GPT4 confirms for me that the Meissner effect does not require flux pinning:
“Yes, indeed, you’re correct. Flux pinning, also known as quantum locking or quantum levitation, is a slightly different phenomenon from the pure Meissner effect and can play a crucial role in the interaction between a magnet and a superconductor.
In the Meissner effect, a superconductor will expel all magnetic fields, creating a repulsive effect. However, in type-II superconductors, there are exceptions where some magnetic flux can penetrate the material in the form of tiny magnetic vortices. These vortices can become “pinned” in place due to imperfections in the superconductor’s structure.
This flux pinning is the basis of quantum locking, where the superconductor is ‘locked’ in space relative to the magnetic field. This can create the illusion of levitation in any orientation, depending on how the flux was pinned. For instance, a superconductor could be pinned in place above a magnet, below a magnet, or at an angle.
So, yes, it is indeed important to consider flux pinning when discussing the behavior of superconductors in a magnetic field. Thanks for pointing out this nuance!”
I think Sabine is just not used to seeing small pieces of superconductor floating over large magnets. Every Meissner effect video that I can find shows the reverse: small magnets floating on top of pieces of cooled superconductor. This makes sense because it is hard to cool something that is floating in the air.
I would have considered fact-checking to be one of the tasks GPT is least suited to, given its tendency to say made-up things just as confidently as true things. (And also because the questions it’s most likely to answer correctly will usually be ones we can easily look up by ourselves.)
edit: whichever very-high-karma user just gave this a strong disagreement vote, can you explain why? (Just as you voted, I was editing in the sentence ‘Am I missing something about GPT-4?’)
GPT4 confirms for me that the Meissner effect does not require flux pinning: “Yes, indeed, you’re correct. Flux pinning, also known as quantum locking or quantum levitation, is a slightly different phenomenon from the pure Meissner effect and can play a crucial role in the interaction between a magnet and a superconductor.
In the Meissner effect, a superconductor will expel all magnetic fields, creating a repulsive effect. However, in type-II superconductors, there are exceptions where some magnetic flux can penetrate the material in the form of tiny magnetic vortices. These vortices can become “pinned” in place due to imperfections in the superconductor’s structure.
This flux pinning is the basis of quantum locking, where the superconductor is ‘locked’ in space relative to the magnetic field. This can create the illusion of levitation in any orientation, depending on how the flux was pinned. For instance, a superconductor could be pinned in place above a magnet, below a magnet, or at an angle.
So, yes, it is indeed important to consider flux pinning when discussing the behavior of superconductors in a magnetic field. Thanks for pointing out this nuance!”
I think Sabine is just not used to seeing small pieces of superconductor floating over large magnets. Every Meissner effect video that I can find shows the reverse: small magnets floating on top of pieces of cooled superconductor. This makes sense because it is hard to cool something that is floating in the air.
I would have considered fact-checking to be one of the tasks GPT is least suited to, given its tendency to say made-up things just as confidently as true things. (And also because the questions it’s most likely to answer correctly will usually be ones we can easily look up by ourselves.)
edit: whichever very-high-karma user just gave this a strong disagreement vote, can you explain why? (Just as you voted, I was editing in the sentence ‘Am I missing something about GPT-4?’)