Which website do you mean? There is no video on that Ars Technica article and the original article just has a standard YouTube video player with no autoplay.
I believe the rule is not to play until clicked, for videos with sound. However, for videos that don't have sound, they are allowed to play at page-load. Also, due to this functionality, sites now have a sound-less video first play and then switch to a version with sound (faking "un-muting") when clicked. This does have the nice side-effect of eliminating those really annoying ads that used to play at full blast whenever I forgot to mute my laptop's sound. (Nonetheless, I still reflexively turn my laptop's speakers down to 5% when I am not using them after getting burned so many times in public.)
Let's say there was a superconducting material that operated at atmospheric pressure and 25C. While waving the magic wand, let us also pretend it costs $1000/kg.
What are the immediate applications for such a thing? I can trivially imagine long distance electrical cables, but HVDC is already pretty efficient. Would maglev applications suddenly become more widespread? Anything involving magnets (MRI, NMR) could maybe gain resolution? Are there revolutionary applications just waiting for this material?
Not at all to be dismissive, but I am genuinely curious what opportunities this could create.
The first and easiest application would be "high Q" radio-frequency components such as antennas. I asked a similar question a few years ago a bunch of electrical engineers were basically salivating at the possibility.
The next one would be as thin films to replace copper or aluminium power delivery wires in silicon chips. This would make them run significantly cooler. While copper is a good conductor, very thin copper wires transferring multiple amps(!) is a recipe for a space heater. Even a superconductor that cost $1K per gram would be worthwhile in this application, let alone $1K per kilogram!
Next up would likely be electrical motors. Higher magnetic field strengths and lower heating losses would allow some really tiny but crazy powerful motors.
A lot would depend on the critical current and critical field that such hypothetical superconductor could have. If it's too low, its usage where large currents are needed, like motors or chips will be small.
As example, look into the generation of high magnetic field. In a typical physics lab or MRI machine, the current state of the art is by superconducting coils, but for very large magnetic fields (several tens of teslas) you need to fallback on copper, since there are not known practical superconductor able to sustain such fields without losing their superconductivity
>there are not known practical superconductor able to sustain such fields without losing their superconductivity
I don't think this is still correct. Mass production of REBCO has ramped up in the past few years which is capable of 250 T internal fields and is being sold on tapes with 100,000+ A/cm^2. We're currently at the "hundreds of miles of tape per year" stage.
I think we have to be approaching the "thousands of miles per year" stage. The TF magnet demoed at CFS/MIT had 166 miles of tape and "contained close to 10% of the world’s supply of commercially available HTS" at the time. SPARC will have 18 of those magnets.
While HTS magnets may be "state of the art" they are still substantially more expensive than LTS magnets and it will be a few years before they start showing up in MRI machines.
> Let's say there was a superconducting material that operated at atmospheric pressure and 25C. While waving the magic wand, let us also pretend it costs $1000/kg.
That depends, because you've under-specified it. Critical magnetic field and critical current density at the very least, probably also fragility on more than one axis.
Let's say it's got "enough" strength and critical magnetic field, and a density of 5 so that's $5000/litre. At a critical current of 1A/cm^2, fairly useless. At 10,000A/cm^2 that can make some neat medical equipment that no longer needs coolant that condenses the oxygen out of the air if it leaks.
It's been a while since I read about the idea — and this might have been an amateur blog rather than a serious claim — but I think 100,000A/cm^2 for reasonable density is enough to fly by pushing against earth's magnetic field?
Magnetic field of earth is ~50µT, a superconducting loop with diameter 1m (circumference ~3,14m) with 100kA will feel a force of ~15N, with 1cm² it has a volume of 0,314 liters, in aluminium thats about 0,85kg or 8,5N, in copper thats about 3kg or 30N. So with a material density of 5kg/dm³ or less it could be possible to fly. Changing the current in the superconducting coil to control lift and propulsion could be tricky though.
