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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

#271

Post by martindbp »

OJFord wrote: post #246
ironborn123 wrote: post #205

Earlier quoted context omitted.

You are right, but probability estimation of possibly novel phenomena is an ill posed problem. So either you do not model it at all, or come up with some mental model of what probability you are comfortable with and due to which factors; the factors being more important than the final number.

That's not what GP means - even if you assume they're independent variables, 2x 10% probabilities combine to a 1% ('10% of 10%', they multiply, not add) probability of the total outcome, not 20%.

Huh? I think he's saying OR not AND. Why would two separate pieces of evidence make the whole less probable, that makes no sense, whether you spell out the whole thing more formally or not.

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

#272

Post by trehalose »

disconcision wrote: post #19
marginalia_nu wrote: post #14

Earlier quoted context omitted.

We've levitated a living frog in a magnetic field. Starting to remind me of the logic of the witch test in monty python and the holy grail.

If LK-99 has the same resistance as the weight of a levitating frog, it's a superconductor

What does it mean for an electrical resistance and a weight to be the same?

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

#273

Post by rjh29 »

rurban wrote: post #77
lifthrasiir wrote: post #73

Earlier quoted context omitted.

There are at least 2 samples definitely produced: one in the original videos and another in the video released by Hyun-Tak Kim via nytimes which definitely look different. It is unclear if the sample sent to KENTECH for the analysis is the first sample or a fresh one. Young-Wan Kwon is also known to have his own sample (confirmed in MML 2023 sightings), but it is unclear whether it's distinct from other samples too.…

If you cite Korean (or Chinese or Japanese) names, please write them correct. There is no Hyun-Tak Kim, he is called Kim Hyun-Tak. Likewise Kwon Young-Wan. In Korean it's trivial to detect, in Chinese not so, in Japanese very hard.

It's not difficult to detect in Japanese either, because the set of names used for personal and surnames are different. However, both Japanese and non-Japanese alike don't follow any consistent order when writing their names in English, so neither is 'correct'. In fact it could be called a hypercorrection, similarly to using '-san' when addressing Japanese people in English.

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

#274

Post by gus_massa »

Accujack wrote: post #56
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...

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.)

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

#275

Post by EthanHeilman »

itsoktocry wrote: post #249
smcl wrote: post #162

Earlier quoted context omitted.

I've seen this on here before. Guys convincing themselves that they're being rational and you're being emotional - because they put little numbers besides their feelings and perform some calculations to produce a percentage that "proves" their theory about Antivax stuff, Putin/Ukraine or whatever is credible.

> their theory about Antivax stuff, Putin/Ukraine or whatever is credible. Your politics are revealed with your choice of examples here. Who needs a decision-making mental model when we can just trust what the experts tell us about these things, or maybe "trust your gut"? That's never failed.

I agree with the main claim you are making here. That decision-making models are important an aspect to minimizing the chance of failure when considering decisions. Nothing I said is an attempt to contradict your main claim.

> Your politics are revealed with your choice of examples here [Antivax stuff, Putin/Ukraine or whatever is credible].

I understand that antivax has been claimed by the mainstream right (there are antivaxers on the far-left but they have limited influence), but it feels like I'm living in some bizarro world that people see the efficacy of vaccination as being "political." It feels like I'm living a ham-handed allegorical story about dangers of irrationalism.

> Who needs a decision-making mental model when we can just trust what the experts tell us about these things, or maybe "trust your gut"? That's never failed.

I'd argue that trusting your gut or trusting experts are both decision-making models. They both work well within the right context and fail outside those contexts.

* Trusting your gut is often the right option when you have to make an immediate decision and you don't have time to weight the various options. Something weird is happening on the highway ahead of me should I break now? I have 0.3 seconds to decide.

* Trusting the experts works if the experts are experts in that field and that experts in that field have a long track record of correct predictions and the experts are talking to are in fact experts in that field and have access to the level data which has rendered correct predictions in the data. I'd assign a near 100% probability to a statement by an astronomer that tomorrow night will be a full moon over Toronto, I'd be less likely to assign a high probability to a physicist saying that this new experiment they have will detect sterile neutrinos.

