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Comment by semajian | Hacker News Reader

It's hard to imagine how this could be faked short of digital manipulation, and it seems implausible that it would be a known high TC superconductor because it would warm up too fast. Absent the former explantation, I'm starting to believe this is real. Also, it's not like all the author's are unknown hacks. Hyun Tak Kim has about 10k citations (Google scholar, which sometimes combines people who have the same name though) and authored a paper in scientific reports which got L&K interested in collaborating with him. The guy seems to know superconductivity so I'm feeling rather optimistic about this.

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According to this video: https://twitter.com/xmal/status/1300754522218913799 it is possible to have stable levitation using a copper plate below the magnet.

OP's video has two stacked metal objects – could the lower one possibly contain copper?

That one is clearly rotating. Magnetic levitation with a rotating field is not too difficult (you can get levitating flower pots as cheap novelty toys) but the sample in the new video appears fully static.

Edit: relevant Wikipedia: https://en.wikipedia.org/wiki/Spin-stabilized_magnetic_levit...

The video in the reply (https://twitter.com/xmal/status/1300794329347260417) seems to show levitation even when the magnet isn't rotating?

They're stacked to increase the field density.

The object that is rotating is a magnet. It's not what we're seeing with the flake which appears to be flux pinned.

If this is fake, it's a very well-done fake. I'm feeling 60% sure that LK-99 is RT superconductor at this point. It has theoretical support now since last weekend.

Most flux pinning examples on youtube allow rotation (With round superconductors and magnets, though.)

> It's hard to imagine how this could be faked short of digital manipulation

So, it's easy to imagine how this could be faked.

Well, yes

I'm holding a small basket until one of the reputable labs reproduces this. Anonymous videos on Twitter are a bit too anonymous for me.

I guess the point is, it can be a fabrication, it can be something very important, and it can't really be anything in between.

Alternatively, https://en.wikipedia.org/wiki/Pyrolytic_carbon is discussed in the Twitter thread by the OP as a possible explanation of "not superconductivity" . . .

Not an expert, but my understanding is that magnet configuration could not create a stable levitation for pyrolytic graphite - you need an array of magnets, e.g. https://arxiv.org/ftp/arxiv/papers/1010/1010.5761.pdf

Doing a quick sanity check on youtube videos, every example I can find of it levitating involves use of magnet arrays as well.

It can easily be faked, using a technique that would destroy the poster's career. It's one thing to not do something to the letter, and another to commit blatant fraud. Most career academics would not burn their career for the lulz.

It's an anonymous video.

I think it would be tough for a lay scientist to go from 0 media expertise to faking it this quickly.

> Hyun Tak Kim has about 10k citations (Google scholar, which sometimes combines people who have the same name though) and authored a paper in scientific reports which got L&K interested in collaborating with him.

It appears he was a latecomer to the project, mostly borrowing his reputation to the trio of anonymous, non anglosphere native original authors.

Let's be less cynical. Nothing to do with borrowing reputation.

The original authors have something. They don't have the expertise in condensed matter physics to really know what. They don't know how to report results and what results would be conclusive. Their work is simply not convincing, and if they were experts they would also not be convinced.

That's why they brought in another collaborator who is an expert. But because the paper was released early it's clearly a mess. You can see the big quality improvement though just between the two drafts.

It's not cynism. The disagreement about authorship apparently was motivated by someone in the original team being pushed aside to open a slot for the well connected "10k citations" guy. It's a old problem academia still fails to address. See:

https://journals.plos.org/plosbiology/article?id=10.1371/jou...

https://en.m.wikipedia.org/wiki/Neo-colonial_science

No one knows if this version of events is true

Indeed. But if further investigation reveals the situation to be what it appears to be, this would follow a long list of similar occurrences, the likes of César Lattes and Jocelyn Bell.

> Nothing to do with borrowing reputation.

It's a pretty common practice across science.

The flake is a magnet, and a known type two liquid nitrogen cooled superconductor is inside the blocks at the bottom?

Seriously? To me this looks like a chip of graphite glued to an invisible thread. The way the object moves is not what I would expect from magnetism (see second 10 for instance)

How can it look like something that is ostensibly invisible? It's not swinging around like a pendulum, so what exactly are you seeing that makes you think it looks like an invisible string?

The thread is horizontally positioned, left to right, not vertically.

Finding a thread that small would be a feat of its own. I wonder if your eyes might be getting tricked by the watermark?

But you haven't explained how it looks like that. It could be that, but it looks like it's floating. What is it about the appearance of this thing which has you believing there is a string?

If there is a magician on the stage, you can safely presume there is no actual magic involved, even though you do not know how exactly the trick works.

For actual flux pinning, the first thing you would do is show what happens if you put the thing upside down. It should stick. Even if it does not, you would show that it does not.

The point of the illusions in a good magicians act is that they look like magic. If the illusions look like invisible strings/etc, then they were poorly done. Even if you know there must be a string, it shouldn't look that way.

So what I'm saying is that even if it's reasonable to deduce that this supposed magnet is being suspended from a string, it doesn't look like it is. If it is fake, it's a well-done illusion not a shoddy illusion.

Whether it "looks like it's on a string" is highly subjective. Suppose I primed you by saying: Look at this speck of dirt on a string, does it look like a speck of dirt on a string to you?

https://imgur.com/a/AY1oaIO

In all likelyhood, your answer would be: Yes, it does.

It's clear however that a lot of us (myself included) don't want to see a speck of dirt on a string. They want to see history in the making.

What accounts for the smooth “settling” into place after the last touch around 10s?

I have no idea what I’m talking about, but in other flux pinning demonstrations the sample seems to oscillate around the fixed point. That smooth settling looks like some sort of damping, like maybe a force that increases with distance, like maybe spring tension.

(Of course, “we have no idea” is an acceptable answer if that turns out to be the case.)

Air resistance seems like a reasonable explanation for the dampening. Furthermore if it's not pure and only partially superconducting, the dampening could be due to magnetic fields forming eddy currents in the sample.

> (Of course, “we have no idea” is an acceptable answer if that turns out to be the case.)

Of course.

Good hypotheses both! “We’ve never been able to pin something this size before” covers a lot of wiggle room. So to speak.

(FWIW I’m thrilled about the possibility of a rtrp drop this year, and I have to assume 'pera is as well. But this video doesn’t look just like flux pinning we’ve seen before. It’s visibly a little different in a way that wants explanation. I wouldn’t come out the gate calling it a hoax, but I’d feel better about not doing that if the basis for skepticism were at least acknowledged.)

Have you watched other videos of flux pinning? This sure looks like those to me, it's a weird phenomenon.

It's not that weird, it just looks weird if you don't have any idea of what is going on. But it's fairly logical if you get the principle behind it. Nullc's excellent video below shows a much clearer example.

This video describes quantum locking as strings going through a superconductor.

https://youtu.be/8GY4m022tgo?t=957

This is what a pinned superconductor looks like. Here is a video I made of some YCBO over a small magnet: https://nt4tn.net/random/superconductor.mp4 you can see it settle back back when I move it with tongs (until i push hard enough to get it to snap into a new orientation).

If I had a magnet that was much bigger than the superconductor it would look even more similar (less 'pivoty').

Excellent video, really very nice. I like it how you forced the flux pinning by punching a hole in the middle of the superconductor, that makes it all much more visible. You can practically visualize the fieldlines escaping through the middle and becoming an elastic pivot connected to the magnet.

If only all videos of LK-99 (and UFO sightings for that matter) came in such high, crisp resolution. Thanks.

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