That makes me even more sceptical. In recent years confirmed discovery of superconducting materials have gone from working at best up to ~100K below room temperature to at best a few 10s of K below. To jump to a material that claims to exhibit superconductivity as far as >100K above room temperature, at ambient pressure too, is an extraordinary claim and so needs to be presented with extraordinary evidence.
I mean, the paper has experimental results and it should be easily reproducible by pretty much any lab. Do you think they should be hopping on CNN to give a public demonstration with the announcement?
If a material with the properties described actually exists, this paper is exactly the kind of announcement and evidence we'd want for it.
No, I agree with you that a quiet “this is what we've found, this is what we think it means, please reproduce or tell us if you find something we've misinterpreted”, rather than a public fanfare, is how a potential scientific breakthrough should be done IMO.
I think I cross-pollinated this thread with another where someone was asking “if this is true why isn't it on the front pages”. The extraordinary evidence I'd want before it hits the front pages and TV talk shows is other scientific/engineering groups managing to reproduce the findings, or at least showing a significant improvement over previous discoveries (there could be a mistake that means the result isn't that big a thing while still leaving room for it to be a significant finding).
But this is exactly the quiet please reproduce? It's a preprint posted to arxiv, with a very easy to follow material synthesis process in the supplemental materials section?
In fairness, the paper isn't exactly humble about its claims. But I appreciate their candor, and if they believe they've found a RTP superconductor and sufficiently verified it is a RTP superconductor, a bit of arrogance isn't unwarranted.
Yep. But that doesn't stop me being sceptical of such a jump in success (from tens of K below room to tens+ above at ambient pressure) which is where this sub-that started.
As already stated ("I think I cross-pollinated this thread with..." in the post you replied to) I confused things by mixing replies to different posts in the same place.
It's not out of line with previous the previous jump: the difference between the originally known superconductors and 'high temperature' superconductors was similarly large. If it is a novel mechanism allowing for it then we would not expect that the threshold would necessarily wind up close to room temperature (TBH, I this makes me think it is less likely to be fraud: I think a fraud would temper expectations by claiming it barely works at room temperature). I do agree it needs backing up, though, it could still be an error or more savvy/brazen fraud.
The critical temperature (Tc) >= 400 K or about 127 C, so apparently this material requires relatively high heat to reach superconductivity.
This is unusual, superconductivity is a low temperature phenomenon. Recently though, other researches have claimed room temperature superconductivity at high pressures, but low temperatures.
Uh no, I'm pretty confident they are just saying that whatever the Tc is, it's at least 127°C. I don't think they're redefining Tc to mean that it superconducts above that temperature. That would be... interesting.
"You can't run across this bridge without falling? Here, I'll have an elephant bounce up and down on one end, that'll make it easier!"
I share your doubt, but on the other hand I wonder why? Could you tell how a breaking message of this magnitude should be decorated to make all doubts go away?
> Could you tell how a breaking message of this magnitude should be decorated to make all doubts go away?
You'll never make all doubt go away on a new extraordinary discovery, mainly because most claims of an extraordinary discovery turn out to be mistakes (like the FTL neutrino thing a while ago that turned out to be a wiring fault that caused a minute timing error) or occasionally fabrications.
A quiet publication of “this is what we've found, this is what we think it means, please try reproduce or tell us what you think we've misinterpreted” is the way it should go. Unfortunately too subtle a release would be at risk of being ignored, and on the other side you get the mad public press and massive recriminations when it turns out a mistake was made and the finding is not reproducible (like the cold fusion thing I remember from the late 80s).
The cold fusion people were actively touting data that didn't align to known fusion reactions. Like there are a limited number of elements one can fuse, but for some reason their reaction (which is known) had the energy off by like 300-400 KeV. For example: a proton signal of 2.6 MeV instead of the known 3MeV signal.
Wasn't there some recent excitement about some hydrogen sulfide superconductor thing? But the pressure required was wild/not-useful-for-use or something like that?
Yes, H2S is superconducting at higher temperatures than anything else up to that point (but still well below zero), but it required very high pressure making it impractical for a lot of applications.
Mainstream press doesn't have the ability to replicate physics research results you may indeed first get the results in a journal. It can take some time before the research community manages to decide if something replicates or not.
But there doesn't seem to be any indication in the link that this has been published in a peer reviewed journal, or received kinds of community peer review, either.
AFAICT this has not yet been published in a scientific journal, and has not passed peer review of any sort. Having said that, there's been at least one story on HN this past week where researchers were chastised for going to the press before properly vetting their results.
Almost all research are published in scientific journal. News outlets then pick some to report deepening on many factors from breakthrough development to just pure chance. So this is not something strange.
Actually the opposite is the strange. I would be skeptical of any group the report something in media before publishing the results in a journal (or arxiv like this case).
This is not to say anything about this particular paper. I still have to read it eventually.
That’s not how either science or NY Times works. First you write the journal article. Then if it’s peer-reviewed, published and seems otherwise legit, your university writes a more layman-friendly press release. If it’s something huge, they’ll probably even arrange a press conference. But they have to be pretty darn certain that it’s legit because retracting something that’s already in the wild is very embarrassing. Then NY Times may make an article of it.
Science is based on replicability, and you just don’t go straight to mass media before at least other groups have had a chance to replicate your findings. Definitely not when it’s something this big. Or if you do, your institution will likely be incredibly pissed. I’d say that the more careful they are, the more slowly and by the book they proceed with this, the more, not less, likely it is that this is a real deal.
Ok, looks like I forgot this is HN for a moment there. Must have been excited. Yes, I am familiar with how science works, including the publishing side.
What I was trying to say was more along the lines of, if this is legit, I’m surprised we weren’t first hearing about it in the mainstream media after a leak.
I’m absolutely not in favor of any more Pons & Fleischmann moments.
big if true. far from a chemistry expert here, but synthesis looks basically trivial (if you consider 10e-5 torr vacuum to be trivial), and the materials are readily available. hell, from the instructions alone i could probably make it at home.
i mean the search space is unfathomably large, so i suppose it’s possible that something like this exists, but the paper quality itself doesn’t.. spark joy? :)
i’ll maintain a healthy level of skepticism until some real materials scientists opine and/or someone else is able to reproduce.
well.. my understanding is that the difficulty with those projects is converting fast moving neutrons into electricity without degrading the material.. :)
but a room-temperature superconductor would certainly lower the operating costs of all of the prototype fusion reactors that currently exist.
I've looked briefly at the materials synthesis (first part of their Supplementary Materials section). I agree with you, the synthesis is trivial. The 10e-5 vacuum is easily reached with a turbopump backed by a mechanical pump, nothing exotic or expensive.
indeed, and i wonder if you could elide the vacuum entirely with a noble gas (presuming the vacuum is required to avoid reactions with atmospheric gases)
I've made YBCO superconductors in my garage many times and the solid state synthesis method in the paper is very similar to that used by hobbyists. In fact, it seems to not require the usual careful slow annealing under flowing oxygen.
I wouldn't be at all surprised if even simpler methods are feasible.
For instance, there's a rapid synthesis method for YBCO that uses a small alumina boat, some glass wool, a residential 800w microwave oven, and slightly modified mixture of precursors to allow free oxygen to be liberated in the mixture during heating and trapped in the wool around the sample so you don't need to rig an oxygen concentrator up. IIRC it only takes about 15 minutes to prepare a sample.
This is extremely exciting! I've read hundreds of papers on superconductor manufacture and testing over the years and this has all the hallmarks of legitimacy, at least from my citizen-mad-scientist perspective.
Its not hard to achieve at all. Electron beam welders at work have 10E-6/10E-7 in the E-gun chamber all day long held by a little turbo or diffusion pump. The chambers aren't made from anything exotic just stainless steel and/or aluminum with viton o-rings.
Its not hard to achieve at all. Electron beam welders at work have 1E-6/1E-7 in the E-gun chamber all day long held by a little turbo or diffusion pump. The chambers aren't made from anything exotic just stainless steel and/or aluminum with viton o-rings.
My little e-gun experiments are all done with a Alcatel Pascal 2008 and I can achieve ~3E-3 with just that pump. I'm building a bigger system with a VHS4 diffusion pump w/cold trap that should get me into -6 territory easily.
Neat. I had a Thermal Dynamics 12 KW plasmacutter and a rig to control it across three axis. Best tool I ever owned bar none. From thinking about something to having it in your hand in a couple of minutes in steel up to 1" thick. Amazing toy.
I figured out that by moving it faster than it can cut you can 'score' steel and if you use that creatively you can make fold-at-the-lines steel structures that you then weld up on the edges. You can make super complex stuff like that in no time at all and you usually don't need any jigs other than a few magnets to line things up prior to tack welding.
The instructions they provide in the paper seem fairly straightforward and reproducible, I'd expect that if this is in fact legit, there will be many attempts to replicate the result quite quickly.
Thanks for commenting, as I'm not qualified to evaluate this. Authors providing such instructions should be commended, even if their result turns out to be false due to errors in measurement or interpretation.
This stuff is the materials science equivalent of making a baking soda volcano, in terms of difficulty. If their results are BS we will know quite quickly. I have no doubt people are attempting to reproduce their results right now. If they wanted to get the credit for a BS discovery they definitely could have picked something harder to reproduce. They're making a very easily verifiable or falsifiable claim.
Let's hope so. The easiest way to convince the world that you have a room temperature superconductor is to make up a big batch of samples and offer to distribute them to national labs for testing. First test, does it levitate a small permanent magnet, demonstrating diamagnetism?
It's unlisted as well but published back in January of 2023. I wonder what they are going to think with the influx of views on it, (43 views as of this post)
Is it just me or is it odd not seeing the normal condensation of the surrounding air due to a chilled superconductor like you get with a YBCO.
They wrote the recipe. It looks like it's easier (for people that has a similar lab) to make your own instead of filling all the import reports to get one.
Some superconductors get destroyed by humidity, so it may be difficult to ship them.
If nobody can reproduce them, then they can send samples or travel the word making samples on site, or receive researches to train them.
The good part of publishing the recipe, is that other people can make small variations. If this is true, there is just now a big race to get a higher record temperature.
This is an unreviewed preprint coming out of South Korea. If it’s reproducible it would be the biggest scientific discovery of the last hundred years. It will literally reshape the world.
However, the most likely thing is they made a mistake and the paper will be withdrawn.
Yes, normally when people come up with some BS about room temperature superconducting, they really just mean they've observed one of the indirect effects of superconductivity. "If you put an ohmmeter in my funky circuit, it displays zero!" Which usually just means you've come up with a clever way to break an ohmmeter.
Ejecting the magnetic field (the Meissner effect) is a way better sign.
I find it very hard to believe that this could be true, but at least they're measuring the right things.
Less than a week. It's a simple material to synthesize, and the tests conducted on it are pretty typical with effect sizes that don't require any sophisticated statistics to observe.
Desperate people do crazy things. This is career-ending fraud. South Korea has the highest suicide rate in the world. The pressure to achieve is enormous and makes people shortsighted.
I haven't touched much physics since college. Could the Meisner effect be observed in a material that is not superconducting? Or would that be new physics if it were the case?
I suppose that would be a useful material even if it couldn't be used for high current applications.
That also means that electrons flow unimpeded from one side to the other.
Great for energy transmission (though you can't put too much current, superconductivity breaks down under strong fields).
Great for fast circuits, such as CPUs, that don't waste energy just transmitting data.
Great for storing energy (in principle) by just making a loop and let current flow indefinitely.
Related, great for building powerful magnets (that are just such a loop) without wasting too much energy. Applications: MRI machines (they already use superconductors but are bulky due to the need for cooling) and other powerful magnets: LHC/particle accelerators, Tokamaks/plasma control/fusion. But also improved motors and generators.
Nice for levitating stuff since they levitate above magnets "for free" (due to their interaction with electrical fields, they reject magnetic fields). Possible applications for maglev (trains, etc), magnetic bearings, etc.
And possibly a lot of new applications opened up if you remove the need for cooling (Faraday cages?).
Of course, it all depends on how much current and temperature it can handle. But if this is real, just having one material is game-changing, and it will surely be improved upon by looking for similar properties in other materials. This one contains lead, which is a non-starter for a lot of applications due to its toxicity.
> This one contains lead, which is a non-starter for a lot of applications due to its toxicity.
We've been using cadmium-based batteries for ages despite Cadmium being even more toxic than lead, and are still using lead batteries in ICE cars AFAIK. Lead toxicity isn't really a problem unless you burn it, deliver water through it or you put it on paint that end up in kids' mouth…
I agree that it can still be used in a lot of applications, but this would probably restrict its use in everyday items, such as over-the-counter magnetic bearings,long-distance transmission lines, or consumer electronics (RoHS).
Lead batteries for cars are a bit special, as the whole supply chain goes both ways for recycling, while batteries are rather self-contained and not usually exposed to harsh environments.
Though I suspect you are right in the end, as it's a matter of judging the risk vs reward, I wouldn't be surprised if other materials with a similar structure end up performing similarly.
Pb is also quite hard to use in integrated circuits, as far as I know. I am no material scientist, but it could be due to its low melting point or tendency to contaminate other metals.
This isn't even wrong. A voltage can be present without a current flowing. Touch any live wire to get an instant demonstration that there indeed was a voltage present even if no current was flowing. Not because the wire is an insulator but because it wasn't at that point in time conducting any current. Your finger (also not an insulator) closing the circuit however and then allowed current to flow.
The definition of an insulator is a material that holds (up to some amount of) voltage without electrical currents appearing.
Your example needs two wires. And the wires themselves don't have any voltage. All of the voltage is between them, and is only there because they are insulated from each other.
When you cool some materials down until they are very cold, something weird happens: Their electrical resistance vanishes, and they start rejecting all magnetic fields. It's important to note that this is not a continuous process where things slowly change until it reaches zero, it is a step change after which everything related to electricity works very differently.
This doesn't mean there is no resistance in the wires that move electricity to your house, because superconductors only work when cooled to unpractically low temperatures, meaning they can only be used for special things like the magnets in MRI machines and fusion reactors.
That is, until now. This paper reports on a material that remains a superconductor at 127C.
To put this in further context, RTP superconductors mean compact, low-power MRIs and a massive shrinking, simplification and superpowering of magnetic-confinement fusion and ion propulsion designs. It blows apart chip designers' thermal constraints and opens up entire classes of energy-storage chemistries.
If this is real, it will be the defining discovery of our lifetimes.
Even if we found the perfect material, where it was easy and cheap to create long strong wires for power transmission as well as semiconductor-scale nano wires, we'd be gaining something like (wild ass guess) 20% gain in efficiency. 20% would be nice but would it really beat the last hundred years of discoveries? I don't think so, especially with digital tech's profound world-reshaping continuing to accelerate.
Specifically you could lay undersea superconducting cables around the world and rely on a global electrical grid which allows for nearly 100% solar generation.
Superconducting magnets become cheap and widely available which allows for maglev trains at massive scale. Costs for the LHC and similar experiments would drop dramatically. MRIs would only require air conditioning, if that; Modern cell phones are sufficient to compute tomography. Magnetic confinement fusion also becomes cheaper and easier. Electric cars could use superconducting motor magnets allowing for even greater power to weight ratios and efficiency.
Just a few things off the top of my non-mechanical-engineer head.
I think not just maglev: a lot of typical bearings could possibly be switched from ball / roll to maglev, saving a lot on friction and maintenance.
