The magnetic shield

I posted this as a respond in another topic but got no answer for it, so here is ones again the things a heard ones about a magnetic shield that the navy was developing if anyone can find more about it please feel free to corect me or add more to the concept:


The movement of a magnet towards a closed system like the wire on the pic (or the movement of the system towards the magnet) creates electricity in the system. That electricity creates another magnetic field around the wire which counteracts to the change of the overall magnetic forces created by the inkcoming magnet. So when the magnet moves towards the wire the wire's field has the N pole to the N pole of the magnet or the S pole to the S pole of the magnet(it depends on which pole the magnet comes first with). And because equal poles repel each other than the wire will try to repel the incoming magnet(the wire is just an example of a closed system wich every peace of metal can be).




and here is how that would work with a ship with a superconductive magnet mounted on it





so do i make sense or I'm stupid

And what about every other attractive metal that is on this superconductive magnetic ship?

Would they not get sucked into the field or is it directive beam magnetic?

Originally posted by evecasino
And what about every other attractive metal that is on this superconductive magnetic ship?

Would they not get sucked into the field or is it directive beam magnetic?

good question you just might hve to make everything from plastic(plastic has many faces) but you wouldn't have to make the ship from plastic though

and as for directing the field
well it is very weak at its centre and the axe but you could turn it on only when threatened

Dude, dont worry I often thought about this as a solution for a shield, but there are way to many problems with this idea, for example, unreactive objects will be ammune, people could still pass through it, and if the thing was set up wrong then it could cause, and object to accelerate.

It might repel rain, but a missile or a shell has somewhat more inertia for a really big magnet to do more than make the people on the ship look stupid.

RAIN ? how would it repel rain ? Rain wouldnt be magnetically effected :|

You are correct! But it wouldn't repel munitions either!!!

Im reminded of the "philadelphia project"... Is this where you got your idea?

Woud the incoming bullet have its field changed when it encountered the field? So when at first it is repelled, after the bullets field #s it would be pulled toward the ship.
Magnets are very intersting though. I might go research Nicoli Tesla. He had some wild ideas.

Originally posted by racos
RAIN ? how would it repel rain ? Rain wouldnt be magnetically effected :|

With enough magnetic force just about anything can be effected. You can even make something like a frog float I have seen it done.

In a strong enough field, all the atoms inside the frog act as very small magnets creating a field .You could say that the frog is now built up of these tiny magnets all of which are repelled by the large magnet

[edit on 20-10-2004 by ShadowXIX]

[edit on 20-10-2004 by ShadowXIX]

Heres a picture of even water floating thanks to a magnetic field


They have pictures of the frog here

www.hfml.sci.kun.nl...

[edit on 20-10-2004 by ShadowXIX]

Originally posted by ShadowXIX
Heres a picture of even water floating thanks to a magnetic field


They have pictures of the frog here

www.hfml.sci.kun.nl...

Great site Shadow, I work with superconducting magnets everyday, I saw a statement that gives me pause, I'll investigate and report back. In the meantime, here is a letter sent to the gentleman who did the frog experiment... I leave everyone to their own devices on this one.

An inquiry due to frog levitation.

Mirthful Me interesting letter to say the least. I think he would have better luck asking david blaine how he did his little floating trick.

The funny thing is the guy that made the frog float said it would work on humans if you built a big enough version of the chamber. I forgot how big he said it would need to be but the energy required to power it at that size was pretty insane if I remember right.

Even if they did build one that big you would just be in that chamber like the frog floating around like you were in zeroG.

Originally posted by ShadowXIX
The funny thing is the guy that made the frog float said it would work on humans if you built a big enough version of the chamber. I forgot how big he said it would need to be but the energy required to power it at that size was pretty insane if I remember right.

Even if they did build one that big you would just be in that chamber like the frog floating around like you were in zeroG.

A couple notes about �supercons�, the bore diameter on the frog magnet was 32 millimeters, the magnet body was most likely 1.5 meters across (it takes a fair number of windings to get 16 Tesla! Also even though the magnet was said to be a high temperature device (using Nitrogen opposed to Helium to keep the coils in the superconducting state) the cryostat still has to have a hard vacuum, to keep the cryogens from boiling off (it stakes some room to do this efficiently. My concern is a high temperature coil operating at 16 Tesla, I am just not familiar with a stable high temperature ceramic that can be ramped to that field. That leads to another misconception... These magnets require no power to generate the field once they are "ramped" up. The superconducting state allows the current to spin happily along, unimpeded by cumbersome properties like resistance (providing a frog floating field for "free" ). That being said, the magnet requires constant maintenance (just no power), a certain level of cryogens (be it LN, or LHe), and the safety considerations are tremendous (magnetism at this strength is dangerous, even deadly.

