Oh, sure, if true, then this is phenomenal, and while it’ll take more work to get the process consistent enough to be practical, that’s just incremental advancement. But even at best, it’s certainly not quite ready for prime time yet.
Definitely. The paper is frustrating because there aren’t any details of the test setup or procedures, so the results shown in the figures can’t really be peer reviewed.
Measuring resistance versus temperature is never a proof of superconductivity. There are lots of temperature dependent effects that can result in drastic reductions in resistance. Superconductors are, theoretically and as far as anyone can measure in years long circulating current experiments, truly zero resistance.
As can be seen from the diamagnetic levitation of pyrolytic graphite, simple levitation is not a good way to prove the Meissner effect is occurring. You need a good magnetization measurement versus temperature and magnetic field or a physical measurement of an array of fluxoids (STM), at least a picture of a ferromagnetic particle decorated surface showing a fluxoid array in a magnetic field.
The absolute best way to prove superconductivity is to make a SQUID using a Josephson Junction(JJ). A SQUID is actually a single macroscopic quantum object and its magnetic and RF properties can’t be duplicated using normal materials and normal tunneling. If they can make samples as big as the one shown in the levitation experiment, there are a number of ways of making JJs that don’t require integrated circuit processing (point contact JJs are easy).
True, but on the other hand, it’s a question of what you’re really looking for. Suppose someone found a material whose resistivity at room temperature was, say, one ten thousandth that of copper. That wouldn’t be a true superconductor, and it couldn’t do some of the things that superconductors do, but for the vast majority of applications, it’d be good enough.
I’m surprised by that. I don’t have the scientific knowledge to even read the paper, but on other forums people are saying this is extremely easy to replicate the experiment (which I understand it not at all what peer review does). One called it the something like “the materials science equivalent to a baking soda volcano” and said there should be multiple groups having their own experiments in two weeks.
I have seen lots of people complaining about the quality of the paper itself and the charts contained therein, though. And it’s a very big claim. I always enjoy talking about it and hearing the “what ifs,” but I’m waiting for replications before I’m going to believe it.
Actually, many of the effects that cause drastic drops in resistance are due to creation of low current capability channels with little utility for real world conduction needs (like magnets).
Creating the material is relatively easy. How they tested the material is the more opaque part.
But that’s something that should be remedied by those groups who are following up.
Okay. Definitely seen some speculation on testing artifacts, too. Guess we’ll see.
That’s what I’m reading, too.
… which in itself is quite unscientific / unprofessional … so I am pretty sceptical
darn … how I’d love to be WRONG!!!
A good summary about the latest from the inimitable Derek Lowe:
https://www.science.org/content/blog-post/room-temperature-superconductor-new-developments
The short version is that while there have been some possible replications, we’re still waiting on something more solid. But that should probably be expected at this point since the material synthesis looks like it might not be entirely trivial (in particular, because there’s a step involving substituting copper into lattice locations with lead, but there are two different locations and the one that is useful here is not the energetically favorable one).
So far, the material also looks to be theoretically sound. Two groups have run it through simulations, and some of the properties are what you would expect with a high-temperature superconductor. That doesn’t prove anything, yet–but it doesn’t obviously violate anything we know. As Lowe mentions, this puts it in a different category than cold fusion, where our understanding of physics would have had to be totally wrong for it to be true.
Overall, definitely still reason to be highly skeptical, but I’d say it’s well past the point where it’s just some obvious fraud. There is probably something interesting about the material even if it isn’t superconductivity. Who knows; maybe it’ll have an entirely new electrical property that hasn’t been predicted before.
Here’s a long message board thread that purports to follow all the replication experiments that have been publicly announced. I’m linking to the last (currently) page, which has a table that they’ve been updating. (FYI Reliability of Claim is based on the trust they have in the replicating organization)
Claims of Room Temperature and Ambient Pressure Superconductor | Page 19 | SpaceBattles
Since you can get some sort of levitation for paramagnetic, diamagnetic, and superconducting materials, I’m not sure I find videos of levitating chips to be much of a step forward. I do wonder why no one picks up the magnet and turns it upside down. I believe that only superconducting samples will hang suspended from the magnet by the flux lines.
I would not want to try to count the number of theory papers that appeared in the late 80’s showing conclusively why certain materials would be superconducting. Not even the ones that predicted perovskite superconductivity were absolutely correct. As far as I know, there is still no trustworthy predictive theoretical treatment of superconductivity (even the elemental superconductors).
Speaking of the late 80’s, here is a short message I just received from a colleague (in regard to the current excitement).
This does not feel like the 1987 frenzy but it should be lively for a while.
Thanks for the link! That’s a good summary. Though I wish it was a live online spreadsheet or something instead of a forum post.
I agree; outside of the original, the only video I’ve seen was of a very tiny chip, and the demonstrated levitation could have been from any number of sources. It isn’t a step backward, but not much forward either. Still–not going backward is probably the most we could really expect this early in the process.
