Huazhong University demonstrates LK-99 diamagnetism

https://twitter.com/Andercot/status/1686286684424691712

by b800h • 3 years ago

593 283 3 years ago

At the very minimum, this reduces the chance of fraud to 0%. Clearly it is possible to replicate something similar to the levitation shown in the original video.

SunghoYahng• 3 years ago

What if the claim of replication is a fraud?

unsupp0rted• 3 years ago

Then it increases the chance of fraud to 0% ~ 100%

b800h3• 3 years ago

Currently the replications look less professional than the (one) failure to reproduce. The next couple of days will be a rollercoaster.

deyiao• 3 years ago

The probability is quite low, because that guy conducted the experiment through live streaming, and failed once. Then, he conducted the second experiment after adopting some suggestions from netizens.

jrflowers• 3 years ago

I like the confidence here. At the minimum the chance of fraud has gone to zero. At the maximum the chance of fraud has gone to negative infinity.

yreg• 3 years ago

At the maximum it is a superconductor obviously

3cats-in-a-coat• 3 years ago

Nothing is reduced to 0%.

I'd also abstain from differentiating "fraud" and "error" as this is irrelevant to whether the paper is reproducible.

What we care about is true positives and negatives. But we'll also get false positives and negatives.

So replication will have to happen at scale. Individual outcomes don't matter much.

constantcrying• 3 years ago

I think the chance of fraud was always very low. The whole debacle of how it got published seems to make certain that there is very little to gain and utter humiliation if it turns out to be irrelevant.

Even if it isn't fraudulent it still may be false, but it seems quite certain that the authors believe in their own claim.

Jweb_Guru• 3 years ago

Yeah, it's good to see that because there were some concerning signs in the last day or so.

nubela• 3 years ago

I have been thinking what the incentive is for universities to defraud people with fake LK99 results?

b800h3• 3 years ago

It's difficult to understand the full context. For all we know this is some sort of maverick with a Weibo channel (or whatever) to promote. But I think we'd know that by now? No idea.

anonylizard2• 3 years ago

The author posted this statement under the video: "Under the guidance of Professor Haixin Chang, postdoctor Hao Wu and PhD student Li Yang from the School of Materials Science and Technology of Huazhong University of Science and Technology successfully for the first time verified the LK-99 crystal that can be magnetically levitated with larger levitated angle than Sukbae Lee‘s sample at room temperature. It is expected to realize the true potential of room temperature, non-contact superconducting magnetic levitation."

He is putting his name out there, including his professor's, and his schools (A decently reputable uni in China).

I utterly fail to see the incentives for being fraudulent here.

blitzar2• 3 years ago

I have been thinking what the incentive is for the west to suggest that their people should ask why universities might be motivated to defraud people with fake LK99 results?

eganist• 3 years ago

I think OP's point is that they're trying to think adversarially about whether such incentives exist, not implying that they actually do. It's a good thought experiment with a claim this large - to see how the claimant would benefit if they're fibbing, I mean.

ginko• 3 years ago

There's a prediction market on it. Went from ~25¢ to >50¢ since yesterday.

https://polymarket.com/event/is-the-room-temp-superconductor...

gnatman• 3 years ago

I don't think that an accredited university science department is going to commit fraud to win $10,000 USD.

m3kw95• 3 years ago

Get funding

m00dy• 3 years ago

I want to believe.

zevv• 3 years ago

https://nitter.net/Andercot/status/1686286684424691712

pier25• 3 years ago

Thanks

techdragon2• 3 years ago

This further confirms the existing discourse around sample makeup and quality, the video, to me at least, looks like a large flake of inert material attached to a smaller whiteish looking bit of reactive material at one end of the flake, each time it’s demonstrated that end of the sample is the end that moves and the rest of it looks like it’s hanging down… the same sort of thing we saw with the original demonstration with the larger lopsided sample in the very first publication on by the QCenter original Korean researchers…

As I said in an earlier post on another article, smash the samples… let’s see some clear unambiguous levitation of small grains with little dead weight, this process is clearly not yet refined enough to give large samples of high enough quality to visibly demonstrate levitation… several of the existing failures to replicate could actually just be failures to have a high enough ratio of superconducting to normal mass and thus no levitation… these powered based bulk material processes are tricky as hell, even when you aren’t trying to modify the chemical properties and do reactions it can be hard to get structural cohesion of samples and a lot of dry powder based ceramic products have had notoriously bad quality control issues… we “mastered” wet clay ceramics thousands of years ago, yet depending on what your trying to do, something as “simple” as dry ceramic sintering can be challenging!

