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Comment by VHRanger | Hacker News Reader

After reading the r/physics thread on LK-99 [1] I've cooled significantly on the matter.

Basically: people who work in SC think the initial science seems very sloppy and the replication attempts don't come close to what you need to demonstrate a RT SC

[1] https://www.reddit.com/r/Physics/comments/15i3h9d/lk99_megat...

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The SNR of this saga is very low. A speck of something floating under a magnetic field on a blurry video is not proof of room temperature superconductivity. We've seen memes, jokes, shitposting, bravado, Soviet fan fiction, play-by-play updates from non-SMEs cooking stuff under improvised conditions. No actual resistance measurement of LK-99 with a 4 point probe.

If this is real, then discoverers found this in 1999, apparently couldn't synthesize with good yield, couldn't analyze rigorously, sat on the discovery for 24 years, were recently rushed to publish half-baked papers, and are now silent. None of this inspires confidence.

LK-99 could hypothetically be the real deal, and I want to believe, but I'm patiently waiting for people who actually know what they're doing to offer experimental evidence.

Adding on to that: the researchers are from a private corporation that falsely claimed partnerships with several South Korean enterprises and universities which have all disavowed any connection, the "Quantum Energy Research Centre" website has gone private[edit: not suspicious as described in comments below] and the co-authors are apparently feuding over project direction with one of them since removed from the paper.

I know nothing about the subject matter but as a curious layperson I've been surprised a pre-print is being taken so seriously with this background and have assumed people much smarter than me interpret the physics as plausible.

> the "Quantum Energy Research Centre" website has gone private

In this particular case however, the website repeatedly hit the daily traffic quota before the closure. So I guess it would be no surprise that the hosting provider [1] forced them to close the website.

[1] The website itself was probably hosted by https://imweb.me/ (the parking page also supports this observation---the asset path and the admin page path matches).

Interesting, so that's the expected parking page for such a situation?

I have no idea how web hosting works in SK and was going off this article, my interpretation was that this was changed after the traffic warning hence why I assumed malice:

While the company’s website previously displayed a message that it has been blocked due to excessive traffic, it has now been shut down altogether as of Thursday with a message saying that it is “under construction."

I guess that's one less red flag.

https://koreajoongangdaily.joins.com/2023/08/03/business/tec...

Edit:

Is the Safari translation of https://imweb.me/price correct in saying unlimited traffic is 24,000 won ($18 USD) per month?

If so, I'll add back that a private company that has discovered a room-temperature superconductor but is skimping out on $18/mo for web hosting does not inspire confidence.

To make my point concrete, compare these 3 Wayback Machine captures:

1. https://web.archive.org/web/20230730033806/https://qcentre.c... when it was still available.

2. https://web.archive.org/web/20230802204310/https://qcentre.c... when it hit the quota. The title and texts roughly translate to: "The access was denied due to the excessive traffic" and "The website you've visited reached the agreed daily traffic limit and thus is automatically made unavailable now. You can connect again when the limit resets on 10 AM [UTC+9]. Please upgrade the version if the traffic repeatedly hits its quota."

3. https://web.archive.org/web/20230805041306/https://qcentre.c... when it was closed down.

All three pages are probably from imweb's own solutions, given its assets and links. So there is no dedicated server or virtual machine instance, everything is on whim of the provider.

> Is the Safari translation of https://imweb.me/price correct in saying unlimited traffic is 24,000 won ($18 USD) per month?

Yes, but you need to read the asterisk: "But atypically large number of connections or DDoS attacks may be limited for the optimal operation of system." It is very frequent that this unstated "limit" is much lower than expected for Korean hosting providers.

Got it. Apologies if it came across like I was questioning you, I'm just trying to understand the only part of this I potentially can (not the physics) and I'm clearly ignorant of how hosting works with SK providers.

I couldn't tell from the Korea JoongAng Daily and Bloomberg articles if this was implying deceitful behavior.

Thanks for taking the time to explain.

Yes, that's what caught my attention too: no actual conductivity measurement, but only magnetic levitation.

Because the levitation is a much better proof. It can only levitate if the resistance is really exactly 0.