Even those fields in which I am an expert in, I weigh the claims of other subject matter experts when I do not have the time to do the necessary reading and work. The biggest problem with trusting experts is determining is a particular "expert" is actually an expert in that field when you are non-expert in that field.

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

#276

Post by smcl »

itsoktocry wrote: post #249
smcl wrote: post #162

Earlier quoted context omitted.

I've seen this on here before. Guys convincing themselves that they're being rational and you're being emotional - because they put little numbers besides their feelings and perform some calculations to produce a percentage that "proves" their theory about Antivax stuff, Putin/Ukraine or whatever is credible.

> their theory about Antivax stuff, Putin/Ukraine or whatever is credible. Your politics are revealed with your choice of examples here. Who needs a decision-making mental model when we can just trust what the experts tell us about these things, or maybe "trust your gut"? That's never failed.

> Your politics are revealed

My beliefs and my politics are pretty transparent in my comment history, I'm not trying to avoid them being "revealed" whatsoever.

> Who needs a decision-making mental model when we can just trust what the experts tell us about these things, or maybe "trust your gut"? That's never failed

Not me? I saw people applying the methods we're talking about to convince themselves that the likelihood of their pet conspiracy theory is true is around the same as a coin toss. You can reach bone-headed conclusions if you're determined to do so, whether you use some decision-making mental model or not.

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

#277

Post by falcor84 »

throwanem wrote: post #260
itsoktocry wrote: post #248

Earlier quoted context omitted.

> but somehow I doubt it You doubt it? That means you're assigning some underlying probability to the event (not) occurring. Why does it seem strange to you if people are explicit about their priors?

It's not that it's strange, it's that it is transparently silly to claim to precisely quantify in the absence of anything resembling sufficient information for the problem to be treated probabilistically.

How about this? I keep a running probability (e.g. a 32bit float) for the successful outcome of each future event I have absolutely no idea about. At first I make it 50%, but I gradually adjust with each result, such that I aim to minimize my bias. It might sound silly, but at the minimum it would encode some information about the kind of events I'm typically asked to predict. And I do expect it could end up something like 0.5642635 for a particular time in my life.

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

#278

Post by loeg »

stavros wrote: post #190
influxmoment wrote: post #138

Earlier quoted context omitted.

Seeing mistakes about Korean names in the media is very common. It's a lost cause at this point

That's not the issue, though, the issue is staunchly defending something on behalf of some other group. It's noble, but it sometimes backfires because the group itself doesn't even care that much about the thing being defended. It reminds me of the time that I got reprimanded at work for saying I'll "wear a rainbow scarf" together with a gay coworker and friend, when the coworker didn't even see what could be offensi…

What is offensive about wearing a rainbow scarf?

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

#279

Post by carabiner »

ironborn123 wrote: post #195
tw1984 wrote: post #151

Earlier quoted context omitted.

> Hyun-Tak Kim is unlikely to ruin his career and legacy for something careless and frivolous. you came with presumption that this man knows & understands the subject matter. that is a very bold assumption given the mounting evidence against such brief. > so lets assign a 10% probability why 10%? not 0.01%? because of his "prof." title or previous publications? Surely that won't change the course of nature I thought?…

- Nothing against Russian researchers, but apart from Iris who is somewhat anonymous and doesnt have the required equipment to create good samples, I havent seen anyone from there interested in performing expts on this - There have already been some retractions from China after the initial replication claims. I get the feeling they have been overeager about this to prove themselves. Maybe if they approach this with c…

> When i said western labs, i spiritually include japan, taiwan, south korean labs in that, since they generally have similar practices and rigor (even if geographically they are in the east)

It's difficult to communicate with you if you just redefine common expressions however you see fit. It's like saying "by left, I mean right." Just... stop.

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