Huazhong University demonstrates LK-99 diamagnetism | Hacker News Reader

Huazhong University demonstrates LK-99 diamagnetism

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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.

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

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).

This is already possible using Halbach arrays with compensating coils. It only needs a bit of support until it 'takes off', after that it is entirely self correcting.

Do you have a link to this? I’m interested to learn more.

Huge list of papers:

https://www.science.gov/topicpages/h/halbach+magnetic+bearin...

Here is one for planar arrays:

https://www.researchgate.net/publication/228401193_Electrody...

Here is one that apparently doesn't need the coils either (haven't checked it beyond the abstract):

https://www.sciencedirect.com/science/article/abs/pii/S03048...

I think he's referring to inductrack:

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

Never really took off due to IP, which I believe recently expired

No, I'm referring to a circular arrangement, not a planar one, but the effects are much the same, think of it as a rolled up version of a Halbach array with coils connected across the opposing sides in such a way that bringing the coil closer to the side will increase the attractive force on the other side. It's a pretty clever arrangement, that requires no control electronics and has very low loss once it has centered itself.

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

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.

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.

You're correct, I updated my comment. I'm having trouble keeping track of all the videos of floating specks of junk. At any rate, there are currently no "successful replications" of the superconductivity result.

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.

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

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?

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.

> 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...

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.

https://xkcd.com/2501

Imagine how laypeople feel when they hear IT people talk.

Even inside tech we have a tendency to artificially inflate complexity: if only to self-aggrandize, increase job security, and/or source more capital.

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.

Will batteries still explode like LiPo batteries?

Well there wouldn't be fires that produce toxic fumes and burn even under water, but if the coil fractured in an accident all that energy would be released in a tiny fraction of a second instead of a combustion event that takes time. That seems bad...

> all that energy would be released in a tiny fraction of a second

Probably along with a large electromagnetic pulse...

Necessarily with a large EMP, as the energy is stored in the magnetic field.

Fortunately the energy density[0] is comparable with rubber bands[1] and supercapacitors[1], so while the EMP is large, it's not terrifyingly large.

[0] at least according to wikipedia, 4-40 kJ/kg: https://en.wikipedia.org/wiki/Superconducting_magnetic_energ...

[1] 1.6-6.6 kJ/kg and 10-30 kJ/kg respectively: https://en.wikipedia.org/wiki/Energy_density

The energy density isn't the scary bit, the power density is. The referenced paper in that Wikipedia article indicates ~10^5 higher power density than li-ion. So while it stores 10x less energy than li-ion it dumps it so much faster. The difference between a combustion and a detonation if you will. I'm guessing the vicinity of the thing would get turned to plasma.

A very small and localised plasma near the normal conductors that suddenly experience a rapidly decaying magnetic field; but the total energy is still (relatively) low compared to, say, the thermal heat capacity of the air of about 1.3 kJ/K/m^3.

That energy density number likely includes the cooling system.

That is what I thought too, but reading the paper referenced it seemed like they only included the coils, not even the support structure to keep them from collapsing. But it wasn't that clear.

Edit: they were clear that the limiting factor on energy and power density was the forces exerted on the coils.

No, they’ll explode unlike LiPo batteries. LiPo batteries merely catch fire.

An electromagnet, superconducting or otherwise, has large internal forces. If the support structure lets go, it will move. And, if part of the circuit becomes non-conducting, an inductive kickback will occur, generating enough voltage to (initially) sustain the original current.

You could cut a Li-ion battery in half, and the two halves will continue to store their chemical energy, at least until they burn up. If you cut an inductor in half (which is what this type of energy storage device is), that energy will dissipate very quickly whether you like it or not.

A battery that transform all energy it stored into heat sounds more like a bomb instead. Imagine someone accidentally heat up the 'super-conductive' battery to the point that it is no longer super-conductive.

That goes for any sufficiently dense energy storage system, including most batteries. Imagine someone accidentally shorted out a car battery with something that can withstand a few thousand amps. (Come to think of it, a room temperature superconductor would do nicely for that purpose...).

I did something similar once with a high power lowish voltage battery array - my soldering iron's shroud literally vaporized with a deafening bang before even triggering the fuse.