Undersea cables are a pie in the sky; current high-load cables in urban an industrial areas could be made much smaller, simpler, and lossless.
I wonder if transformers, currently huge and expensive, could be made better with this, too; at least the ohmic losses could be removed, and thus a lot of need for cooling, and the fire hazards.
Global electric grids aren't on a common standard. They're not all the same frequency or voltage, so you can't just wire them together. And changing over would be a mess. MRIs require very high field strength that this superconductor likely cannot sustain.
But the interties between grids are often high voltage DC which would work fine between incompatible AC grids. I think, but am not sure, that you'd always want DC superconducting transmission lines to avoid inductive losses.
You could also build power transformers that are more efficient. Transformers can be up to 95-98% efficient when running at their ideal power levels, but those numbers fall off when they are operating outside of that range. So you're probably looking at an almost 10% reduction of power usage by electronic equipment even before you get to making superconducting integrated circuits.
> Specifically you could lay undersea superconducting cables around the world and rely on a global electrical grid which allows for nearly 100% solar generation.
Not really, when the sun is up over the Pacific ocean, there's not that much sun over land. Maybe a global grid happens anyway, but cabling losses aren't the only source of cost, so I'd put my money on more localized improvements.
Better interconnection between and within local grids (maybe a viable Tres Amigas interconnection, but even just better connections between sections of the major grids would help with grid management. Improvements in motors, MRIs, magnetic bearings, transformers, etc.
EMF becomes a fungible energy medium. Imagine storing energy in a field, just as we do with MRI machines, momentarily in the poles of motor windings, essentially anything inductive, or that operates as an electromagnet. Apart from dielectric losses and other environmental factors that are inescapable, the magnetic field becomes elastic like air [in] a balloon. The potential for this to modify energy consumption patterns is mind-boggling.
I'm not an expert, and everything that follows comes from a quick reading of this Wikipedia article.
It seems like (counter-intuitively) refrigeration isn't a significant cost compared to all the other stuff that's necessary. So at first glance it seems like high-temperature superconductors might not make a big difference.
However, that Wikipedia article does say this:
> The critical temperature of a superconductor also has a strong correlation with the critical current. A substance with a high critical temperature will also have a high critical current. This higher critical current will raise the energy storage exponentially. This will massively increase the use of a SMES system.
Right now, superconducting energy storage has a lot of advantages, but it doesn't have very good energy density (by mass). Not even a tenth of what lithium-ion batteries have. I assume you couldn't power a car with it. But it has some compelling advantages in other areas. It has unlimited charge/discharge cycles. It has zero self-discharge. It has unlimited (in theory) power density, so you could charge or discharge it arbitrarily fast.
Depending on what the energy density ends up being, it might suddenly become way more useful. It would have to be a gigantic leap in energy density, though.
Also, not needing refrigeration could potentially open up smaller scale applications. Maybe you could have a residential superconductor storage system for your solar panels. (Although I don't know about its safety, so maybe not.)
All this assumes the cost to build it is reasonable compared to other alternatives, that the discovery is real, etc.
> the biggest scientific discovery of the last hundred years
I would say that electronic computers would take take the first spot for me, but I don't deny that room-temperature superconductors would be pretty close to the top.
I'd say that not keeping electronic computers in mind is a testament to how big of a discovery they were, in the sense that we need to think hard about transformative discoveries to realize that not so long ago humanity didn't had electronic computers,and yet they are everywhere.
I’d say electronic computers were the biggest invention of the last 100 years. But it wasn’t one discovery, that built upon many, many discoveries and breakthroughs.
As a singular discovery goes, it’s hard to think of something that tops this. Of course, even if this is true, bringing it to market in a practical way will probably look a lot more like the invention of electronic computers.
Hmm, maybe the atomic bomb? The wright brothers's first flight took place about 120 years ago, so it doesn't qualify. However, in both cases, people knew it was a matter of time before someone figured the proper recipe. Room temperature/pressure semiconductors? That was still science fiction yesterday.
In short, you are probably right, with the sibling commenting on (BJT) transistors.
This (or something derived from it) would be used for power delivery literally everywhere in the world. It might well be bigger in scale and volume than all the computers.
Probably both? At least the first. For integrated circuits, I think lead is a hard pass (for now), and the deposition process needs to be worked out.
Ideally, this could be useful for the hottest paths: clock tree, high-speed buses, as well as the power supplies.
There are a few hurdles though: high-speed voltage changes create changing currents, which creates variable magnetic fields, which IIRC may be a problem depending on the superconductor's characteristics. Processors also work at low voltages, which means that they need huge currents. Both magnetic fields and large current (as well as high temperatures) can break down superconductivity. So it's challenging, but probably doable.
You're right. But, we should also do things that matter. This wouldn't. Right now, our horizon is literally 5 years. Anything that doesn't help in the next 5 years needs to get in line, because we've got 50 years of inaction to make up for.
OTOH, I am also not sure what we as a species can do in the next 5 years that actually will matter.
I think it's comparing incomparable technologies. Like the wheel and the alphabet; both changed human history in profound ways, without competing with one another.
Dunno. A fancy tape or such made out of lead compounds would be a hard sell in comparison to ordinary copper for household wiring.
But yes, for serious uses, this will be a big deal if it works out and can be made into a flexible cable. And I’m sure people will work on a less-toxic version.
Long distance electrical transmission will still require huge capital investments and lots of maintenance even if transmission losses are eliminated. And as a practical matter, strategic political concerns will take precedence. In the current political climate it's hard to imagine connecting our grid to potentially hostile nation states which might cut off power supplies to apply pressure during a crisis.
If we can't handle / get motivation for long-line HVDC transmission I guarantee you we aren't going to be able to put together the will to make an entire transmission system out of a novel material with unknown mechanical constraints. Long distance transmission is not a solved problem, but it's close. We have the technological capability now to make much, much better transmission systems. We just don't want to.
While that would be nice, it's not exactly revolutionary. We can already build cables to transmit power over vast distances and can certainly imagine a world where we do the same, but with higher efficiency. The computer transformed how we live our lives and reshaped our culture, to the point where what we are doing right now - casually chatting with anonymous people spread around the globe about a scientific paper that we can all read at our leisure immediately upon publication - was inconceivable within living memory.
I think it would still change the world less than computers have changed it. Without computers we wouldn't have this conversation. So much in the modern world is basically impossible without computers.
Superconductivity will for sure enable some innovations and could change how we are building power grids, but I don't see it changing the world to the same extent.
I don't agree. Producing something at scale is only relevant if the goal is mass commercial distribution. Communication satellites changed the world and they are practically all (i.e., some exceptions such as space-x constellation) one-off builds of single-shot projects.
People use the same stupid argument when commenting on quantum computer. But in case of QC, one is powerful enough to compute everything and we might not even need two, except for spare. Say a 1000 qubits QC exist, Work that it can do is the sum of all computering power in human history. You cannot even verify if the result is right or not because simply you don't have any classical alternative for that workload.
> But in case of QC, one is powerful enough to compute everything and we might not even need two, except for spare. Say a 1000 qubits QC exist, Work that it can do is the sum of all computering power in human history. You cannot even verify if the result is right or not because simply you don't have any classical alternative for that workload.
A 1000-qubit QC can't break a RSA-2048 key, let alone a lot of other interesting tasks. Quantum computers aren't magical things that provide exponential speedups on absolutely everything; they can only provide exponential speedups on some algorithms, and those algorithms generally require linear numbers of qubits to the problem size, so 1000 qubits is greatly limiting to problem size.
Neither any classical computer can. We don't even have enough harddrive to store all quantum information in a 100 qubit QC, let alone 1000qubit. QC is limited to solve a subset of problems do not automatically equals to QC is useless comparing to classical ones. Also not able to invalidate the powerfulness of QC beyond 100 qubits.
Not necessarily. If this material is legit, this proves that room temperature superconductors can exist. If it works in this material, others might also work. Eventually it may lead to a material that can be manufactured cheaply enough. The potential monetary savings of such a material is so great, that you'll see billions flow into materials research.
I was with them until I came across Figure D on page 7. It uses Comic Sans and calls the entire paper into question.
Please note: this comment is an attempt at humor. Various people seem to have a difficult time discerning humor or sarcasm and choose to downvote. It is also possible (but unlikely) that I am not funny.
And yet humor and sarcasm can add spice to the conversation. I really did read the entire paper at the level of detail that allowed me to spot the inconsistency in the font. That was not made up, was substantive and should be corrected before it goes to print.
The PS was also very real as the grandparent gets buried under downvotes.
South Korea has been desperate for a Nobel prize for a long time. Don't be surprised if they jumped the gun for a false exciting result for national pride.
I mean that's almost exactly what happened with cold fusion, not faking so much as convincing yourself. What's the Feynman quote? "The first rule is do not fool yourself and you're the easiest person to fool" - something like that anyway.
It's absolutely a possibility in the space of this situation. However, any judgement, positive or negative, should be withheld until other labs and people claim to reproduce or not.
No. It's not. The impact won't be bigger than, say, the jet engine (1935), nuclear power (1951), the computer processor (???), the internet (???), DNA (1953), or many others.
I mean- not really? They have developed / synthesized the material, and they collaborated with another lab that had the skills and equipment to conduct and interpret specific experimental techniques and results.
Fairly common, especially in life sciences, and I suspect chemistry and materials science.
Added in edit: This doesn’t make the result any more or less credible; for that, the true test is independent replication of both the synthesis as well as the experimental measurements. But the fact that the two authors published two papers with different groups is orthogonal to whether the result is real / an experimental error / fraud. I so hope its true - but..lets wait for replication and validation by other qualified experts :)
I think they also make mention of the other paper in the one being discussed, pages 12,13:
"The Additional experimental results and discussions on LK-99 will be published immediately in the next paper, including an interesting controllable levitation phenomenon and the coexistence of magnetism and superconductivity, theoretical calculation, etc."
After skimming the paper, it reads like a legitimate paper even though I have zero expertise in the area. That it is in Word instead of LaTeX makes it feel a bit less legitimate to me and they could of course always have some error in there setup.
The most notable thing to me was that this was done in a thin film where structural defects are supposedly responsible for strain in the material which in turn enables the superconductivity. Probably because it is only a thin film, the material could only support about 250 mA at 25°C before losing superconductivity. So even if the paper is correct, it might turn out to be challenging to get to higher currents. Or maybe not and one could just roll up a wide thin film and have as much amps as one likes.
EDIT: I misread the thin film thing, they also produced a thin film but primarily they describe the material testes as follows without any dimensions I could immediatly spot.
After the reaction, a dark gray ingot was obtained reproducibly and then made into the shape of
thin cuboids for electrical measurements [...]
Yeah, it seems like (to me, a naive layperson) to be similar to how a prince rupert's drop exerts strong forces thanks to the mechanism of its cooling/shape. The copper somehow forcing other structures to form in an atypical way which enables the superconductivity.
And even at 250mA, there'd be tons of different usecases for a superconductor.
I got this wrong, they also produced a thin film in addition to bulk material. And my worry was that one could maybe not easily scale this up in case the effect relied on it being a thin film in which case you can only make ever so wide before it becomes impractical or you have to layer or fold the thin film which might also be problematic. But as I said, I just read this wrong.
LaTeX is of course big in math and physics because its math typesetting is unparalleled. And generally it’s just much more convenient to write a lot of math in LaTeX than a wysiwyg editor once you’re proficient. Outside hard sciences it’s probably not common.
As a physicist, it's not a red flag... It's a red klaxon blaring out an alarm.
I have only met a few physicists who don't write papers in latex. They are all 65+ and generally work with younger scientists/grad students who prepare the paper in latex for final drafts and submissions.
TeX was written in the 1970s for typesetting when there were no word processors by a computer programmer who couldn’t afford professional typesetting and couldn’t be bothered to learn assembly language so he wrote his own fictional one for his book — the same book he wrote TeX to publish.
This is already very tangential, but just for the benefit of anyone who may miss the humour and take the above comment seriously:
- re “couldn't afford professional typesetting”: Knuth was happy when Addison–Wesley approached him, specifically because he liked the high-quality typesetting of their books (like Thomas' Calculus) that he had used as a student. He was happy with the typesetting of the first editions of Vol 1 and 2, and only for the second edition, when the publishers moved from hot-metal typesetting to phototypesetting (that is, when the quality of the best achievable professional typesetting deteriorated), and he learned of the existence of digital typesetters, that he was motivated to come up with his own solution.
> There should be no hesitation about learning a new machine language; indeed, the author has found it not uncommon to be writing programs in a half dozen different machine languages during the same week! Everyone with more than a casual interest in computers will probably get to know several different machine languages…
When I was still in academia in two years ago, there was plenty of materials scientist, chemists and yes, experimental physicists I worked with who used Word, depending on the journal.
Sometimes you have to collaborate outside of physics!
My advisor was a physicist, and a Fellow of too many societies (IEEE, IoP, APS, etc).
He did not know LaTeX. Most of his papers probably were in LaTeX, as his students knew it. But I remember multiple papers he "authored" in Word, because that's what the student preferred.
I was in a top 10 school (in physics and engineering), and I can assert that the fraction of physics faculty who did not know TeX/LaTeX was at least a quarter, and could be as high as 50%.
All the major physics journals would accept Word submissions.
Word is one of the most common tools for writing papers. There was a study a while back that looked at the quality of Word or Latex papers. The study found that researchers using Word were more effective, and the working theory that explained it was that people who focused on the research did better research, and people focusing on the typesetting do better typesetting.
I can believe that this is true today. As recently as 15 or 20 years ago, Word was awful enough that seeing through significant technical documents was a terrible experience. Horror stories of large corrupted documents and mysterious formatting behaviors were very common.
Today, Word is much more capable as a scientist's tool.
I've done professional typesetting and cataloging with QuarkXPress and InDesign both and it was extremely fast, that's for professional high quality publishing. .doc and .md is fine for information first publishing.
Latex is not simple and is in my opinion just a big nerd snipe, its the intrusive thought of layout software, for humanities sake we'd be better off with simpler tools like markdown + math notation and if latex had been never invented.
Every task? If I want to rename all of the .pdf files in the folder to .avi I would just do it in the command line
Or would you rather have me google a GUI that lets me "quickly rename" and download a few programs that have this capability? Or do a few hundred files by hand?
There are these things called programming/scripting languages, look it up. python for example.
And you end up with very short and simple - and most importantly - human readable programms instead of cryptic Unix two letter commands with bunch of arcane single letter flags and other legacy pdp11 nonsense from 1970ties
The GUI for that is called file manager, there are quite a few available and they can be far more sophisticated than an ad-hoc command pipeline. If you manage your files on a regular basis (manual sorting, metadata, mass renaming etc), you already have a serious file manager that allows you to do this.
Command line is... fine for doing this occasionally, but it's hardly "quick" or usable for this, I'm saying that as an advanced commandline user. You're just using the tool that you already have and know, and it happens to be the system shell. It doesn't have to be.
(another question is that classic file management at the scale where a sophisticated tool is needed is mostly automated nowadays, and yes there's scripting as well)
I think it would be nice if everyone can decide for themselves which software they prefer. Some people prefer Latex, others prefer Word or InDesign etc.
I would prefer not to have gatekeeping either way, both "It was written using Word, it must be fake" and "Latex should never have been invented."
