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Room-Temperature Ambient-Pressure Superconductor LK-99 preprint revision 2

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Re: Room-Temperature Ambient-Pressure Superconductor LK-99 preprint revision 2

#271

Post by kickopotomus »

sanxiyn wrote: post #145
maho wrote: post #130

Earlier quoted context omitted.

Note that the resistance of superconductors is 0 only for DC currents. The AC resistance is not 0 and typically gets larger for higher frequencies!

Yes, but computer chips are powered by DC.

High-end CPUs are actually not powered directly by DC. Basically all server (and growing portion of consumer) CPUs are powered by multiphase buck regulators[1] which split the power from from the DC PSU rails into a parallel set of modulated buck regulator power stages. The outputs of the parallel regulators are recombined to generate DC (as the combined waveform of the phased AC parts).

The reason for this multiphase design is because it offers better power efficiency and better transient response to the CPU as the CPU moves between it's different power states (high vs low load).

[1]: https://www.ti.com/lit/an/slva882b/slva882b.pdf?ts=169087951...

Re: Room-Temperature Ambient-Pressure Superconductor LK-99 preprint revision 2

#272

Post by s1artibartfast »

tdehnel wrote: post #259
s1artibartfast wrote: post #252

Earlier quoted context omitted.

Well sure, that's the point that you're trying to make. I thought anything most people felt you were claiming you need a theory related to the novel Discovery or convention. That is to say how it might work and what the expected outcomes are. I can't go to the lab without a theory that my car can get me there. That doesn't mean I have a hypothesis for what will happen when I mix two substances in the lab. Thinking th…

> Thinking that something will either happen or not happen if I mix those two substances is not a theory. OK I'll bite. What is it then?

Nothing, just words that don't have any predictive value or convey any understanding of the world.

Maybe an example would help clear things up. go into the lab with a 1 lb weight and a 2 lb weight and weigh them together.

Saying that the total weight could either equal 3 lb or any value other than 3 lb does not constitute a predictive theory for how the physics of summing Mass works.

It might be a theory that a scale display a value when I put things on top of it, but that is a different topic, and not what I'm testing.

This Theory doesn't tell me how the world works and if the expected value is 0 lb, 3 lb, or 1 million pounds.

I could go into the lab with no operating Theory or hypothesis on what the value of two masses should be when added together and collect data.

I can collect data with no expectation of correlation, and after measuring the combination of many weights, deduce that there is a relation between the combined weights and the total mass, and in fact it is a simple sum.

Re: Room-Temperature Ambient-Pressure Superconductor LK-99 preprint revision 2

#273

Post by 2bitencryption »

jboggan wrote: post #184

Preprint by Griffin from Livermore Labs gives a theoretical explanation of LK-99's superconductivity and also explains why labs are having a hard time synthesizing it. There are two Pb sites in the crystal structure that Cu can substitute at, the lower energy one does nothing but it's the higher energy site that creates superconductivity. https://arxiv.org/pdf/2307.16892.pdf "Finally, the calculations presented here…

Questions from a total layman-

Are the superconductivity properties "all or nothing"? Meaning, if you get the synthesis wrong of the material, would you expect it to be "kind of" superconductive? (I guess, a very low, but non-0, resistance)?

Or is it something where it has normal resistance in all cases unless you get it just right, and then it becomes superconducting?

One more question - in physics, it seems like something having a value "0" is never really possible. Like, you can have something with low friction, but not zero friction. We pretend things have zero friction for high school physics problems, but they don't really. Is superconductivity like that? Is it actually, genuinely, exactly 0.0000(...)? Or is it just very close to zero, so close that it can behave like something with zero resistance (but in reality it's resistive, but just barely)?

Re: Room-Temperature Ambient-Pressure Superconductor LK-99 preprint revision 2

#274

Post by hutzlibu »

hutzlibu wrote: post #153
robinduckett wrote: post #107

Earlier quoted context omitted.

It’s a ceramic so hard to make wires from

Only some applications require flexible cables. All of "my" use cases should be fine with using ceramics. I really don't think this will be the problem ...

In case I was missunderstood: it won't be the problem to use ceramic, compared to making mass produced room temperatur superconductors. This will be hard either way, if currently no other lab can even reproduce it.

Re: Room-Temperature Ambient-Pressure Superconductor LK-99 preprint revision 2

#275

Post by sbierwagen »

2bitencryption wrote: post #273
jboggan wrote: post #184

Preprint by Griffin from Livermore Labs gives a theoretical explanation of LK-99's superconductivity and also explains why labs are having a hard time synthesizing it. There are two Pb sites in the crystal structure that Cu can substitute at, the lower energy one does nothing but it's the higher energy site that creates superconductivity. https://arxiv.org/pdf/2307.16892.pdf "Finally, the calculations presented here…

Questions from a total layman- Are the superconductivity properties "all or nothing"? Meaning, if you get the synthesis wrong of the material, would you expect it to be "kind of" superconductive? (I guess, a very low, but non-0, resistance)? Or is it something where it has normal resistance in all cases unless you get it just right , and then it becomes superconducting? One more question - in physics, it seems like s…

It really is authentically zero. No resistance at all.

