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Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

arxiv.org

181–190 of 389 posts

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#181

ELI5, if these folks confirmed zero resistance at room temp and atmospheric pressure, isn't that confirmation of the original paper? Edit: I read 100 K as 100°c. Mea culpa.

100 degrees kelvin is about 338 degrees Fahrenheit below room temperature.

Duh. Thanks. I think my brain must have transposed that K to C.

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#182

Earlier quoted context omitted.

Even a 'very small resistance' would likely be prohibitive. Pure silver for instance is an excellent conductor, but when you're talking about the last little bits it's orders of magnitude difference between that and a superconductor, and those orders of magnitude difference in resistance translate into orders of magnitude more current. So even a small resistance would cause your MRI machine to have a resolution so lo…

Actually, there are infinite orders of magnitude between the resistance of silver and that of a superconductor.

[deleted]

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#183

Earlier quoted context omitted.

We'll probably know for sure within the month!

Somewhat disappointed the russian twitter anon isn't included, since they seem to have made the first replication attempt that might have panned out.

I suspect that account is just a troll who knows a bit about material science. They spend more time arguing and promoting the Soviet Union than sciencing. I gathered that after just 5 minutes of scrolling through their twitter. I suspect a retired and bored Soviet scientist maybe?

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#184

Earlier quoted context omitted.

I think it's a fair question. I guess the answer is "because we have superconductors, and no material with 'very small resistance' instead". Also note that while there is zero resistance you still have parasitic currents and general interaction with the rest of the environment. So no perpetual motion for us today!

Even a 'very small resistance' would likely be prohibitive. Pure silver for instance is an excellent conductor, but when you're talking about the last little bits it's orders of magnitude difference between that and a superconductor, and those orders of magnitude difference in resistance translate into orders of magnitude more current. So even a small resistance would cause your MRI machine to have a resolution so lo…

MR imaging is possible with permanent magnets and resistive (copper wire wound) magnets at low field strengths, below 0.35T or so. Above that the heating of the magnet windings becomes excessive and it would be very difficult to maintain a stable enough field strength.

Superconducting magnets are very nice as long as there is no quenching. The material used for conductors must be mechanically stable and perform consistently from one production batch to another. One reason why current high tc superconductors are not popular...

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#185
post #150

As a lay person not graduated in STEM subjects, can someone ELIFY how is this research useful to society?

This exact paper is the newest progress on recent hype regarding a semi-trustworthy not-peer-reviewed study claiming 'superconductors at room temperature'.

'Superconductors at room temperature' are cool because they would answer questions like "How would we get solar power from [your local desert] everywhere else for free?" and "How are we going to use MRIs when the helium runs out?" as two examples.

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#186

For comparison, per this Wikipedia page ( https://en.wikipedia.org/wiki/High-temperature_superconducti... ) currently, the highest temperature, ambient pressure superconductor is around 138 K (−135 °C). I'm no expert but based on my limited understanding, this result (if confirmed) while far from room temperature would still make LK99 a pretty interesting discovery in the SC world. And once a new SC like this is vali…

It's always interesting to discover a new class of materials that make high temperature superconductors even if they haven't discovered a room temp one.

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#187

Earlier quoted context omitted.

> Worst case scenario, we got another class of high temp (warmer than liquid nitrogen but cold enough that applications are limited) superconductor but nothing revolutionary since at this point, it is pretty conclusive that there is something interesting with LK-99. I don't think that's the worst case scenario. The worst case scenario is that there is actually nothing interesting with LK-99, and everything we've seen…

You're right that this is the worst case scenario, but each interesting replication or semi-replication, even sloppy replication, or theoretical model erodes at that. Being perma-skeptic is as bad as being a perma-fanboy Anyways your memory is really short. Don't you remember how when it first came out (not even a week ago) everyone was hollering that it was fake? Inb4 "extraordinary claims...": there is no fundament…

I read through this thread and I can't help to feel reminded of the discussion about cryptocurrencies. So many people that want to believe, rational people that try to explain why it has to work when there is just not enough information right now. As if we believing it will change the outcome of the replication everybody that doesn't believe is shunned and called a heretic. Suddenly people that studied social sciences try to explain to me (a certified electrical engineer) why this is a big deal, because they saw a few videos on youtube about it, with theories of how this solves all energy problems that are so far removed from practical reality that this can only become a let-down.

Note: I am cautiously optimistic myself, but damn, just wait and don't overhype it.

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#188

Earlier quoted context omitted.

> Worst case scenario, we got another class of high temp (warmer than liquid nitrogen but cold enough that applications are limited) superconductor but nothing revolutionary since at this point, it is pretty conclusive that there is something interesting with LK-99. I don't think that's the worst case scenario. The worst case scenario is that there is actually nothing interesting with LK-99, and everything we've seen…

The reason I don't think this is the case is that they have literally been working on this thing for a quarter of a century. While the people involved are not full on superconductor experts, they are also not super stupid and realize that their claim is a huge one. How could you work on something for years and years and years, make a claim that it is the first room temperature SC and be _totally_ wrong about it. Even…

Can you really be working with a material for a quarter of a century AND not know how to make the material?

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#189

Question for the cognoscenti: supposing that LK-99 superconducts with T_c = 110 K, how significant a discovery would this be? I.e., does it establish a brand new class of high-T superconductors, or is it merely one unremarkable member of a known class? Further, does it offer advantages over other high-T superconductors such as ease of fabrication or cost?

To add to the other reply, it'd be a new class especially since it would be at standard pressure. I think the current highest Tc SC at standard pressure is at much lower temperatures. Frankly, there's probably a lot that you can do with a superconductor that you can cool with liquid nitrogen even if it can't carry much current or handle high magnetic fields. Moving from liquid helium cooling to liquid nitrogen alone…

Don't YBCO superconductors already work at liquid nitrogen temperatures?

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#190
post #187

Earlier quoted context omitted.

You're right that this is the worst case scenario, but each interesting replication or semi-replication, even sloppy replication, or theoretical model erodes at that. Being perma-skeptic is as bad as being a perma-fanboy Anyways your memory is really short. Don't you remember how when it first came out (not even a week ago) everyone was hollering that it was fake? Inb4 "extraordinary claims...": there is no fundament…

I read through this thread and I can't help to feel reminded of the discussion about cryptocurrencies. So many people that want to believe , rational people that try to explain why it has to work when there is just not enough information right now. As if we believing it will change the outcome of the replication everybody that doesn't believe is shunned and called a heretic. Suddenly people that studied social scienc…

As for crypto, tgere is nothing to believe in - it’s doing well after 14 years.
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