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this post was submitted on 01 Aug 2023
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Technology
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Wires that wouldn't electrocute us?
Is it because we would have resistance and it wouldn't so it'd ignore us?
Yes basically.
You get electrocuted when you touch a bare copper wire because the human body is less resistant to electricity than copper (your nervous system is optimized to not be resistant to electricity). Electricity would prefer to go through you than the cable.
But your nervous system still has some resistance, and you can't get less resistance than zero resistance, so regardless of what you're doing, the electricity would prefer to stay in the superconducting cable.
For the same reason you could also submerge the cable in water and nothing would happen.
The reason all this is very useful is that currently in order to prevent everybody getting electric shocks you have to insulate the cable in rubber. If you could safely make bare cables you could save an awful lot of rubber.
This has so many errors. Copper is a far better conductor than people. Set up a multimeter for resistance across your skin if you're dubious, it'll be in the kΩ per cm. Current will flow if a potential difference is present, regardless of whether there is a less resistive path available. Also the material in question is a metal oxide, not a metal. It's brittle. So making it into a cable in the first place will be incredibly difficult and expensive. And even in their own paper they showed a limiting current of something like 400 mA, which is not suitable for high power applications.
Your skin actually has quite a lot of resistance especially compared to a copper wire, while it's definitely bad news for a current to be flowing through your nerves it would need to get there first. Current doesn't really 'choose' a particular path either; if you have a potential difference V between two points the current will take all paths available between them and Ohm's law I = V/R tells us that the current will be greatest through the path with the least resistance. The reason you don't get a shock when you touch a properly insulated wire is that the path that includes your finger also includes the resistance R of the insulation which is very high so correspondingly I is very low.