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[nepawolf]

My bad, thought you were talking about the emp bomb. An Electro-Magnetic Pulse works basically by causing fierce micro-vibrations inside of Integrated Circuits. It can pass through some solids better than others (depending on how thick), it can pass through water, but also only to a limit. It is radiation in the concept that visible light is radiation. Unless you're subject to a high density of EMP, there is no real effect on living material. For that matter, vacuum tubes are unaffected. The EMP only really effects the newer (relatively), more densely packed electronics that tend to have IC chips in them. Almost every electronic produced nowadays does, for many years at this point. IIRC, the insides of the IC chips are so densely packed that the magnetic vibrations inside them destroy them, whereas the older styles have more space for the vibrations to not really effect them.