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Superconductor news: What’s claimed, and how strong the evidence seems to be

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Re: Superconductor news: What’s claimed, and how strong the evidence seems to be

#461

Post by Koiwai »

elfbargpt wrote: post #288

One interesting thing I saw pointed out on twitter: both of the published papers have "Lee" and "JH Kim" as the first two authors (LK-99 material namesake). The first paper was published by YW Kwon with himself as the third author. The second paper was published a few hours later by Hyun-Tak Kim with himself as the third author. As others have pointed out there can only be 3 names on the ticket for a nobel prize. To…

If this is true, I think the nobel prize committee would happily make an exception for them.

Re: Superconductor news: What’s claimed, and how strong the evidence seems to be

#462

Post by cma »

pjc50 wrote: post #373
cma wrote: post #197

Earlier quoted context omitted.

> sudden resistivity changes at a critical temperature (bizarrely high though that is in this case) How high? Just wondering if it might eventually be possible to use it in some power/clocking distribution layers of a semiconductor chip without bulky cooling.

> Just wondering if it might eventually be possible to use it in some power/clocking distribution layers of a semiconductor chip There's an additional obstacle factor here which is that the material has to (a) be "sputterable" onto the surface, which may rule out things with fancy crystal requirements, and (b) not adversely react with the rest of the chip, which is why coppper is ruled out (!) and chips use aluminium…

Copper replaced aluminum some time ago (starting ~1997) regardless because of the resistivity, and they just had to find different barrier materials to prevent electromigration and overcome other issues.

Re: Superconductor news: What’s claimed, and how strong the evidence seems to be

#463

Post by IshKebab »

babypuncher wrote: post #450
IshKebab wrote: post #339

Earlier quoted context omitted.

But then we don't know how anything works...

But their point is we don't need a 100% complete scientific understanding of something in order to engineer it into something cool or useful.

That is true, but it's still incorrect to say we don't understand how bicycles work.

Re: Superconductor news: What’s claimed, and how strong the evidence seems to be

#464

Post by p1mrx »

soligern wrote: post #454
m4x wrote: post #302

Earlier quoted context omitted.

In the same way that the pushback from the earth you're standing on is an infinite source of energy

It isn’t though. You can use gravity to apply the weight to the superconductor and the pushback would be against gravity.

You can also hang a weight on a spring. Neither helps you override the laws of thermodynamics.

Re: Superconductor news: What’s claimed, and how strong the evidence seems to be

#465

Post by hinkley »

wiredfool wrote: post #380
denimnerd42 wrote: post #312

Earlier quoted context omitted.

what do you mean it's not tension at the top? did you misspeak? bicycle spokes are solely under tensile forces. they can't support compressive forces at all. i'm a hobbyist wheel builder and a once upon a time professional bicycle mechanic during hs & college. if you want to test this take nearly all the pretension out of your spokes and sit on your bike. feel which ones are taught and which ones are completely loose…

This dialogue is reminiscent of rec.bycycles.tech arguments with Jobst, ca 1993. A bike wheel is a linear elastic system, that can be thought of as a superposition of a uniformly set of tensioned spokes as one state, and a set of spokes in compression in the loaded zone (bottom of the wheel) as the other state. So long as the superposition of the two states obeys the limiting conditions (i.e. spokes in tension) they…

Hey do you happen to recall, did Brandt prove this theory with a tensiometer or did I just hallucinate that?

Re: Superconductor news: What’s claimed, and how strong the evidence seems to be

#466

Post by hinkley »

denimnerd42 wrote: post #456
hinkley wrote: post #439

Earlier quoted context omitted.

And thread. Thereby proving my point: Almost nobody knows how bicycle wheels actually work.

