News for hackers. Stuff that matters.
Re:LK-99: Phonon Bands, Localized Flat Band Magnetism, Model... by whatshisface on Tuesday August 08, 2023 @07:28PM (#37056839)
Levitation with a corner touching the magnet can be accomplished by iron. It's what iron filings do when you put them on a magnet!
Re:LK-99: Phonon Bands, Localized Flat Band Magnetism, Model... by brucethemoose2 on Tuesday August 08, 2023 @07:54PM (#37057053)
There have been multiple videos of tiny LK99 specs completely levitating on single magnets, and resisting motion when pushed, and staying afloat when the magnet is inverted.

That is not possible in any known material. Unless thats an array of very elaborate fakes, its a RT superconductor.

But the simulation papers and conductance tests make me suspect its a topological superconductor that would fail such tests.

Re:LK-99: Phonon Bands, Localized Flat Band Magnetism, Model... by lamontcg on Tuesday August 08, 2023 @08:32PM (#37057315)
> There have been multiple videos of tiny LK99 specs completely levitating on single magnets, and resisting motion when pushed, and staying afloat when the magnet is inverted.

One of those has already been admitted to being outright faked:

https://www.tomshardware.com/news/lk-99-video-fraud-taken-do...

Re:LK-99: Phonon Bands, Localized Flat Band Magnetism, Model... by brucethemoose2 on Tuesday August 08, 2023 @08:36PM (#37057339)
I havent seen this video.

I am on mobile now, I will have to go back through my history and check the claims... But one such reproduction is from the Meissner or Bust channel. They have been documenting the production for days, and IIRC they showed full levitation on a single magnet.

Re:LK-99: Phonon Bands, Localized Flat Band Magnetism, Model... by crdrost on Tuesday August 08, 2023 @09:07PM (#37057564)
I believe you are remembering [1] and it is not a full levitation.

1. https://twitter.com/andrewmccalip/status/1687405505604734978

Re:LK-99: Phonon Bands, Localized Flat Band Magnetism, Model... by zhangjunphy on Tuesday August 08, 2023 @10:19PM (#37057997)
Some additional context here. The author has a further statement, in which he apologizes that the previous video was misleading due to two points: 1. The sample was not LK99. 2. Both the larger piece held by the tweezers and the smaller levitating one were from the same sample. But he also states that no tricks of any kind were used nor the video was edited.

So, some other material levitating itself in seemingly room temperature?

Currently this guy is practically using his real name, with his university and professor exposed. It takes some courage to lie at this point.

link(in Chinese): https://bilibili.com/video/BV1Zh4y1r7XL

======================

Edit: People sometimes speak in convoluted ways. I feel "The sample was not LK99" could have two interpretations here: 1. It is a completely different compound. 2. It is a derivative from LK99 with a different synthesis/doping method.

Re:LK-99: Phonon Bands, Localized Flat Band Magnetism, Model... by imtringued on Wednesday August 09, 2023 @09:47AM (#37062570)
>Currently this guy is practically using his real name, with his university and professor exposed. It takes some courage to lie at this point.

No, it doesn't. It is a nine second video. Not a research paper. Right now the topic is being hyped up and you might care but next year nobody is going to give a damn about some random video uploaded to bilibili.

Why does everyone on HN pretend that even the smallest of missteps is going to end a reserachers career and therefore even videos with almost no effort put into them, that to feed the rumor mills, are somehow the paragon of truth?

Re:LK-99: Phonon Bands, Localized Flat Band Magnetism, Model... by vinnyvichy on Wednesday August 09, 2023 @10:43AM (#37063458)
There's a third interpretation: he took an x-ray of both bits of the sample and found that the XRD pattern of the levitating flake didn't match LK99's
Re:LK-99: Phonon Bands, Localized Flat Band Magnetism, Model... by ummonk on Wednesday August 09, 2023 @01:59AM (#37059184)
That video was so obviously not LK-99 I doubt anyone sane was fooled by it (anybody who has played with magnets knows that’s how ferrous metal hangs off of them).