I don’t think a lot of the researchers rushing to perform replication are being sufficiently thoughtful about the nature of the samples they are producing. They are smart capable people who potentially have very little powder process knowledge or may have it from a background where this sort of thing isn’t as important… heck I only have my knowledge of this stuff from research into ultra high temperature ceramics for use in rocket engines, where poor powder process control can affect the structural and thermal properties and lead to all sorts of erosions cracks and other kinds of material degradation and sample destruction… so yeah I don’t expect all these teams to fully understand the challenges of powder based solid chemistry and I think we are seeing it brought out in the visible evidence we’ve seen posted online.

Also… It’s interesting how often people are using the same new AI powered video translation service … which I’d literally never heard of before the initial release and some of the interested parties using it to translate the original Korean information. Everyone following along has heard of this service now and it seems to be a happy accident that they are getting publicity and interest from being associated with the community gathering around the internet to follow LK-99 related work!

kleene_op• 3 years ago

Considering the trouble everyone seem to have making the material and considering how few of the stuff they managed to produce, it's understandable that they're hesitant about breaking their sample into smaller bits.

If I were them, I would keep producing more samples before deciding to break some of them to get full levitation confirmation.

throw310822• 3 years ago

Could you, ehm, just make it a into a fine powder, then use a magnet to separate the powder that levitates from the powder which doesn't, then collect the levitating powder and stick it back together... with glue?

yorwba2• 3 years ago

The video is actually showing an already quite tiny flake of material – the wooden object he's using to point at it in the beginning is a toothpick. That's why the rest of the video just shows the view through a microscope.

Breaking it into even smaller pieces is going to require some specialized equipment. And it's only been a few hours since the video was posted.

ManuelKiessling• 3 years ago

If you are interested, we have taken this video translation concept a step further, and also translate the spoken audio in a source video, and create a new video with the spoken audio in the target language. See https://lingosync.ai/en for some demos and the signup link.

moralestapia• 3 years ago

let’s see some clear unambiguous levitation of small grains with little dead weight
we “mastered” wet clay ceramics thousands of years ago
I don’t think a lot of the researchers rushing to perform replication are being sufficiently thoughtful about the nature of the samples they are producing. (lol)

I'm now interested in seeing your characterization and replication efforts.

marcosdumay• 3 years ago

each time it’s demonstrated that end of the sample is the end that moves and the rest of it looks like it’s hanging down

It's quite possible that the entire sample is reacting, so the part with the largest "reaction area" / weight ratio goes up, while the part with the smaller one stays down and provides extra sustenance to the entire thing.

If that's the case, breaking it down won't make any difference.

vbezhenar• 3 years ago

Why don’t they break this sample to pieces to hopefully demonstrate real levitation?

MrPatan• 3 years ago

Because all the king's horses and all the king's men can't put the sample back together again

saberdancer• 3 years ago

They are making more samples (bigger ones to test resistance).

My guess is that they already broke it to pieces and this one levitates slightly. Until they get more samples they will keep this one intact.

odyssey7• 3 years ago

Already met the replication requirements.

thomasmg2• 3 years ago

I think they didn't show that yet because for scientists, what they did already proves diamagnetism: they show that both sides of the magnet lift the sample.

They could more or less easily demonstrate levitation even with the current sample, by using four (maybe slightly stronger) magnets. Four magnets are needed so that the sample doesn't float to the side. Typically four magnets are used to demonstrate diamagnetism of e.g. pyrolytic carbon, see the picture in https://en.wikipedia.org/wiki/Diamagnetism

So in summary, they don't show levitation because that's scientifically not needed. It would be much more impressive for the non-scientist however, so I guess eventually they will show this. I assume another reason they didn't do that so far is that they are afraid to lose the tiny sample :-)

computerfriend• 3 years ago

If you have four magnets all stuck together, the magnetic field is the same as if you have one large magnet.

epups• 3 years ago

For those wondering, the Huazhong University of Science and Technology where this replication was produced is a large and credible university, top 100 in the world according to some rankings [1].

[1] https://en.m.wikipedia.org/wiki/Huazhong_University_of_Scien...

baal80spam• 3 years ago

if successful LK-99 would be a watershed moment for humanity easily on-par with invention of the transistor

Is this really true? I've seen comments that "it would make a lot of things quite a bit more efficient, but it's not a revolution".

edit: Reading through the linked material now: https://nitter.moomoo.me/Andercot/status/1685088625187495936...

curiousgal• 3 years ago

It just grinds my gears when the response to a simple question, that is meant to be addressed to a layman, is peppered with acronyms and complicated diagrams/graphs.

lijok• 3 years ago

https://xkcd.com/2501

jacquesm21• 3 years ago

Imagine how laypeople feel when they hear IT people talk.

TheLoafOfBread3• 3 years ago

Superconductors allow creation of non-chemical energy storage whose capacity is only limited by storage's mechanical resistance from being crushed by its own magnetic field and which has nothing like "finite charge-discharge cycle life limit"

Additionally it has no internal resistance, so you can charge such battery virtually immediately, but you can also discharge it immediately. This will be important for energy based weapons.

op00to• 3 years ago

Will batteries still explode like LiPo batteries?

ajago• 3 years ago

Can you elaborate on this please? How can superconductors be used for storage?

choeger2• 3 years ago

That's a physics-based assumption, not an engineering-based one.

