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Magnet strong enough to rip the iron out of your body feasible?


Is it possible, given a strong enough magnet, to rip out iron based molecules out of the blood stream/body of a person/animal? Would such an event be the thing that kills someone or are there other adverse effects that would kill a person. I've seen reports of dizziness and metallic taste during MRI scans, but it's not fatal, and AFAIK, the effects of strong magnets on a vertebrate have not been tested.

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Actually, they have been tested. I've seen a video of a frog being held in a magnetic field strong enough to keep it suspended in air without touching any object. ‭Olin Lathrop‭ about 2 months ago

DonielF's very good answer mentions this, but I feel that the obvious (and common) misconception behind the question is also worth highlighting clearly here: Iron in its metallic form is strongly magnetic. Iron-containing biomolecules are generally not more magnetic than most other substances (i.e., hardly at all). Hence the silly-sounding extremes reached in the factual answers below. ‭xtal‭ 10 days ago

2 answers


This question was discussed by Kyle Hill in his early video on the scene in Days of Future Past in which Magneto rips out iron from the security guard. He begins by noting that the large majority of a person's iron is bound in hemoglobin, and nearly all of the rest in proteins in the spleen, bone marrow, and liver.

Iron bound in hemoglobin is somewhere between weakly diamagnetic and weakly paramagnetic. Solid iron is one of the most magnetic materials — hence the name of that category being ferromagnetic. There's 9-10 orders of magnitude difference between how responsive bound iron is to a magnetic field and how responsive solid iron is. Additionally, you'd have to output a magnetic field capable of overpowering the covalent bonds. I'm sure you can already see why this is going to be difficult.

To put actual numbers to this, Kyle poses the following reference points:

  • 1T: Nothing. This is your average refrigerator magnet. Enough to wipe his credit cards, maybe.
  • 8T: Enough that if your target moves, he might have a sensation of metal taste in his mouth, see flashes of light, or feel weird on his legs. This has nothing to do with iron; rather, the magnetic field induces an electric current in the target, which stimulates his nerves.
  • 16T: Scientists with way too much time on their hands have experimental evidence that frogs can be levitated at this field strength, and still live to croak the tale. The security guard is still tasting metal and seeing stars.
  • 50T: Probably enough to levitate the guard off the ground.
  • 100T: Either he'll die immediately of cardiac arrest (assuming the mental shock from everything else didn't already) from the magnetic field inducing a strong enough current to stop his heart, or he'll die later of DNA mutations as the magnetic field interacts with it on a molecular level.
  • 10kT: Yes, kiloTeslas. That's enough to unwind his DNA.
  • 100kT: The atoms in his body are so deformed that instead of being fuzzy spheres, the electron clouds are stretched into oblong ellipsoids. Chemistry doesn't work properly anymore. The iron is still covalently bonded to his hemoglobin, but if your target is somehow still alive by this point, he's dead now.
  • 1.0MT: At 1 million Teslas, your target is no longer a human, not even a human corpse. It's more like a levitating blob of organic mush. The blob separates into a few smaller blobs, differentiated by subtle molecular differences in how they respond to magnetic fields (Kyle skips over the details, but I'm going to appeal to molecular orbital theory I think to explain this one.)
  • 10MT: Finally the magnetic field can overcome the covalent bonds and rip the iron out of the now-blobified former human. For reference, this is roughly the magnetic field outputted by a neutron star; everyone within a few hundred kilometers is at best dead and at worst similarly blobified (probably Magneto included).

I haven't even gotten into the fallout of this; Kyle doesn't discuss things like the magnetic field interacting with the electric grid, or causing an EMP shockwave, or possibly messing with LEO satellites. Even if you're far enough away to survive, your credit cards are still wiped. Californians might survive, but they'll be seeing stars and tasting iron.

TLDR: Technically it's possible, but you'd need a homemade neutron star to pull it off. Also, it has a seriously large area of effect.

1 comment

@James Wasn’t meant to be literally coins, but I removed that line just to remove any confusion that it’s causing. ‭DonielF‭ about 1 month ago


Yes and No.


Therefore, strong enough magnetic fields have the ability to deform and even break objects. When a magnetic field gets stronger than about 500,000 Gauss, objects get ripped to pieces by the intense forces.

But No:

For this reason, scientists cannot build a machine that creates a magnetic field stronger than 500,000 Gauss and survives longer than a fraction of a second. Strong enough magnetic fields therefore destroy objects as we know them. Note that the magnetic fields used in medical MRI scanners are much weaker than 500,000 Gauss and are perfectly safe when used properly.

Source of both quotes What is the strongest magnetic field possible? Is there a limit? Answers provided by Dr. Christopher S. Baird

In theory it could happen, but creating the field is going to cause catastrophic events that make your experiment moot.

Edit to respond to comment

So if I understand this correctly, technically you could accomplish this in some sense, but you would already be dead by the magnetic forces required to accomplish it? — Cazadorro about 8 hours ago

The person would probably die when the machine exploded. As I understand it, the magnetic force required would not just rip the iron out of your body it would destroy the entire cell structure.

If you wanted to take out your kitchen sink, and the plumber used 1000 pounds of TNT, yes your sink would no longer be in the kitchen, and the kitchen would no longer be in the house, and your house and the neighbors houses would no longer be houses, and if you ever found your kitchen sink it would no longer be a sink.

1 comment

So if I understand this correctly, technically you could accomplish this in some sense, but you would already be dead by the magnetic forces required to accomplish it? ‭Cazadorro‭ about 2 months ago

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