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by quesera 1538 days ago
Agreed that electrical potential is present in all points of a uniform conductor. And that it takes only a tiny amount of current to interrupt a beating heart (as low as 60mA).

However it is not correct that the path of the current is not important.

Current will not flow between two points of equal electrical potential. There are some complications in the modelling (skin is a better insulator than internal bits, bags of salty moist flesh and bones are not resistively consistent, etc), but you're still in a much better situation to reduce potential difference across your heart, if the external potential difference occurs between two fingers on the same hand, vs two fingers on opposite hands.

OSHA says:

> The currents that pass through the heart or nervous system are the most dangerous. ... If a hand comes in contact with an electrical component with current (and at the same time the other side of your body makes a path to the ground), this will make the current pass through your chest and possibly produce injuries to the heart and lungs.

https://www.osha.gov/sites/default/files/2019-04/Basic_Elect...

1 comments

> However it is not correct that the path of the current is not important.

I never claimed this. I claimed that even with the "safest" path through your body, the chance of your heart stopping is still there.

My point is that it's never "safe" to do, and as a homeowner (and even for a vast majority of non-lineman electricians) you never have to do it.

> I never claimed this.

You absolutely did. You said it doesn't matter. It matters.

And I never said anyone would have to work on live wires. And I wouldn't recommend it to anyone.

Nevertheless, it does sometimes happen, and being a bit smart about it is a good idea.

The wording from the post that started this discussion is:

> Is "one hand in back pocket at all times" to avoid a circuit across your heart?

To which I responded:

> it doesn't matter if the circuit appears to "crosses your heart", because some portion of it will still flow through your heart regardless.

Which, as we have by now agreed, is the case.

The dispute is about whether that 'portion' is enough to kill you, which I avoided making concrete statements on. I didn't take a stance because the answer is "it depends". The variables that make up the answer are vast, and many folks have survived lightning strikes and died to static discharges thanks to those variables.

> being a bit smart about it

I will still contend that working on live wires with bare skin at all is the opposite of "being a bit smart about it".

If your really being smart about it, and can't avoid it, use tools and protective gear created explicitly for working with live electricity. Or call someone with that gear.