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Successful room temperature ambient-pressure magnetic levitation of LK-99

arxiv.org

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Re: Successful room temperature ambient-pressure magnetic levitation of LK-99

#441

Post by leptons »

cthalupa wrote: post #246
leptons wrote: post #230

Earlier quoted context omitted.

It means we won't lose MRIs when the earth finally runs out of helium as they require liquid helium to run the superconductors that generate the magnetic field. We're running out of helium with no way to replenish it. Helium is the only element on the periodic table which is a non-renewable resource on Earth. So MRIs will get much cheaper, and they could end up being as cheap as taking an x-ray today.

Based on our current data LK99 isn't a replacement for helium cooled superconductors for the same reason YBCO and similar aren't - critical current/critical magnetic field aren't in the right ranges for what we need out of MRI machines. I do think it's too early to say one way or the other what all of this ends up looking like, so we might find that purer/larger samples have better properties than what was measured s…

I never claimed LK99 had the properties needed for MRIs, the question I was answering was "how will the world change with room temperature superconductors", and my answer is valid in the context of the question.

Re: Successful room temperature ambient-pressure magnetic levitation of LK-99

#442

Post by jjallen »

King-Aaron wrote: post #438
jjallen wrote: post #432

One somewhat ironic fact of this story is that the rogue former employee perhaps deserves some credit for bringing this thing out into the world. They had been working on this for quite a long time themselves, rightfully so. But now the whole world is working on it and exploring other methods and combinations of materials I would assume (to improve upon the original design and avoid any patents). How long would they…

Have you got any back-story on that? I only saw that their team posted it to arxiv, hadn't heard the other drama

A former employee was the first to publish a paper with only three authors. I am surprised you haven't heard about this.

Then a few hours later a paper was published with six authors (without one of the original three authors), ostensibly by the core team that has been working on this.

There should be much more detail on the Internet if you search for it.

Re: Successful room temperature ambient-pressure magnetic levitation of LK-99

#443

Post by gibolt »

carbonguy wrote: post #54
MBCook wrote: post #47

Earlier quoted context omitted.

At this point, even if this doesn’t turn out to be the holy grail this seems like it would still be a very big step/promising avenue for research on the path right?

IANA physicist, so grain of salt etc. but yes, I agree with your assessment - even if not as impressive as we're all hoping, at the least we have a very promising new vein of superconductor research to mine (as it were). In other words: even the downside here is great, and the upside is...

It still hasn't been a week. Giving a bunch of these teams and one's with no announcements yet an additional year will hopefully lead to some very exciting findings

Re: Successful room temperature ambient-pressure magnetic levitation of LK-99

#444

Post by pjerem »

ChuckMcM wrote: post #129

For those experiencing this type of "black swan, but good" event for the first time, it is helpful to recognize that the human tendency to believe that all future "big events" will be dystopian downers, is statistically unsound. For a while I've kept a list of the things that could be "good" swan events, but to be fair I didn't have "room temperature superconductor on that list" :-) Other things that could happen: 1)…

Can you ELI5 how is this possibly a black swan event ?

Re: Successful room temperature ambient-pressure magnetic levitation of LK-99

#445

Post by soulofmischief »

hwillis wrote: post #348
mycall wrote: post #314

Earlier quoted context omitted.

I still don't understand 0D and 1D. Quantum dots, nanoparticles.. are they really 3D but too small to measure?

1D just means it conducts in one direction. Like it's got tiny wires in it. It's not particularly unusual; anisotropic conductive adhesive is used in your cellphone to glue the screen on. They tape over the electrical pads, then line up the corresponding LCD pads. The tape allows current to flow vertically between the pads, but for adjacent pads it's insulating. Neodymium magnets are another example. They're made up…

2D in materials science means 1 dimension is nano-sized, typically referring to sheets of material that are 1-2 atoms thick. 1D means 2 dimensions are nano-sized.

I'm not hip on superconductor science and haven't heard of 1D/2D being used to describe conducting in 1 or 2 directions, do you have any further reading on that?

Re: Successful room temperature ambient-pressure magnetic levitation of LK-99

#446

Post by Cthulhu_ »

anovikov wrote: post #385
nindalf wrote: post #267

Earlier quoted context omitted.