A bit of an understatement. It could be possible to fly like helicopters, but all the way into lower space, reach an orbit, stop again, go for another one, etc.
What about two loops attached rigidly to each other, with currents running in opposite directions? (I suppose that for practical stability a larger ring of coils would be needed.)
The resolution of MRI/NMR is more limited by pulse sequence design and magnetic gradient control. The cryogenics built into the scanner don't contribute meaningfully to those. Instead, you'd gain a huge amount of portability and/or a huge reduction in cost/complexity.
You can't spell cryogenics without "cry", and being able to sustain a large field without needing cryocoolers or a wet system would lead to impossible-to-imagine gains. Medical/industrial imaging, maglev (for sure), even fundamental physics would hugely benefit from the tech.
For NMR the resolution depends directly on the strength of the magnetic field, so if those superconductors allow higher magnetic fields they also increase resolution. See e.g. the new Bruker 1.2 GHz NMR spectrometer which uses some high-temperature superconductors while the spectrometers with conventional superconductors could not get higher than 1 GHz.
There are other effects at higher fields that are not necessarily positive, so just cranking up the field has limits. But in general higher fields provide more resolution and sensitivity in NMR, and it's quite a big increase.
Oh, that's an important correction! If this magical superconductor has a higher critical current density than current tech, then a larger field would be possible.
What about magnetic confinement fusion? My understanding was that tokamaks use superconductors to produce their magnetic fields. Does a low temperature superconductor help with that?
No more gearboxes -- you can have direct drive motors controlling everything. This would revolutionize robotics, compared to current systems that require a large gear ratio between motor and joint, adding large amounts of inertia.
The magnetic field of a coil depends on the current, and the number of turns. If you have a sufficiently thin superconductor, and keep below the critical current density, you can ramp up the number of turns until you reach the physical space limitations.
When you're working with a copper conductor, the thinner the wire, the higher the resistance, and you trade off turns for conductance (1/resistance).
Thus, a superconductor offers the ability to put many more turns, or much higher current, into a given volume.
You're limited with steel cores as to the maximum magnetic flux, but you could get the same flux with much lower power levels using superconducting coils. Alternatively, you could redesign your motor or actuator to be a coreless design, and you can then use much, much higher magnetic fields (up to the critical field of the superconductor).
In a typical brushless motor, the torque is proportional to the magnetic field from the rotor times the current in the stator (non-rotating part). The best conventional magnets and conductors (neodymium-iron-boron and copper) can only generate a certain amount of torque without overheating due to the I^2R loss in the copper. This isn't nearly enough for most applications from driving vehicle wheels to robot joints, so motors need a step-down gearbox. For something like a walking robot knee joint, it needs around 15:1 torque multiplication. This makes it move "robotically", and not be able to absorb the impacts of running and jumping.
A superconductor can handle much larger amounts of current than copper, and maybe also generate a higher magnetic field in the rotor, so you could get much higher torques directly from the motor.
Superconductors still aren't ideal -- they stop being super in really high magnetic fields, perhaps because the electrons are moving in curves rather than straight and the complicated quantum effect that causes superconductivity doesn't work. But plausible superconductors could give great results.
You could build coreless transformers that worked at 60 Hz, with no losses.
You could build electric motors without loss.
You could fill the Tevatron tunnel at Fermilab with new magnets and use it as either an accelerator, or an energy storage facility, depending on the time of day and demand.
I'd make a wedding ring out of it, and be able to feel magnetic fields.
I'd make a SQUID with it, and experiment with the |A| field (electromagnetic vector potential).
> I'd make a wedding ring out of it, and be able to feel magnetic fields.
What about biohacking? Imagine those little magnets that people like to implant below their fingertips—would a superconductor be especially cool to have there?
Maglev applications strongly depend on a sufficiently high critical field. Unfortunately, high temperature superconductors have serious issues with it.
10% is not negligible and it would be way more across continents around the globe.
But if one could build indeed a global lossless energy grid, than this would mean solar power for everyone all the time, as somewhere on the planet, the sun is always shining.
