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Science Forum

  1. 30 Apr '15 18:15 / 3 edits
    http://physicsworld.com/cws/article/news/2015/apr/30/portable-battlefield-mri-comes-out-of-the-lab

    I am really seriously put-off by the big emphasis in that link on its military application.
    I really wish they didn't even mention that.
    But, still, once I get past that, this looks good to me!
  2. 30 Apr '15 20:05
    Originally posted by humy
    I am really seriously put-off by the big emphasis in that link on its military application.
    There is money to be made in military applications.

    Is there such a thing as a Faraday Cage for magnetism?
  3. 30 Apr '15 21:01 / 1 edit
    Originally posted by twhitehead
    There is money to be made in military applications.

    Is there such a thing as a Faraday Cage for magnetism?
    but a Faraday Cage cannot be used for peacetime medical scanning.
  4. Standard member sonhouse
    Fast and Curious
    01 May '15 11:25
    Originally posted by humy
    but a Faraday Cage cannot be used for peacetime medical scanning.
    A faraday cage holds off only electric fields. You could make something similar for magnetics if you used Mu-metal, which conducts magnetic field lines into itself and shields something from the magnetic field, but I have no idea how thick such metal would have to be to make a good shield big enough for the human body. Obviously it would be more than 2 meters long and a meter wide and high for use on humans.

    It might also be possible to make a repelling shield similar to noise cancelling earphones for audio. You could see series of magnetic sensors coupled with reverse field coils that could null out external fields.
  5. 01 May '15 11:51
    Originally posted by sonhouse
    It might also be possible to make a repelling shield similar to noise cancelling earphones for audio. You could see series of magnetic sensors coupled with reverse field coils that could null out external fields.
    That is essentially what they are trying to do in the device in the article - or have plans to do that.
  6. Standard member sonhouse
    Fast and Curious
    01 May '15 14:20
    Originally posted by twhitehead
    That is essentially what they are trying to do in the device in the article - or have plans to do that.
    For shielding against Earth's magnetic field, at least it wouldn't take much energy, since our field is around 1 gauss or so.