Timeline for Cancel out Earth's Magnetic field
Current License: CC BY-SA 3.0
15 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Apr 28, 2013 at 20:38 | comment | added | Olin Lathrop | @Eduardo: A iron cage can shield a static magnetic field to some extent, but that is different from a general Faraday cage. A Faraday cage could be, for example, made from a mesh of aluminum wires, which static magnetic fields would go right thru. | |
| Apr 25, 2013 at 11:02 | comment | added | Eduardo Guerras Valera | @DavidH, statements based on experimental facts are quite doubtful here, specially if the faraday cage is far from perfect, because magnetic compasses are very sensitive, unless you are talking about a real experience in some well built laboratory cage aimed at that purpose. Frankly, I have not paid any further attention to this question, but the decisive fact here would be either a good theoretical explanation, or at least a reference to a paper. I guess some simple explanation involving a closed fictitious surface and Ampère's law or something similar is required. Nothing too complicated. | |
| Apr 25, 2013 at 8:53 | vote | accept | ecabuk | ||
| Apr 25, 2013 at 1:46 | comment | added | David H | @EduardoGuerrasValera The fact that a magnetic compass has no problem finding geomagnetic North inside a Faraday cage is contrary to the idea that Faraday cages make good magnetostatic field shields. | |
| Apr 25, 2013 at 0:59 | answer | added | Brandon Enright | timeline score: 5 | |
| Apr 25, 2013 at 0:28 | comment | added | Eduardo Guerras Valera | I am not so sure. At least an iron cage will deviate and concentrate the magnetic lines through the walls, thus leaving the room inside the cage devoid of lines. Look for example here (I guess the issue with other, non-ferromagnetic material is different, but this with iron is close to the picture I have in mind) | |
| Apr 24, 2013 at 23:22 | comment | added | Olin Lathrop | @Eduardo: No, a Faraday cage is for shielding electric fields, not magnetic fields. It will attenuate changing magnetic fields somewhat because those will cause currents in the cage, which causes some of the energy to dissipate. Since the cage does not have zero resistivity, the currents caused by the magnetic change will decay and the net static magnetic field will go right thru the cage. | |
| Apr 24, 2013 at 23:08 | answer | added | David H | timeline score: 5 | |
| Apr 24, 2013 at 23:02 | comment | added | Eduardo Guerras Valera | Forgive my ingorance but, isn't a Faraday Cage good for shielding a static magnetic field as well? | |
| Apr 24, 2013 at 21:29 | comment | added | Tesseract | A box made of thick iron plates maybe. However that iron could become magnetized and then the box might produce an internal field instead of cancelling it.. | |
| Apr 24, 2013 at 20:39 | comment | added | dmckee --- ex-moderator kitten | I am not ware of any other named coil configurations for that purpose because the one Helmholtz found is perfectly adequate. It is not, however, unique. | |
| Apr 24, 2013 at 20:34 | review | First posts | |||
| Apr 25, 2013 at 2:11 | |||||
| Apr 24, 2013 at 20:33 | comment | added | ecabuk | Thanks @dmckee ! Helmholtz coil is my term paper topic. I just want to know that if there any. | |
| Apr 24, 2013 at 20:29 | comment | added | dmckee --- ex-moderator kitten | Well, you could build a more complicated coil if you really wanted to, but it would be a pretty silly thing to do unless a Helmholtz coil is failing you for some fundamental reason. | |
| Apr 24, 2013 at 20:18 | history | asked | ecabuk | CC BY-SA 3.0 |