We’ve seen proper levitation of specks that hasn’t been falsified yet.

That said, I believe theory has shown it’s actually possible for a diamagnetic object to fully levitate over a magnet as long as it’s light enough, but unlike a flux-pinned superconductor, it will only levitate over the center of the magnet, as is happening in all the levitation videos.

Re:LK-99: Phonon Bands, Localized Flat Band Magnetism, Model... by jacquesm on Tuesday August 08, 2023 @08:34PM (#37057322)
I have yet to see a video that I would say is 100% unambiguous and from a credible source. Lots of 'maybe's' and a couple where my fraud meter pegged and seems to have broken something inside.
Re:LK-99: Phonon Bands, Localized Flat Band Magnetism, Model... by Waterluvian on Tuesday August 08, 2023 @09:18PM (#37057633)
All it would take for me to begin playing much closer attention are a few credible labs saying, “we spent some time on this and we can reproduce it a little bit, sometimes. There’s something up but we’re not ready to throw the weight of our reputation behind it just yet.”

You’d think that with the current excitement and relative simplicity of the apparatus, labs all over would be putting in some weekend hours to muck about.

Consistency might be a problem for fabrication and commercialization.

Re:LK-99: Phonon Bands, Localized Flat Band Magnetism, Model... by fooker on Wednesday August 09, 2023 @05:14AM (#37060308)
> labs all over would be putting in some weekend hours to muck about.

That's unfortunately not how science is incentivized.

The lab reproducing this would get exactly zero academic credit. Maybe a day of press fame, but that's it.

On the other hand, once/if this is proven to be real, there would be thousands of labs racing to improve it and cite each other's work.

Re:LK-99: Phonon Bands, Localized Flat Band Magnetism, Model... by drdeca on Tuesday August 08, 2023 @08:20PM (#37057229)
I thought there was just one video of it completely levitating, and that that one was somewhat questionable (having an unclear source, and being deleted by original poster)?

Do you have a link to more than one showing complete levitation?

Re:LK-99: Phonon Bands, Localized Flat Band Magnetism, Model... by hackerlight on Tuesday August 08, 2023 @09:41PM (#37057769)
I recall one showing full levitation (BilliBilli anon poster). If there is a different video, the poster above should link it.
Re:LK-99: Phonon Bands, Localized Flat Band Magnetism, Model... by fnordpiglet on Tuesday August 08, 2023 @09:48PM (#37057812)
The iris videos were full levitation
Re:LK-99: Phonon Bands, Localized Flat Band Magnetism, Model... by rrssh on Tuesday August 08, 2023 @11:51PM (#37058510)
We distinguish between videos and photos in this context.
Re:LK-99: Phonon Bands, Localized Flat Band Magnetism, Model... by Jweb_Guru on Wednesday August 09, 2023 @04:25PM (#37067896)
Iris photo is completely unconfirmed outside of "Twitter likes her." She said she would make a video over a week ago and never did. Additionally, due to the fleck being confined to a tube, it would not fall afoul of any proofs about ordinary ferromagnetic levitation being impossible.
Re:LK-99: Phonon Bands, Localized Flat Band Magnetism, Model... by fnordpiglet on Thursday August 10, 2023 @01:09AM (#37072203)
True. However no internet hottake will be a proof of anything. The fun is over and now it’s time for science to work it’s laborious work. Nothing has been proven, nothing confirmed. But it was fun!
Re:LK-99: Phonon Bands, Localized Flat Band Magnetism, Model... by carabiner on Tuesday August 08, 2023 @08:21PM (#37057236)
Are any of those from legit research institutions? I know there have been a bunch of fake hover videos in the past 48 hours.
Re:LK-99: Phonon Bands, Localized Flat Band Magnetism, Model... by marcosdumay on Tuesday August 08, 2023 @10:54PM (#37058186)
I haven't seen any such video with a high credibility stance after it, like the author using the real name.
Re:LK-99: Phonon Bands, Localized Flat Band Magnetism, Model... by penjelly on Tuesday August 08, 2023 @09:37PM (#37057754)
thank you for providing nuance