Wrapping up a cellphone in aluminium foil or putting it inside a microwave will block out all signals. Somebody suggested to me that forcing two very powerful neodym magnets against each other and securing them inplace with screws or ducttape will create a similar shield which will cause cell phones within a certain radius to lose signal.

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Is this true? I want to replicate the experiment with 2 magnets like this one:

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  • $\begingroup$ Why not do the experiment? $\endgroup$ – G. Smith Jul 6 at 16:59
  • $\begingroup$ it's true if you want to kill your phone for good :D $\endgroup$ – xray0 Jul 6 at 17:50
  • $\begingroup$ @xray0 elaborate please $\endgroup$ – AzulShiva Jul 6 at 17:51

NO, it is not true. Radio waves and other electromagnetic waves pass through magnetic fields with no interaction at all. The reason metal foil can block radio waves is that the metal has plenty of free electrons that do interact with radio waves.

  • $\begingroup$ It's not about a simple magnetic field. It's about a magnetic field created by two opposing magnets forced together with a few hundred Newtons of force. $\endgroup$ – AzulShiva Jul 6 at 18:13
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    $\begingroup$ That makes no difference. Three people who know what they are talking about have now told you the same thing. Whoever made this suggestion to you does not understand electromagnetism. $\endgroup$ – G. Smith Jul 6 at 18:58

Neodymium magnets won't stop radio waves, but the strong magnetic field may stop/kill your device.

Think about it this way... If the strong magnetic field would anyhow shield from radio waves then we could not receive any radio signals from space (from probes far away like Voyager/Pioneer, from satellites orbiting Earth/Mars, nor from Radio galaxies millions of years away) because of the magnetic field (far superior then all neodymium magnets combined) of our planet which is shielding us humans from deadly solar winds.


  • $\begingroup$ Well the point is to force two magnets together that are pushing away from each other not simply being near a magnet... $\endgroup$ – AzulShiva Jul 6 at 18:12
  • $\begingroup$ it still wouldn't matter how you arrange your magnets. the stream of radio waves won't be anyhow influenced by a strong opposing magnetic field. if your mobile device won't die from strong magnetic field exposure then it will receive radio signals just fine $\endgroup$ – xray0 Jul 6 at 18:17
  • $\begingroup$ @AzulShiva webapps.stackexchange.com/help/someone-answers $\endgroup$ – xray0 Jul 8 at 18:18

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