While measuring it somehow always adds errors, because the probes themselves have resistance. And then you can't be sure if it's 0 or just really low.

There are measurement configurations that can be used to eliminate contact resistance (such as a van der Pauw measurement). Resistance, and electrical measurement in general, is the true proof - the Meissner effect is secondary and more confusing as, since this paper shows, a small ferromagnetic phase can give rise to the same effects.

You can't completely eliminate contact resistance, and all instruments have a noise floor, so electrical measurements don't constitute "true proof", they are an element of proof among others. The Meissner effect is perfect diamagnetism which can cause levitation and is not like ferromagnetism which only can allow a piece of material to stand up to align itself with field lines (and which is what we've seen so far).

>No actual resistance measurement of LK-99 with a 4 point probe.

You are misinformed. It's in the original Korean paper.

>No actual resistance measurement of LK-99 with a 4 point probe.

https://postimg.cc/TyYbv284

http://journal.kci.go.kr/jkcgct/archive/articleView?artiId=A...

Machine translated: https://www.docdroid.net/UiUrs8c/kci-fi002955269-1-pdf

Interview: https://hackmd.io/@sanxiyn/seize-interview

Man I got so many down votes last week for pointing out that like 6 attempts have failed to replicate this miracle thing that a fraudulent paper describes that’s supposedly existed for 24 years now. My point was simply that regardless of whether some combination of the elements described actually exists with roughly the properties described, we don’t know how to make it and neither do the people who published the paper. It should be more clear than ever, now, that there are significant gaps in our understanding of whatever LK-99 is.

I cooled significantly after watching Asianometry on the history of superconductors:

https://youtu.be/wUczYHyOhLM

The research field is apparently fraught with failures when looking back at previous breakthroughs.

People were saying the initial papers were trash in the first day of their release over a week ago, so that's ancient history and immaterial now. Same with the "replications," they're obviously insufficient when they're generating pieces the size of a pin head that can't be attached to probes. All of us are in a holding pattern waiting for some big lab like Argonne to confirm or deny its SC status.

How would you *deny* the SC status?

Replications keep failing until everyone is pretty sure it's not it. Proving the absence of something is rare to see.

Checking the original samples, for one.

I hope that ultimately it will come to that because I don't think anything else will put this to rest one way or the other (unless it is 100% confirmed/reproduced by another lab). It also seems to be the shortest path to a resolution.

That also adds little value. It would add no information on whether or not the sample is a fluke. We need to understand the material properties and its composition.

If it is a fluke or not doesn't matter. The only thing that matters is whether or not it is real, not how it was made. If it is real then we can expend a fortune on the 'how it was made' question, if it isn't real we can all descend from this holding pattern.

What benefit does that bring?

Appropriate allocation of resources is intrinsically beneficial.

Exactly right. If we concede that our present level of societal R&D is appropriate then it's easy to argue that resources are presently wasted pursuing less promising leads.

Until we have definitive evidence that LK99 is a SC, there's no reason to believe that it is a promising lead.

If it's real, "we" can brute force a reproduction. Just make each graduate student that works in a superconductivity lab spend two random months trying variants of LK99.

The attempts will fail. The idea is that the rest of the time the graduate student will be making standard superconductor to collect enough boring papers to escape the rat lab. But if the LK99 clone is a lucky one, everyone in the lab gets a groundbreaking paper.

To stop the waste of resources in case the whole thing turns out to be a dud. By providing proof that it is not many more resources would become unlocked.

Grinding against worse leads is not a better use of resources.

If the original sample is superconducting, you can perform XRD / other analysis on it to establish a proximate structure and then simulate things / find better methods for synthesis.

Couldn't there be solid evidence that the observed behavior was due to a different effect?

There is, a combination of strong (but not amazingly strong) diamagnetism at low field strengths and soft ferromagnetism (in floating samples) at high field strengths. Which is exactly what the paper in the link observed while getting the same results everyone else has. The only unambiguous sign of superconductivity was the original resistance graph which can apparently be explained by contact issues with four point probes (you can argue that they must have done many experiments and surely didn't cherrypick just the one where they found "superconductivity", but consider the quality of the rest of the paper...)