I'm not saying latex should be banned or disallowed anywhere, no actual gatekeeping in that regard.
There are big geek communities that lead newbies astray by recommending it, it's a nerd snipe that wastes a lot of brain cycles better used elsewhere. It's only little b bad, not big B bad.
I am saying it's a poor tool, a waste of time and an evolutionary dead end, people are allowed to fetishize poor tools, efficiency, simplicity and legibility are very poor in latex world with a high learning curve for a task that is at best tertiary to the task of doing real research, it's a tool that promotes rabbit trails, bike shedding and procrastination.
And the small amount of research that has looked into this has apparently born this out in at least some small degree. It's not a hot take if it's got backing.
Ironically, the paper itself was republished to fix figure placement [1].
To your main point, no, theoretical physics paper are almost all written in latex. I can't recall word-written theory paper. Experimental papers are sometimes word, but pretty rarely. You can try randomly sample papers from cond-mat arxiv to verify it.
So you're saying it could be a great sensor, similar to a Josephson junction? :-)
Update: "yes", from the paper: "The Josephson-like phenomenon for the under-damped junction of superconductor-normal metal-superconductor(21, 22) or Inter-grain coupled superconductors(23) and the thermoelectric effect(24-26) of the inter- or intra-grain network were also observed."
(note: using language that accepts the claims of the paper for simplicity -- I remain skeptical)
For what it's worth, superconductors have a shared budget[1] of (magnetic field, temperature, current). At 25°C, the material is near its critical temperature, so its current-carrying capacity is necessarily diminished. At a lower temperature, the film should be able to carry more current.
That said, 250mA is plenty of current if you're interested in making a superconducting CPU.
edit after reading the paper: they claim an extraordinarily high critical temperature of ~126°C. You can see the temperature dependence in Figure 1e; they're much further from the critical temperature than I expected, and at room temperature, a little cooling appears to go a long way. I'm eager to see an attempt to reproduce this result. That said, the material is essentially a 2d molecule -- we've been hyped on graphene for decades, and have yet to see it integrated into a scalable process.
What's more interesting is flexibility. Current ceramic liquid-nitrogen-cooled superconductors are not flexible at all; they are brittle. This can be fine for a transmission line, but makes things hard for various coils.
If you read some real papers and some crackpot papers, you can learn to identify bad papers without having to have much knowledge on the topic. Bad papers will, for example, often lay out trivial things at length, i.e. have very low information density. Or they will say things that are incoherent even if you do not understand all the details. Or there will be no references to legitimate other literature. This paper is dense and coherent and does not contain obvious nonsense even to an non-expert. More I did not want to imply, just that it does not look like a a crackpot paper. For a more detailed judgment, for example whether the experiments they performed or the numbers they got are reasonable or something like that, I am indeed unqualified.
Ohh ... this could actually be relatively big.
From abstract: "The superconductivity of LK-99 originates from minute structural distortion by a slight volume shrinkage"
There was previously research done investigating how changes in atomic structural alignment affect superconductivity (such as by cooling). I think researchers were trying to maintain the spacing that superconductors had while cool even when it was heated up. This sounds line with that other research, though I can't find the article again, please correct me if you find otherwise.
Still likely to be rather fragile and temperamental to work with ... but this seems like it's possibly legit.
Yes! That was exactly what I was thinking of! I love one of the comments - "But might this physical stretching then also allow room temperature superconductors, if not why not?"
They were thinking of stretching at a macro scale (like bending a bar of stuff), rather than essentially "stretching" at the chemical scale which is what I understand they did here. Super cool!
It gets even better. fwlr, in a comment further down that thread, expands:
> I think the “tension axis” is more likely to be fruitful in a different way, where we find some structure e.g. a crystalline formation that happens to hold atoms apart with just the right amount of tension. But this is all very speculative - the “tension axis” is just a random thought I had while reading the article!
They hit the nail on the head pretty well, I’d say!
As someone who knows more about words than superconductors, gentle correction in case it is an actual misunderstanding instead of misspeaking, but a correctly running MRI shouldn't ever CONSUME the liquid helium, it would recycle as much as possible.
But as a newly self-proclaimed expert on superconductors as well, yeah this would probably help MRIs. My understanding is that the reason for superconductors in MRIs is so that the wires doing the electricity stuff don't interfere with the small electrical responses from the tissue it's measuring. Without resistance, you don't get magnetic fields around the wires or something.
Liquid helium is very sneaky stuff. Sure, they try to keep it in as much as they can (it's expensive!) but it's gonna leak eventually. A quick web search indicates that MRIs in common use lose 1-6% of their helium per month.
One of the authors in a related paper[1] is Hyun-Tak Kim. He has many publications in peer-reviewed journals[2]. One even has > 1500 citations[3].
I can't tell if there is a catch anywhere, this seems pretty legitimate. Also, unlike some previous claims that required sophisticated setup to reproduce, this seems dead simple. I think we will hear from other researchers very soon.
1. Superconductor Pb10-xCux(PO4)6O showing levitation at room temperature and
atmospheric pressure and mechanism: https://arxiv.org/pdf/2307.12037.pdf
The actual picture of (poor) levitation in the paper you linked is pretty compelling. This isn’t a complex, noisy measurement showing something that’s related to superconductivity — this is a magnet and a supposed superconductor repelling each other.
As far as I know, that’s possible with permanent magnets (and it would be weird, but not impossible, if the group instead synthesized a novel ferromagnet and didn’t notice), electrets (seems pretty unlikely here), very extreme amounts of static charge (again, seems unlikely), and actual superconductivity (would be awesome).
Random bits of cooked oxides, ceramics, and such don’t float on a magnet.
Yeah, that thing does really want to stay in a constant level on the magnetic field. That would dispel every other explanation on the GP, as it's not simply being repelled or attracted.
I found that video very compelling. If it was eddy current, the float standoff distance would have decayed. It sure looked to me like there was no decay at all, and wow! if true.
Eddy currents can be induced in non-superconducting materials that make it look like levitation, but the catch is that there has to be relative motion between the magnet and the object 'levitating' to generate the currents in the first place.
But in this sample video, the standoff distance doesn't appear to be slowly dropping at all, which would rule out eddy currents as a source of the behavior. If you continue watching the linked video to 13:27, he talks about how and why superconductors levitate.
Copper and a magnet can certainly interact. Drop a magnet through a copper pipe and the eddy currents will induce a field that's opposed to the magnet causing a damping effect. Maybe something like this is going on where movement of the magnetic field is inducing an opposed magnetic field in the copper, and thus interacting.
Anyhow it will be interesting. if It can generate a field of 1.5-2 Tesla you could have more efficient solenoids and probably motors.
>As far as I know, that’s possible with permanent magnets (and it would be weird, but not impossible, if the group instead synthesized a novel ferromagnet and didn’t notice)
As far as I know a stable arrangement of permanent magnets levitating is impossible without a baring surface to keep them aligned. (i.e. free floating levitation is not possible without active control)
* ferromagnetic - attracted to one pole of a magnet but not the other (in a given orientation), this is what everybody thinks of when they think of "magnets"
* paramagnetic - attracted to both poles, i.e. stuff that sticks to magnets
* diamagnetic - repelled by both poles, except in superconductors, this effect is very weak compared to the forces experienced involving ferro-ferro or fero-paramagnetic materials.
There isn't another category, everything fits in to one of those buckets.
Saying
>Just so everyone is on the same page, static passive diamagnetic levitation is possible with materials like pyrolytic graphite.
is a bit deceptive, as what people know as "magnetic" materials are ferromagnetic.
That's not quite true. There is a Halbach array with a bunch of compensation coils that will nicely center as long as it is moving, no active control or bearing required.
stationary. Hence the 'as long as it is moving' bit above. Because the motion allows for the coils to generate enough of a current to drive the compensation. So you need a support system to bring the assembly up to a certain minimum speed above which it will stably levitate.
I wonder how long you could get one of those to spin in a vacuum.
Halbach arrays with compensating coils have been proposed for some interesting applications, such as low loss flywheels for electrical storage. I don't know if that ever got commercialized but I do recall that some prototypes were made by a US company. I can't find a reference to it though.
I would say that this type of levitation where it sort of half levitates is quite common. I taught YBaCuO superconductor experiments for a few years. That Meisner effect would get full marks in my institution!
Believe it or not, the levitation effect can be found in non-superconducting materials with a high diamagnetic constant such as pyrolytic carbon. Induced magnetic fields are created by "effective currents," which can occur in zero-resistance systems that are not called superconductors (because they can't conduct across a significant distance, only around a tiny loop) like molecular or atomic orbitals.
> Superconductor Pb10-xCux(PO4)6O showing levitation at room temperature and atmospheric pressure
Is it late April Fools joke?
It can’t be true.
Edit: I am not surprised it levitates. I am astonished by how much it will reshape our world if it is real room-temp and ambient-pressure superconductor. Also is easy to produce. Just too good to be true.
I would guess that it'll take a month or two to repro the procedure. The paper was uploaded in the last week, so we're still probably a few weeks out on peer review.
Superconductors will typically levitate if placed above a magnet, and vice versa. Magnets are weird--superconductors even more so. I assume that's what they were referring to?
Edit: Judging by Fig 4, which has a large object conspicuously labeled "magnet", that's probably what they're referring to.
This whole experiment is quite reminiscent of an experiment I did in high school. We synthesized a high temperature superconductor (IIRC it was YBCO) by grinding some powders together with a mortal and pestle and baking the result. And we stuck it in a little cup of LN2 and floated a magnet on it. It really works!
This group used somewhat nastier powders, they had to cook parts of it in a vacuum, and they floated the result on a magnet instead of vice versa. And it only floated a bit. But they did it without any cooling!
Levitation is to be expected for any superconductor when it's in a superconducting state; that part is banal. The big question is whether it's actually a superconductor at RTP. Their results are strong enough that it's unlikely to be a mistake, though fraud is possible too (although it is so easily uncovered given the simplicity of preparing the material and the strength of the reported effects that fraud seems almost pointless since it'll be uncovered immediately).
The recipe in the paper is so simple that it's giving me Pons-Fleischmann vibes. It reads more like an entry from an alchemist's journal, reproducible with chemicals and equipment you could buy on eBay or Amazon.
Silicon is one of the most abundant elements on Earth and for thousands of years humans had no idea what would be possible with very controlled etching of it.
Mildly-topical Terry Pratchett amusement quote, since it involves a society that has overlooked the power of silicon plus the potential of superconductivity:
> Detritus blinked. There was a tinkle of falling ice. Odd things were happening in his skull. Thoughts that normally ambulated sluggishly around his brain were suddenly springing into vibrant, coruscating life. And there seemed to be more and more of them.
> 'My goodness,' he said, to no-one in particular.
> This was a sufficiently un-troll-like comment that even Cuddy, whose extremities were already going numb, stared at him.
> 'I do believe,' said Detritus, 'that I am genuinely cogitating. How very interesting!'
> 'What do you mean?'
> More ice cascaded off Detritus as he rubbed his head.
> 'Of course!' he said, holding up a giant finger. 'Superconductivity!'
> 'Wha'?'
> 'You see? Brain of impure silicon. Problem of heat dissipation. Daytime temperature too hot, processing speed slows down, weather gets hotter, brain stops completely, trolls turn to stone until nightfall, ie, colder-temperature,however,lowertemperatureenough,brain operatesfasterand—'
> [...] Detritus sat down again. Life was so simple, when you really thought about it. And he was really thinking. He was seventy-six per cent sure he was going to get at least seven degrees colder.
I wonder if anyone has tried to contact one of the authors to confirm the paper is legitimate (i.e. someone isn't spoofing the author's names in order to create chaos).
Assuming the lift is there or the magnets are strong enough, it would be plausible to have an electromagnetic hover skate park where you could pay by the hour, and possibly even future X-game like events where the boards and riders could move in any direction they can get acceleration in.
I want them to have enough current passing through them in a rod shape that it will run the current against the Earth's magnetic field to cause vertical movement.
MRI will get much cheaper, but you still need a good upper critical field and a proper access control (Zone 2/3/4) protocol. So probably not in very small buildings.
From what I can tell this material can't provide higher than 0.3T. We've had permanent magnet MRI at 0.3T but the drawbacks vs superconducting magnets are weight and lack of active shielding.
With room temperature superconductivity doesn't it become possible to turn the magnet on and off far more easily? MRIs would be much safer if they were only energized during the actual imaging process.
They are already superconducting and using liquid helium to cool. They have failure modes of spilling gas out into the room (patient and operators have to evacuate.)
Not so fast... These superconductors although revolutionary loose superconductivity in high magnetic fields (or with high currents).
If this proves true I'd see their use more in electronic circuits. Novel sensors etc rather than classic high power high field uses people dream about when the words "room temperature superconductivity" gets thrown about.
It's more about producing toxic waste and contaminating the environment - no one's licking the solder joints in their electronics either, but you still have to use lead-free solder.
Compared to refining traditional conductors and recycling/disposing of used electronics?
> you still have to use lead-free solder
One, fumes. Two, people touch their solder and then grab a cookie.
We're premature. The results need to be proven. But the benefits of RTP superconductors is mindblowingly high enough that risks from lead contamination (far from a novel problem, I might add) can be safely ignored.
It's like fundamental best practice to always wash your hands thoroughly with soap if you handle leaded solder.
You might want to read more in the links I shared about the harmful effects of lead before "whatabouting" to other problems of electronics recycling/waste.
and yes, it's entirely possible this application would get an exemption from usual restrictions on lead. For example in the EU directive, one of the exemptions is:
> Lead in solders for servers, storage and storage array systems, network infrastructure equipment for switching, signalling, transmission, and network management for telecommunications
> fundamental best practice to always wash your hands thoroughly with soap if you handle leaded solder
But people don't, particularly students, and sometimes they also let their irons run too hot at which point fumes become an issue. Also, there is an easy alternative, so why not.
If the choice is lead superconductor or not, nobody is going to pause on a use case because there is lead. If they do, and if this is real, please let me know--I'd love to have them as competition.
> might want to read more in the links I shared about the harmful effects of lead before "whatabouting" to other problems of electronics recycling/waste
The point is, whether a RTP superconductor does or doesn't contain lead is irrelevant to its adoption. The advantages are too large. What current directives say are, similarly, irrelevant.
Oh, sure. You could have just said that then. You instead originally said something about "no one licks the insides of the computers", which isn't the reason lead in electronics/PCBs/etc. is restricted, and what I was pointing out.
Usually people who are making the argument you were making with the words you were using are signalling that lead is "lump of rock from center of nuclear reactor" dangerous. Honest to god, a lot of people believe this
Soldering temperatures don't produce significant lead fumes. The fumes you see are flux fumes (which are also bad to inhale).
IMO, the most dangerous thing about lead solder is cleaning the iron. Both the common methods (damp sponge and brass wool) create many tiny little balls of solder that are hard to see and bounce about all over the place. Because of the high density of lead they're less affected by air resistance than you might expect, and they roll easily, so they can move surprising distances. They can easily end up caught in clothing, and from there fall into food. This will result in much higher lead ingestion than just touching solder then touching food.
I personally always use lead-free solder. If you have a good temperature controlled soldering iron it's nearly as easy to use as leaded solder.