Unlike the effect on nuclear fusion, the idea of using SC as storage devices is pretty much pure theory.

Edit: it's currently leaving the theory part at MW scales as pointed out below. That makes using LK-99 much more likely. But using LK-99 in a SC storage device is still theoretical.

cbolton• 3 years ago

The storage capacity is also limited by the superconductor's critical current. I imagine everything is fine until you add that extra bit of current that causes the material to switch out of superconductivity and all the concentrated energy has to find an escape real quick...

tetris11• 3 years ago

As one of the posters in that thread asked, "who is this guy?"

WJW2• 3 years ago

We could do solid state current switching before transistors, with diode valves and whatnot. Transistors "just" made it more efficient.

Room temperature superconductors would not just just make a host of things more efficient, it would also enable devices that rely on high-strength magnetic fields to become much more widespread. For example, if you could remove the cooling requirements for MRI scanners then they could become much more usable "in the field".

littlestymaar5• 3 years ago

For example, if you could remove the cooling requirements for MRI scanners

But MRI is almost the only tech we know today to be affected by this (and we could count maglev as well, but I don't think it'll change the landscape too much here, as the deployment of high speed trains un general is less technologically limited than it is by limited politcal will).

And even for MRI, room-temperature SC is only a big deal if you can find zone that works for high current, wich isn't the case here son far.

trelane• 3 years ago

Transistors "just" made it more efficient.

Sort of, the thing about transistors isn't the efficiency as much as the scalability.

You'd be very hard-pressed to make a modern processor out of vacuum tubes. It would be enormous, tedious to build (couldn't use modern lithography), and also consume tons of power.

ben77992• 3 years ago

This wouldn't have any effect on MRI scanners generating such magnetic fields.. they would be too dangerous to use in a non-prepared environment. They'd be small and use less power but still require a prepared environment wouldn't they?

Use it on a battle field and it'd be like Magneto was throwing shrapnel around I'd think.

phh• 3 years ago

I think that this is kinda like the lamp => transistor change. The immediate usages are not revolutionary, moving from lamps to transistors in amplifiers didn't change everything overnight. First products with transistors were barely better than the ones before. But oh boy did it create an infinite new horizon of opportunities on the long term

I don't really know whether the analogy holds, but I find reasonable reasons to think it does (we could finally get our low-voltage DC home \o/ maglevs \o/ routine/cheap IRMs \o/. that's just the "simple" applications that we can already foresee right now)

panki27• 3 years ago

What do you mean by lamps? Electron tubes?

spamizbad• 3 years ago

As far as I'm concerned, I enjoy the rich, full sound of silicon semiconductors. I won't be putting any of these LK-99 abominations near my ears any time soon. /s

RugnirViking2• 3 years ago

consider that a big part of why we cant make better processors is because they get hot, and they get hot because of resistance. I'd say dramatically faster chips in smaller form factors (think enormous graphics card in your phone, most of the bulk in those is cooling) would be quite a revolution !

ben_w3• 3 years ago

Depends on the details, as always.

I don't know the superconductivity mechanism here (does anyone?), but IIRC Cooper pairs in BCS theory can be separated by much larger gaps than the transistors in a modern CPU — hundreds, rather than single-digits, of nanometers.

Might make fully-3D processors much more viable though, from lack of heat dissipation; and if it does, that in turn might be able to make up for a coarser resolution.

Kirby64• 3 years ago

Heat is a big factor, but part of limitations on speed really come from physical dimensions. At some point, speed of light travel becomes a limitation.

Also, the transistors themselves generate a lot of the heat... So you still have large amounts of heat to handle even if the interconnect traces are heatless.

xwdv• 3 years ago

Oh yes… with more frequent and routine MRI we have a path to helping maintain longer human lifespan.

mkoubaa• 3 years ago

Vacuum tubes were quaint tools for labs, but then someone figured out how to program logic on them.

You can't a priori plan out a path to new technology, it's usually surprising. This new category of materials can be a platform for lots of surprising uses

nerdchum• 3 years ago

energy storage is the big one in my opinion.

you can just pump electricity into the superconductor capacitor and it wouldn't have any loss it would just stay there until discharge.

jonnycomputer2• 3 years ago

Sounds like a bomb.

jacquesm21• 3 years ago

It's not a capacitor. It's a coil.

mnw21cam2• 3 years ago

Capacitors are fairly good at keeping charge - there isn't much loss over time. In fact, capacitors used in high voltage equipment should generally have a discharge resistor wired across them to deliberately discharge them slowly, to prevent them being a hazard to anyone repairing the equipment.

