If the Eel is the positive terminal, where’s the negative terminal? If you’re grounded by the water, would that mean the Eel can only shock you if you are in the water too? If the water is the final destination, why wouldn’t the current directly go from the Eel to the water? Why would it take a high resistance path through your body?
In: Physics
so the whole electricity takes the path of least resistance thing is misleading, electricity takes all paths, paths with less resistance will see more current, but all paths are taken
so basically what the electric eel does is that it has both the positive and negative on its body, however the current flows through the water around it, so the water around it will also be electrified, and anything near enough though it will become part of the circuit and be shocked
People (and fish) are surprisingly conductive, more conductive than the freshwater that electric eels live in. Even in saltwater, a significant portion of the current could flow through the target.
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The head of the eel is positive, the tail is negative. You can think of them as like a temporary battery when they are zapping something.
When eels are hunting, they generally just produce positive voltage in the head, which spreads out around them in the water to ground and induces muscle twitches in fish in the field, allowing them to be caught and eaten.
When an eel wants to zap struggling prey to stun it, they curl around to put the prey between head and tail to zap the crap out of it
https://ars.els-cdn.com/content/image/1-s2.0-S0960982215011471-gr2.jpg
When an eel wants to really damage a big predator, they tend to leap partly out of the water and touch their head to the animal, creating a circuit through the animal from head to critter to water to tail, again delivering maximum shock.
https://www.researchgate.net/publication/319854986/figure/fig1/AS:869115212349441@1584224622974/Attack-on-a-Human-and-the-Paradigm-for-Circuit-Analysis-Electric-eel-attack-and.png
How do they not electrocute themselves?
AC current.
Think of the voltage as the surface level of a pool. Let’s say electrocution means drowning a person in the pool. If there’s someone in the pool I can’t drown him with a non completed DC circuit. That’s like raising the water level. It accomplishes nothing, because he just floats along with the water level.
A completed DC circuit would be the equivalent of tying a rope around the person’s ankle and the bottom of the pool. This is the equivalent of *grounding* said person. Now if I raise the water level, he won’t follow the surface.
But, the point here is that we can’t ground him. So we rapidly lower and raise the surface level. If we do it fast enough, he’ll not be able to rise as fast as the surface does, and will get caught under the water.
When you change a voltage rapidly enough, the electrical “inertia” of a person’s body(parasitic capacitance) that they have relative to ground is enough to allow significant current to flow. The net average current will be zero, but rapidly going from positive to negative current back and forth is actually even more dangerous to our bodies if it matches the frequency our nerves operate at. This is, of course, the exact frequency the eel targets.
Electricity flows from places of high potential (high electron density) to places, of low potential (low electron density). Those places don’t need to be connected through a loop, for electricity to flow.
As I understand it, these eels have organs that can chemically produce electricity in bursts, some mild to find prey, stronger to stun it. When attacking they’ll leap across the prey’s body and jolt it until the prey stops moving or the chemical reserves are exhausted.
I’ve seen a video of them ganging up on a wayward caiman that strayed into a pool the eel’s had gotten trapped in when the river floods receded. The caiman was twitching with every jolt, eyeballs clicking up. After the eels were exhausted, the animal slowly crawled away. Being cold blooded, the momentary paralysis wasn’t deadly as it would be to a mammal.
BTW, the eels are blind, the constant jolting kills the eyes. But they can sense any sort of electric current, it’s how they locate prey, much like part of a shark’s hunting ability.
>why would it take a high resistance path through your body?
Pure fresh water isn’t actually a creat conductor of electricity. Your body, being salty, conducts much better. That’s why animals in the water can get shocked by an eel.
That’s also why a dangling electric cord at a freshwater marina can be so dangerous — if you’re in the water anywhere near, the current would like to go through you to get to its opposite terminal.
Electric eels generate electricity through specialized organs called electrocytes. These cells work similarly to batteries, with a negative and positive charge on each side. When the eel decides to discharge, it aligns these cells in such a way that a current is created along its body¹.
In water, the eel is not the only positive terminal; the electric organ discharges create a potential difference between the eel and the water around it, effectively making the water the negative terminal. When you’re in the water with the eel, your body can become part of this electric circuit. The current prefers the path of least resistance, which is usually through the water. However, if your body provides a path that’s more conductive than the surrounding water, the current may flow through you.
The reason the current doesn’t go directly from the eel to the water is that the water itself is not a perfect conductor. The current will spread out in all directions and will take all available paths according to their respective resistances. If your body is in the water, it becomes one of the many paths the current can take. Since the human body is mostly water and contains ions, it’s quite conductive, and thus, a significant amount of current can flow through it if you’re close enough to the eel.
The severity of the shock you’d experience depends on how much of the current passes through your body, which is influenced by your distance from the eel, the conductivity of the water, and your body’s resistance compared to the water’s resistance¹. Electric eels use this shocking ability to defend themselves and to stun prey, making it easier to capture². They can control the intensity of the electric discharge, using lower voltages for navigation and communication, and higher voltages for defense and hunting².
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