Lead-free through-hole soldering is easy and practical. Unfortunately, for SMT prototyping (including reflow soldering), lead-free work is no longer that easy. Another problem, even in through-hole devices, is when you have large metal parts - a tough problem for RF/microwave circuits full of SMA and BNC connectors, backed by 1 or even 2 layers of solid ground planes, providing excellent a heatsink and a lot of cursing during work and rework. With lead-free solder, I found the iron needs to be cranked up to 420°C for a usable experience (but a larger iron tip may reduce that to a more reasonable level), and I don't know what temperature does it take to desolder them.
The last time I checked, low-temperature bismuth-tin alloy is only available as solder paste, unfortunately not available as flux-core solder wires (they're not really a good choice for connectors to begin with as the alloy is brittle, but I only need it to survive before the next prototype...)
It's trivial to experimentally demonstrate that solder fume contains almost no lead, the quantity is negligible. Claiming the contrary is the electronics equivalent of saying HTML is a programming language. Please don't do that again. The fume is indeed toxic, but it's due to the VOCs from the flux core, not the lead in the alloy.
A more solid (no pun intended) argument can be the hazards of debris. Furthermore, in my opinion, a newer and more serious problem of leaded solder today, in a workshop setting, is its use in solder paste. Solder paste and a reflow oven are required for prototyping any circuit boards with surface-mount components (SMT) - basically any modern circuit board today. Solder paste is a tube of toothpaste-like chemical mixture that contains tiny, micrometer-sized metal particles, mixed with sticky flux. If they're used without care, a solder paste spill is a sure way to contaminate the floor or work surface of your workspace. The sticky paste is also hard to wash away from skin.
Unfortunately, reflow soldering of surface-mount components can be really challenging, even more so when doing it by hand. Thus, classic lead-tin alloy is often used to reduce difficulties of assembly during workshop prototyping due to its technically superior properties. Switching to lead-free is only possible when you have a tightly-controlled and consistent work flow.
If you want lead-free, for small-scale prototyping and rework, a non-toxic bismuth-tin alloy is sometimes a good alternative to standard SAC305 lead-free solder thanks to its low melting temperature, which is one main reason that makes most lead-free alloys difficult to use (it even has considerable popularity in mass production of LED devices, as they are heat-sensitive). But its surface tension is slightly different, weakening the self-alignment effect of components during reflow soldering, increasing the chance of defective joints - a concern in prototyping. Its brittle nature also increases failure rates in the field, among other caveats.
> Solder paste and a reflow oven are required for prototyping any circuit boards with surface-mount components (SMT) - basically any modern circuit board today.
This is incorrect. You can easily do small scale work with almost all SMT components without solder paste. Solder paste is required for automated assembly processes. But almost anything done by hand can also be done with conventional solder.
Source: I worked as an electronics designer for a few years, and assembled prototypes and small production batches by hand with SMT parts (0603's, TTSOPS, etc) every day.
The one exception is BGA devices, because the solder pads are underneath the device. But doing those by hand requires precise alignment that is difficult enough that few people do it. Also, for smaller BGA devices with fewer pins, skilled operators can still solder them in place with a heat gun by covering the pads with solder and flux and just melting them into place.
I know two people (one of which is here on HN) who do fairly large BGAs by hand, I wonder if that skill is really that rare. I couldn't do it myself though, I did try but for some reason I can't make it work reliably enough to risk it on stuff that matters.
> This is incorrect. You can easily do small scale work with almost all SMT components without solder paste. Solder paste is required for automated assembly processes. But almost anything done by hand can also be done with conventional solder.
I disagree. I don't consider 0603 passives and TSSOP packages "modern" anymore. Of course these components can be hand soldered with ease (possibly at top quality with the aid of a microscope). Unfortunately, the industry is gradually abandoning TSSOP and QFP in favor of DFN, QFN, and LFCSP in recent years. For anything that does high-speed signaling or multiplexing above 1 Gbps (which is old by computer's standard) like USB 3.0, PCIe 1/2, QFN goes without the need for a mention (short of using BGA). But the thing is, even in simpler ICs like DC-DC controllers, you can see the same trend. Simple RFICs are another source of heavy users of these packages, reduced circuit parasitics is certainly a factor.
These packages are all leadless, and frequently with thermal pads at the bottom. An older term for leadless packages is BTC - Bottom Termination Components. [1] After a few successive and multiple failed QFN soldering attempts, I switched to ordering stencil, solder paste, and a hot plate. It worked perfectly on my first attempt, so I never looked back.
Unless you have top 10% soldering skills, which I don't (experienced smartphone repair technicians seems to have mastered the art of QFN), I found solder paste is required for maintaining your sanity with leadless packages. Furthermore, without reflow soldering, prototype assembly can be very time-consuming and takes hours, especially when you need 3 or more prototypes.
Occasionally, leadless packages also have optional difficulties turned on, completely eliminating the possibility of hand soldering, such as multiple bottom pads for different nets (to minimize parasitic inductance), or having two layers of contacts, one row on the exterior and on row on the interior.
> You can easily do small scale work with almost all SMT components without solder paste. [...] The one exception is BGA devices
And DFN, and QFN, and LFCSP, and...
Thanks to industrial and automotive users, some ICs still have QFP versions for these markets (due to their vibration resistance) that are friendly for hand operation, but you have to pay a premium.
Finally, even plain-old QFP chips have bottom thermal pad these days (in that case, you can manually apply a blob of solder on the PCB and reflow again with a hot air gun, but manually apply a drop of paste is easier to work with).
---
[1] But these days it would make people think it's some kind of a Bitcoin mining ASIC. BTW, the last time I've checked, these ASICs are indeed QFN, so one can say they're BTC BTC chips...
Why is this being downvoted into oblivion? It's a completely valid, good-faith point explaining why lead has restrictions on its uses other than "someone might lick it"... It would be nice if people actually responded and vocalized their disagreement or described the flaws in my reasoning, rather than just suppressing my message.
Its not a dirty secret, but just like the rules on chemicals under the organic certification, if you can show that there's no way to do what you want to do with lead-free, you can get an exemption. I suspect that "significantly lowers the cost of power generation" would outweigh "contains lead".
Yeah, I just mentioned in another comment that there already exist exemptions such as server/networking hardware:
"Lead in solders for servers, storage and storage array systems, network infrastructure equipment for switching, signalling, transmission, and network management for telecommunications"
> if you can show that there's no way to do what you want to do with lead-free
The bar is even lower than that. For example, bullets are still made of lead, not because it's necessary, but because it's cheap, and despite the fact that it contaminates the meat of the hunted animal with lead.
Tangentially, the US Army has completely stopped using lead in bullets. Their 5.56 NATO ammo has copper where the lead used to be (i.e., inside a brass jacket) which reduces performance because copper is only 2/3 as dense as lead.
Copper bullets date back to the 80s, they're not a new development. Copper bullets have higher penetration despite having less mass, which makes them better against armored targets, and NATO still held on to lead for so long just because it's cheaper.
They date back further than that. In WW1, French troops were mostly shooting full copper/bronze shot. The reason was that it was cheaper and easier to mass-produce solid copper bullets than it was to increase the production of jacketed bullets by a similar amount, and with Germany excluded from naval trade, there was suddenly a lot more copper available on the market.
First, terms - brass is not used to "jacket" a bullet. Brass is used as the case material for the cartridge. Steel, and nickel plated steel are some times also used here. "Jacketing" (as in, Full Metal Jacket) refers to the material that wraps around the exterior of the projectile. As far as I'm aware, the material used here is almost always copper, or a copper alloy (cupronickel).
The US standard bullet is the M855. It's a lead core with a soft soft steel penetrator at the tip, that's jacketed with copper.
There's an advanced version of the M855, the M855A1, which is an entirely steel slug, jacketed with copper. This bullet has better terminal performance at longer ranges, and slightly better armour piercing capabilities.
The US army standard training round is the M193. It is a lead bullet jacketed with copper. Interestingly, it in many ways has better terminal performance than the M855 because this is the bullet the M16 and M4 rifles were designed around, and the M855 only exists because of NATO politics.
There are no bullets in the US inventory, to my knowledge, that use a copper core. Copper is simply far too expensive to be used at that scale, and, as you pointed out, reduces the weight of the projectile which has negative effects on terminal performance.
"Why are bullets jacketed in copper" you might be wondering here - when rifle cartridges were invented, they still used black powder, and all bullets were lead. When smokeless powder was invented, it became possible to have more explosive power per unit of volume. However, this had two negative effects - one, the lead projectile would either disintegrate, or became entirely inaccurate, at the speeds it was accelerated to. Second, the force of the bullet against the rifling of the barrel was rubbing away metal from the bullet, leaving lead deposits which fouled the gun and made it inaccurate. All steel bullets solved this problem, but increase the wear on the barrel. The solution was to coat (jacket) each bullet in a thin layer of copper, which was stiff enough to withstand the force of friction in air, while also softer than the steel barrel and reduced wear and tear on the rifles
M855 has a lead plug behind a steel penetrator. M855A1 has a copper plug behind a steel penetrator. So, I stand by my "copper where the lead used to be". I never said there wasn't a steel penetrator.
>For general issue, the U.S. Army adopted the M855A1 round in 2010 to replace the M855. The primary reason was pressure to use non-lead bullets. The lead slug is replaced by a copper alloy slug . . . The U.S. Marines adopted the Mk318 in early 2010 due to delays with the M855A1. This was a temporary measure until the M855A1 was available for them, which occurred in mid-2010"
As you probably know, most combat soldiers in the US Army and Marines carry a rifle (usually an M4 these days IIUC) that fires 5.56×45mm NATO, so it is probably the ammo type that the US military uses the most of.
This post is a master class in why you shouldn't get all your information from Wikipedia. Press releases are not reality.
Yes the M855A1 was developed and started operational testing in 2010. However, it wasn't available to anyone who wasn't forward deployed until...my memory says 2015. The M855 is still used on post because a) it's cheap, and ballistically similar to the M855A1 and b) the production lines at Lake City are still geared for them
The Marine corps didn't formally adopt the M855A1 until 2017/2018. Brass didn't like it because it broke the feed ramps on machine guns. There was a big procurement SNAFU about this.
I get that you're trying to be snide because you were so publicly wrong, but your tone here really just makes you sound like you're trying to sound smart about something you know nothing about. Something to consider. Frantic googling does not an expert make.
You're right about the copper core on the new model A1 - I thought it was steel entirely with thin jacket. I would argue that when, by weight, the majority of the bullet is steel, my original point still holds.
I worded my original assertion the way I did (lead replaced with copper) so that it would be true even if the majority of the bullet is steel.
>I get that you're trying to be snide because you were so publicly wrong, but your tone here really just makes you sound like you're trying to sound smart
Right back at you. I don't think I'm motivated by trying to sound smart, but rather by curiosity about the subject. Well, OK, half by wanting to sound smart (and win arguments) and half by curiosity.
In particular, I'm still curious about whether ammunition containing lead is still routinely used by the US military--if you still want to talk about it. I realize Wikipedia can be totally wrong. So far I haven't succeed in wringing information out of Google Search that would corroborate or support your assertion. When's the last time you (or someone you know to usually tell the truth) has observed M855 being used by the US military in significant quantities?
Answering without doxxing myself is harder than I thought. The last time I was on a US military range, which to be fair was right before the pandemic so things probably have changed - we drew green tip (M855) from the range master. My understanding was that a) the steel targets were getting beat up by A1 and there wasn't any money to replace them and b) we weren't a combat group so we didn't rate the good shit.
EDIT TO ADD:
I don't know if that qualifies as "quantities" and anecdotes are just that, but that's been my experience.
Thanks for taking the time to set me straight on that. I didn't realizes I was posting misinformation when I wrote, "the US Army has completely stopped using lead in bullets".
>The US army standard training round is the M193. It is a lead bullet jacketed with copper. Interestingly, it in many ways has better terminal performance than the M855 because this is the bullet the M16 and M4 rifles were designed around
As I understood the standard M4 with 1:7 barrel can't shoot M193 accurately
Lead is used everywhere. Not in paint anymore but you can buy lead weights at hardware stores. Don't grind it up and put it in your muni water supply, but it's a household substance that is harmful if ingested, like many others.
Both lead solder and lead-free solder are commonplace. Lead is standard in aerospace and military applications, while lead-free is standard in most products sold in the EU.
I mean, modulo edge cases, lead is a lot scarier than CO2; it's only because of the ridiculously obscene quantities of CO2 being produced that it's a more immanent threat. There's obviously not enough information yet to weigh the value/consequences of the amount of lead used here, but if your measure of whether something is a good idea for mitigating carbon emissions is just "it's not carbon emissions", you're going to find yourself kicking a can a bit down the road, or (much) worse.
Maybe they could pack it into epoxy encapsulated modules of standard size, so you could always reuse it in another motor or transformer or what have you, assuming you were willing to disassemble the scrapped gadget?
If you think carbon dioxide is scary, wait for your cup of Pepsi.
(Low toxicity of CO2 is actually one of the reasons it is not treated seriously enough).
Cobalt is way more toxic than lead and yet every consumer grade lithium ion battery contains it. The fact something is toxic is not that important. What is that we manage the end of life for the products it contains responsibly.
As for how to avoid lead poisoning, coat the lead with a thin layer of some substance, perhaps a plastic or rubber that doesn’t affect its magnetic capabilities.
Or perhaps they can galvanize it with safer metal, leaving a really small part exposed.
I think people are talking about RoHS rather than practical danger. Since RoHS is incredibly strict about quantities, e.g. if you can mechanically seperate a piece of the widget, that's what gets measured.
I believe MRIs use superconductivity, so I assume any application of superconductors that doesn't require heavy, large, energy-consuming cooling will benefit greatly.
Perhaps MRIs will become ubiquitous and cheap, something we all get every time we go to the doctor?
Superconduction also has some weird magnetic properties I believe, so there could be benefits regarding maglev transport.
And finally and most basically, the movement of electrical energy across potentially large distances with zero loss would be a great thing.
I have no real idea what I'm talking about but figure 1 has critical magnetic flux curve ranging up to 3000 Oe so... in MRI-speak maybe it tops out before 0.3T? IIRC permanent magnet MRI have already been built in the 0.3T range, but they're very heavy and outclassed by the higher-field scanners. Clinical MRI nowadays typically runs at 1.5-3T (with some clinical scanners at 5-7T).
Having said that there is a resurgence of interest in low-field MRI lately, primarily marketed for use in developing nations and for combination machines that integrate radiation therapy. From what I've heard from diagnostic radiologists, the low-field MRI scanners seem to be of limited diagnostic value on their own.
Anyway that's just my thought that the best/first applications here may not be about generating magnetic fields.
Superconductors are basically perfectly conductive wire. Wires that transfer 100% of power over arbitrary distances and that don't heat up. Obviously there are limits, you can't put arbitrary power over a hair thin filament but as long as you're under that limit you get perfect efficiency.
MRI machines can be made a lot simpler as you no longer need to use liquid nitrogen to cool the superconductors. MRI machines could end up being small and cheap.
Perfectly efficient electromagnets make a lot of problems in fusion reactors simpler, I'm not sure that room temperature superconductors make fusion reactors instantly viable but it's a big step and would reduce the energy requirements for a fusion bottle by a lot.
Basically anything involving electromagnets becomes a lot more efficient. Motors can be made smaller, generators can be made much more efficient for the weight, maglev trains can require very little power to hover. It has effects on almost every industrial process as it fundamentally changes the weight and energy efficiency of anything involving electromagnets.
