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OpenPlex t1_j68kodp wrote

Reply to comment by Jaffacakereddit in ELI5: why can't we use electricity to kill microorganisms in small amount of water ? by FreshT3ch

The analogy is that voltage is like water pressure, so how does distance increase that?

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Jaffacakereddit t1_j69iumy wrote

The surface beneath our feet usually has fairly high resistance. So voltage fades away quickly, electricity doesn't travel too far. If there's a live wire in the earth underground that's broken, a front hoof and a back hoof can be at very different voltages, so the power travels through the horse in preference to the earth. This is not a good thing.

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OpenPlex t1_j6a2de5 wrote

Ah, so a larger distance wouldn't guarantee a larger voltage, it would merely raise the chances because of changes to the surface being walked on.

Or, wait. No, the voltage difference is because one hoof is over electricity while the other hoof is over zero or fewer electricity, so now electricity will travel through the horse which is electrically conductive.

> The surface beneath our feet usually has fairly high resistance

That's if we're wearing sneakers, right?

Like if one foot were barefoot and the other wearing a sock, we'd create a large difference in voltage?

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DiscountFoodStuffs t1_j6a6py0 wrote

There is less of a distance between a person's two feet than that of a horses front/back legs. Earth, the surface beneath our feet, typically has a high resistance. There is a higher chance "electricity" will choose to flow through a horse, as it has to either travel that distance through the horse, or through the ground. For a person, that distance is smaller, therefore less resistance, and less likely to use us a bridge between two spots on the ground.

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JimmyTheBones t1_j691to0 wrote

Imagine it more as water flowing downhill. Small horizontal distance, not too much change in gravitational potential energy, but from the top of a mountain to the bottom there's a huge difference there.

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OpenPlex t1_j697mrn wrote

Doesn't make sense in the context of one horse's leg to another. (vs the distance from one human leg to another being a lower pressure)

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JimmyTheBones t1_j699a6q wrote

So imagine the horizontal distance, not the diagonal distance.

The front foot is the equivalent of the top of a river up a mountain, and the back foot is the equivalent of the estuary at sea level.

The human's horizontal foot distance is much less, so there is a much smaller difference between the potential from one foot to the other.

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