ETA: I did order a flake of pyrolytic carbon to have some fun with. Still on its way…
For about $100, you can buy a small YBCO puck. All you need is some magnets and a thermos full of liquid nitrogen and you too can try this (I’ve played with one of these):
Now I just need a convenient source of liquid nitrogen…
I’ve always had easy access to LN, but I’ve been told you can buy it pretty much everywhere, at welding supply stores or gas suppliers like Airgas. Apparently, at some suppliers it is like buying a keg of beer. You leave a deposit for the dewar and they’ll sell you the LN that fills it.
On the plus side, you can also make ice cream…
taking home Derek’s conclusion (same link posted by Dr. Strangelove)
Conclusion
I am guardedly optimistic at this point. The Shenyang and Lawrence Berkeley calculations are very positive developments, and take this well out of the cold-fusion “we can offer no explanation” territory. Not that there’s anything wrong with new physics (!), but it sets a much, much higher bar if you have to invoke something in that range. I await more replication data, and with more than just social media videos backing them up. This is by far the most believable shot at room-temperature-and-pressure superconductivity the world has seen so far, and the coming days and weeks are going to be *extremely damned interesting.*
(my emphasis)
interesting times, indeed
I’ve been to a party where we all made ice cream with liquid nitrogen. The guy who hosts is usually short on cash. It can’t be very expensive to get liquid nitrogen. (And it does make excellent ice cream.)
So… If this is for real, what does it mean? I confess i have visions of rampant lead pollution. But what does a room temperature super conductor do for us?
LN2 is cheap, and not that hard to get. But it’s not easily storable and not something you can pick up at the grocery. So a bit annoying.
I went through a lot of extra effort in building a cloud chamber that didn’t need dry ice to operate. Aside from alcohol, it needs no consumables at all. Dry ice actually is available at most grocery stores, but still annoying to get. So I’d rather have something that was self-cooling.
As for the practical applications here–it’s too early to tell right now, as it depends on the properties of the material. There’s a good chance the current material won’t be very practical, but just having an example will undoubtedly lead to other variations.
But what’s at least potentially on the table? A few possibilities:
- Extremely efficient power lines. The grid loses around 5-10% just in transmission, and that would go to zero with superconductors. Superconducting transmission only exists in very limited scenarios due to the cooling requirements.
- More efficient motors and generators. It would also totally eliminate the need for rare-earth materials, since you can just have a superconducting magnet instead of a permanent magnet. Useful for EVs, wind turbines, etc.
- Same goes for passive converters such as electrical transformers. They can be smaller and more efficient.
- Better and lower-cost MRI machines. Current ones typically need cryogenic cooling (because they use normal superconductors), or have lower quality due to using ordinary electromagnets. Room-temperature superconductors can get the best of both worlds. This could make MRIs so cheap that they are used even for very routine purposes, as well as cheap enough to be widely deployed in the developing world.
- Gets us one step closer to practical fusion. Fusion depends heavily on magnets, to the point where doubling the magnetic strength gets you 16x the efficiency.
- Extremely sensitive antennas. This could give cell phones higher bandwidth and make them more power efficient, make radar more accurate, and so on.
There are lots of other possibilities, but those are some big ones. Whether they pan out depends on the characteristics of the material–in particular, the maximum amount of current it can pass and the maximum magnetic field strength. The initial report suggests that their material is fairly weak in this regard. But it remains to be seen how it works out. Not to mention the possibility of variations on the material.
I wouldn’t be concerned about the lead. The stupidest thing you can do with lead is put it in your fuel and burn it so that everyone is constantly breathing it. That’s obviously not happening here. In its various solid forms, lead is pretty inert (as long as you keep the kids away from “wall candy”).
Almost every car on the road has several kilograms of lead in its battery. But it’s not a significant source of contamination because it’s among the most highly recycled things out there. And in this application, it will be even less of a problem because the cabling will be quite valuable in its own right and have only a small proportion of lead in it anyway.
that!
weren’t the first “filaments” in light-bulps made with carbonized plant fiber or so … which pretty much worked just as “proof of concept” … I assume the new material (TL-99 sp?) will hold a similar place in history (if things work out)
… and I agree that this norm.temp.SC would make millions of things (even the most insignificant ones) work better/more efficient (think: e-cars with twice the range) … so it will eventually filter into anything …
One point I’d like to add to Dr.S’s list:
- batteries (a key characteristic of a good Lithium battery is their low internal resistance (IR) … if you do not have low IR, that means a lot of the energy stored in the battery will be mis-used heating the battery up when “driven hard” (something you do NOT want) … so - that could filter in nicely into all the new energy-storage-thingies going on right now on the planet
- lower noise-floors for everything (where this might be relevant) … so better Signal-to-Noise ratio (audio, video, telescopes and all kinds of image-creating-tech)
I can’t wait for my new LG - Superconductor (R) washer-dryer combo to arrive!
Can you have superconducting semiconductors ?