Electromagnectic forcefields

[Sarevok]

I am wondering whether strong electromagnetic fields can be used as a forcefield. One of Mr Wong's essays on shield technology mentions that electromagnetism is much stronger than gravity. Electromagnetic fields would definately stop particle beams, plasma bolts and railgun projectiles all of which are strongly influenced by magnetic fields. But what about non metalic objects ?. Given the fact that not only metals but all matter are effected by powerful electromagnetic fields can they be used as forcefields ?

[Arrow]

I forget whos doing the research, but there is one college (I believe one of the ones in Ohio) is using powerful electromagnetic fields to suspend organic objects (spiders, ants, and the like). They say that if they get 20+ megawatts, they could float a human.

I think its only a question of power, as everything is slightly magnetic.

The real question is can you create a magnetic field that interferes with lasers?

[Sarevok]

I forget whos doing the research, but there is one college (I believe one of the ones in Ohio) is using powerful electromagnetic fields to suspend organic objects (spiders, ants, and the like). They say that if they get 20+ megawatts, they could float a human.

I think its only a question of power, as everything is slightly magnetic.

The real question is can you create a magnetic field that interferes with lasers?

Saw that one on the discovery channel. As for lasers magenetic fields won't stop them. you would need things like superconductive armor or cold plasma shields.

The point here is whethere a magenetic forcefield can work. Power should no be a problem since likely applications of the technology such as a space warship will have fusion or matter - anti matter reactors

[Admiral Valdemar]

Well you're right, railguns and particle beams (plasma weapons aren't feasible without containment no matter what Hollywood says) would be stopped by fairly powerful EM fields.

Now, all matter relies on EM interactions and yes, there are EM fields of several Teslas that can hold non-metallic/magnetic objects, so even projectiles that aren't magnetic or neutral particle beams would be stopped.

The laser thing, since these weapons would be most popular, would only be stopped by having ablative materials as armour or super-cooled highly conductive materials that would disrupt the beam as they vapourised and weakened it and didn't let the heat reach critical systems.

[JodoForce]

I think DW was saying that if you could reproduce the EM field of the surface of a solid object by a projection you can stop anything cold

[Admiral Valdemar]

I think DW was saying that if you could reproduce the EM field of the surface of a solid object by a projection you can stop anything cold

Provided it has a charge of some sort, without that, e.g. with photons that have no net charge, then you can't stop them.

Everything has a charge in the form of electrons circling a nucleus. It's the electrons that make physical objects interact, not the solid nucleus which is miniscule and mostly wasted space. So an intense EM field would be, for all intents, a solid wall.

[JodoForce]

and would it or would it not stop lasers?

A solid wall does stop lasers

[Admiral Valdemar]

and would it or would it not stop lasers?

A solid wall does stop lasers

A solid wall stops lasers because of the nucleus, a simple EM field does not have such a property.

[kojikun]

i think you're all forgetting that unless the object fired is magnetic and has gyroscopic/spin stabilised orientation, magnets will only accelerated it towards you. If its metal or nonmetal, it'll be attracted to the magnet, and if its magnetic and not spin stabilised like a bullet, it will just flip over.

Electromagnetics simply cannot be used as forcefields. And lasers are entirely unaffected, so its pointless.

[kojikun]

A solid wall stops lasers because of the nucleus, a simple EM field does not have such a property.

Also because of absorption and remission by the electrons.

[Admiral Valdemar]

A solid wall stops lasers because of the nucleus, a simple EM field does not have such a property.

Also because of absorption and remission by the electrons.

That too and ablation if the thing is strong enough.

[kojikun]

Yeah. Ablation too. Electromagnetics is nothin to light (because light is, afterall, pure electromagnetic waves!).

Now, using a big ass mirror, thats another thing.

If you want to create a forcefield, either discover a nifty new law of physics to fuck with the String Theory physicists minds, or develope a new ultra strong alloy or something, because you aint gettin one otherwise.

[Raoul Duke, Jr.]

I forget whos doing the research, but there is one college (I believe one of the ones in Ohio) is using powerful electromagnetic fields to suspend organic objects (spiders, ants, and the like). They say that if they get 20+ megawatts, they could float a human.

I think its only a question of power, as everything is slightly magnetic.

The real question is can you create a magnetic field that interferes with lasers?

I'm a little concerned by this... wouldn't being exposed to that level of electromagnetism hurt someone? Shouldn't they at least have some idea whether or not it could, before they try exposing people to it in such a proposed experiment?

[CaptainChewbacca]

They suspend small frogs in such fields, it doesn't seem to do much to them. As I understand it, unless there's foreign matter in your body magnetic fields don't do a whole lot.

I worked for a while in a lab shielded from the earth's magnetic field so you could do magnetostratigraphy on core samples. Didn't even notice.

[Darth Wong]

They suspend small frogs in such fields, it doesn't seem to do much to them. As I understand it, unless there's foreign matter in your body magnetic fields don't do a whole lot.

I worked for a while in a lab shielded from the earth's magnetic field so you could do magnetostratigraphy on core samples. Didn't even notice.

The magnetic fields in MRI machines are fearsomely strong, and there doesn't seem to be any long-term effect.

