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Suppose I was standing in the sea, and touched an electric fence; I would receive an electric shock, because both my body and the sea are conductors, and create a path for the electricity to flow. The sea is so big that it has the capacity to draw and dissipate a great quantity of charge. However, if the sea was drained away, and I was standing on some rocks, would I still receive an electric shock, even though rock is not a conductor? And if I did receive a shock, where would this electricity even flow to? Would it just be dissipated amongst the rocks / soil / sand beneath my feet (even though they are insulators)?

My question comes from me wondering why we receive electric shocks at all, when there is usually some form of insulator between you and the charged object, such as your shoes, the carpet, several layers of bricks, and indeed the entire composition of soil and rocks beneath the building that make up the "Earth".

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No, there is no such thing as perfect insulation. All insulation is merely a very very high resistance with a high breakdown voltage (Insulation is the ability of a material to block the flow of current through it, so that means that this material has a high resistivity. It is measured in Ωm.) the current doesn't go via the rock, Do you know where the current is lost, let say power supplied or Power dissipated is $P=i^2R$,, and The effects of this electric shock are many, and most of them seem to do with neuropathy, that is, damage to the nervous system, including the brain., 10mA through the heart can be enough to kill a person, regardless of voltage. Now coming to your last part. The fact that a current can flow through the materials you mention means that they're not full isolators. Soil is somewhat conducting as it contains water and that water will contain ions which can conduct electricity.

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I think an insulator does not completely stop charge transfer, if viewing it to act in the same way as maybe ie. a thermos cup, which does significantly increase the cooling time of a hot coffee inside, but does not fully prevent heat from escaping, hence allowing the hot coffee/material inside to cool.

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Static electricity is not like regular electricity in that it does not involve closing a complete circuit; it just needs a large difference in voltage potential between one object and another. When you shuffle your feed on a nylon carpet and touch your finger to a doorknob, you are not closing a circuit. Instead, you are building up a large negative charge by shuffling your feet, and when your finger gets close to that doorknob, the large voltage difference, which can be larger than 20,000 volts, causes a spark to fly between you and the doorknob. In fact, static electricity could not happen if there was a complete circuit, because that voltage difference would never happen. Or to put it another way, you need that insulation for a static charge to build.

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