Earlier quoted context omitted.
Since this was an exceedingly short cycle, we were spared one of the negatives. Well, mostly: - some folks massively hype this as the "next big thing", extract money from investors and take mindshare away from more promising, but less exciting work
You say it’s a short cycle now. But I bet a non-trivial number of people are still talking about this and trying to get results long after the initial cycle. It took years for cold fusion research to go away.
Ferromagnetic half levitation of LK-99-like synthetic samples
251–260 of 331 posts
Re: Ferromagnetic half levitation of LK-99-like synthetic samples
#252Has anyone even seen a ferromagnet stand up like that in a magnetic field?
Yes. https://nitter.net/VanGennepD/status/1688052003216261120 And this new paper finally rigorously explains away all the half-levitation videos. They can no longer be considered any evidence of SC at all.
Re: Ferromagnetic half levitation of LK-99-like synthetic samples
#253Earlier quoted context omitted.
What benefit does that bring?
Appropriate allocation of resources is intrinsically beneficial.
Re: Ferromagnetic half levitation of LK-99-like synthetic samples
#254Someone on YouTube mentioned that LK99 is ceramic ie not metal which nullifies many of its potential uses even if it does turn out to be superconducting
Re: Ferromagnetic half levitation of LK-99-like synthetic samples
#255After 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...
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,…
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
Re: Ferromagnetic half levitation of LK-99-like synthetic samples
#256I knew it was fake, there would have been a huge rise in the stock market. Financial markets would have sniffed this out. The market never lies. If anything, this was an obvious opportunity to short it on prediction markets.
Whilst this can sometimes be true, e.g. Disney stock decline tied to "go woke go broke", in general this is demonstrably, incredibly false.
The market is based on a mix of widely known facts, speculation, hopes, dreams, fraud, and a bunch of other weird goofy phenomena.
Re: Ferromagnetic half levitation of LK-99-like synthetic samples
#257Earlier quoted context omitted.
If fake those researchers careers are over. Like, they'll have to go into programming or something. And they've also besmirched the good name of Korea, and their moms are going to beat the shit out of them for fucking up that bad. They've got a LOT to lose if this is fake, which is why I think it's most likely true. But hey, sometimes people just do crazy shit.
Impossible, wall street has some of the smartest scientists on the planet. They absolutely went through the research and determined it was a fake. Look at the AI boom, nasdaq rallied 40%. Superconductor would have had the same effect
Same with this, until someone figures out how to make WIRES from LK-99-like-stuff that can be made into useful MAGNETS, it will stay flat.
Markets may be very smart... but they're hyyyyyper-conservative :P (an it makes sense to be so, there's the $$$ powering agriculture and healthcare and pensions floating on the seas of markets nowadays).
Re: Ferromagnetic half levitation of LK-99-like synthetic samples
#258Has anyone even seen a ferromagnet stand up like that in a magnetic field?
Yes. https://nitter.net/VanGennepD/status/1688052003216261120 And this new paper finally rigorously explains away all the half-levitation videos. They can no longer be considered any evidence of SC at all.
Re: Ferromagnetic half levitation of LK-99-like synthetic samples
#259Earlier 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.
The exact numbers don’t matter, but your post indicates that you seem to have the wrong mental model of how to adjust your credences. The probability of each factor decreases the overall probability, not increases.
K event = Kim says Material L is RTSC
D event = DFT says L is RTSC
S event = L is actually RTSC
we have assumed P(S/K) and P(S/D) are each 0.1, though we could have chosen other numbers for them as well.
We want to estimate P = P(S/(K and D))
P = P((K and D)/S)P(S)/P(K and D)
Assuming Kim and DFT are in the business of making positive predictions, they always get it right when L is actually RTSC.
so P(K/S),P(D/S) and P((K and D)/S) are all taken as 1
hence P = P(S)/P(K and D) = P(S)/(P(K)P(D/K)) = P(S/K)/P(D/K) = 0.1/P(D/K)
(similarly, P = P(S/D)/P(K/D) = 0.1/P(K/D))
But ofcourse we dont know P(D/K) or P(K/D). We could check historical data on how often D aligns with K, a messy exercise at best. Say they dont perfectly align, then the conditionals are less than 1,and P>0.1. Even intuitively when K (or D) gets additional support in the form of D (or K), your P should increase, not decrease.
If we assume D and K align on average, then P(D/K) or P(K/D) is 0.5, and we get P = 0.2.
You may estimate everything above differently, thus getting a different P. You can also come up with your own way of modelling this. I came up with my particular estimate to understand how frequently should i follow the news, and care about the whole thing. You should model it according to your usecase.
Re: Ferromagnetic half levitation of LK-99-like synthetic samples
#260Earlier quoted context omitted.
Reminds me of how Data in Star Trek would say things like "There is a 79.85 probability of success". I mean, maybe it is possible to assign probabilities to future events that you have never seen before, but somehow I doubt it (with 12.88% likelihood).
> 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?