Radiologist/Biomedical Engineer here. I once did a review of the physiological effects of magnetic fields as was our current understanding in the last decade. in general, things that get altered with sufficiently large magnetic fields:
- Cardiac electrical conductivity
- Muscular electrical conductivity
- Fibrin (protein necessary for clotting blood) meshes get distorted
- There is DNA genotoxicity, and mutations start to appear
- Diamagnetic effects start taking over (Most extreme demonstration I've seen so far is the levitating frogs and grasshoppers, which seem quite content afterwards, so no ill effects apparent)
Bottom line is that pretty much everything in our bodies that contains water can be affected by a sufficiently large static magnetic field. Some critical physiological processes may get disrupted way earlier than the atomic distortions cited in the article, so I believe much less than 100k Tesla would be needed to kill a person.
I think that you'd end up with neurological effects before the electrons were ripped out of atoms. I mean, our nervous system is effectively controlled ionic exchange.
Definitely. Furthermore, the effects of motion in that field could induce a lot of current and heating in a person. Some of the experimental super-high field strength MRI scanners are reportedly prone to zapping experimenters.
This is awesome. Wonder if it could be possible to make military helms that would prevent solders from disobeying orders or for helping them stay calm and focused by shutting panic part of brain.
Then a magnetic field of sufficient power would probably kill you long before the effects described in the article. I'm amazed that someone other than me has thought about this!
Blood electrocution would get you first. Moving conductor in a magnetic field generates a current, and you'd just need a current big enough to confuse the cardiac nerves. Given that existing MRI research magnets can give weird nervous system feelings when patients wiggle, just an order of magnitude or two more and you'd get knocked out by your own circulating blood.
Don't most of the problems with nerve stimulation in existing MRI systems come from the gradient coils rapidly modulating the magnetic field, rather than people moving around?
The sci-fi book Blingsight by Peter Watts explores humanity's 1st encounter with an alien object that contains extremely powerful magnetic fields. Has all sorts of interesting consequences.
Off-topic, but Blindsight kicks ass on any number of levels. Scientifically plausible vampires! In space! And the only genuinely creepy aliens I think I've ever come across in fiction.
I read that one. Not the greatest from a raw storytelling point of view, but one of the more interesting portrayals of what alien life might be like that I've read.
Has anyone looked at the effects not on particles, but on changes to reactivity in the presence of magnetic fields? You don't need to rip apart molecules to kill us. Make certain reactions a little more or less likely to occur and we stop functioning.
I have seen some discussion of how heavy water could be lethal if it were to replace all of a body's water based on its very slight differences in reactivity.
Something called Transcranial Magnetic Stimulation alters brain activity at about one Tesla (10,000x earth's field).
TMS has been shown to induce euphoria, amnesia, and relieve depression. Unclear what stronger magnetic fields could do. A ten Tesla magnet can levitate a small animal.
I work in this sector, and what you say is correct, however it is important to note that in TMS the fields are pulsed over millisecond time intervals. In doing so they can induce an electric field which can cause neurons to fire. The time varience is crucial. A 3T static field from the magnet of an MR scanner is far less dangerous than a 1T field pulsed in the vicinity of your brain. That is providing that there aren't any ferromagnetic objects close to the MR scanner!
Radiologist here. We regularly image patients in 3T MRI scanners. As long as they don't have certain metal surgical implants, a pacemaker, or metallic foreign bodies, there is no problem.
The effect depends on field signal characteristics (frequency, amplitude, wave shape), duration of exposure, genetics and metabolism. Some bacteria can be negatively affected even by 10 mT.
In clinical trials people were "safely" exposed to up to 3 T.
Not necessarily. Iron oxide is somewhat ferromagnetic but iron chloride is paramagnetic. So just having some iron atoms in something isn't enough to make it ferromagnetic.
Interesting: ... "scientific research can provide some measure of confidence that short-term, acute exposures up to about 1-2 T [1000-2000 milliT] should be safe... However, it is not possible to determine whether there are any long-term health consequences even from exposure in the milliT range because, to date, there are no well-conducted epidemiological studies with sufficient power to be able to come to any conclusion on this, and there are no good long-term animal studies."
I think a lot of new technologies will emerge when we can routinely control very large magnetic fields. I just think the technological implications are largely unexplored.
What about semipermiatic structures such as the blood brain barrier? According to The Internet(tm), permeability in rat brains is affected by a mere 0.1T.
I've wondered about this exact question for a while now.
If I were to become a lunatic dictator, this is how I would deal with dissidents. (Disclaimer: I have no intention of ever becoming a lunatic dictator!)
Bottom line is that pretty much everything in our bodies that contains water can be affected by a sufficiently large static magnetic field. Some critical physiological processes may get disrupted way earlier than the atomic distortions cited in the article, so I believe much less than 100k Tesla would be needed to kill a person.