EM field experiments on bacterial cultures in petri dishes do not show any tendency to cause serious harm, although it was noted that an increase in reproduction rate occurred. This might have been due to a simple warming effect, however (depending on how close the electromagnet was to the petri dish and how much current was flowing through, it might inadvertently serve as a heater).

PS. It appears you've shed the "Newbie" title. Congrats

[Raoul Duke, Jr.]

That's a relief. It's good to know that, should electromagnetic shielding ever become a widespread technology, the shields won't be pulling people's brains out through their hair follicles or anything.

(Okay, I know that can't literally happen, but that's the image I had)

[Hobot]

Wouldn't an EM shield produce a lot of EMR?

[kojikun]

EM field experiments on bacterial cultures in petri dishes do not show any tendency to cause serious harm, although it was noted that an increase in reproduction rate occurred. This might have been due to a simple warming effect, however (depending on how close the electromagnet was to the petri dish and how much current was flowing through, it might inadvertently serve as a heater).

So magnetism makes you horny? Cool. >D

[EmperorChrostas the Cruel]

That's funny, I seem to remember reading that when an MRI is turned way up in power, humans start "twiching" as a result of induced current in the nerves.
The scanning resolution, based on field strenth, was limited by what the subjects could tolerate. The MRI, as it presently stands, is only just powerful enough to induce twichies, at max or near max.
I have also seen "alien abdution experiences" induced by powerful EM field near the brain. We are talking bright lights, paralysis, and a feeling of ominous presence. "I would have run from the room in terror, if I hadn't been immobile." Test subject quote.

[ecky]

I am wondering whether strong electromagnetic fields can be used as a forcefield. One of Mr Wong's essays on shield technology mentions that electromagnetism is much stronger than gravity. Electromagnetic fields would definately stop particle beams, plasma bolts and railgun projectiles all of which are strongly influenced by magnetic fields. But what about non metalic objects ?. Given the fact that not only metals but all matter are effected by powerful electromagnetic fields can they be used as forcefields ?

a correctly formed EM field is capable of halting charged particles, whilst you can use a plasma(preferably a 'dusty' one if in space) within it to reduce the effectiveness of lasers against an object. their only weakness is in interference - you can set up an opposing field or beam that would create holes in it via destructive interference.

the way around *that* is to have 2 'shells' creating areas of constructive and destructive interference by having two overlapping fields in each shell - the inner 'shell' covering the holes in the outer 'shell'

as others have said it can also be used 'magneto' style to counteract gravity (nasa and boeing are currently bankrolling a method of using this plus interefering with gravity to reduce it - i'll believe when i see it).

as for it harming you, well theres been various studies and nothing conclusive considering the datasets used. EM fields have been attributed to causing cancers in the case of mobile phones and power lines. i wouldnt advise spending a long term in a strong one though

[AdmiralKanos]

as for it harming you, well theres been various studies and nothing conclusive considering the datasets used. EM fields have been attributed to causing cancers in the case of mobile phones and power lines. i wouldnt advise spending a long term in a strong one though

Most of the work done to establish correlation between power lines/mobile phones and cancer is highly questionable, usually relying on forensic statistics and false cause fallacies. In the case of power lines, EM field intensity from the power lines running through your own house are usually stronger than EM field intensity from nearby power lines, so it really doesn't make any sense to find a correlation unless there's something else causing it (eg- homes near power lines are low-income housing, and there is already a known correlation between income and health).

[kojikun]

Studies have shown that microwaves from cellphones increase brain activity and function.

Honestly, if magnetic fields caused CANCER, thenwe should worry about the gigantic magnetic field around the earth, or something, not just POWERLINES outside.

[Admiral Valdemar]

Studies have shown that microwaves from cellphones increase brain activity and function.

Honestly, if magnetic fields caused CANCER, thenwe should worry about the gigantic magnetic field around the earth, or something, not just POWERLINES outside.

Mobile phones are a hazard after prolonged exposure to kids mainly due to the way the microwaves work, it's just like a microwave oven though not as intense. It has been shown that heating does occur and the denaturing of proteins such as haemoglobin and anitbodies can happen.

I have heard varying views and reports on powerlines, personally, I wouldn't live next to a pylon or a telecom aerial even if it was cheap, even if future studies give them the all clear healthwise, they're damn eyesore.

[kojikun]

Are you sure? heating in microwaves requires a large pwoersource and for there to be standing waves. Otherwise you could beam yourself with microwaves and not worry. AFAIK, anyway.

[Sarevok]

i think you're all forgetting that unless the object fired is magnetic and has gyroscopic/spin stabilised orientation, magnets will only accelerated it towards you. If its metal or nonmetal, it'll be attracted to the magnet, and if its magnetic and not spin stabilised like a bullet, it will just flip over.

Electromagnetics simply cannot be used as forcefields. And lasers are entirely unaffected, so its pointless.

I see your point. The magenetic field would simply accelerate incoming matter. In case of a particle beam you can reverse the polarity of the field and repulse the beam, perhaps generating a cool shield flare the same way auroras happen.

However a non magenetic object would need a different strategy. How about refracting an incoming projectile than reflecting it ? Perhaps a spaceship can have long poles on the sides with electromagnets attached. An incoming projectile would be attracted away from the ship towards the poles. The field would then be shut down to keep the projectile from hitting the electromagnets.