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The first room-temperature ambient-pressure superconductor?

arxiv.org

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Re: The first room-temperature ambient-pressure superconductor?

#621

Post by colechristensen »

floxy wrote: post #250
colechristensen wrote: post #232

Earlier quoted context omitted.

>As far as I know, that’s possible with permanent magnets (and it would be weird, but not impossible, if the group instead synthesized a novel ferromagnet and didn’t notice) As far as I know a stable arrangement of permanent magnets levitating is impossible without a baring surface to keep them aligned. (i.e. free floating levitation is not possible without active control)

Just so everyone is on the same page, static passive diamagnetic levitation is possible with materials like pyrolytic graphite. https://en.wikipedia.org/wiki/Diamagnetism https://www.kjmagnetics.com/blog.asp?p=diamagnetic-levitatio... ...and superconductors are usually perfectly diamagnetic.

Every substance is one of

* ferromagnetic - attracted to one pole of a magnet but not the other (in a given orientation), this is what everybody thinks of when they think of "magnets"

* paramagnetic - attracted to both poles, i.e. stuff that sticks to magnets

* diamagnetic - repelled by both poles, except in superconductors, this effect is very weak compared to the forces experienced involving ferro-ferro or fero-paramagnetic materials.

There isn't another category, everything fits in to one of those buckets.

Saying

>Just so everyone is on the same page, static passive diamagnetic levitation is possible with materials like pyrolytic graphite.

is a bit deceptive, as what people know as "magnetic" materials are ferromagnetic.

Re: The first room-temperature ambient-pressure superconductor?

#622

Post by jacquesm »

ClumsyPilot wrote: post #597
jacquesm wrote: post #587

Earlier quoted context omitted.

Fuel cells are just another transformer like the dynamo, or any kind of motor. They turn one kind of energy into another and in the context of hydrogen (which you could produce out of water using electricity as a means of storing energy) it serves to reverse the storage step. This is nice to have but just like nuclear power it's a variation on stuff that we already have, it is at best a quantitative change (and hopef…

> This is nice to have but just like nuclear power it's a variation on stuff that we already have By that logic a super conductor is just a variation of a conductor. Nuclear power is more distinct from burning coal than any superconductor is distinct from copper wire.

> By that logic a super conductor is just a variation of a conductor.

No it is not. The difference between 0.1 and 0.0 can't be expressed in orders of magnitude.

> Nuclear power is more distinct from burning coal than any superconductor is distinct from copper wire.

Nuclear power is an incredible invention. Unfortunately it has some problems that won't go away by wishing it to be so, and there are many similarities with coal (as well as some obviously differences).

But this thread isn't about coal vs nuclear.

Frankly, if you don't actually see the difference between the relative importance of superconductors vs copper wire and nuclear vs coal then I really don't think I have anything to say that will interest you. Suffice to say that nuclear didn't change the world all that much (except in a weapons sense) but superconductors at room temperature and ambient pressure have the potential to change the world in ways that would be hard to even imagine. Even if true I still don't think it would be in time to help us address some of the more urgent problems we are facing. Neither does nuclear. And come to think of it: if this tech is real (big if) then it will actually probably cause a revolution in nuclear as well because it would allow for nuclear power to be transmitted the world over without the non-proliferation headaches associated with shipping reactors to various countries. It wouldn't solve the waste problem (though there are some interesting reactor designs now) and it won't happen overnight but it would make a difference.

Re: The first room-temperature ambient-pressure superconductor?

#623

Post by XorNot »

achr2 wrote: post #571
XorNot wrote: post #512

Earlier quoted context omitted.

AFAIK doesn't pyrolytic carbon need a N-S field in order to levitate? That's the one key difference I can see - this looks like the traditional superconductor trick of just levitating in a simple field. i.e. not like some of the ones you'd see here: https://www.youtube.com/watch?v=Vy9uWXgbKy0

Not if a corner is anchored, as is visible in their video. This is an obvious scam.

This video seems to show the best example of a possible effect like that: https://www.youtube.com/watch?v=VC3r9-OaWes

But it still looks dependent on their being a NS pole at a corner.

That said...from this video https://sciencecast.org/casts/suc384jly50n I'm very suspicious of the behavior you see in the last few seconds where it gets pushed over to the corner and seems to fall right to the magnet That would be consistent with their being a ring magnet underneath the top magnet their, and once suitably over into the corner it loses the diamagnetic property because there's no N-S pole. The "seam" on what should be a bulk magnet in both videos that are out seems like an obvious problem.

So yeah...I think put me down for this is diamagnetism with pyrolytic carbon (the image in the paper also notably hides what you see in the video - that there's a seam on the magnet where it looks like it's a stack of two).

Re: The first room-temperature ambient-pressure superconductor?

#624

Post by labster »

fijiaarone wrote: post #385
xxpor wrote: post #322

Earlier quoted context omitted.

