Just curious. I know humans are not “magnetic” in any meaningful sense, but is there a point that a magnetic field becomes so strong it could effect a person biologically?
It’s my understanding that effecting a human is the basis for how an MRI machine works. Off the top of my head it aligns the dipoles in your body, then does something else and takes a picture.
In fact it vibrates the nucleii in the atoms in your body, thus its old name Nuclear Magnetic Resonance. But that has no biological effect on the human, which is the OP’s question.
Yes, there is certainly a point at which a strong enough magnetic field will cause harm to a human.
According to this link, a magnetar is capable of producing magnetic fields on the order of ten gigateslas (which are hundreds of thousands of times stronger than any man-made magnet).
Upon further reading the link, the magnetic field of a magnetar would be lethal even at a distance as great as 1000 km, tearing tissues due to the diamagnetism of water. Atoms would also be greatly distorted–for example, a hydrogen atom would be elongated into a spindle shape 200 times narrower than its normal diameter in a field of 10 gigateslas.
Unless you’re a cheela, this can’t be healthy.
P.S. I wonder if the magnetic field generated by a magnetar would be strong enough to rip the iron atoms out of the hemoglobin in a person’s blood. 
Transcranial magnetic stimulation will totally mess with your head. It can be (and has been) used to temporarily stop specific parts of someone’s brain from working normally. Whether there are any long-lasting effects (bad or good) remains controversial.
The magnetic field of a magnetar is so strong that the energy density in the field is much greater than that of any Earthly material. That is to say, if you took a cubic meter of lead and annihilated it with a cubic meter of antilead, the energy released would be significantly less than that in two cubic meters of the magnetic field. Now think of the kind of pressures needed to support something that dense, in a neutron star’s gravitational field.
A buddy of mine did his Ph.D. research on some applications of NMRI imagining. Sometimes they’d test stuff out on themselves because it was more convenient than getting a volunteer in. He said that if you move quickly through a strong field, it would make you dizzy or make your head hurt. That’s not major damage, but it’s an unpleasant effect.
Look what they did to Desmond on Lost.
Couldn’t vibrating the nucleii in the atoms in your body be considered having an ‘effect’ on a human being?
There are readily available videos of frogs and spiders being levitated with man-made magnets. Just scale them up a bit.
Gah!
Would it AFFECT a human being.
Would it have an EFFECT on a human being.
The only thing that can effect a human being is combining a human sperm and a human egg.
Unless we’re willing to believe that Jesus happened when Mary wandered too close to a magnetar.
In the comics, Magneto occasionally reversed the flow of someone’s blood (by grabbing the iron in their hemoglobin) to stun someone. In the movies, I believe he may have yanked the hemoglobin right out of someone’s body.
According to genius scientist Alex Chiu, the answer is YES.
For the movie, not exactly. A guard was dosed with metal (into his bloodstream), and when he got close enough to Magneto, he was able to pull that metal back out.
Human brains (and cognition) are manipulated with magnetic fields during research because it is non-invasive and generally non-destructive.
Water is diamagnetic. I believe this means that is is repelled and distorted by a magnetic force although the magnetic force needs to be massive in order to have this affect (or the amount of water very tiny) which is why it’s not something you’ll notice with a common magnet. You can easily imagine then that a powerful enough magnetic field could rip a human apart.
Human blood is electrically conductive (because it’s saline). So if the flow of blood crosses magnetic field lines, an electric current is generated. With a powerful enough field the flow of your own blood would interrupt your heart or brain.
But we’re electrical conductors. There are supposed to be effects from induced currents while shaking your head around in a strong magnetic field. Oooo, the lights, the colors, the Magnetophosphenes
“When magnetic fields were used in earlier research to disrupt electrical activity in this part of the brain, previously numerate volunteers temporarily developed discalculia, finding it much harder to solve maths problems.”
I’m pretty sure magnetic fields have never effected a human being. They may have had an effect on someone’s nuclei, however.