The thing that prevent infinities showing up, or letting us pour gigawatts of power into a single superconducting magnet until it turns into a black hole is that superconductors have a "critical current" over which it falls out of the superconducting state. (At which point it enters the normal, resistive state, suddenly becomes very hot, and boils off all your very expensive liquid helium, a "magnet quench" https://en.wikipedia.org/wiki/Superconducting_magnet#Magnet_... )

LK-99's published critical current is actually quite low, maybe because of sample purity issues. Hopefully it can be improved, otherwise we might be in the comical situation where room temperature superconductors exist and can be used but the cables end up being too thick and can't compete economically with copper.

Re: Room-Temperature Ambient-Pressure Superconductor LK-99 preprint revision 2

#276

Post by fragmede »

fastball wrote: post #254
kijin wrote: post #248

Earlier quoted context omitted.

Elon Musk must be feeling much better lately, having confirmed that Twitter is still relevant.

And yet you'd think Elon Musk would've been quick the jump on this particular bandwagon – in past years I would've expected Musk to have setup competing teams at Tesla and SpaceX, first to replicate wins. Alas recently it seems that he does not have the singular focus he once had.

I am sure materials nerds (said affectionately, I am a computer nerd) at materials labs at top corporations, like SpaceX are working on this.

Picture this. You're a material's person. You have a collection of each of the elements in the table of elements. You've got a successful career in your field. You've got your dream job working in a materials lab as a scientist or engineer. Along comes this paper, describing a pretty easy process, with things you already have on hand, to create a revolutionary new material that will change the world, if the paper is true.

That person, at SpaceX, Apple, BASF, Google, GE, Samsung, DuPont, everywhere where there are passionate materials people in a lab who just want to believe, is going to do it over the weekend and after hours, just for the fun of it, nevermind Elon. They might not have the showmanship for a Twitter account with millions of followers but they have the lab and the materials and the drive to make it.

Musk doesn't need to setup competing teams, and if he had, would he be forced to tell the general public about it?

Re: Room-Temperature Ambient-Pressure Superconductor LK-99 preprint revision 2

#277

Post by xdennis »

smcameron wrote: post #185
anotheryou wrote: post #137

Earlier quoted context omitted.

love the atomic full screen button on the video player XD

Better than the WWII era German aircraft insignia youtube uses for the "unfullscreen" button.

Ha, it really does look like the Balkenkreuz[1]. Although it was in use before Hitler and it's just a cross.

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

Re: Room-Temperature Ambient-Pressure Superconductor LK-99 preprint revision 2

#278

Post by nomel »

mcpackieh wrote: post #257
beowulfey wrote: post #212

Earlier quoted context omitted.

Wow, I’ve never thought about it like that before. You’ve done a good job explaining your opinion on this matter! Thanks for the feedback.

I'm not him but I share his confusion. Honestly I can't figure out what sort of point you're trying to make here. What's the point of all the island and pink cats stuff if not to make the point that the researchers didn't have adequate video cameras available to them at the time? jiggawatts's gripe is that the researchers seem generally incapable of effectively using the cameras they already possess (including iphone…

> jiggawatts's gripe is that the researchers seem generally incapable of effectively using the cameras they already possess (including iphones)

I’m not sure why there’s an expectation that they know how. Expertise in one subject doesn’t make you capable in others. I’m not sure if you’re ever worked with phds before, but there’s often an extreme contrast in ability and lack of ability, depending on the context.

There’s a good chance these people don’t spend much time messing with their phones.

Re: Room-Temperature Ambient-Pressure Superconductor LK-99 preprint revision 2

#279

Post by jesse9766 »

XCSme wrote: post #195
asimpletune wrote: post #68

Earlier quoted context omitted.

The battery one is crazy, where you just store the electrons in a loop.

But how do you get them out? Don't electrons prefer the path of least resistance, so that is staying in the superconductor? Or they won't stand still?

Converting magnetic force into electrical current (electromagnetic induction) is the principal behind of all electrical power generation. SMES (superconducting magnetic electrical storage) is essentially an inductor made using superconductors. Electrical current gets converted into magnetic force and then back into electrical current when the circuit is discharged.

Re: Room-Temperature Ambient-Pressure Superconductor LK-99 preprint revision 2

#280

Post by ckmiller »

brunooliv wrote: post #12

What are the implications in general of room temperature superconductors? I just know that they needed typically ultra low temperatures right? But what would be the practical implications?

Power conversion losses account for about 60% of the energy that goes into electricity generation in the US [1]. Superconducting generators and transformers could take that figure down to a fraction of that.

[1] https://www.eia.gov/totalenergy/data/flow-graphs/electricity...

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