One catch would be the use of lead would restrict the use cases fairly heavily

If you think lead is scary, wait till you hear about carbon dioxide.

If you think CO2 is scary, wait til you hear about methyl mercury.

Re: The first room-temperature ambient-pressure superconductor?

#625

Post by m463 »

jacquesm wrote: post #456
andreiklochko wrote: post #389

Guys, even if everything in this paper is true, the material as it is might have limited applications. From what they show, the critical field and critical current seem very low. 2500 Oe is like 0.25 Tesla. Even REBCO at 77K is >1T. And 2500 Oe is not even at critical temperature but much lower. From skimming through the article I couldn't find the sample size of the current measurement to get the critical current de…

This is a dancing pig. The thing to appreciate is not how well it dances but that it dances at all .

https://xkcd.com/2798/

Re: The first room-temperature ambient-pressure superconductor?

#627

Post by manjalyc »

marcosdumay wrote: post #293
obblekk wrote: post #150

The method to produce this material as described in the related paper [1] is fairly simple and could be done at home with a $200 home metal melting furnace from amazon and the precursors (which also seem to be fairly standard easy to obtain metals). If this is real, I'd expect some smart people from hackaday / youtube to reproduce this within weeks if not days. If this is real, it'll change society quickly and perman…

Ok, let me just add the obvious disclaimer: don't try this yourself unless you have a pretty good understanding of chemical lab safety. Really. It's more likely that you will contaminate your land, and possibly your neighbors land too than that you will manage to replicate it.

Given the materials and methods involved it really isn’t that dangerous. With basic precautions I’d say go for it, worst case is honestly just blowing a few hundred bucks. If this pans out, there will definitely be some do it yourself tutorials on YouTube in the coming weeks.

Re: The first room-temperature ambient-pressure superconductor?

#629

Post by techdragon »

opwieurposiu wrote: post #484
andreiklochko wrote: post #389

Guys, even if everything in this paper is true, the material as it is might have limited applications. From what they show, the critical field and critical current seem very low. 2500 Oe is like 0.25 Tesla. Even REBCO at 77K is >1T. And 2500 Oe is not even at critical temperature but much lower. From skimming through the article I couldn't find the sample size of the current measurement to get the critical current de…

You can improve the current density a lot if you can make a single crystal, or at least make your crystal grains larger. Impure superconductor samples often come out as a spongy mixture of superconducting and non-superconducting bits, the critical current is limited because less then 25% of the cross section is actually carrying current. When I was DIYing YBCO this is what happened most of the time. Every now and the…

Yeah, it’s been a pretty solid trend line, new superconductor, first batch is usually kinda shitty, but proves the basics, refining the mix nails down its exact performance characteristics.

It’s spongy grainy crap indeed… but as long as their analysis holds up to scrutiny and replication… and whoa boy do I bet there are people already trying to replicate this result as I’m typing my reply and reading the rest of the comments…. As long as the results hold up and this isn’t an abnormally low performing superconductor… i have no doubt this is going to win a Nobel prize. This has been the prize for a long time in this whole discipline, and they may have finally nailed it.

We as a species may be on the bring of a revolutionary step forward in what we can achieve in engineering and science. Better instruments and more powerful or sophisticated motors and power systems. It’s heady stuff to think it may happen in my lifetime.

Re: The first room-temperature ambient-pressure superconductor?

#630

Post by jacquesm »

colechristensen wrote: post #614
jacquesm wrote: post #399

Earlier quoted context omitted.

It's a thin film according to the article linked, but there is no mention of how thin it is (it could be a monolayer) and there is no mention of how wide the film was so the 250 mA figure can not be used to determine whether or not there is 'room for improvement' or even a necessity for that (unless it was already normalized, for which I see no evidence). The 'Critical current' isn't mentioned at all in terms of the…

If it is a thin film it may have to be a thin film to get the effect in which case you still need a million of them bundled together to get comparable currents. It's not a certainty but a fact that dials back the excitement of this announcement from potentially world changing to interesting but quite limited applications. >In 2008, Gozar et al. reported hightemperature interface superconductivity between metallic and…

Absolutely, but layers can be stacked (if they really are superconducting there won't be much of an issue to get rid of waste heat, there will be very little of that).

As for cooling my jets: I don't think we'll see any real application of this in the next 10 years at a minimum, this stuff is the first step on a very long road towards commercialization. From the first mention of the photo electric effect (~1890) to practical (1956), affordable (1990's) solar panels took roughly a century.

https://en.wikipedia.org/wiki/Timeline_of_solar_cells

I hope that this superconductor, assuming it's real can be fast tracked given our much improved knowledge of materials and fabrication methods. But I'm realistic enough to realize how much work would still have to be done even if it is real. The road from the lab to the shelf is a long and expensive one and even in the best of scenarios I can't imagine anything on a timescale of less than a decade.

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