Ri of those is typically 1 Ohm or thereabouts, which at 500 A develops 500W in the battery itself and a large multiple of that in your 'load' (in this case your soldering iron :) ).

When working with large battery arrays I use tools that are taped in all the way except for the business end, just in case. All you need to do is drop a wrench in the wrong spot and it's party time.

Not 1Ohm, in my case the array had an internal resistance of 15 milliOhms, which is way more fun. Though I imagine the BMS and fuse were relatively effective resistors in that situation too.

Agreed about taped tools, I figured that one out right after replacing the fuse :)

Oh that's really danger territory.

A BMS typically has a small shunt that helps to figure out the state of charge as well as a large transistor in series with the current to allow switching the battery in and out of circuit.

Yes, I had an additional fuse in series, what I was referring to is that the BMS's own internal resistance is larger than that of the battery pack. Indeed in an overcurrent situation you can't rely on the MOSFET not to fail short.

I've seen fets in BMS in Bosch packs cracked in half, top blown off. Quite impressive.

Well, for starters, batteries have their own internal resistance. Not a whole lot, but enough that whether you short out with copper wire or superconductor, the effect would be the same.

> Well, for starters, batteries have their own internal resistance.

Indeed they do.

> Not a whole lot, but enough that whether you short out with copper wire or superconductor, the effect would be the same.

Not necessarily, assuming a charged battery in many cases with a copper wire the wire will simply heat up to the point of evaporation and then break the circuit as it sprays molten copper bits all over the place. Some heat will be generated in the battery as well. Watch people mess up with starter cables for some ideas on how this tends to go (and do so from a distance...).

Using a massive copper connector that you some how instantly put across the terminal and manage to keep there would indeed make the balance of the resistance shift to the guts of the battery, which would heat up faster than that that energy can be shed and hence in all likelihood (violently) explode. Besides bits of molten lead and zinc for a car battery you now also have the joy of having to deal with spraying acid. Which depending on the state of charge of the battery can be really nasty stuff.

With a superconductor there would be no chance of the conductor evaporating first, there isn't any work done in the superconductor so it will stay cold, an explosion of the battery would be all but guaranteed.

Keep in mind that a superconducting energy storage device is kind of the opposite of a battery. An idle battery at full charge has some voltage and zero current, and it’s perfectly happy to stay like that.

An idle superconducting energy storage at full “charge” is not carrying a charge at all — it’s carrying a current. If you cut the wire (or blow a fuse), V = L dI/dt will generate an arbitrarily high voltage to keep that current flowing.

I imagine one would need some spark gaps and/or capacitors to limit the voltage.

It's a coil. You can just place another inductor around it and increase / decrease that current at will. This is how Kamerlingh Onnes injected current into his superconducting media during the original experiments and that is a two-way street.

https://www.lorentz.leidenuniv.nl/history/cold/DelftKes_HKO_...

When an MRI machine has a quenching event, it's a very serious deal. All the energy from the electromagnet gets dumped as heat, which boils off the coolant very quickly. MRI machines have to have a quench pipe which allows the now-gaseous helium to escape to the outside just in case of such a thing happening.

The LHC had a quench event in 2008, which explosively vapourised about 6 tonnes of helium, resulting in considerable damage, and it took more than a year for the accelerator to come back online.

I haven't taken a science class since I was 16 but could the battery be grounded to prevent an explosion?

How do you intend to keep the grounded battery charged ?

A colleague recently showed me the coil of a broken superconducting magnet after it quenched. There was an easily visible rip in the structure, even though the whole thing was enclosed. It must have at least had enough kinetic energy to tear the metal apart.

I've had a relatively small (about 2" x 2" x 1") ceramic magnet explode on me. The shrapnel was embedded deep into the adjacent wall.

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

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

For now, this is restricted to special applications due to great size and cost. The great size and cost are caused mainly by the cooling systems.

The magnetic field of a superconducting electromagnet contains a lot of energy because the field can be very strong with a large cross section. It’s the conjugate of a capacitor after all, it’s just that the energy density of normal inductors is much lower than that of capacitors. Using a superconductor also avoids resistive losses for (dis)charging.

