eli5 Electricity


So electricity always tries to find the fastest way to ground right? So say you get shocked and it goes through you. Where does electricity go when it goes into the ground. Thank you

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Electricity doesn’t care what the ground is. You can still build up static electricity and shock yourself on an airplane or on the international space station. It just goes from something with a higher potential to a thing with a lower potential. It’s called “ground” because some systems use giant metal rods driven into the ground that we use to dissipate the charge. The electricity literally goes into the ground and is absorbed. Since the earth is huge compared to you, the earth really doesn’t notice an extra few hundred million electrons that shocks you and it’s not even enough to be measured. It’s like dumping a cup of salt into the ocean, did you make the ocean saltier? Yeah, is it measurable? Not really.

I’m not an expert or anything so I’m sure someone can offer a better explanation but from what I understand it goes like this:

Electricity needs to flow THROUGH something and so whatever you touch that has electricity needs to “go somewhere” and if you’re touching the ground it will go through you and into the ground. Where it goes is not important, what’s important is that it’s current flowed through you.

Also a tidbit of why standing on rubber is important (or staying INSIDE your car during a thunderstorm) is because electricity doesn’t flow through rubber and your tires are made of rubber, so if your car gets struck by lightning you’ll be safe.

Electricity flows in a loop, almost always. For any reasonably large loops, the ground is intentionally or unintentionally connected somewhere.

Thus, when you connect it to the ground elsewhere too, you form another link to the loop.

Electricity is a flow of electrons. Electrons are tiny things and they have a property called charge (a charge of -1). Stuff is also made up of protons, which also have a charge (of +1) – and neutrons, but they have no charge so we’re going to ignore them. Stuff with positive charge is pulled towards stuff with negative charge and vice versa, while being pushed away from other stuff with positive charge.

So you can think of it as having a room full of two kinds of people, where each person wants to be as close a possible to the other kind of people, while as far away as possible from their kind of person (but where one kind of person – the protons – generally can’t move much).

Generally what happens is they pair up (or cluster up), so that overall everything evens out, and everyone is as happy as possible. If there is an imbalance, things will move around to try to gain balance.

So what this means is that if you have an area with more electrons than protons (so negatively charged), electrons will try to escape – ideally to find somewhere with more protons than electrons (positively charged) or, at best, somewhere with a smaller number of extra electrons (i.e. less negatively charged).

Electricity works by creating areas where there are way too many extra electrons at one part of a circuit, and way too few at another part, and so the electrons will rush around the circuit, and we can take energy out from that (kind of like water flowing down the side of a mountain, and turning a water wheel on the way).

When we talk about something being “grounded” or “earthed”, what we mean is that it is connected to the Earth (directly or indirectly). The Earth is really big. Like, massively, hugely big. Which means it can afford to gain a few extra electrons, or lose a few extra electrons, without any part of it getting too charged (as the remaining electrons have a large space to spread out over).

However, electrons can’t just move through anything – well, they can, but it takes more of a push or pull to get them to move through some stuff than other things. Air, for example, is pretty hard for electrons to move through (but with enough of a push it can – which is what sparks and lightning are). Humans aren’t that great, but are more conductive to electrons than air. Most metals are really great for it, and electrons can zoom through them.

So when you get shocked you have touched something that had either too many or too few electrons, so that either more electrons want to rush to it, or electrons are desperate to get off it. Not desperate enough to jump through air, but desperate enough to go through a person. Depending on whether the thing is positively or negatively charged, either some electrons from the ground (where there are plenty of spare electrons) will rush up through you onto it (if it was positively charged), or some will rush away from the object through you into the ground (where there is plenty of space for extra electrons). And when they flow through the point of contact between you and the object they may burn a bit, because of the energy they have (like that water wheel).

There’s a lot of overlap between electricity flowing and fluids flowing. In both there is current, resistance, but in electricity there is voltage too. Voltage equivalent in fluid dynamics is kinda like how strongly strongly a fluid wants to flow somewhere. Like water pressure pushing a fluid to flow strongly in one direction.

Building upon this analogy, ground is where there is no ‘water pressure’ since the ground can typically just keep on taking more electrical charge without practically ever getting full. That doesn’t mean that electricity always wants to flow there. If for instance you have a high negative charge area full of electrons, that’s a lot like having water under pressure. It may flow outward towards ground if given the chance, but it’ll prefer flowing to a area of high positive charge to neutralize it’s own charge. That’s a lot like there being a vacuum in our fluids analogy.

Once this vacuum/positive charge area sucks up so much water/electrons that it becomes neutral, taking on any more water/electrons actually puts it negatively charge/pressurized. At which point the electrons/water prefer to flow to the neutral place, or ground.

To answer your question about where electricity goes when it shocks you, that only happens when your body is the path of least resistance to flow somewhere where it can neutralize it’s charge. It’s a bit like a bottle being so pressurized it overcomes the resistance of the cap containing it to violently pop it’s cap.

Electricians often work on wires one handed to prevent this. They’re acting like a bottle in this regard. A bit of charge can flow into them but then they become ‘pressurized’ with no where else for more charge to flow. Touching charged wires with two hands is potentiality forming a pipe from one arm to the other with their heart in the middle. Electricity may flow from the high charged area to the low from one arm to the other and paralyze the heart on the way.