I think it is negligible. In particular, PV is much more than 10% cheaper than many other options, and this would be a replacement for whatever the round-trip cost is even in a zero-$ storage system.
My default number for HVDC is 5%/1000km, but I think that's out of date now; at that level, antipodal power would be 1-(0.95^20) = 64% loss, and while that's certainly something I'd avoid if possible, it's still good enough to make PV beat the TCO of batteries or fossil fuels or nuclear… if you ignore the TCO of installing and maintaining the cable, geopolitics, and all the other reasons we've not done that yet.
(I have no idea what the TCO of undersea HVDC cables is).
Ultrasensitive low cost magnetometers could usher in a wave of low cost MRIs. The burden would shift from exotic hardware and power electronics to signal processing and computational reconstruction, which scales great.
It matters to me because it's the difference between $5 of fancy metal and $500 of transceivers to make a 10 foot thunderbolt cord.
I mean "long" in a somewhat relative sense because at tens of gigahertz your signal integrity goes to garbage after several inches, but also I found a paper talking about fractions of a decibel per kilometer if you completely isolate the wire.
In a nutshell: a previous close-to-room-temp superconduction article from this group was retracted from Nature due to two main concerns; (1) a diagram of a measurement needed to confirm superconductivity seemed a lot like one from a 2009 paper, (2) no one else was able to create this material. Oh and that measurement in the 2009 paper was done by the same scientist as the measurement in the retracted paper - and is the source of why the 2009 paper is also under suspicion.
Moreover, it turns out the principal investigator's doctoral thesis has copied substantially from another thesis without proper attribution.
So it seems many are taking a "let's wait and see" approach.
I'm also a bit skeptical given they plan to commercialize this and refuse to release any real information about their fabrication process. Would not be the first breakthrough result that can't be replicated, and as the group has already tampered with data before it's not improbable that this is the case again, from a purely Bayesian point of view.
If I was to make such a discovery I'd be hell-bent to have other labs reproduce it independently as fast as possible, as that would, with very high likelihood, earn me a Nobel prize. Not releasing any information about my wonder material because I might want to get a patent on it (which they probably already filed before publishing results anyway) seems just weird.
The question is: was it demoed in front of a magician? I'd like a scientist AND a professional magician present. It was the key to debunking the homeopathy story that went into Nature.
Whatever the form of a demonstration, if potential fraud is a concern then you want somebody with expertise in fraud in that domain. So for a demonstration that is statistical, a hotshot statistician is needed. For a physical demonstration you want a hotshot manipulator of the physical world, such as a practical magician. Somebody who already knows a long list of techniques and trade secrets for appearing to defy known.
Moreover, the demonstration is very indirect, like watching a curve in an oscilloscope, not a flying orb that can be seen directly.
We worked with a high temperature (i.e. liquid nitrogen [1]) ambient pressure superconductor. The experiment was quite unimpressive. You put the small block inside liquid nitrogen, with enough wires [2] and a thermocouple to measure the temperature, and connect it to an oscilloscope. You watch how the temperature decrees in the thermocouple and hope the drawing in the oscilloscope does something weird. There is a lot of room to connect the wires to another device [3], or just show fake data in the oscilloscope. [4]
[1] "high temperature" means more than −195.8 °C = −320 °F = 77 K, that is quite cold for most people
[3] For example, in the OP, they can have a fake ambient temperature superconductor, and connect that cables to a real liquid nitrogen temperature superconductor that is in another room and is put inside and outside the nitrogen by a hidden person.
[4] We had some problems with our superconductor, and we wanted to repeat some measurements. It was sensitive to humidity, and it worked quite well until another student wanted have another stable temperature to compare, and put it in water with ice :( .
The important thing with any superconducting discovery is the operating temperature and pressure.
In a historic achievement, University of Rochester researchers have created a superconducting material at both a temperature and pressure low enough for practical applications.