(Inductors are very frequently used for very short-term energy storage (~fractions of a millisecond). For example, all energy output by a flyback converter was briefly stored in the transformer’s magnetic field. Unlike a regular transformer/forward converter, where the magnetic field is just a side effect of coupled inductors, so none of the energy is stored in it.)

But obviously you can't exactly carry multi-Tesla electromagnets around. So no car batteries, much less phone batteries. Large energy storage facilities for grid power regulation, possibly.

Could you shield them with mumetal? Maybe make tiny arrays of thousands of them each with smaller atorage surrounded by mumetal to let them be close. That way if they break it is only those along the break that would discharge instantly.

The quantities of energy released would heat up the material around it to the point that it may well lose its superconducting properties as well. Likely failure of any winding in such a setup would set off the rest as well unless there is a lot more separation. Mu metal has a relatively low saturation limit.

And that's before we get into the purely mechanical stresses created by such an event, which likely will destroy the vicinity of the carrier of the current.

Fermi check: Mu metal boxes are only good enough to reduce the influence of this planet's magnetic field, not eliminate, and that's a really weak field (in terms of flux density, it's of course also really freakin gigantic).

Well, they are used in electromagnetic shielding but you'd need an awful lot of it to overcome the kind of field that even a single winding of a superconductor puts out, my intuitive guess is that for any realistically available level of shielding that the magnetic field would punch right through it as if it wasn't there at all.

Just look at what happens if you leave something made out of metal lying around near an MRI machine when it is switched on and that's not for want of attempts to shield it.

If you will close it into ferrite cup as it is done today with coils, then all the magnetic field should be limited only on coil on ferrite material itself.

Basically, just push more and more electricity into a coil of superconductive wire. Because the wire has no resistance, the electricity just loops around forever.

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.

It is actually used and it exists. https://en.wikipedia.org/wiki/Superconducting_magnetic_energ... See applications

That's neat, but it misses the point. LK-99 is not even available for engineering, yet. You might be able to use one of the existing designs. Maybe you need to come up with a new design. But you cannot do that just yet.

> But using LK-99 in a SC storage device is still theoretical.

Of course it is, any kind of use of this stuff is still theoretical. That's a content free statement. But GP was making the assumption that if it works it can be used for storage. But that doesn't really follow from the properties of the material as described so far. You'd need a lot more current carrying capacity for that to become a realistic possibility.

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...

Sounds like an energy weapon to me!

This (unplanned loss of superconductivity) sometimes happens to accelerator magnets in LHC. To prevent stuff from melting/blowing up, there's an elaborate protection system integrated ([1]).

[1] LHC Magnet Quench Protection System https://cds.cern.ch/record/259538/files/P00021565.pdf

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

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".

> 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.

Petrol is just "better" coal. Except that you can't make flight with steam engines.

When room-temperature SC becomes possible, previously unthinkable applications suddenly become viable.

Maybe, but the same was already said when cuprate SC appeared in the late eighties with their relatively high critical T°, but they haven't really fulfilled their promise…

Iirc the LHC experiment would not be possible without those superconductors. That’s a pretty big deal.

Are they really the same though? I mean we are talking about room temperature, not the"(relatively) high temperature", a term that is arguably misleading to a layperson.

I'd imagine most people who are informed of the difference would recognize that cuprate SC is nowhere near as useful.

Every article older than a couple weeks talking about superconductors goes on and on about how useful they are, except for the logistics of keeping them cold

Example: https://en.m.wikipedia.org/wiki/Superconducting_magnetic_ene...

Superconductors suporting high current are incredibly useful, but that's a big caveat. There's a reason MRI scans still use the super tedious helium-cooling instead of a much simpler nitrogen cooking allowed by cuprates: the cuprates SC aren't good enough for MRI.

Just to be the pedantic one… I did some searching and found one single example of a steam-powered aircraft that actually flew. A bunch of other attempts are listed on wiki, all unsuccessful.

https://books.google.com/books?id=AygDAAAAMBAJ&dq=Popular+Sc...

And thanks, now I am researching small steam boilers that I could install in a Pietenpol homebuilt aircraft that a friend and I have been talking about building for a few years now. All I need is 30 kilowatts.

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

I knew it!

