Earlier quoted context omitted.
It has lead in it.
Lead is safe to handle, you just can’t eat it.
Handling lead tends to result on lead being on your hands, which has a nasty tendency to result in lead being on your lunch if you are not careful.
Flux Pinning in sample of LK-99?
161–170 of 225 posts
Re: Flux Pinning in sample of LK-99?
#162Earlier quoted context omitted.
https://twitter.com/Andercot/status/1687748594563268608 seems to indicate that simply diamagnetic levitation cannot create the level of stability shown in this video.
I don't think that's right. Diamagnetic levitation is one of the ways you can get around Earshaw's theorem. Funny enough this is a quote taken directly from the wikipedia article that Andercot linked, in the "loopholes" section: >Earnshaw's theorem has no exceptions for non-moving permanent ferromagnets. However, Earnshaw's theorem does not necessarily apply to moving ferromagnets,[4] certain electromagnetic systems,…
How can a diamagnet be stable on top of a single dipole? Earnshaw's criterion being invalid just means that there is at least one static arrangement of magnetic dipoles that lead to stability. However, if you have a point-like diamagnet resting on top of a single dipole it can't possibly be stable because there is no point at which it will have zero net force and stable higher-order derivatives. You need something like a bowl-shaped magnetic field arrangement for it to stay in a single point, or have the diamagnet itself be shaped something like a bowl over the field.
Re: Flux Pinning in sample of LK-99?
#163Earlier quoted context omitted.
Seriously? To me this looks like a chip of graphite glued to an invisible thread. The way the object moves is not what I would expect from magnetism (see second 10 for instance)
This is what a pinned superconductor looks like. Here is a video I made of some YCBO over a small magnet: https://nt4tn.net/random/superconductor.mp4 you can see it settle back back when I move it with tongs (until i push hard enough to get it to snap into a new orientation). If I had a magnet that was much bigger than the superconductor it would look even more similar (less 'pivoty').
Excellent video, really very nice. I like it how you forced the flux pinning by punching a hole in the middle of the superconductor, that makes it all much more visible. You can practically visualize the fieldlines escaping through the middle and becoming an elastic pivot connected to the magnet.
Re: Flux Pinning in sample of LK-99?
#164Can anyone explain if the specimen was found through rigorous research or just sheer luck? Because it is starting to seem like it's the latter.
There is a combinatorial number of different materials out there. They chose a particular small subset of them that they predicted might have some interesting properties and, over two decades, discovered one that may have those properties.
Most hypotheses are wrong, and even if they turn out right it may well be a case of being right for the wrong reasons. Regardless, this is top tier research: unglamorous, uninstagramable drudgery guided by intellect. Sure, there's luck involved, but research always involves luck.
Re: Flux Pinning in sample of LK-99?
#165Earlier quoted context omitted.
According to this video: https://twitter.com/xmal/status/1300754522218913799 it is possible to have stable levitation using a copper plate below the magnet. OP's video has two stacked metal objects – could the lower one possibly contain copper?
That one is clearly rotating. Magnetic levitation with a rotating field is not too difficult (you can get levitating flower pots as cheap novelty toys) but the sample in the new video appears fully static. Edit: relevant Wikipedia: https://en.wikipedia.org/wiki/Spin-stabilized_magnetic_levit...
The video in the reply (https://twitter.com/xmal/status/1300794329347260417) seems to show levitation even when the magnet isn't rotating?
Re: Flux Pinning in sample of LK-99?
#166Earlier quoted context omitted.
I don't think that's right. Diamagnetic levitation is one of the ways you can get around Earshaw's theorem. Funny enough this is a quote taken directly from the wikipedia article that Andercot linked, in the "loopholes" section: >Earnshaw's theorem has no exceptions for non-moving permanent ferromagnets. However, Earnshaw's theorem does not necessarily apply to moving ferromagnets,[4] certain electromagnetic systems,…
How can a diamagnet be stable on top of a single dipole? Earnshaw's criterion being invalid just means that there is at least one static arrangement of magnetic dipoles that lead to stability. However, if you have a point-like diamagnet resting on top of a single dipole it can't possibly be stable because there is no point at which it will have zero net force and stable higher-order derivatives. You need something li…
Yeah you bring up a good point... I don't think it can.
But you CAN do it with concentric rings of magnets. Such magnets seem common for this exact demonstration actually. It doesn't look like one of those in the video though.
Re: Flux Pinning in sample of LK-99?
#167The most likely explanation: This is a speck of dirt on a string filmed as an attempt to manipulate the prediction markets.
Re: Flux Pinning in sample of LK-99?
#168Earlier quoted context omitted.
The thread is horizontally positioned, left to right, not vertically.
But you haven't explained how it looks like that. It could be that, but it looks like it's floating. What is it about the appearance of this thing which has you believing there is a string?
If there is a magician on the stage, you can safely presume there is no actual magic involved, even though you do not know how exactly the trick works.
For actual flux pinning, the first thing you would do is show what happens if you put the thing upside down. It should stick. Even if it does not, you would show that it does not.
Re: Flux Pinning in sample of LK-99?
#169Someone linked to this on the manifold market: https://imgur.io/a/AY1oaIO it does look a bit weird to me but I am not expert enough to tell if this could be explained by optical/compression effects.
Looks unlike any compression artifact I have ever seen. Two remarkable discoveries in one video! Big, if true.
Re: Flux Pinning in sample of LK-99?
#170Earlier quoted context omitted.
Such tiny samples warm up to room temperature very quickly, on the order of a few seconds. In my experience, it's not possible to make such small pieces of YBCO superconductor levitate, they warm up too fast.
No frost on the sample either. The only way I can think of to fake this in camera is to make the "sample" out of a strong magnet, and make the "magnet" a hollow shell concealing a chilled piece of YBCO!
You would be surprised what can be achieved with bit of nylon string and an appropriate camera setup. If this is a most groundbreaking discovery, why waste all that screen resolution on the backdrop?