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My main character is one with the gift to control electricity. Despite this obvious flaw in reasoning I try to keep it as scientifically accurate as possible so he cannot for example zap someone from miles away but must touch him or be really close (within a meter) and expend a lot of mana. My idea is as follows: In a dire situation he uses all of his mana to power an electrical current in his body and induces a magnetic field which will induce an opposite electric current inside the bullet which in turn will create an opposite magnetic field which will fight it out with the one created by the MC thus diverting the bullet.

Is my thinking and understanding flawed in this? If so is there any way to achieve this effect? (He doesn't die because he has been blessed by the mana. Yes I know not very scientific) Thank you all for your time and answers

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    $\begingroup$ Minor side effect: the ginormous EMP required in order to induce a significant current in tiny conductor (= bullet) will destroy any electrical appliance, motor, generator, power line etc. on a radius of many miles... (And the current necessary to generate said ginormous EMP would be awesomely huge, think a zillion amperes. The electrothermic effect on the superhero's body would be something so see on the silver screen.) (The fundamental fault in the premise is forgetting that the tiny bullet is not the only conductor in the vicinity.) $\endgroup$
    – AlexP
    Commented May 2, 2020 at 17:25
  • $\begingroup$ The Other Answer Site says no. quora.com/… $\endgroup$
    – SRM
    Commented May 2, 2020 at 17:37
  • $\begingroup$ Bullets are made of materials that are not affected by magnetic fields much. This video shows steel pellets being deflected by a strong magnet, but those aren't normal bullets and are a lot slower than normal bullets. $\endgroup$ Commented May 2, 2020 at 21:52
  • $\begingroup$ @StephenG - any conductor in motion relative to a magnetic field can be influenced by the field, because the conductor becomes an electromagnet. . Back reading: en.wikipedia.org/wiki/Electromagnetic_induction $\endgroup$
    – Willk
    Commented May 2, 2020 at 22:25
  • $\begingroup$ @willk But not in any useful way for a bullet — the conductivity is too weak, the speed too high — unless you are generating a field of such strength as to carve up humans in the area who have iron rich blood. $\endgroup$
    – SRM
    Commented May 3, 2020 at 3:42

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Melt the bullet with ohmic heating

Melt the bullet.

https://www.youtube.com/watch?v=qkeRp8h3soo

Lead bullets are not ferromagnetic, so no stopping them with electromagnetism that way. They are weakly diamagnetic and repelled by a magnetic field but it would need to be phenomenally strong to stop a bullet. A bullet traveling thru a magnetic field could induce a magnetic field in the bullet, producing an opposing force - lead is a decent conductor and so it could work the way proposed in the OP with a strong enough field.

But stopping bullets with magnetism - so Magneto! Been done, been done.

Your hero instead magnetically generates an electrical field inside the bullet. Electrical resistance then melts the bullet. That is what is happening in this video. The lead melts pretty quick.

The former bullet is still coming through the air, and it means the hero gets splashed with molten lead. It does not have penetrating power but it will splash him with molten metal which will burn and smoke. The former bullets will probably stay mixed with his clothes. Hopefully he is not wearing his favorite jacket.

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    $\begingroup$ a melted bullet will still kill a person quite effectively. molten lead will still deliver a significant portion of its kinetic energy. $\endgroup$
    – John
    Commented May 3, 2020 at 2:31
  • $\begingroup$ @John Molten lead will quickly be dispersed into droplets which will be much more effected by drag than a solid bullet. I don't know the specific numbers, but the range of a liquid bullet will be much lower than that of a solid bullet. $\endgroup$
    – Ryan_L
    Commented May 3, 2020 at 3:31
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    $\begingroup$ @Ryanl If it is already moving at full bullet speed when you melt it only a couple meters out from yourself, it won’t decelerate that much I don’t think. I’m having a hard time trying to figure a way to test my hypothesis, however. $\endgroup$
    – SRM
    Commented May 3, 2020 at 3:45
  • $\begingroup$ @Ryan_L no it really won't the surface tension compared with the incredibly small amount of time means it stays more or less as a single droplet. of course if they are generating that strong of a magnetic field the ground under their feet will be molten as well and the gun will likely be dragged out of the hands of whomever fired it and come hurtling toward them and high speed, as will any ferric compounds in the soil. and anyone nearby will be thrown back or drown forward by the magnetic reaction of their own tissues. $\endgroup$
    – John
    Commented May 3, 2020 at 3:56
  • $\begingroup$ @SRM we don't know the range on this ability. Maybe you can melt the bullet as soon as it leaves the gun rather than near yourself. I agree it won't help you if the shooter is at arm's length, but how about across a street? What about even further? $\endgroup$
    – Ryan_L
    Commented May 3, 2020 at 4:03
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High current atmospheric discharge localized on the bullet. The plasma will find a discharge channel created by the energetic burn of the propellant.

Specific heat of vaporisation for lead (aka latent heat of fusion) = 4.799kJ/mol
1 mol of lead = 207g - a bullet of 7.62x39mm weights 7.9g, so the energy required to vaporize the lead in bullet is somewhere around 200J (to account for the energy require to heat the lead to melting point). Then, the copper jacket left behind is lightweight enough to go astray due to the drag.

Let's make it 10x that to account for losses and you get 2kJ to vaporize the lead in the bullet.

Putting 2kJ in perspective:

  • equivalent of lifting 102kg over a height of 2m
  • the average energy intake for a human is 8,700kJ/day - 2kJ is 0.023% of that

Now, I'm too lazy to compute what it would be to use tungsten bullets.

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Won't Work Given Your Constraints

I'm taking you at your word that you want to divert (aka, deflect) the bullet. Not melt it. Not destroy it. But move it out of the way.

On the one hand: Old cathode ray tube (CRT) TVs did this with electrons all the time: but pay attention. Tens of thousands of volts were needed to deflect one electron. Bullets are just a bit bigger than electrons.

On the other hand: Consider how much power it takes to operate a rail gun. The projectile needs up to 25 megawatts to do its job. But, rail gun projectiles are just a bit bigger than your bullet.

Finally, let's assume you have a third hand, upon which we find that when it comes to magnetism, lead stinks. In other words, you might need every joule of those 25 megawatts to move your bullet.

But, after looking at all those hands... can your superhero do it?

Sorry, no.

Worse, your superhero had better have super-observation and mental acuity. Using the average velocity for a 7.62mm NATO round of 2,700 ft/s, a bullet fired from 300 yards away would only need 0.33 seconds to travel from the gun to your superhero's heart. That's a third of a second to realize what's going on, figure out a solution, spin up the magnetic field, and divert the bullet. Those reflexes alone would make Superman look like a chump.

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