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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

#481

Post by blagie »

ddalex wrote: post #369
blagie wrote: post #281

Earlier quoted context omitted.

> You can build a pretty good mental model of flight with either simplified mechanism, but you end up underestimating performance by a fair bit. I've never hear of a good mental model built on Bernoulli's Principle. They are either: - Wrong - Give no intuition The key question is /why/ air moves faster on one side, and once you get away from the misconception of same time, I've never heard an intuitive argument. Redi…

Why are you benchmarking models to human intuition? If you apply the same reasoning to quantum mechanics you'll have a bad time. I'm sure models can accurately compute how much of the wing lift comes from the suction effect on the top of the wing versus the push on the bottom of the wing.

Because it's literally what I'm responding to:

"You can build a pretty good mental model of flight with either simplified mechanism"

For computational models, neither of these are great starting points. When I last looked, finite element methods were where the action was.

And if you don't apply the same to quantum -- looking for intuition -- you'll have a bad time. Quantum computing algorithms came from human insight.

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

#482

Post by blagie »

Linosaurus wrote: post #422
blagie wrote: post #281

Earlier quoted context omitted.

> You can build a pretty good mental model of flight with either simplified mechanism, but you end up underestimating performance by a fair bit. I've never hear of a good mental model built on Bernoulli's Principle. They are either: - Wrong - Give no intuition The key question is /why/ air moves faster on one side, and once you get away from the misconception of same time, I've never heard an intuitive argument. Redi…

> The key question is /why/ air moves faster on one side, and once you get away from the misconception of same time, I've never heard an intuitive argument. Since the air follows a curved surface instead of straight ahead, you could perhaps apply your intuition for centrifugal force. Momentum sort of pulls the air away from the surface. I’m not even sure this explanation is wrong.

That's interesting.

Counterpoint: A wing with the opposite curvature would work too, just much less efficiently. Your explanation has an element of truth, but an element of untruth. It'd take more analysis to tease them apart.

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

#483

Post by justinclift »

Thrymr wrote: post #480
justinclift wrote: post #455

Earlier quoted context omitted.

Seems to be a single post?

Because X (sigh) doesn't show replies in public (if not logged in) anymore.

Ahhh. Thanks. :)

Yeah, I can't be bothered logging in.

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

#484

Post by kaashif »

doctorwho42 wrote: post #316
burtonator wrote: post #286

Earlier quoted context omitted.

I want ONE breakthrough like this in my lifetime. Something completely game changing.

Live to see SPARC turn on, there are some pretty smart people with models actually showing it breaking Q>3. Turns out the hardest part about productive fusion is the sustained high compression, and HTC tape really helps increase the compression by a large amount. (See their 20 Tesla test at the start of the pandemic)

Meanwhile as someone who had to deal with writing code for Solaris and using Sun's compiler, I think I've achieved my goal by seeing my last SPARC turn _off_!

But yeah, nuclear fusion is cool.

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

#485

Post by m463 »

terafo wrote: post #375
m463 wrote: post #353

Earlier quoted context omitted.

like parking tickets for supercars... :) FAA says even superconducting superdrones can't go over 400 feet.

And can you also explain "indefinite levitation" to me? IIRC you can do some levitation over metallic surfaces or magnets, but that would require power, wouldn't it?

not qualified to explain the levitation, seems to be some sort of self-stabilizing magnetic field due to zero-resistance current.

But there is plenty of magnetic levitation right now without power:

https://www.amazon.com/dp/B01N2Z9QAP

also, balloons.

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

#486

Post by codethief »

justinclift wrote: post #483
Thrymr wrote: post #480

Earlier quoted context omitted.

Because X (sigh) doesn't show replies in public (if not logged in) anymore.

Ahhh. Thanks. :) Yeah, I can't be bothered logging in.

There you go: https://nitter.net/andrewmccalip/status/1684433849781202944

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

#487

Post by justinclift »

codethief wrote: post #486
justinclift wrote: post #483

Earlier quoted context omitted.

Ahhh. Thanks. :) Yeah, I can't be bothered logging in.

There you go: https://nitter.net/andrewmccalip/status/1684433849781202944

Fantastic, thank you. :)

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

#488

Post by [deleted] »

ryzvonusef wrote: post #473

https://twitter.com/alexkaplan0/status/1684622263339884544 > I have bad news. I am growing increasingly convinced that LK-99 is simply diamagnetic, rather than superconducting. It lines up well with existing evidence (susceptibility, levitation, lack of heat capacity singularity, etc.) https://twitter.com/alexkaplan0/status/1684622265403465728 > Discovering a new diamagnet is cool, but .... obviously way less cool __…

[deleted]

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

#489

Post by intrasight »

dotnet00 wrote: post #442
intrasight wrote: post #265

Earlier quoted context omitted.

We don't know how photosynthesis works but we know a ton about GROWING things. And life as we know it depends on photosynthesis.

How photosynthesis works at a cell machinery level is high school level biology.

That's not an understanding of how it works

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

#490

Post by intrasight »

MVissers wrote: post #412
intrasight wrote: post #265

Earlier quoted context omitted.

We don't know how photosynthesis works but we know a ton about GROWING things. And life as we know it depends on photosynthesis.

I thought we had a pretty good understanding of this up until the molecular and electron level. Am I missing something?

My daughter did her research in this field while an undergrad, and explained to me that photosynthesis is not yet well understood. Some of the theories of the mechanism are discussed here: https://physicsworld.com/a/is-photosynthesis-quantum-ish/
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