One neat things would be surgical robots that can work as an MRI while also levitating a small blade in a 3D space. Challenging for sure but when you can replace complicated liquid-nitrogen cooled coils with an array of simple passive coils a lot of options open up.
Superconductors can also be used for power storage, and at room temperature that becomes a lot more viable.
Superconductors are a transferring energy technology, not a storing energy technology. Although they would likely augment the efficiency of storage technologies.
> What kind of energy density could we get using it for energy storage?
Actually, not a lot. The are some very compelling uses of them for storing energy, but they are much more relevant for distribution grid stability and control than for raw energy storage.
There are people here are pushing some really non-compelling use cases (like long distance power distribution), but there are plenty of transformative ones.
(But the thing is that this one on the paper is much less useful than it could be. There is still some work on understanding why and fixing it.)
A note about MRI machines: they use liquid helium, not liquid nitrogen. LN2 isn't cold enough. Being able to eliminate liquid helium would be huge, as helium is scarse and quite expensive. Its roughly 10x the cost of LN2 and only going to get more expensive.
Previous improvements in high-temperature superconductors already made it possible to build a MRI machine using LN2 instead of LHe. I think all existing operational units still use LHe, but using LN2 has been demonstrated in lab conditions, and the next generation of machines will almost certainly use it instead of helium.
It still might be worth cooling this with LN2, in many applications, assuming critical current and critical field scale up as temperature decreases as they do with other superconductors.
It takes a long time to validate new stuff for medical devices. Even if this discovery completely pans out, there will be two or three generations of MRI machines based on LN2-cooled superconductors.
They use both liquid helium and liquid nitrogen. The nitrogen is used to cool the helium. On MRI scanners that have come to market in the last few years, helium volume has been reduced at least 100x and is now only a few liters (i.e. previously >1000L and requiring frequent top off to <1L and requiring refill only after emergency/full power loss).
Don't forget about computer chips that do not emit heat. So much wasted power at the datacenter scale simply to keep things cool. At a personal computer level things get way more efficient, too, resulting in cheaper, smaller, quieter computing devices.
Superconductors change every assumption about how we harness electricity and magnetism. Beyond reducing the cost of electricity transmission, they enable all sorts of fascinating applications:
- They enable low cost, continuous, passively-stable magnetic levitation. Superconductors could replace ball bearings in many applications.
- They enable permanent magnets that are far stronger than any we make from conventional magnetic materials. For example, motors tend to run at high speed and low torque, so as to minimize heat generated from current in the copper windings. Superconducting direct-drive motors could allow for ultra-high-torque actuators without any need for gearing, and with minimal heat generation or losses. So superconducting electromagnets could replace everything from electric motors to hydraulic pistons to simple springs.
- Superconductors allow for very sensitive antennas and magnetic field sensors, allowing for near-field detection of very small signals (such as from neurons firing in the brain). There is a lot of impressive technology that only exists inside research labs where a generous supply of cryogenic liquids are always on hand. Those could make their way into mass-market products.
It probably wouldn't greatly affect the heat generation in a PC, unless the transistors could themselves be replaced with some superconducting alternative. Harnessing the efficiency from that would probably require that the computer be designed as a reversible computer. It would be its own research avenue.
Unfortunately, as soon as you actually use the result of the computation in any kind of practical manner as an output, you break reversibility, though you could make the heat production happen away from the computation.
I don't think you actually need reversibility if you don't discard the energy but return it to the power supply?
In other words, "reversibility", but you can actually pool the useless results together, you don't need to separate them later. Or so I read somewhere...
I might be wrong since I've studied this a long time ago, but from what I remember, in order to do that classically, you need to copy the output bits somewhere else before uncomputing your system and recovering the ancilia.
That's technically fine, as long as you have an infinite supply of stably initialized bits onto which to copy your result. Initializing those bits is going to be non-reversible in some way.
The idea of reversible computing is that if you only add heat in a few instructions, you can have a much more economical computer. And magnetronics is a good candidate for implementing this, so yeah, computers that use a lot less power are an application too.
I haven't seen any reversible low power superconducting gate that can credibly operate at a high temperature - not because of the superconductor itself, but because of thermal noise. Again, I haven't read through the literature in this field for a while (and it wasn't that extensive either), but from what I recall what you're proposing is roughly as difficult as making a gate for a quantum computer, and you have to keep your system way colder than your critical temperature from that due to thermal noise. If you have any links for high temperature physically reversible logic gates I'm all ears.
Computation inherently generates heat, but if you could make chips that release negligible amounts of heat, you would unlock the third dimension which would help with reducing signal length and enable computers to be significantly faster.
That this as a solution applicable to _personal_ computing is a bonus. The real benefit is in datacenters which could be made smaller, more efficient, and cheaper while simultaneously adding capacity.
Something that immediately comes to mind for me in Sweden, is that the country is fairly long in latitude, and most of our electricity production is from hydroelectric power in the northern half of the country, while most of the population is in the southern half of the country. Better energy transmission could help a lot.
Other commenters have science fiction dust in their eyes, and speak of room temp superconductors in general. But this particular discovery is a brittle crystalline structure that cannot be extruded into wires, and does not have the high current capacity required for power transmission or rail-guns.
It's an important, exciting step but it's very far from world-changing at this stage. Or if it is in a limited way. The first transistors were clunky affairs, of limited usefulness, world changing for ship-to-shore communication in the military. But then people discovered how to make them with deposition instead of factories, and they got smaller and faster, and they really did change the world. We're in the "clunky transistor" period.
Exactly. But that clunky transistor was in fact world-changing. It just took a while for the changes to take place but the stage was set when that first device showed that it could be done at all.
Oops, the first practical radios were powered by semiconductor rectifiers, not transistors. The Pickard silicon point detector circa 1906 was used in WWI (btw owning/making a radio was illegal during the war!)
I assume we could make CPUs stupid fast if we didn't have to worry about heat as much, though I'm not sure how much is lost to resistance vs operating transistors.
Basically really high density batteries that work efficiently forever, zero friction bearings via levitation, zero resistance long haul energy transport, and an MRI you can probably run on household current.
Plus maximally efficient (not perfect efficiency just the best we could theoretically practically get) energy storage, transport, generation, and conversion back to motion.
The graphs on page 3 are exactly what you would expect with a real superconductor. The current/voltage/temp relationship especially. In fact I don't see how you get graphs that look like that unless you either created a superconductor or are just blatantly making up the data. This could be enormous.
My first thought was “I really hope this is real and not someone having left the data collection software in simulation mode.” If this reproduces, it’s historic. If it doesn’t, it’s either cold fusion or faster-than-light neutrinos.
The Sagan standard is the adage that “extraordinary claims require extraordinary evidence” (a concept abbreviated as ECREE). But one can hope such evidence is forthcoming. And if it is, then short the oil majors.
Depending on the expense of making the new material, it may become actually feasible to build solar panels across Sahara and feed both Africa and Europe with the electricity generated, because transmission will become lossless and physically compact.
Maybe it could be a stabilizing factor, because the many interests involved would be mostly aligned. However unstable Middle East is, most of the time no oil well is on fire, or in a war zone.
It is not about the steady state being unstable on its own, it is about how easily it can be brought out of equilibrium with a very small force (of a hand full of people). An inherent flaw in the centralized nature of such a system
The other paper from them claims to have a video of room-temperature magnetic levitation with one of their samples, but I haven't been able to find the link.
Regular evidence will suffice. If people can make the material and levitate a small permanent magnet above the sample at room temperature, that will be sufficient.
That's a pretty high bar. Everyone has their own threshold of skepticism, but if NREL announced next week that they followed the recipe and it was superconducting at room temperature, I'd be willing to bet money on it being real.
I think that "reproduced at 100 labs" is near the level of reproduction at any university lab, maybe even as a part of students coursework. Which would actually be great, since we don't have trouble reproducing some other important electromagnetic and quantum phenomena, like light diffraction, at an ordinary university lab.
If you're not sure what a superconductor is, basically anything that conducts electricity has resistance in it.
That resistance turns the energy that is being transmitted through the conductor into heat, essentially wasting it for useful purposes unless you're running a hair dryer or oven.
For instance, one of the reasons why power plants have to be near the cities they serve, aside from practical logistics, is that if you send electricity over power lines, you lose some of that electricity to the resistant line drop, the voltage decreases over time, and ultimately you could lose all of your usable power to heat.
However, that changes when superconductors come into play. Many power plants already use them for short distances where the heat is high and the line drop is also high, but if you replaced every power line in America with superconducting lines a power plant in Florida could sell extra spare power to Alaska with no loss between the two plants. (This is in theory, it is still likely that there would be losses where the lines are split and connected, but that would still be far less than the greater than 100% voltage loss over 7,000 miles of traditional copper lines that you would expect.)
Room temperature superconductors would provide many benefits aside from power transmission as well. Electric vehicles would be more efficient with power coils made from them, allowing more of the electricity from the batteries to be turned directly into vehicle movement.
Cell phones would heat up less with superconducting wires, losing less of their battery power to heat and lasting longer.
Computers would run longer. CPUs would heat up less, requiring less cooling to operate at higher speeds and less power to run closer to the atomic limit of processing.
If it is proven that this works, then we may be very close to the system by which superconductivity works, and solving that may allow for hundreds or thousands of compounds exhibiting superconductivity to be made for myriad applications, allowing for us to live closer to the way we tend to while being a bit greener in the process.
The method to produce this material as described in the related paper [1] is fairly simple and could be done at home with a $200 home metal melting furnace from amazon and the precursors (which also seem to be fairly standard easy to obtain metals).
If this is real, I'd expect some smart people from hackaday / youtube to reproduce this within weeks if not days.
If this is real, it'll change society quickly and permanently for the better. There's obvious wins in energy transportation and even generation, but actually having a room temperature superconductor is likely to result in an explosion of engineering use cases. It will be like the discovery of lithium ion which slowly transformed the use of energy throughout society, but faster.
> could only cause problems solvable by more superconducting railguns
If the projectile is ferromagnetic, or potentially even just diamagnetic, a defense system involving shaped ultra-high intensity magnetic fields becomes conceivable.
Seriously, people should stop panicking about lead that much. You know there is this fairly common hobby people have, it's called casting bullets. With lead. I've done it, I know many people that do it regularly and they're all fine.
Furthermore, shooting ranges are full of lead in the ground. The laws around here(Poland) require a cleanup by specialised companies every few years and a concrete slab to separate the lead/soil mix from the groundwater near the targets, but still there are tons of the stuff just sitting there for years and no one gets hurt. Fun fact. These specialised cleanup companies don't cost anything for big ranges. They're either free, or they pay the shooting club that owns the range money, because the lead they recover is worth a lot.
I think it's more that a generation of people grew up with lead paint and that decreased the average IQ so much that you have people suggesting that lead smoke is harmless.
Since when lead emits smoke? You'd have to heat it beyond it's boiling point that is 1750C,while the typical lead casting is done at around 450C.even if you managed to vaporise minute amounts of lead it's going to condense and fall out long before it reaches "your neighbour's house".
I wonder, does everyone that scared of lead own smartphones? (with cadmium in their batteries). Cadmium is very toxic and it boils at under 800C so your average wood flame will vaporise it. But everyone talks about lead.
Why? IMO because lead used to be added to petrol/gas as an anti knock agent. So there was quite a bit of contamination present back in the day. This has been outlawed decades ago, but the collective memory remains.
Actually, firing ranges almost certainly are bad for your health and you should wear a particulate filter when going into one. https://ehjournal.biomedcentral.com/articles/10.1186/s12940-... for instance. I'd wager there is no small link between heavy firearm hobbyist and a proclivity for paranoia, conspiratorial thinking and other Q-Anon adjacent traits.
"No one gets hurt" - perhaps no one dies, but there are no safe levels of lead exposure.
I doubt this one chemistry will be all that useful on practice. But after people understand it, I expect them to recreate the effect with completely different components, not on just slightly different ones.
For years, and then after the explosion too. The last reactors were decommissioned around 2015 (it takes years, so the dates are bit washy).
Chernobyl wasn't the accident people seem to think. It wasn't inevitable, it was the result of numerous self-serving decisions exacerbated and even required in the very messed up Soviet system of management that enforced following the party instructions over all other possible complications.
Unfortunately they have a point, in that there is no ISO or DIN standard that covers a plant that has been rigged with explosives by invading barbarians.
The solution isn't to abandon nuclear power, but to make it very costly for aggressors to meddle with it. E.g., deploy UN forces to the plant at the first sign of trouble.
Given the materials and methods involved it really isn’t that dangerous. With basic precautions I’d say go for it, worst case is honestly just blowing a few hundred bucks. If this pans out, there will definitely be some do it yourself tutorials on YouTube in the coming weeks.
Is the superconductivity present in the powder? Or does it require vapor deposition?
If the latter, it implies a cloth versus fibre topology, which forces an interesting rethink of many paradigms forced by the ductility of our present conductors.
The companies that are licensing the tech. Unfortunately that'll be the big names so you're already pretty heavily priced out of a serious buy. There will be small startups around the world to working on smaller, less-sexy applications (medical implants come to mind since the power requirements for batteries would bottom out) that you very well could make a lot of money in, but there won't be an Edison here, the world is too diversified already and this is a new version of existing tech, not something new.
Who knows though, maybe we'll be able to finally launch ships into space without rockets?
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[ 2.6 ms ] story [ 576 ms ] threadIf a material with the properties described actually exists, this paper is exactly the kind of announcement and evidence we'd want for it.
I think I cross-pollinated this thread with another where someone was asking “if this is true why isn't it on the front pages”. The extraordinary evidence I'd want before it hits the front pages and TV talk shows is other scientific/engineering groups managing to reproduce the findings, or at least showing a significant improvement over previous discoveries (there could be a mistake that means the result isn't that big a thing while still leaving room for it to be a significant finding).
Yep. But that doesn't stop me being sceptical of such a jump in success (from tens of K below room to tens+ above at ambient pressure) which is where this sub-that started.
As already stated ("I think I cross-pollinated this thread with..." in the post you replied to) I confused things by mixing replies to different posts in the same place.
Also this is a preprint so clearly it's not vetted by others yet.
This is unusual, superconductivity is a low temperature phenomenon. Recently though, other researches have claimed room temperature superconductivity at high pressures, but low temperatures.
"You can't run across this bridge without falling? Here, I'll have an elephant bounce up and down on one end, that'll make it easier!"
But there will likely be very many bogus preprints for each true extraordinary finding.
Therefore most things showing up like this are untrue.
You'll never make all doubt go away on a new extraordinary discovery, mainly because most claims of an extraordinary discovery turn out to be mistakes (like the FTL neutrino thing a while ago that turned out to be a wiring fault that caused a minute timing error) or occasionally fabrications.
A quiet publication of “this is what we've found, this is what we think it means, please try reproduce or tell us what you think we've misinterpreted” is the way it should go. Unfortunately too subtle a release would be at risk of being ignored, and on the other side you get the mad public press and massive recriminations when it turns out a mistake was made and the finding is not reproducible (like the cold fusion thing I remember from the late 80s).
Color me skeptical, with a hint of optimism.
But there doesn't seem to be any indication in the link that this has been published in a peer reviewed journal, or received kinds of community peer review, either.