Superconductors don't help with this (much - just maybe with the wires leading up to a capacitor). Superconductors allow much better inductors instead. You can also store energy in an inductor, but it's different because in a capacitor the charge stays put and in an inductor the current is constantly flowing.

m463• 3 years ago

The point contact transistor was rudimentary too.

https://en.wikipedia.org/wiki/Point-contact_transistor

that said, it was still manufactured and sold before being replaced by more "conventional" transistors.

themagician3• 3 years ago

Weapons.

Energy weapons are still mostly science fiction right now. This changes that. Energy storage increases by an order of magnitude and with no resistance you can charge and discharge batteries instantaneously.

Probably some other really interesting uses, but energy weapons is what we'll figure out first. And not just giant ship mounted rail guns—if true this will start a new arms race for personal handheld weapons. No more gunpowder. Think rifles with almost no maintenance. Outrageous magazine capacity with shot capacity limited only by energy storage capacity… which can easily and quickly be resupplied if you are behind a supply line.

If this is real you'll seen an untethered Boston Dynamics Atlas with a 7-minute runtime and a placeholder handheld railgun by year's end. That will kick off a series of RFPs, and in 3-5 years… real life Terminators baby. While we take refuge under the rubble we'll hear them chanting above us, "Hello, I'm calling about your car's extended warranty."

jychang3• 3 years ago

Wtf are you talking about? Superconductors are limited to 40kJ/L energy density.

For reference, gasoline is 33,000 kJ/L.

junon• 3 years ago

Really, really crazy to think we might actually be on the brink of something so incredibly life altering. I want to believe so much.

m3kw95• 3 years ago

What would be a life altering application for you?

55555• 3 years ago

Less lossy energy transmission, storage, use, etc.

themagician3• 3 years ago

Getting shot in the chest with a new high powered energy weapon will be life altering alright.

jwmoz• 3 years ago

When flying cars

adrian_b3• 3 years ago

For now, it has become very likely that it is possible to make in this way a material that is strongly diamagnetic, unlike the usual diamagnetic materials, whose magnetism is very feeble.

It remains to be seen whether the diamagnetism is associated with superconductivity, because the diamagnetism could also be caused by paired electrons whose movements are restricted to small regions of the crystal, around the lattice nodes where atoms are substituted, and which are not free to move through all the material, to be able to carry an electric current through it.

Magnetic levitation can also be done with a few other relatively strong diamagnets, like elemental bismuth or graphite.

martincmartin• 3 years ago

Is the diamagnetism itself useful? In other words, even if it's not superconducting, does this have industrial applications?

adrian_b3• 3 years ago

One possible application for a cheap strongly diamagnetic material would be in passive diamagnetic bearings for replacing the active magnetic bearings that are used in flywheels with very high rotational speeds.

This would cause a reduction in cost and size and an increase in energy efficiency, which could make the flywheels competitive for more energy storage applications than the niches where they are used now (i.e. for very high power density, but low energy density and short storage times).

codexb• 3 years ago

Free mag-lev? Yeah, that's useful.

gary_02• 3 years ago

The headline is misleading because this is not a "claimed successful replication" of the superconductivity experiment. All they're confirming is that they produced a diamagnetic substance: https://forums.spacebattles.com/threads/claims-of-room-tempe... See Notes for the Huazhong University entry.

The translated sources do not have the scientists claiming superconductivity either.

tatrajim• 3 years ago

You appear to be mixing up this claim with another. This one is from Huazhong University of Science and Technology, not Southeast University. The situation is fluid and many extraordinary claims are being made, e.g. see the link below "Second #lk99 replication from China".

https://twitter.com/lereguy/status/1686363900651151360

To some extent this particular thread on HN is dated.

fnordpiglet2• 3 years ago

The tweet says Huazhong University of Science and Technology, and it’s more recent than the most recent change for Huazhong University of Science and Technology on the space battles forum.

dang2• 3 years ago

Ok, we've changed the title above to one that you suggested elsewhere. Thanks!

jostmey• 3 years ago

If the material exhibits diamagnetism because electron movement is restricted to small regions of the crystal where relevant atoms were substituted, then does this suggest a room temperature superconductor might be possible if all the relevant atoms could be substituted during manufacturing? This sounds like a synthesis problem?

anon848736282• 3 years ago

Well, the problem then is that you are changing the total number of electrons, structure of the crystal lattice, and overall electrical properties of the material, to the point where it may not have any of the original useful properties. For example if you lightly dope silicon it modifies the semiconducting properties in useful ways, but if you go overboard with the doping it just becomes a regular conductor that isn't very special at all. All of these properties are inter-related, hence why it is so hard to find a recipe that balances them perfectly.

Thoeu3883• 3 years ago

If this is true, I wonder what it does with western corporate green agenda. There are huge money invested in it. Cheap superconductor would change a lot.