Yeah, I really meant coal-powered steam engines.

If you built a coal gasifier, or maybe used a powdered/pelletized form of coal, I could see it being plausible. (but still dumb)

Having just returned from a week at the Experimental Aircraft Association’s yearly gathering, I’m kind of interested in using up some of my employer’s time to see if I can make it work, at least on paper. Luckily I even have a budget line available for silly studies like this.

Sweet! I found a video clip at https://archive.org/details/turner_video_11514 at timestamp 54:47 for about 20 seconds.

(Found that reference via https://web.archive.org/web/20030203103015/http://www.flyste... which I found via https://archive.org/details/australian_model_engineering-iss... )

But not visiting Andromeda, the next star system. Which would be the only such application I can think of now.

As if the US is the only country. Plenty of EU countries, China, and Japan would invest in developing even higher speed rail options.

I'm French, and France has one of the biggest high-speed train network, and the limitation to build additionnal lines isn't a technological one…

I'd agree that it's not technological: it's cost and practicality.

trains that float above the rail means less maintenance. the high cost of trains is partly due to the maintenance of the rail network.

The speed of trains is generally not limited by engineering. It’s limited by corners, i.e. obstacles. There are already very fast trains in existence that don’t use maglev.

You're assuming they'd replace existing routes rather than build new routes that would suit the higher speeds.

That's the main problem, building a rail line zigzagging around the country is arguably a ton easier than having to legislate, seize, steal and forcibly bulldoze a straight path for a maglev.

…and sometimes there are obstacles that you can’t bulldoze. Mountains, rivers, towns, etc. You can build tunnels and bridges but it’s very expensive just to get people to their destination a little faster. The temptation to add a little bend is strong, but the smaller the minimum turning radius, the slower the maximum speed, and the higher the chance that you don’t need maglev at all.

It’s very dependent on geography. Ironically the US is a much better candidate for maglev than Europe with its wide unpopulated expanses.

Ah, but how many countries would develop superconducting maglevs just to fund their defense program that's using similar research to make superconducting rail guns?

Probably zero. The problem with current railguns is not that they have too much electrical resistance but that their barrel wear is much too high for practical use. Superconductors wouldn't solve that.

In any case countries that want to spend money on military research just do so, using the budget they allot to military R&D. There's no need to try and hide that you are researching railguns.

SMES systems offer grid-level energy storage at about 98% efficiency. You could also move nuclear reactors to the middle of the desert because no one wants them in their backyard, then losslessly transport their power back to the grid. Same for bringing power from solar and wind installations. These are just two examples with immediate commercial application. The economics of energy production shift when you eliminate 15% of the cost and distance limitations. That would have a big impact on decarbonization. Longer term, josephson junctions replace transistors in processors.

You could put nuclear reactors in the middle of the desert today (ignoring cooling for now). The reasons we don't typically do it has nothing to do with resistance.

> 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.

> [...] tedious to build [...]

It (or major parts of it at least) could be built by a fully automatic / robotized manufacturing plant. That isn't "tedious". Even for a one of its kind processor that would be much cheaper than the manual way.

> . It would be enormous, tedious to build (couldn't use modern lithography), and also consume tons of power.

Sounds to me like you're saying that Transistors are more efficient than vacuum tubes, both in terms of space and power consumption.

Many orders of magnitude so.

The last generations of vacuum tube processors were the size of large multi-story office buildings and had 50k tubes.

Compare to your smartphone, it would take billions of tubes to duplicate it.

Later research into thermionic devices did produce miniaturized versions, but nothing close to the scale of silicon transistors today.

If the same R&D might went into thermionics, we might just have devices of similar scales.

Yes. But at some point a quantitative difference becomes qualitativ.

If you're simply using efficient as a synonym for better, then every improvement is tautologically more efficient than what it immediately replaces. But solid state transistors were pursued specifically for their reduced power consumption while their scalability, which at the time was an afterthought, wound up making them revolutionary.

Tubes also burn out regularly (literally every day) when you have thousands of them.

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.

Building a room from copper RF shielding panels [1] and soldering them together is a lot easier in the field than supplying a whole liquid helium or nitrogen cooling system. The former is well within the capabilities of a forward operating base - they can just ship the shielding in on plywood and the electrical technicians are more than capable of soldering copper.

