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Magnetic field created without an electromagnetic field?

  1. Jul 22, 2015 #1
    Magnetic fields are less harmful than electric field and also a lot safer than being exposed to electromagnetic radiation. If data transfer is possible through magnetic flux then cancers and all those kind of diseases can be avoided. So, the question again is can a magnetic flux(movement of magnetic field) be created without or with less electromagnetic radiations as a product while the magnetic flux is produced?
  2. jcsd
  3. Jul 22, 2015 #2
    A changing magnetic field will always produce an electric field and vice versa.

    Communication is not possible with a static field, it needs to change.
  4. Jul 22, 2015 #3
    There is a difference between a electric and a electromagnetic field right?
  5. Jul 22, 2015 #4
    Data certainly can be encoded into magnetic fields, that's how many kinds of computer data storage work.
    On the other hand I have heard of nothing concerning how magnetic storage of data could be of benefit for the treatment of cancer.
    (other than for storing records relating to the patient's condition.)
    Last edited: Jul 22, 2015
  6. Jul 22, 2015 #5
    I was not saying about storing data but transferring data wirelessly (like wi-fi) but using magnetic flux and not electromagnetic radiations. Magnetic field has no effect on a adult human till 5000<mew>(micro)Teslas[Even after that there is no signs of cancer]. But electromagnetic field can affect the chromosomes of humans when exposed. So, if data transfer is made magnetic it will safer.
  7. Jul 22, 2015 #6
    MRI scanning is very useful for diagnosing the condition of a cancer and other diseases.
    I am sure there is not existing technology either magnetic or anything else which transfers data INTO the patient as a form of treatment.
  8. Jul 22, 2015 #7


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    You seem to have missed the fact that was pointed out to you. You can only transmit information with a TIME-VARYING FIELD (caps and bold to ensure it doesn't get missed).

    But when you have time-varying magnetic field, you get, as an automatic bonus, an electric field to accompany that magnetic field!

    BTW, there has been no definitive evidence that the current level of EM wave that surrounds us (i.e. radiowaves etc.) have caused those issues that you mentioned. You are welcome to explore the transmission of signals via magnetic fields, but if you insist on connecting this unproven claim, then I will start to duck if I were you.

  9. Jul 22, 2015 #8
    The magnetic field is an electric field view from another frame of reference, you can google this, this is a consequence of special relativity, when you move an electric, you view from lorentz contraction that is more dense, charge density thus it gets stronger in the orthogonal direction of your motion, the same happens for magnetic field, if you move it relative to a charge distribution, charges will move in the same direction for a moment this creates an electric field !!
  10. Jul 22, 2015 #9
    So, you said that a time-varying magnetic field you get also an induced electric field, if we can transfer data through magnetic flux then we will be able to even charge the phone or a lap that is receiving the signal at a certain frequency simultaneously! Please correct me if I'm wrong and tell me a little more about data transfer through magnetic field.
  11. Jul 22, 2015 #10


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    We can't transfer data through a static field. There has to be a change in something. How would you represent two bits, 0 and 1, with a static field? You could define some value to be 0, but then to get to another value that is defined to represent 1 there has to be a change in the field. This change requires that the field not be static, which generates an EM wave.
  12. Jul 22, 2015 #11
    Hey what' difference between the kind of communication (Radio Waves) we are having now and the one created due to a varying magnetic field?
  13. Jul 22, 2015 #12


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    EM radiation, such as radio waves, is typically used to transfer information to a distance greater than a few inches to a few feet. If you only need to transmit information a short distance, perhaps from your hard drive's magnetic coating to the read head, then you're using the existing field, which isn't static (because it differs between spots on the drive and is spinning). So as your hard drive platter spins, the differences in the magnetic field at different points on the magnetic coating are read by the read head by using the magnetic field to induce a varying electrical signal, which is then amplified. A radio antenna works because incoming EM radiation (EM waves) induce a varying electrical signal in the antenna, which is amplified by the receiver's electronics. Both involve varying fields, but only the latter is usually classified as using EM waves, even though both actually are. The varying signal induced in both the read head and the antenna is itself an EM wave. It just wouldn't be called EM radiation because it is mostly confined to the conductors.
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