Actually the opposite is the strange. I would be skeptical of any group the report something in media before publishing the results in a journal (or arxiv like this case).
This is not to say anything about this particular paper. I still have to read it eventually.
Second, you're literally saying you expect to read important things on mainstream press instead of scientific journals.
Science is based on replicability, and you just don’t go straight to mass media before at least other groups have had a chance to replicate your findings. Definitely not when it’s something this big. Or if you do, your institution will likely be incredibly pissed. I’d say that the more careful they are, the more slowly and by the book they proceed with this, the more, not less, likely it is that this is a real deal.
Welcome to the information age my friend! Where you can know things before the gatekeepers do.
What I was trying to say was more along the lines of, if this is legit, I’m surprised we weren’t first hearing about it in the mainstream media after a leak.
I’m absolutely not in favor of any more Pons & Fleischmann moments.
i mean the search space is unfathomably large, so i suppose it’s possible that something like this exists, but the paper quality itself doesn’t.. spark joy? :)
i’ll maintain a healthy level of skepticism until some real materials scientists opine and/or someone else is able to reproduce.
This seems way too good to be true. But hope that it actuaoly is true.
but a room-temperature superconductor would certainly lower the operating costs of all of the prototype fusion reactors that currently exist.
I guess this will be replicated/not pretty soon then.
If they're processing in a vacuum to avoid N2 and/or O2 and/or H2O chemistry, then a dry inert gas might be useful.
Heating above 100°C to drive off H2O, followed by a purge with dry Ar might give the desired result without needing a vacuum system.
I wouldn't be at all surprised if even simpler methods are feasible.
For instance, there's a rapid synthesis method for YBCO that uses a small alumina boat, some glass wool, a residential 800w microwave oven, and slightly modified mixture of precursors to allow free oxygen to be liberated in the mixture during heating and trapped in the wool around the sample so you don't need to rig an oxygen concentrator up. IIRC it only takes about 15 minutes to prepare a sample.
This is extremely exciting! I've read hundreds of papers on superconductor manufacture and testing over the years and this has all the hallmarks of legitimacy, at least from my citizen-mad-scientist perspective.
You just need PbO, PbSO4, Cu, and P powders.
not that i think it matters that much. the paper doesn’t indicate that synthesis is a particularly sensitive step.
Its not hard to achieve at all. Electron beam welders at work have 10E-6/10E-7 in the E-gun chamber all day long held by a little turbo or diffusion pump. The chambers aren't made from anything exotic just stainless steel and/or aluminum with viton o-rings.
Its not hard to achieve at all. Electron beam welders at work have 1E-6/1E-7 in the E-gun chamber all day long held by a little turbo or diffusion pump. The chambers aren't made from anything exotic just stainless steel and/or aluminum with viton o-rings.
My little e-gun experiments are all done with a Alcatel Pascal 2008 and I can achieve ~3E-3 with just that pump. I'm building a bigger system with a VHS4 diffusion pump w/cold trap that should get me into -6 territory easily.
I figured out that by moving it faster than it can cut you can 'score' steel and if you use that creatively you can make fold-at-the-lines steel structures that you then weld up on the edges. You can make super complex stuff like that in no time at all and you usually don't need any jigs other than a few magnets to line things up prior to tack welding.
Would love 3rd party confirmation as well, of course.
Edit: Here's a video! https://www.youtube.com/watch?v=EtVjGWpbE7k
It's unlisted as well but published back in January of 2023. I wonder what they are going to think with the influx of views on it, (43 views as of this post)
Is it just me or is it odd not seeing the normal condensation of the surrounding air due to a chilled superconductor like you get with a YBCO.
Some superconductors get destroyed by humidity, so it may be difficult to ship them.
If nobody can reproduce them, then they can send samples or travel the word making samples on site, or receive researches to train them.
The good part of publishing the recipe, is that other people can make small variations. If this is true, there is just now a big race to get a higher record temperature.
Researchers come to a conclusion and make a paper, this is exactly how it is done.
Others can try to replicate their results, the paper is very explicit with what they've done.
However, the most likely thing is they made a mistake and the paper will be withdrawn.
But imagine if it’s true.
Ejecting the magnetic field (the Meissner effect) is a way better sign.
I find it very hard to believe that this could be true, but at least they're measuring the right things.
All judgement withheld until we get a few more labs chiming in with their results though.
I suppose that would be a useful material even if it couldn't be used for high current applications.
Hell of a way to end a paper.
https://arxiv.org/pdf/2307.12037.pdf
Bronze age
Iron age
LK-99 (®) age
Great for energy transmission (though you can't put too much current, superconductivity breaks down under strong fields).
Great for fast circuits, such as CPUs, that don't waste energy just transmitting data.
Great for storing energy (in principle) by just making a loop and let current flow indefinitely.
Related, great for building powerful magnets (that are just such a loop) without wasting too much energy. Applications: MRI machines (they already use superconductors but are bulky due to the need for cooling) and other powerful magnets: LHC/particle accelerators, Tokamaks/plasma control/fusion. But also improved motors and generators.
Nice for levitating stuff since they levitate above magnets "for free" (due to their interaction with electrical fields, they reject magnetic fields). Possible applications for maglev (trains, etc), magnetic bearings, etc.
And possibly a lot of new applications opened up if you remove the need for cooling (Faraday cages?).
Of course, it all depends on how much current and temperature it can handle. But if this is real, just having one material is game-changing, and it will surely be improved upon by looking for similar properties in other materials. This one contains lead, which is a non-starter for a lot of applications due to its toxicity.
Someone else wrote a few use-cases in that other comment: https://news.ycombinator.com/item?id=36866686
We've been using cadmium-based batteries for ages despite Cadmium being even more toxic than lead, and are still using lead batteries in ICE cars AFAIK. Lead toxicity isn't really a problem unless you burn it, deliver water through it or you put it on paint that end up in kids' mouth…
Lead batteries for cars are a bit special, as the whole supply chain goes both ways for recycling, while batteries are rather self-contained and not usually exposed to harsh environments.
Though I suspect you are right in the end, as it's a matter of judging the risk vs reward, I wouldn't be surprised if other materials with a similar structure end up performing similarly.
Pb is also quite hard to use in integrated circuits, as far as I know. I am no material scientist, but it could be due to its low melting point or tendency to contaminate other metals.
The definition of an insulator is a material that holds (up to some amount of) voltage without electrical currents appearing.
Your example needs two wires. And the wires themselves don't have any voltage. All of the voltage is between them, and is only there because they are insulated from each other.
You are conflating 'insulated' and 'insulator'.
This doesn't mean there is no resistance in the wires that move electricity to your house, because superconductors only work when cooled to unpractically low temperatures, meaning they can only be used for special things like the magnets in MRI machines and fusion reactors.
That is, until now. This paper reports on a material that remains a superconductor at 127C.
To put this in further context, RTP superconductors mean compact, low-power MRIs and a massive shrinking, simplification and superpowering of magnetic-confinement fusion and ion propulsion designs. It blows apart chip designers' thermal constraints and opens up entire classes of energy-storage chemistries.
If this is real, it will be the defining discovery of our lifetimes.
though worth remembering we still don't know how to stabilise plasma or sensibly generate electricity from it.
> It blows apart chip designers' thermal constraints
really? much of the heat in chips comes from the /connections/ between transistors etc?
Superconducting magnets become cheap and widely available which allows for maglev trains at massive scale. Costs for the LHC and similar experiments would drop dramatically. MRIs would only require air conditioning, if that; Modern cell phones are sufficient to compute tomography. Magnetic confinement fusion also becomes cheaper and easier. Electric cars could use superconducting motor magnets allowing for even greater power to weight ratios and efficiency.
Just a few things off the top of my non-mechanical-engineer head.
Undersea cables are a pie in the sky; current high-load cables in urban an industrial areas could be made much smaller, simpler, and lossless.
I wonder if transformers, currently huge and expensive, could be made better with this, too; at least the ohmic losses could be removed, and thus a lot of need for cooling, and the fire hazards.
https://en.wikipedia.org/wiki/Critical_field
Not really, when the sun is up over the Pacific ocean, there's not that much sun over land. Maybe a global grid happens anyway, but cabling losses aren't the only source of cost, so I'd put my money on more localized improvements.
Better interconnection between and within local grids (maybe a viable Tres Amigas interconnection, but even just better connections between sections of the major grids would help with grid management. Improvements in motors, MRIs, magnetic bearings, transformers, etc.
[edit: typo]
https://en.wikipedia.org/wiki/Superconducting_magnetic_energ...
I'm not an expert, and everything that follows comes from a quick reading of this Wikipedia article.
It seems like (counter-intuitively) refrigeration isn't a significant cost compared to all the other stuff that's necessary. So at first glance it seems like high-temperature superconductors might not make a big difference.
However, that Wikipedia article does say this:
> The critical temperature of a superconductor also has a strong correlation with the critical current. A substance with a high critical temperature will also have a high critical current. This higher critical current will raise the energy storage exponentially. This will massively increase the use of a SMES system.
Right now, superconducting energy storage has a lot of advantages, but it doesn't have very good energy density (by mass). Not even a tenth of what lithium-ion batteries have. I assume you couldn't power a car with it. But it has some compelling advantages in other areas. It has unlimited charge/discharge cycles. It has zero self-discharge. It has unlimited (in theory) power density, so you could charge or discharge it arbitrarily fast.
Depending on what the energy density ends up being, it might suddenly become way more useful. It would have to be a gigantic leap in energy density, though.
Also, not needing refrigeration could potentially open up smaller scale applications. Maybe you could have a residential superconductor storage system for your solar panels. (Although I don't know about its safety, so maybe not.)
All this assumes the cost to build it is reasonable compared to other alternatives, that the discovery is real, etc.
I would say that electronic computers would take take the first spot for me, but I don't deny that room-temperature superconductors would be pretty close to the top.
As a singular discovery goes, it’s hard to think of something that tops this. Of course, even if this is true, bringing it to market in a practical way will probably look a lot more like the invention of electronic computers.
In short, you are probably right, with the sibling commenting on (BJT) transistors.
So that wouldn't be in the last 100 years.
However unlike computers, if this idea works, it will get productized quickly.
We'd just make a global energy grid, and the sunny side powers the dark side.
https://news.ycombinator.com/item?id=36836722
Joking aside, besides power transmission, what other obvious things can this tech be used for?
https://news.ycombinator.com/item?id=36867709
Needless to say, this would be game-changing. But extraordinary claims require extraordinary evidence etc, let's be cautiously optimistic here.
Ideally, this could be useful for the hottest paths: clock tree, high-speed buses, as well as the power supplies.
There are a few hurdles though: high-speed voltage changes create changing currents, which creates variable magnetic fields, which IIRC may be a problem depending on the superconductor's characteristics. Processors also work at low voltages, which means that they need huge currents. Both magnetic fields and large current (as well as high temperatures) can break down superconductivity. So it's challenging, but probably doable.
There are also superconducting structures that could replace transistors, see applications of https://en.wikipedia.org/wiki/Josephson_effect
I don’t think you’re right, for the record.
OTOH, I am also not sure what we as a species can do in the next 5 years that actually will matter.
But yes, for serious uses, this will be a big deal if it works out and can be made into a flexible cable. And I’m sure people will work on a less-toxic version.
This would enable really long distance electrical transmission, which solves the whole intermittency issue with solar energy.
Superconductivity will for sure enable some innovations and could change how we are building power grids, but I don't see it changing the world to the same extent.
The hard problem solved by satellites is getting the satellite in orbit and getting it to stay there.
Humanity already could send radio waves across the planet. Emitter and receiver is not the hard problem.
A 1000-qubit QC can't break a RSA-2048 key, let alone a lot of other interesting tasks. Quantum computers aren't magical things that provide exponential speedups on absolutely everything; they can only provide exponential speedups on some algorithms, and those algorithms generally require linear numbers of qubits to the problem size, so 1000 qubits is greatly limiting to problem size.
Neither any classical computer can. We don't even have enough harddrive to store all quantum information in a 100 qubit QC, let alone 1000qubit. QC is limited to solve a subset of problems do not automatically equals to QC is useless comparing to classical ones. Also not able to invalidate the powerfulness of QC beyond 100 qubits.
Please note: this comment is an attempt at humor. Various people seem to have a difficult time discerning humor or sarcasm and choose to downvote. It is also possible (but unlikely) that I am not funny.
The PS was also very real as the grandparent gets buried under downvotes.
Still it'd be a prime new part of "living in the sci-fi future" for me.
https://www.nature.com/articles/d41586-023-02401-2
It's absolutely a possibility in the space of this situation. However, any judgement, positive or negative, should be withheld until other labs and people claim to reproduce or not.
The past century has had a lot going on.
[0] https://arxiv.org/abs/2307.12037
Fairly common, especially in life sciences, and I suspect chemistry and materials science.
Added in edit: This doesn’t make the result any more or less credible; for that, the true test is independent replication of both the synthesis as well as the experimental measurements. But the fact that the two authors published two papers with different groups is orthogonal to whether the result is real / an experimental error / fraud. I so hope its true - but..lets wait for replication and validation by other qualified experts :)
"The Additional experimental results and discussions on LK-99 will be published immediately in the next paper, including an interesting controllable levitation phenomenon and the coexistence of magnetism and superconductivity, theoretical calculation, etc."
Superconducting quantum computing: https://en.wikipedia.org/wiki/Superconducting_quantum_comput...
The most notable thing to me was that this was done in a thin film where structural defects are supposedly responsible for strain in the material which in turn enables the superconductivity. Probably because it is only a thin film, the material could only support about 250 mA at 25°C before losing superconductivity. So even if the paper is correct, it might turn out to be challenging to get to higher currents. Or maybe not and one could just roll up a wide thin film and have as much amps as one likes.
EDIT: I misread the thin film thing, they also produced a thin film but primarily they describe the material testes as follows without any dimensions I could immediatly spot.
After the reaction, a dark gray ingot was obtained reproducibly and then made into the shape of thin cuboids for electrical measurements [...]
And even at 250mA, there'd be tons of different usecases for a superconductor.
I have only met a few physicists who don't write papers in latex. They are all 65+ and generally work with younger scientists/grad students who prepare the paper in latex for final drafts and submissions.
No less than Donald Knuth in fact
This is already very tangential, but just for the benefit of anyone who may miss the humour and take the above comment seriously:
- re “couldn't afford professional typesetting”: Knuth was happy when Addison–Wesley approached him, specifically because he liked the high-quality typesetting of their books (like Thomas' Calculus) that he had used as a student. He was happy with the typesetting of the first editions of Vol 1 and 2, and only for the second edition, when the publishers moved from hot-metal typesetting to phototypesetting (that is, when the quality of the best achievable professional typesetting deteriorated), and he learned of the existence of digital typesetters, that he was motivated to come up with his own solution.
- re “couldn't be bothered to learn assembly language” — Knuth was approached by the publisher in the first place, because even as a student he had become a legendary compiler-writer (http://ed-thelen.org/comp-hist/B5000-AlgolRWaychoff.html#7) in multiple machine/assembly languages. In fact, the fictional “MIX” that he created was literally a “mix” of various then-existent machine languages (https://retrocomputing.stackexchange.com/questions/18117), some binary, some decimal (https://catonmat.net/donald-knuths-first-computer / https://ed-thelen.org/comp-hist/KnuthIBM650Appreciation.pdf), and MIX was introduced in the book with:
> There should be no hesitation about learning a new machine language; indeed, the author has found it not uncommon to be writing programs in a half dozen different machine languages during the same week! Everyone with more than a casual interest in computers will probably get to know several different machine languages…
Sometimes you have to collaborate outside of physics!
