671–680 of 906 posts
Lots of problems with the paper, they claim. It is not up to the standards of current SC research. One of them says Dias's work shows more merit than this.
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The video shows that this is all bollocks
This is the better video: https://sciencecast.org/casts/suc384jly50n
But still rather unconvincing.. especially if this is the best they could produce as a levitation proof video to publish.
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It's my impression, and it seems to be the consensus here that it is very unlikely that this is a mistake. This is either very real or completely fabricated. You don't have a piece of ceramic keeping its distance to a magnet by some unexpected phenomenon or measurement error. And given the easiness in reproducing the study, there doesn't seem to be any point in fabricating it.
The main worry is whether we're dealing with wholly rational actors. People convince themselves they're seeing an effect, and then seemingly completely erratic things to try and prove it on the conviction that with just a bit more effort they'll get it for real. Like you'd question why someone would photoshop results[1] in a paper, because surely they'd have to realize they're fabricating data, but they go ahead and…
Nonscientific objections:
* it was published in a low h-index journal (not a scientific objection)
* poor formatting, misspelled title (not a scientific objection)
* patented and has a company (not a scientific objection)
* seems too simple, it has to be more complex than that, how could we have missed that? (not a scientific objection, also rather ahistorical)
I consider all of these pretty irrelevant given that the authors are not no-names and the actual paper makes clear claims, does exactly what everyone says you should be able to do if you have a real superconductor (show a video of it floating!) and makes replication easy. If it's straight up fraud it will be easy to discover.
There were also many pseudoscientific objections raised by field-adjacent people that I found uncompelling, responses from people actually in the field in parentheses:
* The first video looks like normal copper, the second like other diamagnetic materials or is otherwise unconvincing (not evidence against it being superconducting, at least one materials science lab had several members look at it and thought it looked legit).
* They are trying to hide the magnet structure somehow (the video shows it in clear view).
* The wafer isn't fully levitating or the way it falls is suspicious (not really unexpected given that the superconductive part is supposed to be present in only a few percent of the material).
Scientific objections I find more compelling made by people more familiar with the field, but more bourne of natural skepticism than disqualifying, with there being a lot of subtlety:
* both effects shown can be achieved in known ways by non-superconducting materials (but at the same time? would at least be a major material science advance in that case as it would apparently require diamagnetism ~ 150x as strong as graphite. Author who mentioned this said it would be "materials science magic" and I'm not sure why you'd rather believe in this than superconductivity given that neither have ever been seen before and it's consistent with sueprconductivty. Unless it's straight up fraud).
* Mesner effect graph don't go exactly to zero / happen exactly where you'd expect, maybe reflects a measurement error? (apparently, given the small % of the material that's supposed to be superconducting and material distribution, this isn't really evidence either way. not like we have other room temperature superconductors to compare it to).
* no max temperature where superconductivity vanishes measured, so is it really superconducting? (standard measurement devices only go up to what they reported, scientists seem very mixed about whether it would be easy to DIY measurement at higher temperatures for such a small current)
* not a similar mechanism to known good past "high-temperature" superconductors, and proposed explanation doesn't really make sense given slight deviations in pressure compared to what is in this substance (other scientists seem to disagree and think there could be something there, but it would also not be the first time something novel was discovered and worked for reasons totally different than those the scientists initially imagined)
Overall I find the quality of the objections really weak which increases (to me) the chances that there is something novel here, even if it's not superconductivity. That or it's obvious fraud and we'll know in like three days.
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I think "superconductor MRI" is redundant. The failure modes would mostly be the same as for the big ones: sucking in metal chairs if you're not careful.
I hope I never find out which is worse of chairs vs. piercings…
After skimming the paper, it reads like a legitimate paper even though I have zero expertise in the area. That it is in Word instead of LaTeX makes it feel a bit less legitimate to me and they could of course always have some error in there setup. The most notable thing to me was that this was done in a thin film where structural defects are supposedly responsible for strain in the material which in turn enables the…
Word is one of the most common tools for writing papers. There was a study a while back that looked at the quality of Word or Latex papers. The study found that researchers using Word were more effective, and the working theory that explained it was that people who focused on the research did better research, and people focusing on the typesetting do better typesetting.
A couple of posts about how poor that paper was:
• https://lemire.me/blog/2015/01/14/knauff-and-nejasmic-recomm...
I'll say, for "room temperature", that's certainly no room I'd want to be in.
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My understanding is that modern CMOS circuits dissipate around 1 pJ (10^-12) per bit, so even if we are limited by the Landauer's principle, it would still be a 9 orders of magnitude improvement. I would surely love a CPU that uses microwatts instead of hundreds of watts.
I apologize, I couldn't not resist to the occasion of being technically correct. I should also have stated that a superconductors based CPU would be incredibly cool figuratively and physically!
I work in research, so I understand that it is very important to keep in mind the limits imposed by nature itself. Heck, I had more than one argument with idiot bosses who wanted to break the laws of physics or maths...
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Sure, but the point is that they hardly caused a revolution in energy storage. If fuel cells didn't exist, for the average person life would be exactly the same. Revolutionary tech does change normal peoples lives, and sometimes very rapidly, but a lot of stuff that looks revolutionary just kind of never works out. I'd say nuclear power is probably the prime example of this. It was supposed to bring us electricity to…
> It was supposed to bring us electricity too cheap to meter, but it's actually the most expensive form of generation that anyone bothers to build. That's not a technical issue though. Cost efficiency of nuclear energy has actually declined over time...which, unless science is devolving, should tell you something hinky is happening.
Nuclear can be done safely, we know this, because every single time there has been an accident it's because an operator did something wrong. The problem is that nobody has yet designed a reactor that a sufficiently amoral operator could not make unsafe. Even if you have completely automatic and passive safety features, a bad operator could disable them if a false positive happens even once and costs them money.
For this reason nuclear has a LOT of regulation and red tape. It has far more than any other kind of energy, because even though the risk of accident is low the outcome of an accident is worse than any other kind of energy except hydro. Hydro has fewer things that can go wrong that are cheaper to check however, so regulations there tend to not be as expensive.
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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…