[1] https://www.nelcoworldwide.com/medical-shielding-products/rf...

Sounds like a good idea for supermagnetic landmine or a grenade. Throw one into a trench and all enemies lose their weapons.

It sounds absolutely absurd but I'm thinking of how the military generates EMPs (explosive forcing a puck through inductive coil to generate a huge current which then generates the EMP), and maybe you actually could get some serious "deployable", very strong magnetic fields. Basically take the explosive EMP, and instead of directly trying to maximise EM induction in a pulse, you somehow try and stretch that pulse and apply it to a superconducting coil, generating a brief instant of strong magnetic pull.

The "pull weapons" thing is silly, it's a magnetic field so if you're that close the same weight in explosives should kill them, and with the forces it would need it's not going to be non-lethal.

I could maybe see this as an active defence system. Have a little turret, if you detect an incoming slug you fire your little grenade at the slug, it sets off a pulse that imparts substantial impulse to anything that's magnetic, diamagnetic, paramagnetic (lead, steel, uranium all included). Maybe it could send a high speed slug tumbling, or off course, not sure.

In general I think RTAPS is much more likely to have civilian uses than military ones, aside from banal military uses like "the generator works more efficiently because parts are superconductive now". Maybe railguns, but I don't think electric resistivity is the limiting factor there, more friction or plasma confinement.

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)

What do you mean by lamps? Electron tubes?

My guess would be that those letters are an even more shortened form of linear amp(lifier). That term does not really imply anything about transistors vs tubes, but the way GP uses it suggested some jargon exists where it's exclusively used for the tube incarnation of the concept.

> My guess would be that those letters are an even more shortened form of linear amp(lifier).

No, they were colloquially called (void) lamps in at least French and Slavic languages, because they looked like incandescent bulbs, that were called lamps (lampe/лампа) as well.

And tubes glow like a lamp so it is natural to call them so.

So they are lamps, just very inefficient.

I don't think so, it seems to me it is because its semblance with incandescent bulbs. In Spanish are actually also known as "bulbos"[1] (bulbs).

[1] https://es.wikipedia.org/wiki/V%C3%A1lvula_termoi%C3%B3nica

I think so. In some languages electron tubes are called lamps.

Is this the same as “valves” that were always talked about in the distinctive sound retro (now) guitar amplifiers?

Yes

I have always called them vacuum tubes (in US) but I think they are valves in the UK.

Vacuum or Electron tubes describe how they work, lamps are what they look like, and valve describes the function that they provide.

Yes, they're talking about https://en.wikipedia.org/wiki/Vacuum_tube s

thermionic valves I would guess.

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

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 !

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.

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.

The transistors create a lot of heat because the current carrying capacity of the interconnect is severely limited which increases the time to switch the transistor from off to on or vv. This puts the transistor into a resistive domain where it consumes power and that leads to heat. If you use a superconducting interconnect that transition time will drop sharply and that in turn will lead to less power used by the transistor.

> Heat is a big factor, but part of limitations on speed really come from physical dimensions.

undoubtably. We can't make things infinately fast. But being able to put the most powerful desktop processors and graphics cards we have today into a phone would definately be useful, not to mention laptops. It would also dramatically change how server farms work (their existance right now revolves around cooling, they could be so much more dense)

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

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

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.

Sounds like a bomb.

Is it a bomb?

I don't know.

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

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.

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.

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."

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

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

That's about an order of magnitude more than current batteries.

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

https://en.wikipedia.org/wiki/Lithium-ion_battery

1–10 Wh/kg for superconductors, 100–265 Wh/kg for batteries.

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.

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

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

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

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.

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

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 :)

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).

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!

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.

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?

I would expect that, in the best case, this would give a gluey clump of stuff that can be levitated.

I think it would be more interesting to separate out the magnetically interesting material like this and attempt to analyze it to find out what it is.