Similar situation was when EU banned incandescent light bulbs. Many manufactures (mainly western based) lobbied to have them banned, in favor of fluorescent light bulbs. However cheap LEDs were developed and eat their lunch.

If this superconductor is true, it means major power shift from central government, to local community! Distributed smart electric grids. Electric cars manufactured in a garage...

Conasg• 3 years ago

Don't understimate the ability of the big energy corporations to find a way to profit from this. Greed always finds a way.

reacharavindh• 3 years ago

it means major power shift from central government, to local community! Distributed smart electric grids.

It doesnt even go that far. If it leads to cheaper, safer and denser battery tech, so many people will chose to invest in their own homes and not pay the huge fees for electricity and gas. Electric cars only sweeten the deal even further.

devit• 3 years ago

Wouldn't it have the opposite effect, of massive centralization?

If you can make a perfectly superconducting electric grid, then it's better to build power plants in a single optimal location (e.g. nuclear power plants in an isolated area with no environmental risks) and deliver to the whole world via superconducting wires.

Thoeu3883• 3 years ago

Energy loses on wires are like 10% per 1000 miles.

But energy bill from central government is bundled with many taxes (like 50%). For example:

- CO2 emission tax

- BBC license (or local equivalent), like paying CNN every year...

- subsidy tax for oil energy complex

- loyalty tax for pensioners

- subsidy tax for current war policy....

cyberax3• 3 years ago

No. A superconducting grid will mean the end of nuclear, because you can just put renewables in a really wide geographical area and transfer power arbitrarily. It'll fix the problem with intermittency entirely.

If we move into "light science fiction" area, we can imagine setting up a global grid, so that there's always sun shining over solar panels somewhere in the world. Or maybe allowing countries like Chile to provide energy accumulation services by pumping seawater up the Andes.

euroderf2• 3 years ago

I would love to have a superconducting energy storage device, where I could store up all the excess summer solar power (60ºN, 20h/day) to feed to the heat pump the rest of the year. But I'd bury it, to contain the damage in case it breaks down. Would it need a Faraday cage too ? So many questions.

ChrisRR2• 3 years ago

I genuinely can't figure out the point you're trying to make.

asimpletune• 3 years ago

Is there such a thing as a material that behaves oppositely of a superconductor in the presence of a magnetic field? I mean a material that always attracts regardless of polarity?

littlestymaar5• 3 years ago

How do you think iron behaves?

dghughes• 3 years ago

There are proposed superinsulators.

"superinsulators are the mirror-twins of superconductors with reversed electric and magnetic field effects"

https://www.nature.com/articles/s41598-022-24460-7

blueprint• 3 years ago

casimir plates

no magnetic field even required

supriyo-biswas• 3 years ago

Can we have a link to the original video? The twitter thread links to a video of a screencap.

yorwba2• 3 years ago

https://www.bilibili.com/video/BV14p4y1V7kS if you're on mobile and it tries to force you to download the app after tapping the video thumbnail, choose 继续在网页观看 instead.

EDIT: there's also a follow-up where he tries to attract it with the magnet to show that it's not ferromagnetic: https://www.bilibili.com/video/BV13k4y1G7i1

mazzystar• 3 years ago

https://targum.video/v/2023/8/1/e2ad3b8e86961ccfdcf411d2d4d1...

prakhar897• 3 years ago

I have absolutely zero clue on materials science, chemistry or physics of this experiment. Can anyone explain to me why some teams are able to replicate it while others can't?

7moritz7• 3 years ago

The Indian team didn't follow the actual instructions, they altered them thinking it yields the same substance but it appears the change in process did have an effect on it otherwise

akhilkg• 3 years ago

I think the Indian team's 2nd attempt (after also talking with one of the authors) followed the recipe as-is but was still unable to replicate it

danielheath• 3 years ago

Nobody is certain _why_ it works yet, and even the original team are only able to occasionally get it to work. The exact composition & impurities of the inputs are likely very significant.

euroderf2• 3 years ago

I have absolutely zero clue on materials science, chemistry or physics of this experiment.

Same here. So I wonder, is a superconducting material actually useful "in production" if it is a material that (say) crumbles easily / is not at all flexible ? If we want superconducting wires, does the material have to be ductile ?

ChrisRR2• 3 years ago

There's trade offs to everything. Just because it can't be extruded into wire doesn't mean it can't be cast for example. If it's not ductile it can maybe be supported by a more rigid structure.

It totally depends on the application and how you work around the trade offs. Considering the alternative is supercooling helium and the dealing with the issues of containing such a small atom, managing the fragility of a room temperature superconductor may have huge beneficial trade offs

jacquesm21• 3 years ago

It needs to be flexible, but not so ductile that the magnetic fields produced deform it under the associated stresses, so preferably 'rigid' in one or two dimensions and flexible in the others. You then need to fixate it after you've made your assembly otherwise the stresses will rip it all to bits.

