8 ms·
How strong would a magnetic field have to be to kill you?
- mrfusion 12y agoWouldn't iron in blood be affected well before this point though?
- sp332 12y agoBulk iron is ferromagnetic, but many iron-containing molecules are not. Haemoglobin is not ferromagnetic. http://www.revisemri.com/blog/2006/mri-blood-iron-attraction/ http://www.revisemri.com/blog/2006/mri-blood-iron-attraction...
- tedunangst 12y agoI'd heard that severe haemochromatosis could trigger a metal detector. Is that just an urban legend?
- sp332 12y agoIt is paramagnetic, depending on oxygenation, so maybe.
- msandford 12y agoNot 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. http://www.thenakedscientists.com/HTML/questions/question/2848/ http://www.thenakedscientists.com/HTML/questions/question/28...
- Sharlin 12y agoIndeed, even stainless steel isn't necessarily ferromagnetic, even though it's mostly iron.
- aaronblohowiak 12y agoEven very hot iron is not magnetic. ( http://en.wikipedia.org/wiki/Curie_temperature http://en.wikipedia.org/wiki/Curie_temperature )
- TheLoneWolfling 12y agoI 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.
- simon_ 12y agoYeah, the strength of field that would literally destroy molecules is a ridiculously loose upper bound.
- irremediable 12y agoDefinitely. 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.
- ursidae 12y agoFor a practical example of this, see 'Transcranial Magnetic Stimulation': http://en.wikipedia.org/wiki/Transcranial_magnetic_stimulation http://en.wikipedia.org/wiki/Transcranial_magnetic_stimulati...
- swamp40 12y agoHere's a video of someone braver than myself experimenting with the effects of magnetism on his brain while he speaks: https://www.youtube.com/watch?v=XJtNPqCj-iA https://www.youtube.com/watch?v=XJtNPqCj-iA
- dkirtley 12y ago3 Tesla Magnetic field MRI's are now common and I have heard rumors of up to 7T machines in the works: http://www.healthdiagnostics.com/svc_hi_field.php http://www.healthdiagnostics.com/svc_hi_field.php
- dkirtley 12y agoThis actually a huge issue for space travel, all of the random electronics and possibly magnetic radiation shielding may be serious. http://www.nasa.gov/directorates/spacetech/niac/westover_radiation_protection.html http://www.nasa.gov/directorates/spacetech/niac/westover_rad...
- dkirtley 12y agoInteresting: ... "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." http://www1.mcw.edu/radiationoncology/ourdepartment/radiationbiology/Static-Electric-and-Magnetic-F.htm#.VLRAGyvF940 http://www1.mcw.edu/radiationoncology/ourdepartment/radiatio...
- frozenport 12y agoWould you be mechanically compressed by the field before your atoms deform?
- jorjordandan 12y agoI think you would be killed by the diamagnetic properties of water first... If you can affect water with a small magnet like this: https://www.youtube.com/watch?v=2FvWtEdY4sE https://www.youtube.com/watch?v=2FvWtEdY4sE 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!
- VLM 12y agoBlood 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.
- makomk 12y agoDon'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?
- loveNanaya 12y agoGradient effects in general: http://www.mrisafety.com/SafetyInfov.asp?SafetyInfoID=250 http://www.mrisafety.com/SafetyInfov.asp?SafetyInfoID=250 http://professional.medtronic.com/video-player/index.htm?contentid=ASSETS_117131&chapnum=2#.VLRCJGTF87M http://professional.medtronic.com/video-player/index.htm?con...
- gameshot911 12y agoThe 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.
- V-2 12y agoThere's also "The Invincible" by Stanisław Lem.
- dghf 12y agoOff-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.
- ufmace 12y agoI 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.
- krylon 12y agoI'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!)
- peter303 12y agoSomething 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.
- goodbyegti 12y agoI 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!
- ursidae 12y agoRadiologist 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. Some institutions have research magnets up to 7T: http://www.healthcare.philips.com/main/products/mri/research/ http://www.healthcare.philips.com/main/products/mri/research...
- xaa 12y agoMy research institute has a 11.7T (for small animals). Although I must say, using MRI, even such a powerful one, for research is not as useful or cool as you'd expect since it takes so long to do one scan.
- SixSigma 12y ago> there is no problem We are just beginning to investigative the post operative changes from anaesthesia in adults [1]. Can we be sure that there is no post MRI changes ? While I'm not suggesting there is any cause for alarm I don't think we should dismiss the possibility out of hand. [1] http://www.scientificamerican.com/article/hidden-dangers-of-going-under/ http://www.scientificamerican.com/article/hidden-dangers-of-...
- palakchokshi 12y agoSo I guess this means we are safe from Magneto :)
- mlrtime 12y agoYou mean this isn't possible? ;) https://www.youtube.com/watch?v=etPXBm0zRvM https://www.youtube.com/watch?v=etPXBm0zRvM
- deleted 12y ago[deleted]
- palakchokshi 12y agoHumor seems lost on this crowd... oh well
- sighsigh 12y agoUpboating to save you from the humorless neo-Victorian nationalists that have dominated HackerNews.
- mrfusion 12y agoI 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.
- Cricketwcup 12y agoearth is a very big magnatic field and it wont kill us. well i think we need a trillian times stronger magnatic field than earth to kill human.
- Irene 12y agoRelatively weak MFs could kill as an indirect result of the injury: http://mentalfloss.com/article/18405/mri-magnet-madness http://mentalfloss.com/article/18405/mri-magnet-madness http://boards.straightdope.com/sdmb/showthread.php?t=544233 http://boards.straightdope.com/sdmb/showthread.php?t=544233 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.
- sandworm 12y agoHas 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.
- xorcist 12y agoWhat 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.
- simonmd 12y agoRadiologist/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.
- wallflower 12y agoI've always wondered what would happen if you got trapped in the Superconducting Super Collider. Terminator 3 Particle Accelerator Scene https://www.youtube.com/watch?v=KKFnsFFdPh8 https://www.youtube.com/watch?v=KKFnsFFdPh8
- PhasmaFelis 12y agoWe do have an example of a synchrotron researcher who took a proton beam to his head. http://en.wikipedia.org/wiki/Anatoli_Bugorski http://en.wikipedia.org/wiki/Anatoli_Bugorski Surprisingly, he survived, with significant but not disabling neurological damage.