause that?

At micro levels, like molecules bouncing around in a gas, collisions are lossless. What makes electrons moving through materials different?

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#326

Post by zeroonetwothree »

api wrote: post #314
doingtheiroming wrote: post #195

Earlier quoted context omitted.

There’s plenty of skepticism. It’s the zero-cost position here. But there are good and bad skeptical positions. The good one involves people attempting to replicate and publishing results whether positive, negative or somewhere in between. The bad one consists of sitting in forums and threads being, “the voice of reason”. If there’s a real problem, it’s that we have still not made publication of negative results suff…

> The bad one consists of sitting in forums and threads being, “the voice of reason”. I refer to these folks as the "boring universe brigade." The heuristic seems to be that if it's in any way exciting it's probably bullshit. It's a blind overreaction to memetically-optimized pseudoscience.

Well, that position is right 99.9% of the time.

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#327

Post by ImPostingOnHN »

ekianjo wrote: post #248
drexlspivey wrote: post #242

Earlier quoted context omitted.

This doesnt pass the smell test. Why would multiple independent labs fake their videos? What’s the conspiracy here? There is no upside, we will know in a couple of weeks if it’s real or not.

> Why would multiple independent labs fake their videos Why would different newspapers spread hoaxes? Yet it happens...

why would you respond to the question with an unrelated question instead of answering directly?

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#328

Post by cycrutchfield »

thomasmg wrote: post #233
febusravenga wrote: post #227

I see lead (Pb...something) as main ingredient, isn't it banned in most industries because how toxic it is and how hard it's to handle in industrial scale? isn't that a problem for potential mass applications? (lots of comments about this discovery call this revolution that will change everything around us and that somehow implies mass production I guess)

Lead is still used for example in car batteries (lead-acid), bullets, and solders (electronic components).

Airplane fuel...

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#329

Post by jacquesm »

SantalBlush wrote: post #310
jacquesm wrote: post #266

Earlier quoted context omitted.

> The bad one consists of sitting in forums and threads being, “the voice of reason”. You put it perfectly. I'm mostly skeptical and very guardedly optimistic because something seems to be happening. But I've very carefully marked each and every one of my comments with 'assuming this is true' or 'if this is true' to avoid the impression that I'm already convinced. I'm not. But I'm on the side of everybody getting the…

I think the unqualified negativitiy is based on a common misunderstanding of the scientific process, that if one finds any shortcoming in a result--be it applied or theoretical--one can throw the entire work in the trash under the pretense of falsification. But this is wrong. Science is about weighing the totality of evidence, and refining that evidence in one direction or another over many iterations.

Indeed, lots of progress was salvaged from failed attempts. In a way all of science is a continuous refinement of our model of how things really work by finding how it definitely doesn't work.

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#330

Post by dr_zoidberg »

gabesullice wrote: post #204
mrandish wrote: post #19

For comparison, per this Wikipedia page ( https://en.wikipedia.org/wiki/High-temperature_superconducti... ) currently, the highest temperature, ambient pressure superconductor is around 138 K (−135 °C). I'm no expert but based on my limited understanding, this result (if confirmed) while far from room temperature would still make LK99 a pretty interesting discovery in the SC world. And once a new SC like this is vali…

Agreed. Looking at the timeline on the Wikipedia page, a new 100K ambient pressure SC material is nothing to scoff at. It means LK99 is about as good as the other materials, at minimum. However , its chemical composition is different than any of the other materials on the chart (i.e. it is lead based). That probably means there's lots to learn and new phenomena to be understood and optimized. Furthermore, if this lab…

> It means LK99 is about as good as the other materials, at minimum. However, its chemical composition is different than any of the other materials on the chart (i.e. it is lead based)

While what you say is correct, let's not forget that lead _is_ an elemental superconductor. With a Tc of 7K, it's only bested by niobium (9K) and diamond (11K) as an elemental superconductor.

Yes, cuprates and ceramics were ruling high-temperature SC so far, but it's not like lead was entirely unexpected in the superconducting world.

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