This is why the copper wire in an electric motor is potted: the wire is what the forces in the motor act on, if the wire isn't rigidly fixed it will vibrate (and reduce efficiency) and that vibration will eventually wear through the insulation causing a short in the motor.

cyberax3• 3 years ago

It can probably be made useful. Cuprate high-temperature (LN2, not room temperature) superconductors also have this problem, they are basically a brittle ceramic. However, it's now possible to make flexible tape out of them, by creating them as thin layers on a substrate.

But it took three decades of experimentation to do that reliably.

ozgung• 3 years ago

Maybe it's like making an omelette. I have the recipe, I have the egg, yet I can't make it like a chef.

distortionfield2• 3 years ago

Honestly I think this is very much the explanation behind why the team is standing behind their work. It’s so hard to replicate even just an omelette, I can’t imagine a material like this.

m3kw95• 3 years ago

The exact receipe wasn’t disclosed so there is some guess wirk

SkyPuncher3• 3 years ago

The theory I've seen is there are two places that the copper can dope into the lead - one requiring higher energy. Likewise, the higher energy location is required for superconductivity. Right now, it seems to require a bit of luck to both (1) get that higher energy location to sit (2) getting a large enough grouping of it to be meaningful.

It's kind of like playing Skee-ball at a fair. You aim for the center, but often miss into the outer rings. For this to work, you need to land a bunch of throws in the center in a row.

mysecretaccount• 3 years ago

Is this "replication" using a sample of LK-99 from the original researchers or did they successfully create a new sample?

klysm2• 3 years ago

I think replication is reserved for redoing all the things and getting the same result.

drexlspivey2• 3 years ago

Can someone explain why something being moved by a magnet is cause for celebration? Many metals do that, how does it prove superconductivity?

klysm2• 3 years ago

https://en.wikipedia.org/wiki/Diamagnetism

fnordpiglet2• 3 years ago

It’s not simply moving it’s levitating due to repulsion.

https://en.m.wikipedia.org/wiki/Meissner_effect

hovering_nox2• 3 years ago

When the magnet is moved below the flake, the flake stands up, meaning it is being repelled. This is the case for every magnetic material, but what they do in the video is flipping the magnet around so that poles are reversed, a normal magnet would be attracted = flake flat on the surface but instead it is also standing up. This shows that the material is a diamagnet at least = it always creates an inverted magnetic field to the magnet.

So here's why this could be big: Not all diamagnets are SC but all SC materials are diamagnets.

drexlspivey2• 3 years ago

Thank you!

SkyPuncher3• 3 years ago

In "normal" magnetism, opposites attract and similars repel. To get a metal to repel a magnetic field it needs to have a magnetic charge induced on it. That charge will repel only one of the magnetic poles.

In this situation, this flake repels all magnetism - regardless of pole.

lossolo• 3 years ago

Is it practical? Or it's the next graphene ?

nemo44x• 3 years ago

It will be amazing to see the iterations on the theory and on the physical production of these materials over the next 20 years. LK99 is the gate that opens the understanding of ambient room temp superconductivity. It’s not so much about this particular material but that the theory behind it is objectively true.

The force of many thousands of people will combine to improve this in the coming years.

bonnow• 3 years ago

Here is another video link that successfully replicates the anti-magnetic properties of the LK-99 material: https://www.bilibili.com/video/BV1Ex4y1X7ix.

MayeulC2• 3 years ago

As much as I've been following LK-99 news, this evidence is pretty meh... The video quality is poor, and they do not really demonstrate levitation.

If some of the sample was ferromagnetic, it would always be attracted to the magnet. If that's a small grain in the bottom side, this would explain the sample "standing up", while that side tries to become flush with the surface.

I second the "break the sample up" sentiment on this one.

est• 3 years ago

There are three videos, 2 by HUST, one by USTC.

The USTC sample could stand up on its pointy side, and wobble a bit. https://www.bilibili.com/video/BV1Ex4y1X7ix/

From my limited understanding this excludes ferromagnetism.

Update: a fouth video just got uploaded. https://www.zhihu.com/zvideo/1669820225079070720 . A relatively big sample showing diamagnetism, but author says resistance is few kilo ohms

MayeulC2• 3 years ago

That second (fourth) video has the same issue as the one I pointed out (possible to have this with a ferromagnetic material), but it's also possible we're seeing different things at once, or even novel *magnetic behavior.

