There are different magnets of different strengths, and scientists in labs are constantly pushing the limits, trying to make stronger ones.
And the ones in MRIs are really freaking strong, that’s why these machines are so expensive
or people with like metal filings in skin would be turned into bloody mess. We’re talking all machinists here
Yes machinists are at risk, metal workers are specifically mentioned on this website:
Items that may create a health hazard or other problem during an MRI include:
A metallic foreign body located within or near the eye (such an object generally can be seen on an x-ray; metal workers are most likely to have this problem)
No they are not blended to a pulp, but yes they can be injured
not really possible to make magnets that strong for a number of reasons
What reasons? MRIs use superconductors cooled with liquid helium to overcome electric resistance
magnetic field is in the tube, which is why it works. Shit pulled towards middle
So the magnets in an MRI are electromagnets yes, however they’re not quite the same thing as a nail with some coils of wire and a 6 V battery. They’re super conductors cooled with liquid helium to get them below the critical point. Because of the extreme temperatures and magnetic fields cycling them up and down is a very involved process that shortens the life.
Hospitals basically never turn them off, and certainly by the time patients are being seem they’re on and remain on. They don’t quench them between scans. The pulsing heard during a scan is not the main magnet turning on and off, a common misconception.
strength:
Generally the magnets are powerful for magnets, but they are not that strong in terms of making a buttplug become a bone snapping projectile. Most are about 1 T inside the chamber which is around as strong as the field strength of powerful magnets in consumer devices. The field is larger, and consequently they have more time to accelerate things but you can remove buttplug sized ferromagnetic objects from them by hand. For instance see: https://www.youtube.com/watch?v=I6OHy3MipS4 playing with a keyring at the start. There is not enough force involved, a person would stop approaching when they felt extreme discomfort of buttplug moving and walk backwards.
danger with metal filings:
Safety assessments are absurdly cautious. read for example the SDS for conc. hydrochloric acid. you can pour it over your hand and get a mild itchy rash.
Blinding someone isn’t worth it so they’re very paranoid about largish (e.g. mm sized) filings in eyes. People with iron in their skin frequently get MRIs and report mild pulling and heat (see keyring example). They don’t experience the shards ripping out of their flesh or anything dramatic.
So the question about magnetic strength limits given zero resistance is very interesting! Glad to see interest as it’s an obvious question very few people ask.
All superconductors have a property we call critical field. Above this limit the material is no longer able to compensate for and exclude magnetic fields, and the superconducting properties collapse.
So if we made a coil of say YBCO (a common type 2 in lab examples) and we pumped more and more current through it, eventually it overwhelmed the material and suddenly resistance would skyrocket, generating heat causing a feedback cycle and it would probably melt to slag.
Why are you spounting this half-coherent nonesense?
No, MRIs use electro magnets which can be turned off. But they are on most of the time
Yes the metal would be pulled towards the machine as they approach, but the magnetic force quickly becomes much stronger inside the machine
There are different magnets of different strengths, and scientists in labs are constantly pushing the limits, trying to make stronger ones. And the ones in MRIs are really freaking strong, that’s why these machines are so expensive
Yes machinists are at risk, metal workers are specifically mentioned on this website:
https://www.radiologyinfo.org/en/info/safety-mr#fff2f44ba7624ad1a1ac3b91ab12b599
No they are not blended to a pulp, but yes they can be injured
What reasons? MRIs use superconductors cooled with liquid helium to overcome electric resistance
? Yes MRIs do infact work
There is no need to be so hostile.
always on:
So the magnets in an MRI are electromagnets yes, however they’re not quite the same thing as a nail with some coils of wire and a 6 V battery. They’re super conductors cooled with liquid helium to get them below the critical point. Because of the extreme temperatures and magnetic fields cycling them up and down is a very involved process that shortens the life.
Hospitals basically never turn them off, and certainly by the time patients are being seem they’re on and remain on. They don’t quench them between scans. The pulsing heard during a scan is not the main magnet turning on and off, a common misconception.
strength:
Generally the magnets are powerful for magnets, but they are not that strong in terms of making a buttplug become a bone snapping projectile. Most are about 1 T inside the chamber which is around as strong as the field strength of powerful magnets in consumer devices. The field is larger, and consequently they have more time to accelerate things but you can remove buttplug sized ferromagnetic objects from them by hand. For instance see: https://www.youtube.com/watch?v=I6OHy3MipS4 playing with a keyring at the start. There is not enough force involved, a person would stop approaching when they felt extreme discomfort of buttplug moving and walk backwards.
danger with metal filings:
Safety assessments are absurdly cautious. read for example the SDS for conc. hydrochloric acid. you can pour it over your hand and get a mild itchy rash.
Blinding someone isn’t worth it so they’re very paranoid about largish (e.g. mm sized) filings in eyes. People with iron in their skin frequently get MRIs and report mild pulling and heat (see keyring example). They don’t experience the shards ripping out of their flesh or anything dramatic.
Here is an alternative Piped link(s):
https://www.piped.video/watch?v=I6OHy3MipS4
Piped is a privacy-respecting open-source alternative frontend to YouTube.
I’m open-source; check me out at GitHub.
Ah seeing your edits.
So the question about magnetic strength limits given zero resistance is very interesting! Glad to see interest as it’s an obvious question very few people ask.
All superconductors have a property we call critical field. Above this limit the material is no longer able to compensate for and exclude magnetic fields, and the superconducting properties collapse.
So if we made a coil of say YBCO (a common type 2 in lab examples) and we pumped more and more current through it, eventually it overwhelmed the material and suddenly resistance would skyrocket, generating heat causing a feedback cycle and it would probably melt to slag.