20 ℃ and 10 kilobars pressure.
The temp, I like. the pressure, I don't see how this is practical in engineering deployment. I'd trade some of that heat to get less pressure at this point, contrary to normal "warmer is better" -so what reduction in pressure for what degrees C of cooler temp?
Bulk metals could get into the vicinity of the pressure requirements, but I suppose first applications would be e.g. microwave components that can be fabricated small enough to fit into a diamond anvil cell (think e.g. of lossless inductors or Josephson junctions for high-frequency components). Also, cooling the material might reduce the required pressure significantly, and cooling to e.g. -100 °C is not very expensive and can be done with semiconductor components, so having a superconductor in that range should already open many applications. That said there are some cuprate superconductors that come close to that temperature range already (without needing pressurization) and they still haven't been commercialized widely as the fabrication process is quite involved (e.g. chemical vapor deposition of single atomic layers) and the resulting material (a ceramic) is extremely brittle, so it wouldn't survive long in most environments where semiconductors are used e.g. due to vibration. So whether this will be a commercial success also depends on the material properties. Lutetium hydride has probably better properties than cuprate semiconductors already, but again proving superconductivity is only the beginning, it can be a long way before this becomes commercially viable (if that happens at all).
Materials can be pressurized in other materials. Like a soda can. Curious to see what materials can easily handle maintaining 10 kilobars of pressure.
ChatGPT says Titanium, Tungsten, and Stainless Steel can handle above 10k. Even carbon fiber can. Imagine a tiny resistor-like component where inside is pressurized superconductor. Like a tiny capacitor.
Material stress doesn't work like a soda can. Epitaxial thin films are stressed by an underlying lattice, for example, not by being squeezed in some container. These stresses can be very high (although i don't know the order of magnitude off the top of my head)
Imagine dropping your phone and instead of the screen cracking, the chassis blasts apart. Pressurising materials using other solids doesn’t disappear the energy needed to maintain the pressure.
Funny you mention glass cracking because tempered glass has the same kind of internal pressure. Safety glass on a car has nearly a kilobar. It breaks up without blasting apart.
The use of F and Bar/Psi made me stop reading as every other text in this field always uses K and Pa and I had no reference what they meant. I know bar and Pa can be easily converted but they are odd scales to use.
While I agree F should never be used in favor of K, bar is a common unit of pressure even in metric engineering projects. For strict calculations only using SI units is obviously the way to go. But for science communication and general conversation about engineering, just using bar is often a more easily understood unit because there are more day-to-day comparisons that the average person can make. And thus oftentimes it's easier to comprehend bar than it is Pa.
Yeah...there's been so many papers that have been redacted for bad science that have been displayed here on HackerNews that it's disheartening. The largest startup bank goes bust because startups can't do the math, and people are claiming miraculous breakthroughs in medicine and hard sciences. And they're both on the same page - I know that the comments section is automated, but it's automated tone deafness. Maybe post this again when it's replicated?
> Given the importance of the new discovery, Dias and his team went to unusual lengths to document their research and head off criticism that developed in the wake of the previous Nature paper, which led to a retraction by the journal’s editors. That previous paper has been resubmitted to Nature with new data that validates the earlier work, according to Dias. The new data was collected outside the lab, at the Argonne and Brookhaven National Laboratories in front of an audience of scientists who saw the superconducting transition live. A similar approach has been taken with the new paper.
Until this replicated by another lab I'd say we can't take it at face value not just because the same lab was forced to retract another groundbreaking paper because of questionable results but also because this would be a monumental discovery and needs verification.
Why be a party of the community if you, as it seems, dislike it so? I don't understand the frequent complaining across various forums where people actively participate in something where they have no obligation to do so.
Almost as if we have some kind of goal. If the diversity of ideas for the future in sci-fi may provide a clue the goal is to make people out of plastic to fight the aliens when they come. They wont come but we will be ready.
Good article that contextualises the results and concerns about the lab that published these results.