He did not know LaTeX. Most of his papers probably were in LaTeX, as his students knew it. But I remember multiple papers he "authored" in Word, because that's what the student preferred.
I was in a top 10 school (in physics and engineering), and I can assert that the fraction of physics faculty who did not know TeX/LaTeX was at least a quarter, and could be as high as 50%.
All the major physics journals would accept Word submissions.
It's not at all unusual.
Today, Word is much more capable as a scientist's tool.
I've done professional typesetting and cataloging with QuarkXPress and InDesign both and it was extremely fast, that's for professional high quality publishing. .doc and .md is fine for information first publishing.
Latex is not simple and is in my opinion just a big nerd snipe, its the intrusive thought of layout software, for humanities sake we'd be better off with simpler tools like markdown + math notation and if latex had been never invented.
Or would you rather have me google a GUI that lets me "quickly rename" and download a few programs that have this capability? Or do a few hundred files by hand?
Command line is... fine for doing this occasionally, but it's hardly "quick" or usable for this, I'm saying that as an advanced commandline user. You're just using the tool that you already have and know, and it happens to be the system shell. It doesn't have to be.
(another question is that classic file management at the scale where a sophisticated tool is needed is mostly automated nowadays, and yes there's scripting as well)
I would prefer not to have gatekeeping either way, both "It was written using Word, it must be fake" and "Latex should never have been invented."
There are big geek communities that lead newbies astray by recommending it, it's a nerd snipe that wastes a lot of brain cycles better used elsewhere. It's only little b bad, not big B bad.
I am saying it's a poor tool, a waste of time and an evolutionary dead end, people are allowed to fetishize poor tools, efficiency, simplicity and legibility are very poor in latex world with a high learning curve for a task that is at best tertiary to the task of doing real research, it's a tool that promotes rabbit trails, bike shedding and procrastination.
And the small amount of research that has looked into this has apparently born this out in at least some small degree. It's not a hot take if it's got backing.
To your main point, no, theoretical physics paper are almost all written in latex. I can't recall word-written theory paper. Experimental papers are sometimes word, but pretty rarely. You can try randomly sample papers from cond-mat arxiv to verify it.
[1] https://journals.plos.org/plosone/article?id=10.1371/journal...
A couple of posts about how poor that paper was:
• https://lemire.me/blog/2015/01/14/knauff-and-nejasmic-recomm...
• https://blog.cr.yp.to/20201206-msword.html
Update: "yes", from the paper: "The Josephson-like phenomenon for the under-damped junction of superconductor-normal metal-superconductor(21, 22) or Inter-grain coupled superconductors(23) and the thermoelectric effect(24-26) of the inter- or intra-grain network were also observed."
For what it's worth, superconductors have a shared budget[1] of (magnetic field, temperature, current). At 25°C, the material is near its critical temperature, so its current-carrying capacity is necessarily diminished. At a lower temperature, the film should be able to carry more current.
That said, 250mA is plenty of current if you're interested in making a superconducting CPU.
[1] http://hyperphysics.phy-astr.gsu.edu/hbase/Solids/scbc2.html
edit after reading the paper: they claim an extraordinarily high critical temperature of ~126°C. You can see the temperature dependence in Figure 1e; they're much further from the critical temperature than I expected, and at room temperature, a little cooling appears to go a long way. I'm eager to see an attempt to reproduce this result. That said, the material is essentially a 2d molecule -- we've been hyped on graphene for decades, and have yet to see it integrated into a scalable process.
What's more interesting is flexibility. Current ceramic liquid-nitrogen-cooled superconductors are not flexible at all; they are brittle. This can be fine for a transmission line, but makes things hard for various coils.
Ummm am I the only one who finds this line hilarious?
most humble hackernews commenter
There was previously research done investigating how changes in atomic structural alignment affect superconductivity (such as by cooling). I think researchers were trying to maintain the spacing that superconductors had while cool even when it was heated up. This sounds line with that other research, though I can't find the article again, please correct me if you find otherwise.
Still likely to be rather fragile and temperamental to work with ... but this seems like it's possibly legit.
https://news.ycombinator.com/item?id=36479776
They were thinking of stretching at a macro scale (like bending a bar of stuff), rather than essentially "stretching" at the chemical scale which is what I understand they did here. Super cool!
> I think the “tension axis” is more likely to be fruitful in a different way, where we find some structure e.g. a crystalline formation that happens to hold atoms apart with just the right amount of tension. But this is all very speculative - the “tension axis” is just a random thought I had while reading the article!
They hit the nail on the head pretty well, I’d say!
[1]: https://news.ycombinator.com/item?id=36487946
But as a newly self-proclaimed expert on superconductors as well, yeah this would probably help MRIs. My understanding is that the reason for superconductors in MRIs is so that the wires doing the electricity stuff don't interfere with the small electrical responses from the tissue it's measuring. Without resistance, you don't get magnetic fields around the wires or something.
I can't tell if there is a catch anywhere, this seems pretty legitimate. Also, unlike some previous claims that required sophisticated setup to reproduce, this seems dead simple. I think we will hear from other researchers very soon.
1. Superconductor Pb10-xCux(PO4)6O showing levitation at room temperature and atmospheric pressure and mechanism: https://arxiv.org/pdf/2307.12037.pdf
2. Google Scholar: https://scholar.google.com/citations?user=_P8mux4AAAAJ&hl=en
3. Mott transition in VO2 revealed by infrared spectroscopy and nano-imaging: https://scholar.google.com/citations?view_op=view_citation&h...
As far as I know, that’s possible with permanent magnets (and it would be weird, but not impossible, if the group instead synthesized a novel ferromagnet and didn’t notice), electrets (seems pretty unlikely here), very extreme amounts of static charge (again, seems unlikely), and actual superconductivity (would be awesome).
Random bits of cooked oxides, ceramics, and such don’t float on a magnet.
ETA: the video referenced is apparently available at https://www.youtube.com/watch?v=EtVjGWpbE7k . Interestingly, posted on Feb 26, 2023.
I've linked to a relevant example in a Veritasium video here: https://youtu.be/g0amdIcZt5I?t=543
But in this sample video, the standoff distance doesn't appear to be slowly dropping at all, which would rule out eddy currents as a source of the behavior. If you continue watching the linked video to 13:27, he talks about how and why superconductors levitate.
Copper and a magnet can certainly interact. Drop a magnet through a copper pipe and the eddy currents will induce a field that's opposed to the magnet causing a damping effect. Maybe something like this is going on where movement of the magnetic field is inducing an opposed magnetic field in the copper, and thus interacting.
Anyhow it will be interesting. if It can generate a field of 1.5-2 Tesla you could have more efficient solenoids and probably motors.
As far as I know a stable arrangement of permanent magnets levitating is impossible without a baring surface to keep them aligned. (i.e. free floating levitation is not possible without active control)
https://en.wikipedia.org/wiki/Diamagnetism
https://www.kjmagnetics.com/blog.asp?p=diamagnetic-levitatio...
...and superconductors are usually perfectly diamagnetic.
* ferromagnetic - attracted to one pole of a magnet but not the other (in a given orientation), this is what everybody thinks of when they think of "magnets"
* paramagnetic - attracted to both poles, i.e. stuff that sticks to magnets
* diamagnetic - repelled by both poles, except in superconductors, this effect is very weak compared to the forces experienced involving ferro-ferro or fero-paramagnetic materials.
There isn't another category, everything fits in to one of those buckets.
Saying
>Just so everyone is on the same page, static passive diamagnetic levitation is possible with materials like pyrolytic graphite.
is a bit deceptive, as what people know as "magnetic" materials are ferromagnetic.
https://www.sciencedirect.com/science/article/abs/pii/S03048...
And many others besides. Halbach arrays are fascinating.
https://en.wikipedia.org/wiki/Levitron
Halbach arrays with compensating coils have been proposed for some interesting applications, such as low loss flywheels for electrical storage. I don't know if that ever got commercialized but I do recall that some prototypes were made by a US company. I can't find a reference to it though.
Not too much longer apparently...
https://www.youtube.com/watch?v=mn7IedCgva0
https://en.wikipedia.org/wiki/Pyrolytic_carbon
Is it late April Fools joke?
It can’t be true.
Edit: I am not surprised it levitates. I am astonished by how much it will reshape our world if it is real room-temp and ambient-pressure superconductor. Also is easy to produce. Just too good to be true.
You could almost make this stuff in a pizza oven.
Edit: Judging by Fig 4, which has a large object conspicuously labeled "magnet", that's probably what they're referring to.
This group used somewhat nastier powders, they had to cook parts of it in a vacuum, and they floated the result on a magnet instead of vice versa. And it only floated a bit. But they did it without any cooling!
So, yeah: big if true.
> Detritus blinked. There was a tinkle of falling ice. Odd things were happening in his skull. Thoughts that normally ambulated sluggishly around his brain were suddenly springing into vibrant, coruscating life. And there seemed to be more and more of them.
> 'My goodness,' he said, to no-one in particular.
> This was a sufficiently un-troll-like comment that even Cuddy, whose extremities were already going numb, stared at him.
> 'I do believe,' said Detritus, 'that I am genuinely cogitating. How very interesting!'
> 'What do you mean?'
> More ice cascaded off Detritus as he rubbed his head.
> 'Of course!' he said, holding up a giant finger. 'Superconductivity!'
> 'Wha'?'
> 'You see? Brain of impure silicon. Problem of heat dissipation. Daytime temperature too hot, processing speed slows down, weather gets hotter, brain stops completely, trolls turn to stone until nightfall, ie, colder-temperature,however,lowertemperatureenough,brain operatesfasterand—'
> [...] Detritus sat down again. Life was so simple, when you really thought about it. And he was really thinking. He was seventy-six per cent sure he was going to get at least seven degrees colder.
-- Men At Arms by Terry Pratchett
[0]https://www.greenoptimistic.com/make-superconductor-home/
https://www.youtube.com/watch?v=7KtzyZKSuls
The failure modes would mostly be the same as for the big ones: sucking in metal chairs if you're not careful.
If this proves true I'd see their use more in electronic circuits. Novel sensors etc rather than classic high power high field uses people dream about when the words "room temperature superconductivity" gets thrown about.
Most people aren't licking the insides of their computer processors, fusion reactors, radio telescopes and MRIs.
For instance in EU, https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A...
Canada, https://www.canada.ca/en/health-canada/services/environmenta...
USA, https://www.epa.gov/lead/learn-about-lead
Compared to refining traditional conductors and recycling/disposing of used electronics?
> you still have to use lead-free solder
One, fumes. Two, people touch their solder and then grab a cookie.
We're premature. The results need to be proven. But the benefits of RTP superconductors is mindblowingly high enough that risks from lead contamination (far from a novel problem, I might add) can be safely ignored.
You might want to read more in the links I shared about the harmful effects of lead before "whatabouting" to other problems of electronics recycling/waste.
and yes, it's entirely possible this application would get an exemption from usual restrictions on lead. For example in the EU directive, one of the exemptions is:
> Lead in solders for servers, storage and storage array systems, network infrastructure equipment for switching, signalling, transmission, and network management for telecommunications
But people don't, particularly students, and sometimes they also let their irons run too hot at which point fumes become an issue. Also, there is an easy alternative, so why not.
If the choice is lead superconductor or not, nobody is going to pause on a use case because there is lead. If they do, and if this is real, please let me know--I'd love to have them as competition.
> might want to read more in the links I shared about the harmful effects of lead before "whatabouting" to other problems of electronics recycling/waste
The point is, whether a RTP superconductor does or doesn't contain lead is irrelevant to its adoption. The advantages are too large. What current directives say are, similarly, irrelevant.
IMO, the most dangerous thing about lead solder is cleaning the iron. Both the common methods (damp sponge and brass wool) create many tiny little balls of solder that are hard to see and bounce about all over the place. Because of the high density of lead they're less affected by air resistance than you might expect, and they roll easily, so they can move surprising distances. They can easily end up caught in clothing, and from there fall into food. This will result in much higher lead ingestion than just touching solder then touching food.
I personally always use lead-free solder. If you have a good temperature controlled soldering iron it's nearly as easy to use as leaded solder.
The last time I checked, low-temperature bismuth-tin alloy is only available as solder paste, unfortunately not available as flux-core solder wires (they're not really a good choice for connectors to begin with as the alloy is brittle, but I only need it to survive before the next prototype...)
It's trivial to experimentally demonstrate that solder fume contains almost no lead, the quantity is negligible. Claiming the contrary is the electronics equivalent of saying HTML is a programming language. Please don't do that again. The fume is indeed toxic, but it's due to the VOCs from the flux core, not the lead in the alloy.
A more solid (no pun intended) argument can be the hazards of debris. Furthermore, in my opinion, a newer and more serious problem of leaded solder today, in a workshop setting, is its use in solder paste. Solder paste and a reflow oven are required for prototyping any circuit boards with surface-mount components (SMT) - basically any modern circuit board today. Solder paste is a tube of toothpaste-like chemical mixture that contains tiny, micrometer-sized metal particles, mixed with sticky flux. If they're used without care, a solder paste spill is a sure way to contaminate the floor or work surface of your workspace. The sticky paste is also hard to wash away from skin.
Unfortunately, reflow soldering of surface-mount components can be really challenging, even more so when doing it by hand. Thus, classic lead-tin alloy is often used to reduce difficulties of assembly during workshop prototyping due to its technically superior properties. Switching to lead-free is only possible when you have a tightly-controlled and consistent work flow.
If you want lead-free, for small-scale prototyping and rework, a non-toxic bismuth-tin alloy is sometimes a good alternative to standard SAC305 lead-free solder thanks to its low melting temperature, which is one main reason that makes most lead-free alloys difficult to use (it even has considerable popularity in mass production of LED devices, as they are heat-sensitive). But its surface tension is slightly different, weakening the self-alignment effect of components during reflow soldering, increasing the chance of defective joints - a concern in prototyping. Its brittle nature also increases failure rates in the field, among other caveats.
Lead is really a gift from the devil.
This is incorrect. You can easily do small scale work with almost all SMT components without solder paste. Solder paste is required for automated assembly processes. But almost anything done by hand can also be done with conventional solder.
Source: I worked as an electronics designer for a few years, and assembled prototypes and small production batches by hand with SMT parts (0603's, TTSOPS, etc) every day.
The one exception is BGA devices, because the solder pads are underneath the device. But doing those by hand requires precise alignment that is difficult enough that few people do it. Also, for smaller BGA devices with fewer pins, skilled operators can still solder them in place with a heat gun by covering the pads with solder and flux and just melting them into place.
I disagree. I don't consider 0603 passives and TSSOP packages "modern" anymore. Of course these components can be hand soldered with ease (possibly at top quality with the aid of a microscope). Unfortunately, the industry is gradually abandoning TSSOP and QFP in favor of DFN, QFN, and LFCSP in recent years. For anything that does high-speed signaling or multiplexing above 1 Gbps (which is old by computer's standard) like USB 3.0, PCIe 1/2, QFN goes without the need for a mention (short of using BGA). But the thing is, even in simpler ICs like DC-DC controllers, you can see the same trend. Simple RFICs are another source of heavy users of these packages, reduced circuit parasitics is certainly a factor.