Doesn't diamagnetic levitation require a specific arrangement of the permamagnets that is not recreated in these videos?

That's not clear, but either way--as I've told you several times--there has been no credible demonstration of stationary levitation for even very weak uses of the word "credible."

This is explained in Fig. S2 in TFA.

Maybe the original LK-99 sample was contaminated with actual high temperature superconducting impurities.

> How would you deny the SC status?

Maybe we should adopt the stance that it’s not a SC by default and have the people asserting that it is prove that it’s a SC.

Or even better adopt no stance on truth value and rather adopt a stance on whether there is sufficient evidence to expend further effort.

No need to guess at the truth. Just remain agnostic until you know the truth.

Exactly. That's the only reasonable stance. Everything else is just jumping to conclusions, positive or negative.

Sometimes a decision has to be made though - e.g. is a particular person a murderer.

In most countries, the burden of proof is on the accuser and the accused doesn’t need to proven his or her innocence and is treated as innocent until proven otherwise.

Sure, but science isn't a murder trial, it is entirely evidence based. Show the evidence, if there is none we'll move on and if there is you get a Nobel (in the case of superconductivity at room temperature and ambient pressure).

We (the rest of the world) can't prove a negative, so it is up to the claimant to supply the proof. Given proof it will be believed, no proof then it's a no-op.

With the murder trial you can assume a-priori that there is a murderer, the question then is 'who', not if a murder is possible or not. These are entirely different problems for a logic perspective.

I think this is functionally equivalent to the status quo?

Not on HN where it’s definitely a SC we just need more time for the miracle to happen, failed replication attempts be damned.

What you'd have to do is 1) create bulk LK-99, 2) prove that that's what you'd created, 3) possibly also show that it's monocrystalline or something, and then 4) show that there's electrical resistance.

The problem is that the stuff is really quite difficult to synthesize reliably. Until that can happen, good luck finding out in either direction!

It's definitely difficult to synthesize reliably when people dismiss any replication attempt that doesn't show superconductivity as a priori not being the right compound.

Heh. But it does sound like it's honestly pretty difficult to make, too.

Cool it down until you DO see a SC transition far below room temperature.

I have been very cautious on any analysis on LK99 - especially my own.

I have mentioned to many people that any potential application of this stuff comes with an 'if it is real'. That IF is doing a lot of heavy lifting and it has to be emphasized.

I want this to be a thing, but it doesn't matter how much you want something to be true, it actually HAS to be true.

A beautiful elegant idea can be crushed by a single ugly dirty truth.

As youtuber John Cadogan says "facts don't care about your feelings".

I personally go by "Carpe Diem", as musician Taylor Swift says.

Now, I don't have this guys credentials, but it sounds very close to "This is not a superconductor as we know them to be". Which almost goes without saying, because if this is a room temperature superconductor in some sense, maybe something quite different is needed to explain it. I think we should be excited for new physics.

No, not at all. Meissner effect is constitutive of SC

> Type-II superconductors do not exhibit a complete Meissner effect.

Are type II superconductors not superconductors to you?

meissner effect != complete meissner effect, but i can see how that would be confusing

there was no meissner effect measured in this substance

Yet somehow those "SC people" issue this opinion without having seen the final paper nor the lab data on the original sample, which is presently being examined as part of the peer review process in SK?

The final paper doesn't mater. If you are in the area, you can skim the paper and look at a few key graphics and tables. Those key graphics and tables should be in the initial draft, because the rest of the article is build around them. Perhaps the final graphs will be prettier, or they will fix some minor errors (like a missing label).

(Sometimes it's more complicated. The initial and final version have bigger changes because the writer realize it's better to select other examples instead of the initial ones. But in this case I guess they don't have too many examples to cherry pick.)

In this case, we have only a rough idea how close the leaked papers are to the final paper, with only one statement from a scientist at the national lab in SK stating that there are additional manufacturing steps in the final version of the paper.

I suspect there's a large difference between what was leaked and what will be formally published.

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