Auctions, sanitary towels, retirement, banking, disposable razor, sewing machine, canned food, interchangeable parts, antibiotics, solar cells, postage stamp, light bulb, pencil, air conditioning, insurance, dwarf wheat, spreadsheet, cold chain, double entry book-keeping, S-bend, infant formula, clocks, public key cryptography, passports, batteries, printing press, video games, GPS, contraceptive pill, shipping conta…

Passports are not a good invention. They are a dystopian evil we grew to take for granted and even see as something that exists for our own benefit. Before WWI there were no passports and no need for them. Those were Good Old Days that are not coming back. It's weird to see some people seeing some kind of benefit in them.

The passport is but one piece of the greater system that we have nowadays of international worldwide travel. I can get on a plane and travel pretty much anywhere in the world now, whereas before travel like that was reserved for explorers, missionaries or high ranking dignitaries.

I don't think the passport is an invention itself, so to speak.

Re: Successful room temperature ambient-pressure magnetic levitation of LK-99

#447

Post by adrian_b »

httpz wrote: post #44
cypherpunks01 wrote: post #21

Why are folks trying to prove that this material is a superconductor in roundabout ways, like levitation, dimagnetism, etc? What is the reason they don't just test to see if electrical current flows without resistance? Surely there is something I am missing here.

With the current fabrication process, they're only getting a chunk with LK-99 particles sprinkled in. Since nobody yet knows how to fabricate a pure chunk of LK-99, it'll be hard to measure the true resistance of LK-99.

I believe that with the synthesis method proposed by the Korean team, i.e. by the chemical reaction between a certain kind of lead sulfate with copper phosphide, the chances of progress are slim.

The Korean team appears to have been stuck for several years by the lack of reproducibility of this synthesis method. While it was a great discovery that has shown that this material must have some very interesting properties, perhaps even superconductivity at ambient temperature and pressure, in order to be able to measure its properties and be able to evaluate the possible practical applications, a much more precise method for enforcing the desired crystal structure is required, than mixing powders and baking them into a ceramic.

Perhaps such a method for producing samples with deterministic properties would be to develop first a method to grow monocrystals of the special kind of lead phosphate that forms the base crystal structure, maybe by drawing the crystals from melt.

Once monocrystals of this kind of lead phosphate are available, they could be doped with copper, e.g. by ion implantation. By controlling and varying the parameters of the process, e.g. the angle of incidence and the velocity of the ions and the thermal profile used for annealing, it is likely that reproducible samples can be produced, where the copper ions substitute lead in the useful places and not in the others.

By this method it would be possible to produce only thin layers of LK-99, but that should be enough to enable the characterization of the material.

Moreover, because LK-99 is very fragile, it is unlikely that it could be used to make cables or coils. Practical uses where LK-99 would be deposited as thin films are much more likely.

As an alternative to ion implantation, which might be able to produce thicker layers, perhaps once monocrystals of the base lead phosphate are available it may be possible to develop some method of chemical vapor deposition, to grow epitaxially a layer of LK-99 over the base crystal, but with such a method it is less obvious if there is any way to control which lead atoms are substituted, though this may depend on the orientation of the base crystal.

Re: Successful room temperature ambient-pressure magnetic levitation of LK-99

#448

Post by Cthulhu_ »

MrYellowP wrote: post #431
jzymbaluk wrote: post #201

Earlier quoted context omitted.

Penicillin has gotta be on that list. Just randomly happened to culture on a Petri dish left out on vacation, happened to be the worlds first antibiotic

It wasn't. "Stuff that kills bacteria" has been known for a long time, including times when nobody knew what bacteria were. Not every dirty wound was fatal, there's mixes of plants, applied to wounds, that do a good job. Penicillin was the first highly effective AND mass producible antibiotic, though.

While true, actually applying it in practice took a long time. Imagine the shock and horror when male doctors were told by midwives that washing hands and keeping things clean reduced infant mortality.

Re: Successful room temperature ambient-pressure magnetic levitation of LK-99

#449

Post by Cthulhu_ »

rvnx wrote: post #254
rockemsockem wrote: post #216

Earlier quoted context omitted.

Rockets landing themselves back on Earth was looked at as really weird for quite a while.

? was just a design choice as it's easier

It wasn't easy (else it would've been done earlier), but it was cheaper.

Re: Successful room temperature ambient-pressure magnetic levitation of LK-99

#450

Post by croes »

ChuckMcM wrote: post #129

For those experiencing this type of "black swan, but good" event for the first time, it is helpful to recognize that the human tendency to believe that all future "big events" will be dystopian downers, is statistically unsound. For a while I've kept a list of the things that could be "good" swan events, but to be fair I didn't have "room temperature superconductor on that list" :-) Other things that could happen: 1)…

To be fair all of your examples could go either way
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