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LK-99 isn’t a superconductor

nature.com

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Re: LK-99 isn’t a superconductor

#11

Post by Waterluvian »

thinkingkong wrote: post #2

It’s disappointing news but the excitement and amount of replication on this paper was pretty fun to witness and experience. To me the most interesting part was everyone talking about potential consequences, uses, the order of magnitude improvements we’d see in certain costs or areas. Pumps, MRIs, power grids, chips, etc. Great reminder what materials science can do to some underlying economics.

Agreed!

There's this bizarre reaction I see from many where they see the excitement and curiosity and hopefulness as a form of error and source of embarrassment. When mixed with an open mind and reasonable skepticism, it's a powerful opportunity to get people engaged in imagining a different world.

I had all kinds of exciting conversations about what a validated, commercially viable LK-99 could produce. Why would I ever be inclined to feel that there's pie on my face now that we've got fairly strong evidence refuting the claims?

Re: LK-99 isn’t a superconductor

#12

Post by brutusborn »

chubot wrote: post #5

Well I'm kinda glad I missed this whole news cycle IMO this phenomenon seems to be kind of an artifact of modern media -- I feel like in the old days, peers would have settled it among themselves, and we would have never heard about it The same thing happens in tech -- there is a lot of stuff that people talk about, that ends up being worth ignoring ... I always bring up that whole news cycle in 2017 about a potentia…

I wonder if this is a net positive, since media hype would increase likelihood of future funding or investment, so the hype generates accelerated progress.

It could also be the opposite: shiny result causes over investment in an area of tech which isn’t productive.

Re: LK-99 isn’t a superconductor

#14

Post by vecter »

In their preprint, the Korean authors note one particular temperature at which LK-99’s showed a tenfold drop in resistivity, from about 0.02 ohms per centimetre to 0.002 ohms per cm. “They were very precise about it. 104.8ºC,” says Prashant Jain, a chemist at the University of Illinois Urbana–Champaign. “I was like, wait a minute, I know this temperature.”

The reaction that synthesizes LK-99 uses an unbalanced recipe: for every 1 part copper-doped lead phosphate crystal — pure LK-99 — it makes, it produces 17 parts copper and 5 parts sulfur. These leftovers lead to numerous impurities — especially copper sulfide, which the Korean team reported in its sample.

Jain, a copper-sulfide expert, remembered 104ºC as the temperature at which Cu2S undergoes a phase transition if exposed to air. Below that temperature, Cu2S’s resistivity drops dramatically — a signal almost identical to LK-99’s purported superconducting phase transition. “I was almost in disbelief that they missed it.” Jain published a preprint on the important confounding effect on 7 August.

[...]

“That was the moment where I said, ‘Well, obviously, that’s what made them think this was a superconductor,’” says Fuhrer. “The nail in the coffin was this copper sulfide thing.”

Science is hard. Kudos to everyone involved for trying to replicate it and figuring this puzzle out.

Re: LK-99 isn’t a superconductor

#16

Post by mempko »

chubot wrote: post #5

Well I'm kinda glad I missed this whole news cycle IMO this phenomenon seems to be kind of an artifact of modern media -- I feel like in the old days, peers would have settled it among themselves, and we would have never heard about it The same thing happens in tech -- there is a lot of stuff that people talk about, that ends up being worth ignoring ... I always bring up that whole news cycle in 2017 about a potentia…

It's better to miss news cycles, but at least this one was about exciting science instead of dreadful politics.

Re: LK-99 isn’t a superconductor

#17

Post by zephyrthenoble »

Watching this unfold on HN has been eerily similar to watching r/UFOs whenever someone comes forward with "proof" of UFOs/coverups/whatever. I never want to rain on anyone's parade, as proof of ETs or room temperature superconductors would be great, but the hype only serves to obfuscate the truth. At this point, I'm prepped to disbelieve because of the obvious over-hyping.

People want these things to be true so bad that they will twist every detail to fit the narrative they want. It would be funny, if it weren't so sad.

Re: LK-99 isn’t a superconductor

#19

Post by neolefty »

wayvey wrote: post #3

What are the practical implications of this?

We know why it fooled everybody, but AFAIK the material doesn't have any outstanding properties. With certain impurities and under certain conditions, it:

- has a striking drop in resistivity during a temperature change — a property published in 1951 as a property of copper sulfide

- has some ferromagnetic properties — enough to be tipped up in a magnetic field but not to levitate

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