Well. I wish we could sit in front of a bicycle wheel and discuss it. Because I have a feeling we are shooting arrows at different targets. As a mountain biker I'm more interested in what happens when an extreme amount of load is applied to the wheel, not the model with assumptions applied. Definitely a difficult concept to discuss with only text. Anyways.. glad to have a good discussion with you about bicycle wheels…

I think I would have been a mechanical engineer if I were born 20 years earlier or 20 years later. Software was just new and shiny enough and it let me build things with my mind, at a time when I believed I was clumsy (I actually have always had excellent fine motor skills, it's macro motor control I lagged behind in). One of my better friends in college was an ME. Learned all sorts of things about metal fatigue and oddly enough picosecond lasers from him.

I don't know if I found Lego or Lego found me, but I definitely think in terms of shapes. I was past my midlife crisis before I realized that I don't have a large working memory (smaller than average in fact) it's just that I've been doing mind palaces without pictures since I was very small. When I'm thinking of large computer systems I'm essentially thinking of them as physics problems.

I really should figure out space to have a bike again. I never rode when I lived in Seattle (Seattle drivers are nuts) but I don't live there anymore and I need to catch up on 20 years of tech.

Re: Superconductor news: What’s claimed, and how strong the evidence seems to be

#467

Post by IshKebab »

hinkley wrote: post #439
wiredfool wrote: post #380

Earlier quoted context omitted.

This dialogue is reminiscent of rec.bycycles.tech arguments with Jobst, ca 1993. A bike wheel is a linear elastic system, that can be thought of as a superposition of a uniformly set of tensioned spokes as one state, and a set of spokes in compression in the loaded zone (bottom of the wheel) as the other state. So long as the superposition of the two states obeys the limiting conditions (i.e. spokes in tension) they…

And thread. Thereby proving my point: Almost nobody knows how bicycle wheels actually work.

Nah they both understand it. One of them is just arguing to show off.

Re: Superconductor news: What’s claimed, and how strong the evidence seems to be

#468

Post by xdennis »

nemo44x wrote: post #414
fh973 wrote: post #343

Earlier quoted context omitted.

It's from a guy of the Max Planck Institute for Solid State Research.

He sounds rather bitter and arrogant. He basically just called them idiots. As if none of the researchers would have noticed the measurement error. Perhaps he’s right - we’ll know in a few days I assume. I do hope they are right though not only because it would be a huge leap but also because I’d love to see this guys reaction.

> He sounds rather bitter and arrogant.

That might be your interpretation of it. I think the Germans would call it being straightforward.

Re: Superconductor news: What’s claimed, and how strong the evidence seems to be

#469

Post by VagabundoP »

MattPalmer1086 wrote: post #391
VagabundoP wrote: post #359

Earlier quoted context omitted.

Yeah, but what about Bumblebees. Yeah, didn't think so. ;)

They figured that one out too... Something to do with vortices...

Yeah I was being sarcastic. Forgot the /s. :(

Re: Superconductor news: What’s claimed, and how strong the evidence seems to be

#470

Post by BizarroLand »

scentoni wrote: post #256
BizarroLand wrote: post #215

Earlier quoted context omitted.

Wouldn't it be odd for an amalgam of lead and copper to be non-conductive? I know they were formed from sulfur compounds, but the production process should have eliminated those compounds, and the final forming is done in a vacuum so there shouldn't be any oxide generation to form non-conductive barriers. I don't know much about the process but shouldn't they be testing resistance in a superconductor?

It’s not an amalgam (that means a mercury alloy) or any metallic alloy. It’s an oxide (more complicated than that but there’s more oxygen atoms than metal atoms).

Amalgam can also mean, "A mixture or combination of different things" such as "an amalgam of musical genres" or "an amalgam of unsavory dog food flavors", which, since we aren't talking about mercury at all, nor are we talking about any form of dentistry, should have be evident and deducible from the context.

https://www.oxfordlearnersdictionaries.com/definition/englis...

And we very much are talking about an alloy, which is a "metallic substance composed of two or more elements"

https://www.britannica.com/technology/alloy

Lead is a metal. Copper is a metal, a combination of 2 metals is an alloy.

However, you are right, I did overlook that the compound is an oxide, my bad.

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