I don't have an alternative explication for the pointy side video though, so it could be Meissner effect or diamagnetism. In general it seems like diamagnetism could be consistent with all these videos? So thanks for pointing this video out :)

My knowledge of these behaviors comes from what I know of ferroelectrics, which are different, and playing around with magnets like everybody (and then some), so my observations are in no way authoritative. I remain cautiously optimistic though :)

pera• 3 years ago

In the fourth video the sample appears to be levitating at 00:19 if you see the space between the shadow and the object itself, hard to tell for sure though (the surface of the table is quite porous).

david-gpu6• 3 years ago

Yes, the flake stands up when they approach a neodymium magnet to it -- but the corner that stands up is different! Isn't that consistent with a regular magnetic object, rather than a superconductor?

Look carefully at this video [0].

Which corner stands up around 2:05 ~ 2:10? The levitating corner falls towards the left side of the screen. Notice the color pattern.

Then the researcher flips the Neodymium magnet underneath. The idea being that if the flake was superconducting, the same corner of the flake would levitate.

Tell me, which corner stands up at 2:26 ~ 2:30, after the magnet was flipped? Is it the leftmost corner as before? No. It's the one at the bottom of the screen now. You can look at the color pattern and notice that it's truly a different corner, not caused by a spurious rotation of the flake while we were not looking.

In conclusion, in this experiment the flake behaves like every other regular magnet I've ever seen.

Disclaimer: not a physicist of any sort, but I have a pair of eyeballs.

[0] https://targum.video/v/2023/8/1/2534a4408ccce9c13a811e94f16d...

m3kw95• 3 years ago

That’s not how magnets behave because you missed the part where he switches polarity and it still stands up

david-gpu6• 3 years ago

That’s not how magnets behave because you missed the part where he switches polarity and it still stands up

But a different corner stands up. How do you explain that?

The way it looks to me, the leftmost corner of the flake has one pole of the magnet, and the bottom-most corner has a different pole. That's why different corners float when the magnet is reversed.

Like I said, I'm no physicist, but this looks like every other magnet I played with as a child. Please help me understand how this is any different.

cthalupa4• 3 years ago

At 1:55, we see a drop from the first side of the magnet. As we see it fall, we can tell that it is the rightmost corner that was standing. Take a look at the top edge - the two sequential dips. The bottom edge is a smooth-ish long curve that protrudes out to a bulb on the leftmost corner.

Now let's go to 3:03 and do the same. Once again it is the rightmost corner that was standing, the same as before, even thought the magnet has been flipped, and the right edge has those two sequential dips, and the left edge has the smooth-ish long curve.

However, let's go back to 2:05, and the original magnet position. We see it stand and fall, but we can tell that it was the leftmost corner this time, the one that has the long curve that ends in a protruding bulb - we had different corners in the standing position with the same orientation on the magnet, and the same corner set in the same standing position with the flipped orientation on the magnet.

I don't fully understand why the same magnet orientation could result in different corners being stood up (though I would guess it is related to the object likely being diamagnetic), but the same corner standing up even when the magnet is flipped rules out a regular ferromagnetism, from my limited understanding.

cthalupa4• 3 years ago

https://targum.video/v/2023/8/1/41a0e9f410fbb85bb8f66d6d953b... this video also shows that the sample does not attract, so it cannot be ferromagnetic.

ChrisClark• 3 years ago

Here's a different video where the same side lifts up for both poles of a magnet. The corner that stays down is the same the whole time.

https://www.bilibili.com/video/BV1Ex4y1X7ix

daneel_w• 3 years ago

This video shows the flake standing up in the same orientation (on its pointiest tip) for both applied polarities of the magnet: https://www.bilibili.com/video/BV1Ex4y1X7ix/

david-gpu6• 3 years ago

Thanks for sharing this new video -- having both the magnet and the magnified view in frame continuously makes it much more clear.

jacquesm21• 3 years ago

Note that in a strong enough magnetic field almost can be made to levitate:

https://www.ru.nl/hfml/research/levitation-explained/diamagn...

That little neo cube is pretty powerful, I can get a fairly large steel needle to stand up on one end with a magnet about 1/4 of that volume if placed carefully. So if it wasn't diamagnetism that caused the sample to stand up (which side stands up isn't all that important and may be a reflection of the distribution of the superconducting material in the sample, which need not be uniform at all) the sample may have been partially magnetic and partially diamagnetic, and too heavy to be levitated by that particular magnet due to the limited field strength. I would have liked to see an attempt to pick up the sample with the magnet to rule out any contamination.

horsawlarway• 3 years ago

No idea of the veracity of the video, but this was linked below:

https://targum.video/v/2023/8/1/41a0e9f410fbb85bb8f66d6d953b...

xdennis• 3 years ago

Relevant Veritasum video about levitating things like strawberries or frogs: https://youtu.be/g0amdIcZt5I?t=1017

Ajedi322• 3 years ago

For what it's worth, the prediction markets are going wild right now:

https://manifold.markets/QuantumObserver/will-the-lk99-room-...

https://polymarket.com/event/is-the-room-temp-superconductor...

https://www.metaculus.com/questions/18177/room-temp-supercon...