Effectively you could take a watch glass or a petri dish, either not compress to a pellet in the first place, or just break up your sample gently between your fingers into the onto the watch glass or into the Petri dish, then just place that on top of the biggest magnet you can find and pluck away any floating fragments with plastic tweezers… seems simple… assuming you appreciate the sorts of thing’s about solid powder chemistry (which can seem a lot more like applied geology than the kind of chemistry most people are used to)…

if you want to see some interesting things and like a good chemistry video I thoroughly recommend searching for dry powder on powder chemical reactions… most of them are fire related demonstrations but it can be interesting to see them gently spoon a powder on top on another powder and nothing happens, until they poke it with a stirring rod hard enough to press the powder firmly against the other powder and get the reaction surface area to increase and then it’s off to the races… physical contacts between materials can sometimes not be in as much contact as you think… even when it’s literally pilled on top of the other stuff.

Grug Brained Materials Scientist.

That may eventually be the process.

I'm a layman is material science. My understanding is it's possible these properties only exists on a very specific crystalline structure. Grinding/breaking these samples could cause the failure of the entire structure.

The purity required in these types of materials is high enough that glue would interfere with the result.

But for example when refining YBCO (another famous superconductor - but one that requires liquid nitrogen cooling to demonstrate its properties), you can take YBCO and grind/blend it up into a powder and press the powder into whatever shape you want with a die cast and then re-bake the new piece.

https://www.youtube.com/watch?v=RS7gyZJg5nc

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.

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.

>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.

> 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.

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%.

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.

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.

I interpreted the parent comment to mean the bets don't have an influence in supply/demand behavior as they could in other cases. E.g if the markets heavily favor presidential candidate A to win, that may cause more people to vote for A, or for their opponents to stay home. Nothing like that can happen in this case because it's the laws of physics. It doesn't mean the bets can't instantiate some crowd sourced wisdom about physics or scientific research.

I wonder if there is any quantum theory that can be applied to prediction markets. The act of observation can change a system. https://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_cat

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

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

Metaculus is just forecasting without any betting

Despite that Manifold market having the most traders ever on Manifold, there's still roughly only a thousand dollars to be made on it, and the winnings can only be donated. Hardly a fortune to be made on either of those sites

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

Yes, people with knowledge of the topic can make money from that if the prediction market trends towards the wrong answer.

But that is not how those prediction markets are used. You see arguments like "the prediction markets give only 20% for this to be true" and people take that as "it is untrue". Without any qualifier (it also doesn't help that most people don't understand statistics).

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

Is this where all the crypto enthusiasts migrated to?

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

Notice how Metaculus is a lot lower than the others.

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.

Turns out the resolution criteria on Metaculus are quite strict, while the others are very vague.

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...

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...

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

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

Thanks

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.

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

What would be a life altering application for you?

Less lossy energy transmission, storage, use, etc.

A lot of these applications depend on properties beyond superconductivity. For instance, if the substance is rigid and brittle it cannot be used for cables, etc.

My hope is that, if LK-99 is proven to be superconducting, once the mechanism is understood it will spur the discovery of a whole bunch of new superconductors at room temperature and pressue.

Indeed it sounds like LK-99 specifically is not something we'd want used for power transmission lines. From a difficulty of manufacturing POV (aka cost), and from the nature of the material (more of a ceramic from what I hear?) but also because it's composed with lead.

At this point in civilization, we know better than to string lead stuff all over the place in unconstrained scenarios. Anything built with lead should not be ending up in areas where it will not be contained and maintained professionally,, and surely should not be going into the general consumer waste stream at all.

Seems like the most compelling applications will be in MRI machines, and then within power generation, specialized super computing, etc.

Lead is already a commonly used material in the sheath for medium and high voltage cables[1]. It is not considered a problem for industrial applications, where proper disposal of the cable at end of life is regulated, as far as I know.

[1] https://www.htwirecable.com/products/cables-by-type/medium-v...

I think for computers we want semiconductors, not superconductors.

The thing is that LK-99 -if real, still a big if- opens a new materials science sub-field where we can expect significant improvements over LK-99. So even if LK-99 is not practical for some applications of superconductors, that wouldn't rule out development of new materials that are practical superconductors.

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

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?

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

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

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.

> 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 ?