These packages are all leadless, and frequently with thermal pads at the bottom. An older term for leadless packages is BTC - Bottom Termination Components. [1] After a few successive and multiple failed QFN soldering attempts, I switched to ordering stencil, solder paste, and a hot plate. It worked perfectly on my first attempt, so I never looked back.
Unless you have top 10% soldering skills, which I don't (experienced smartphone repair technicians seems to have mastered the art of QFN), I found solder paste is required for maintaining your sanity with leadless packages. Furthermore, without reflow soldering, prototype assembly can be very time-consuming and takes hours, especially when you need 3 or more prototypes.
Occasionally, leadless packages also have optional difficulties turned on, completely eliminating the possibility of hand soldering, such as multiple bottom pads for different nets (to minimize parasitic inductance), or having two layers of contacts, one row on the exterior and on row on the interior.
> You can easily do small scale work with almost all SMT components without solder paste. [...] The one exception is BGA devices
And DFN, and QFN, and LFCSP, and...
Thanks to industrial and automotive users, some ICs still have QFP versions for these markets (due to their vibration resistance) that are friendly for hand operation, but you have to pay a premium.
Finally, even plain-old QFP chips have bottom thermal pad these days (in that case, you can manually apply a blob of solder on the PCB and reflow again with a hot air gun, but manually apply a drop of paste is easier to work with).
---
[1] But these days it would make people think it's some kind of a Bitcoin mining ASIC. BTW, the last time I've checked, these ASICs are indeed QFN, so one can say they're BTC BTC chips...
Not being in sciences I can’t tell if this sentence is legit or you just got a good joke in there
"Lead in solders for servers, storage and storage array systems, network infrastructure equipment for switching, signalling, transmission, and network management for telecommunications"
( https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A... )
The bar is even lower than that. For example, bullets are still made of lead, not because it's necessary, but because it's cheap, and despite the fact that it contaminates the meat of the hunted animal with lead.
The consumer market still uses it, which is probably a tiny fraction of what the military uses in training.
First, terms - brass is not used to "jacket" a bullet. Brass is used as the case material for the cartridge. Steel, and nickel plated steel are some times also used here. "Jacketing" (as in, Full Metal Jacket) refers to the material that wraps around the exterior of the projectile. As far as I'm aware, the material used here is almost always copper, or a copper alloy (cupronickel).
The US standard bullet is the M855. It's a lead core with a soft soft steel penetrator at the tip, that's jacketed with copper.
There's an advanced version of the M855, the M855A1, which is an entirely steel slug, jacketed with copper. This bullet has better terminal performance at longer ranges, and slightly better armour piercing capabilities.
The US army standard training round is the M193. It is a lead bullet jacketed with copper. Interestingly, it in many ways has better terminal performance than the M855 because this is the bullet the M16 and M4 rifles were designed around, and the M855 only exists because of NATO politics.
There are no bullets in the US inventory, to my knowledge, that use a copper core. Copper is simply far too expensive to be used at that scale, and, as you pointed out, reduces the weight of the projectile which has negative effects on terminal performance.
"Why are bullets jacketed in copper" you might be wondering here - when rifle cartridges were invented, they still used black powder, and all bullets were lead. When smokeless powder was invented, it became possible to have more explosive power per unit of volume. However, this had two negative effects - one, the lead projectile would either disintegrate, or became entirely inaccurate, at the speeds it was accelerated to. Second, the force of the bullet against the rifling of the barrel was rubbing away metal from the bullet, leaving lead deposits which fouled the gun and made it inaccurate. All steel bullets solved this problem, but increase the wear on the barrel. The solution was to coat (jacket) each bullet in a thin layer of copper, which was stiff enough to withstand the force of friction in air, while also softer than the steel barrel and reduced wear and tear on the rifles
>There are no bullets in the US inventory, to my knowledge, that use a copper core. Copper is simply far too expensive to be used at that scale . . .
Photos of cross sections of the M855 and M855A1:
https://twitter.com/izlomdefense/status/1202516482082639872/...
M855 has a lead plug behind a steel penetrator. M855A1 has a copper plug behind a steel penetrator. So, I stand by my "copper where the lead used to be". I never said there wasn't a steel penetrator.
From https://en.wikipedia.org/wiki/5.56%C3%9745mm_NATO:
>For general issue, the U.S. Army adopted the M855A1 round in 2010 to replace the M855. The primary reason was pressure to use non-lead bullets. The lead slug is replaced by a copper alloy slug . . . The U.S. Marines adopted the Mk318 in early 2010 due to delays with the M855A1. This was a temporary measure until the M855A1 was available for them, which occurred in mid-2010"
As you probably know, most combat soldiers in the US Army and Marines carry a rifle (usually an M4 these days IIUC) that fires 5.56×45mm NATO, so it is probably the ammo type that the US military uses the most of.
Yes the M855A1 was developed and started operational testing in 2010. However, it wasn't available to anyone who wasn't forward deployed until...my memory says 2015. The M855 is still used on post because a) it's cheap, and ballistically similar to the M855A1 and b) the production lines at Lake City are still geared for them
The Marine corps didn't formally adopt the M855A1 until 2017/2018. Brass didn't like it because it broke the feed ramps on machine guns. There was a big procurement SNAFU about this.
Marine corps times article on the matter:
https://www.marinecorpstimes.com/news/your-marine-corps/2017...
I get that you're trying to be snide because you were so publicly wrong, but your tone here really just makes you sound like you're trying to sound smart about something you know nothing about. Something to consider. Frantic googling does not an expert make.
You're right about the copper core on the new model A1 - I thought it was steel entirely with thin jacket. I would argue that when, by weight, the majority of the bullet is steel, my original point still holds.
>I get that you're trying to be snide because you were so publicly wrong, but your tone here really just makes you sound like you're trying to sound smart
Right back at you. I don't think I'm motivated by trying to sound smart, but rather by curiosity about the subject. Well, OK, half by wanting to sound smart (and win arguments) and half by curiosity.
In particular, I'm still curious about whether ammunition containing lead is still routinely used by the US military--if you still want to talk about it. I realize Wikipedia can be totally wrong. So far I haven't succeed in wringing information out of Google Search that would corroborate or support your assertion. When's the last time you (or someone you know to usually tell the truth) has observed M855 being used by the US military in significant quantities?
EDIT TO ADD: I don't know if that qualifies as "quantities" and anecdotes are just that, but that's been my experience.
As I understood the standard M4 with 1:7 barrel can't shoot M193 accurately
Those are often bismuth weights.
As for how to avoid lead poisoning, coat the lead with a thin layer of some substance, perhaps a plastic or rubber that doesn’t affect its magnetic capabilities.
Or perhaps they can galvanize it with safer metal, leaving a really small part exposed.
It'd likely be exempt though.
Perhaps MRIs will become ubiquitous and cheap, something we all get every time we go to the doctor?
Superconduction also has some weird magnetic properties I believe, so there could be benefits regarding maglev transport.
And finally and most basically, the movement of electrical energy across potentially large distances with zero loss would be a great thing.
Having said that there is a resurgence of interest in low-field MRI lately, primarily marketed for use in developing nations and for combination machines that integrate radiation therapy. From what I've heard from diagnostic radiologists, the low-field MRI scanners seem to be of limited diagnostic value on their own.
Anyway that's just my thought that the best/first applications here may not be about generating magnetic fields.
MRI machines can be made a lot simpler as you no longer need to use liquid nitrogen to cool the superconductors. MRI machines could end up being small and cheap.
Perfectly efficient electromagnets make a lot of problems in fusion reactors simpler, I'm not sure that room temperature superconductors make fusion reactors instantly viable but it's a big step and would reduce the energy requirements for a fusion bottle by a lot.
Basically anything involving electromagnets becomes a lot more efficient. Motors can be made smaller, generators can be made much more efficient for the weight, maglev trains can require very little power to hover. It has effects on almost every industrial process as it fundamentally changes the weight and energy efficiency of anything involving electromagnets.
One neat things would be surgical robots that can work as an MRI while also levitating a small blade in a 3D space. Challenging for sure but when you can replace complicated liquid-nitrogen cooled coils with an array of simple passive coils a lot of options open up.
Superconductors can also be used for power storage, and at room temperature that becomes a lot more viable.
Here's this big wikipedia page on applications of superconductivity: https://en.wikipedia.org/wiki/Technological_applications_of_...
Also on the less useful side, rail guns.
Maybe it’s competitive with batteries if you don’t need any cooling?
But even if not it could be great for a capacitor alternative or stationary storage.
Actually, not a lot. The are some very compelling uses of them for storing energy, but they are much more relevant for distribution grid stability and control than for raw energy storage.
There are people here are pushing some really non-compelling use cases (like long distance power distribution), but there are plenty of transformative ones.
(But the thing is that this one on the paper is much less useful than it could be. There is still some work on understanding why and fixing it.)
- They enable low cost, continuous, passively-stable magnetic levitation. Superconductors could replace ball bearings in many applications.
- They enable permanent magnets that are far stronger than any we make from conventional magnetic materials. For example, motors tend to run at high speed and low torque, so as to minimize heat generated from current in the copper windings. Superconducting direct-drive motors could allow for ultra-high-torque actuators without any need for gearing, and with minimal heat generation or losses. So superconducting electromagnets could replace everything from electric motors to hydraulic pistons to simple springs.
- Superconductors allow for very sensitive antennas and magnetic field sensors, allowing for near-field detection of very small signals (such as from neurons firing in the brain). There is a lot of impressive technology that only exists inside research labs where a generous supply of cryogenic liquids are always on hand. Those could make their way into mass-market products.
That's just a very short list.
In other words, "reversibility", but you can actually pool the useless results together, you don't need to separate them later. Or so I read somewhere...
That's technically fine, as long as you have an infinite supply of stably initialized bits onto which to copy your result. Initializing those bits is going to be non-reversible in some way.
It's an important, exciting step but it's very far from world-changing at this stage. Or if it is in a limited way. The first transistors were clunky affairs, of limited usefulness, world changing for ship-to-shore communication in the military. But then people discovered how to make them with deposition instead of factories, and they got smaller and faster, and they really did change the world. We're in the "clunky transistor" period.
Exactly. But that clunky transistor was in fact world-changing. It just took a while for the changes to take place but the stage was set when that first device showed that it could be done at all.
Basically really high density batteries that work efficiently forever, zero friction bearings via levitation, zero resistance long haul energy transport, and an MRI you can probably run on household current.
Plus maximally efficient (not perfect efficiency just the best we could theoretically practically get) energy storage, transport, generation, and conversion back to motion.
Verification can be very easy for this particular phenomenon.
How easy was it to do that for Kuwaiti oil industry, and how long did it last?
When enough interests are aligned, equilibria stay pretty steady, exactly because there are several powerful interests.
That's a pretty high bar. Everyone has their own threshold of skepticism, but if NREL announced next week that they followed the recipe and it was superconducting at room temperature, I'd be willing to bet money on it being real.
I think that "reproduced at 100 labs" is near the level of reproduction at any university lab, maybe even as a part of students coursework. Which would actually be great, since we don't have trouble reproducing some other important electromagnetic and quantum phenomena, like light diffraction, at an ordinary university lab.
Realistically, once you get a handful of independent reproductions, the odds that something is an error or a fraud drop to basically nil.
That resistance turns the energy that is being transmitted through the conductor into heat, essentially wasting it for useful purposes unless you're running a hair dryer or oven.
For instance, one of the reasons why power plants have to be near the cities they serve, aside from practical logistics, is that if you send electricity over power lines, you lose some of that electricity to the resistant line drop, the voltage decreases over time, and ultimately you could lose all of your usable power to heat.
However, that changes when superconductors come into play. Many power plants already use them for short distances where the heat is high and the line drop is also high, but if you replaced every power line in America with superconducting lines a power plant in Florida could sell extra spare power to Alaska with no loss between the two plants. (This is in theory, it is still likely that there would be losses where the lines are split and connected, but that would still be far less than the greater than 100% voltage loss over 7,000 miles of traditional copper lines that you would expect.)
Room temperature superconductors would provide many benefits aside from power transmission as well. Electric vehicles would be more efficient with power coils made from them, allowing more of the electricity from the batteries to be turned directly into vehicle movement.
Cell phones would heat up less with superconducting wires, losing less of their battery power to heat and lasting longer.
Computers would run longer. CPUs would heat up less, requiring less cooling to operate at higher speeds and less power to run closer to the atomic limit of processing.
If it is proven that this works, then we may be very close to the system by which superconductivity works, and solving that may allow for hundreds or thousands of compounds exhibiting superconductivity to be made for myriad applications, allowing for us to live closer to the way we tend to while being a bit greener in the process.
My second thought, how does it respond to magnetic fields?
If this is real, I'd expect some smart people from hackaday / youtube to reproduce this within weeks if not days.
If this is real, it'll change society quickly and permanently for the better. There's obvious wins in energy transportation and even generation, but actually having a room temperature superconductor is likely to result in an explosion of engineering use cases. It will be like the discovery of lithium ion which slowly transformed the use of energy throughout society, but faster.
Hopefully it repros.
[1] https://arxiv.org/pdf/2307.12037.pdf page 3
Here you go: https://www.youtube.com/watch?v=icniCydn_kE
I wouldn't call it an easy process, but it's achievable without highly specialized equipment. Just a torch and a vacuum pump.
True.
> and permanently for the better.
You can't know that.
If the projectile is ferromagnetic, or potentially even just diamagnetic, a defense system involving shaped ultra-high intensity magnetic fields becomes conceivable.
Furthermore, shooting ranges are full of lead in the ground. The laws around here(Poland) require a cleanup by specialised companies every few years and a concrete slab to separate the lead/soil mix from the groundwater near the targets, but still there are tons of the stuff just sitting there for years and no one gets hurt. Fun fact. These specialised cleanup companies don't cost anything for big ranges. They're either free, or they pay the shooting club that owns the range money, because the lead they recover is worth a lot.
So don't blow lead smoke over your neighbors house.
I wonder, does everyone that scared of lead own smartphones? (with cadmium in their batteries). Cadmium is very toxic and it boils at under 800C so your average wood flame will vaporise it. But everyone talks about lead.
Why? IMO because lead used to be added to petrol/gas as an anti knock agent. So there was quite a bit of contamination present back in the day. This has been outlawed decades ago, but the collective memory remains.
"No one gets hurt" - perhaps no one dies, but there are no safe levels of lead exposure.
Really.
It's more likely that you will contaminate your land, and possibly your neighbors land too than that you will manage to replicate it.
(Which would effectively make a bizarre form of brass a superconductor)
Brass is copper and zink.
Chernobyl wasn't the accident people seem to think. It wasn't inevitable, it was the result of numerous self-serving decisions exacerbated and even required in the very messed up Soviet system of management that enforced following the party instructions over all other possible complications.
And much of the cost of nuclear is hedging against these decisions, whether by profit-seeking or the tyranny of a totalitarian state
The solution isn't to abandon nuclear power, but to make it very costly for aggressors to meddle with it. E.g., deploy UN forces to the plant at the first sign of trouble.
If the latter, it implies a cloth versus fibre topology, which forces an interesting rethink of many paradigms forced by the ductility of our present conductors.
Who knows though, maybe we'll be able to finally launch ships into space without rockets?