Nothing is certain yet, but that's a pretty big surge of optimism given that prior to now estimates were hovering around 10%-20%.

bhaak2• 3 years ago

I don't think that prediction markets are useful in situations like this.

As it's not about a situation where a large enough group of people can influence the outcome, there's nothing that the pools can make to deduce a more accurate prediction.

Instead you have basically gambling with large volatility every time somebody post a positive or negative news item.

merman• 3 years ago

Your statement that placing bets does not affect the outcome is true but I don't think you draw the right conclusion.

If markets don't capture current sentiment accurately then bet against every news item.

Let's say there's a market for a coin flip, and periodically, news comes out that makes the market lopsided (one way or the other). You should trade against it. Every time. If you are correct, this strategy will win on average, until the true breakthrough news item, which you'll be on the wrong side of. Just don't keep doubling down, because the final trade will be the one you lose.

This will demonstrate who has "deduced a more accurate prediction". Everyone else put together, as events unfold, or the opposite of that.

*changed to will win on average.

stainablesteel• 3 years ago

actually, people in large groups tend to estimate correct answers quite well when you average their responses

jw1224• 3 years ago

That's what makes prediction markets work — if you (or anyone else, for that matter) feel the market has priced the expected outcome wrong, you stand to make a fortune!

Great article on the economic theories behind it here: https://astralcodexten.substack.com/p/prediction-market-faq

cubefox4• 3 years ago

The markets still favor people who read and understand the papers. Admittedly, that will be a few solid-state physicists only.

DonHopkins• 3 years ago

Now is the time to start selling fake LK-99 tablets and NFTs online.

I bet that's exactly what Richard Heart is doing right now, applying all of his "Spam King" experience spamming boner pill ads and scamming people with get-rich-quick crypto shitcoin pyramid schemes.

When is LK-99-Coin going to drop?

https://news.ycombinator.com/item?id=36944841

ativzzz• 3 years ago

Is this where all the crypto enthusiasts migrated to?

jychang3• 3 years ago

To be fair, the prediction market nuts predated the crypto nuts. Totally different group of nutjobs.

cubefox4• 3 years ago

Notice how Metaculus is a lot lower than the others.

Ajedi322• 3 years ago

Yeah I was wondering about that. There was another, older market on Metaculous which was also showing lower odds than the others, but I assumed that was due to the resolution criteria being more strict (it ended up getting resolved to "no" because the question was whether it would replicate with the first independent published paper on the subject). With this new one though the resolution criteria seem similar enough to the others that you'd expect them to converge, but so far that hasn't happened.

lamontcg• 3 years ago

This whole thing reminds me of reddit finding the boston bomber, I guess at least this should be less harmful.

jiggawatts• 3 years ago

It reminds me of the excitement caused by Pons and Fleischmann before the cold fusion reproductions failed.

At the time I felt excitement, wonder, and hope for future.

That it didn’t work out doesn’t matter — the feeling was real and was in part the reason I studied Physics.

Discovery is not an endless series of perfect successes.

Sometimes we can enjoy the process even if it doesn’t work out.

Like Elon said before the first starship launch: “Excitement guaranteed!”

RandomWorker• 3 years ago

There are two bits to this, all superconducting materials are diamagnetic it’s simply the property that a material creates a magnetic field that is opposed to the applied magnetic field. All materials exhibit this property but it’s not strong enough to levitate.

One thing that strongly diamagnetic materials tend to have is very I high resistance, and this material has both low resistance and this diamagnetic property. Something very interesting.

an1sotropy• 3 years ago

Seeing that crummy video of a mystery speck maybe floating reminded me of the floating frog video (thanks, diamagnetism)

https://www.youtube.com/watch?v=KlJsVqc0ywM

MasterYoda• 3 years ago

Out of curiosity, does anyone know what it is that change on an physical level for electrons to move without resistance in an superconductivity material? What is it that change when it happens and the material become superconductive and why?

cyberax3• 3 years ago

In low-temperature (liquid helium) superconductors electrons start slightly sticking to each other. This makes their energy spectrum quantized (I mean, even more than usual), so to transfer any energy to electrons it has to be in a large enough chunk to kick them apart.

And cold atoms don't have enough thermal energy to do that, so there's no energy transfer between atoms and electron pairs.

In high-temperature superconductors (liquid nitrogen) something similar happens, but the exact mechanism is still unknown.

Octokiddie• 3 years ago

The tweet does not link to a paper reporting a "replication," but rather two theoretical papers. The title is therefore misleading.

WiSaGaN• 3 years ago

University name in the (current) title should be changed to Huazhong University of Science and Technology or HUST. [1] Calling it Huazhong University is like calling Georgia Institute of Technology (GT) as Georgia Institute.

[1] https://en.wikipedia.org/wiki/Huazhong_University_of_Science...

Huazhong University demonstrates LK-99 diamagnetism

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