A magnet of sufficient size to levitate a human would be humongous, would create all kinds of engineering nightmares ( containing a field of that size and strength), and most of all, would probably render a human unconscious at that field strength (possibly even kill). I have access to a 7 Tesla whole body MRI scanner, the bed cannot move the patient at more than 2mm per second (think about how little that is) because of vertigo and nausea caused by field effects (in other words... feel sorry for the frog).

You have a much better understanding of these things then I do. I thought you always had to put juice into them to keep them going.

I saw this on some show and was amazed by it I never knew they could do this with living animals. I think they said none of the animals were hurt in this thing. I think they also did it to a mouse and a strawberry on the show.

I never really thought of the negative effects of a very strong magentic field on the body. I think I got to caught up in how cool it would be to float around in a chamber like you were in space. If they could make it safe and not cost millions it might be one fun amusement park ride.

hey guys don't know too much about magnetics, but when i studied them in university, i was wondering if you had a magnet of that caliber, would you be affected by electro magnetic radiation? just a thought

Originally posted by ShadowXIX
I never really thought of the negative effects of a very strong magentic field on the body. I think I got to caught up in how cool it would be to float around in a chamber like you were in space. If they could make it safe and not cost millions it might be one fun amusement park ride.

Subjecting a human body to a field of such incredible strength would cause more than the physiological effects/risks to be considered. Medical implants (pacemakers, ICD, pumps, neuro-stimulators, otological implants, older aneurysm clips, etc.) can have negative if not fatal implications. People who do metal work (welding and grinding), and may have metal fragments in their eyes and are at risk for corneal damage or worse. the bottom line magnetism at this level is definitely not a toy. On the bright side incredible advances are being made due to high field strength magnets.

A brief summary of bio-effects of a strong magnetic field.

Originally posted by spaceghost
hey guys don't know too much about magnetics, but when i studied them in university, i was wondering if you had a magnet of that caliber, would you be affected by electro magnetic radiation? just a thought

SG, the fields generated by these magnets are static (they don't move, or oscillate), they therefore don't have the risks associated with electromagnetic radiation (like radio waves), there won't be any heating affect which could lead to cellular damage (this is not like when you drop your cell phone, that's a different "cellular damage" ). Keep in mind that MRI scanners combine the static field (the magnet itself) a controlled gradient field (varying in intensity, direction and phase, in the milli-Tesla range) and an RF excitation pulse that matches the Larmor frequency of Hydrogen at a particular field strength (42.58 MHz/Tesla).


[edit on 20/10/2004 by Mirthful Me]

A double post... Oh the ignominy...



[edit on 20/10/2004 by Mirthful Me]

I think strong enough magnetic fields might have little too much side effects.


But hope that they won't try to build record strong magnet... because nature has set bar little high.

The Earth's magnetic field which deflects compass needles is measured to be about 1 Gauss, the strongest fields sustainable in Earth-based laboratories are about 100,000 Gauss, yet the Magnetar's monster magnetic field is estimated to be 1,000,000,000,000,000 Gauss. A magnet this strong, located at about half the distance to the Moon would easily erase your credit cards and suck pens out of your pocket.

antwrp.gsfc.nasa.gov...

www.gsfc.nasa.gov...

This object, named SGR 1806-20, is one of only ten unusual neutron stars classified as magnetars, thousands of times more magnetic than ordinary neutron stars and billions of times more magnetic than the most powerful magnets built on Earth. The strength of its magnetic field is approximately a million billion (10^15) gauss (100 billion tesla)

If this magnetar took the place of our moon, its magnetic field would strip the Earth of every piece of metal and rearrange the molecules in our bodies,”

www.gsfc.nasa.gov...
www2.gwu.edu...

A hundred billion MRI scans...

In 1979, an SGR in a neighboring galaxy unleashed a giant flare that packed as much energy into its first 0.2 seconds as the sun produces in 10 000 years...

solomon.as.utexas.edu...

www1.msfc.nasa.gov...
physicsweb.org...
www-star.stanford.edu...