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Ferromagnetic half levitation of LK-99-like synthetic samples

arxiv.org

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Re: Ferromagnetic half levitation of LK-99-like synthetic samples

#91

Post by nntwozz »

VHRanger wrote: post #4

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...

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.

Re: Ferromagnetic half levitation of LK-99-like synthetic samples

#92

Post by lifthrasiir »

haldujai wrote: post #87
lifthrasiir wrote: post #78

Earlier quoted context omitted.

> 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…

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…

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.

Re: Ferromagnetic half levitation of LK-99-like synthetic samples

#93

Post by throwawaymaths »

p-e-w wrote: post #85

So if good old ferromagnetism/diamagnetism is sufficient to explain the half-levitation shown in the video: How can I build my own half-levitating objects from standard materials? I've seen the science toys using pyrolytic carbon, but they are nowhere close to the effect from the video. Levitation height with pyrolytic carbon is like 1/20th of what the video demonstrates. The disc in the video looks like it's just ab…

I believe (could be wrong) diamagnetic levitation also requires arrangements of several magnets that shapes the magnetic field in a particular way

Re: Ferromagnetic half levitation of LK-99-like synthetic samples

#94

Post by Me1000 »

jacquesm wrote: post #31
jgtrosh wrote: post #23

Earlier quoted context omitted.

According to Wikipedia: > On 3 August 2023, the Korean LK-99 Verification Committee requested a high-quality sample from the original research team. However, the team responded that they would only provide the sample once the review process of their paper, potentially submitted to APL Materials, is completed. This process is expected to take several weeks or months.

These sort of answers do not inspire confidence. That looks like a play for time, why would they connect those two, it's clear they have priority locked in if the sample works out, the peer review of their paper is secondary to the questions of whether or not it is the real deal or not.

Time for what though? Eventually the world is gonna need to see the samples or we’re just going to assume they never created it to begin with and move on.

I’m not in a big rush, we’ve made it this far without RTSCs.

Re: Ferromagnetic half levitation of LK-99-like synthetic samples

#95

Post by versteegen »

Very interesting comments on the paper by Prof. Michael S. Fuhrer https://nitter.net/i/status/1688755932275384320

> But I think they buried the lede a little. Ferromagnetism is novel and unexpected in this material system, and might be interesting. But strong diamagnetism even more so

> Even if the diamagnetic fraction is the entire sample (appears less) then it would be the second-strongest diamagnet known (and pyrolytic graphite's diamagnetism is very anisotropic). In both Bi and graphite, diamagnetism results from unusual band topology. It's not common

> Overall, some evidence that as-synthesized nominally Pb_10-xCu_x(PO4)O ("LK-99") is magnetically quite unusual, with different fractions showing soft ferromagnetism and strong diamagnetism

Re: Ferromagnetic half levitation of LK-99-like synthetic samples

#96

Post by haldujai »

lifthrasiir wrote: post #92
haldujai wrote: post #87

Earlier quoted context omitted.

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…

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…

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.

Re: Ferromagnetic half levitation of LK-99-like synthetic samples

#97

Post by fnordpiglet »

versteegen wrote: post #40
fnordpiglet wrote: post #36

Earlier quoted context omitted.

Not all the replication videos show the sample in the middle, see the Varda sample videos. Constructing something that simulates something else is proof of very little, other than there are other possible explanations. The existence of alternative explanations isn’t a proof the proposed explanation isn’t true. This paper doesn’t explain away anything yet - they’re conjecturing based on their experience with their sam…

> Not all the replication videos show the sample in the middle, see the Varda sample videos Andrew McCalip himself says this explains everything he's seen. https://nitter.net/andrewmccalip/status/1688741684316975104#...

You’re reading something entirely different - at the end of a long discussion of sending the samples off for more testing, holding hope it’s a SC but admitting it’s always been a long shot, he notes at the end:

> That said, I think we're getting to the point where magnetic observations may be adding more noise than signal. Yesterday, I did perform the pole flip that was discussed in the last video. Very important to note, however, that ferromagnetism can exhibit pole agnostic behavior too. Check out the excellent video by @vangennepS. nitter.net/vangennepd/statu…. While the amateur magnetics method was fun to try for a screening method, it seems to have too many false positives to be entirely trustworthy.

That’s not at all supportive of “explains everything I’ve seen”

Re: Ferromagnetic half levitation of LK-99-like synthetic samples

#98

Post by eonwe »

throwawaymaths wrote: post #86
Jweb_Guru wrote: post #54

Earlier quoted context omitted.

> Ferromagnetic explains half levitation but it doesn't explain full levitation No one reputable has actually demonstrated full levitation, including the original team. > Sure, metal ones are, but Are ceramic ferromagnets (without iron) common? That lone electron in an orbital is pretty important. They literally reproduced this behavior with a substance that looks identical to the original LK-99, so while it would be…

Never claimed it was impossible, just that it's rare. > No one reputable I don't care about reputability of anyone unless they have a known past of fraud. Gatekeeping in science is lame unless someone makes a claim to break well understood theory or claims to do something technically difficult. RTSC is neither. Do you think this video is faked?: https://twitter.com/Andercot/status/1687740396691185664?s=20

From the same author: https://twitter.com/andercot/status/1688598313497694208

Video behavior can happen also with a diamagnetic substance.

Re: Ferromagnetic half levitation of LK-99-like synthetic samples

#100

Post by adambb »

rishav_sharan wrote: post #99

Naive question, and I hope someone more knowledgeable than me can enlighten me here; Why are we even testing for superconductivity with levitation, instead of just checking for current loss/heat loss while conducting?

The samples are super small and not homogeneous, so its tough to get any kind of accurate reading with probes, is my understanding.
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