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

Usually flexibility is a function of how thin you can make something and what physical shape it has. You can shape it such that it becomes less flexible (think I beam for an example) or you can shape it so that it becomes more flexible (think foil). It's all the same material but the mechanical properties can be quite different. Practical use superconductor material is typically in a ribbon form, this allows for relatively easy shaping along one axis and still allows you to connect to it in a (relatively) simple way. An extra advantage of using a ribbon like conductor is that it allows for very close spacing without much loss in packing. Think 'oranges' versus 'boxes'.

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.

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.

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

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.

Unless you’re slavic catgirl.

True, their twitter has been my most frequent check up on the situation

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

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.

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...

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

> 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.

A normal wouldn’t stand up like that with both polarity exposed to it. Try it with your toy set.

Why would it not?

If you bring the North pole of a big magnet, I would expect the South pole of the flake to be attracted to it, and the North pole to be repelled.

When you flip the big magnet around and bring the South pole this time, I would expect the opposite.

Isn't that what we are seeing in the video?

I would happily do it at home if I had magnets around, but I don't. Sorry.

>Isn't that what we are seeing in the video?

No. All of these videos show the same part of the flake being repelled by both sides of the magnet, as well as other videos showing that the sample does not attract.

> All of these videos show the same part of the flake being repelled by both sides of the magnet

I'm afraid we are not seeing the same, then. In this [0] video I can clearly see a different corner of the flake being repelled at 2:07 ~ 2:13 versus 2:27 ~ 2:30.

However, I agree that the other videos people like you have posted on this thread show materials that are not ferromagnetic.

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

That does not disprove my statement. As I noted in my more in-depth breakdown, compare 1:55 vs. 3:03 - you will see the same corner being lifted despite opposite sides of the magnet being used to lift it.

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.

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

True! Fascinating.

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

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/

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

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.

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

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

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

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

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.

Thank you!

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.

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?

How do you think iron behaves?

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

casimir plates

no magnetic field even required

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

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

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!”

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

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.

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.

Yes, agree. Reaching for possibles, though. This is such a world-changing discovery that I'm trying to curb my enthusiasm, which is lifting off.

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?

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.

Surely it is redundant as they considered and came to a conclusion on this topic months ago when "US scientists confirm ‘major breakthrough’ in nuclear fusion"

That one's pretty standard. When the lab is about to run out of money, they fluff up an incremental improvement as a 'major breakthrough'. No false claims or fake science involved.

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

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

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

Get funding

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

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

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

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?

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.

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

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

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

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.

Already met the replication requirements.

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 :-)

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

Not if 2 magnets are flipped. Over just one magnet, the pyrolytic carbon (or LK-99) would slide off to the side. Over 4 magnets arranged correctly, it stays in the middle. This is described here: https://www.imagesco.com/magnetism/graphite-levitation-kit.h...

Some superconductors will float and stay over just one magnet, but it's a different story: https://en.wikipedia.org/wiki/Flux_pinning - LK-99 is not of this type as far as I know.

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

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

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

I want to believe.

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...

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

> 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.

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.

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....

Setting aside the fact that things like BBC have nothing to do with energy taxes...

Let's say there are X things government currently funds thanks to energy taxes, and overnight everybody stops paying for energy - do you think government's wouldn't just increase other taxes if they needed to make up for lost revenue?

These seem like completely different problems, and your wishing you paid less taxes doesn't mean the world can't move to better energy systems.

Lobbying by companies who make money under the current system and who aren't best places to react to developments is the biggest roadblock, not government fearing the loss of energy taxes.

In some countries BBC tax is auto bundled into energy bills. You have to optout.

> X things government currently funds thanks to energy taxes

Government can do whatever it wants. That is not my problem, I do not care. But right now they can disconnect me from power grid to enforce their BS.

If I generate my own power grid, have my own sheriffs, my own protection...

Sure buddy, you do that. Hire your own sheriffs and they'll defend you against the mean central government.

Please don't respond by breaking the site guidelines yourself. That only makes things worse.

"Don't feed egregious comments by replying; flag them instead."

https://news.ycombinator.com/newsguidelines.html

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.

Geopolitics would like to have a word, unfortunately.

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.

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

When flying cars

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.

What if the claim of replication is a fraud?

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

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

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.

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.

At the maximum it is a superconductor obviously

That was the point.

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.

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.

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

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