3 ms·

Gravity is the driving force behing the flow of water in this example, and a static electromagnetic field (in a DC circuit at least) is the driving force behind

Gravity is the driving force behing the flow of water in this example, and a static electromagnetic field (in a DC circuit at least) is the driving force behind the flow of electrons. The water can do work on physical object (waterwheels, etc), and the electrons can do work on electrical loads (lightbulbs, etc.). However the static electromagnetic field in the DC circuit propagates through the material at near light-speed once the battery switch is thrown, which is a bit different. I suppose if you could throw a switch and turn gravity on or off it would be a closer analogy, i.e. the idea would be to fill the (sealed) maze with water in a zero-g environment (it would fill everywhere equally, comparable to the electons in the conductor with the power off), then turn on the gravity (or the pressure differential for the pipe version) and see what happened.

derefr 4y ago
> suppose if you could throw a switch and turn gravity on or off it would be a closer analogy I mean, you could, insofar as you can mechanically control the height difference between the start and end of the maze. I think the real problem with the analogy was just that the hydrodynamic version wasn't a circuit in the sense that the electrical version was. The water just falls out of the system, so of course you can't control the pressure difference :) The exit of the hydrodynamic version should have been a (sealed) pipe that flows into an (open) buffer-chamber thatis after the maze; from which a pump operating on a control system then brings pumps water back to the (open) buffer-chamber that sits before the maze. Additionally, said pump's speed should be determined by the water-level imbalance between the two buffer-chambers, such that it's always trying to bring the two chambers into water-pressure equilibrium. (This pump is then a proper hydrodynamic analogue of a generator: two terminals with a constant height [voltage] differential between them, that pumps faster or slower [= varies current] to maintain the same potential difference in the system, whether the system is loaded or unloaded.) Then "turning off gravity" would just mean moving everything (the input buffer, maze, output buffer, and pump) from being in a vertically descending sequence (where the pump would be doing constant work to maintain the potential difference despite the "load"), to being on a flat plane (where everything would reach potential equilibrium, and the pump would then turn off.) And you could then represent AC flow, by just alternatingly raising and lowering the two chambers, and using a bidirectional pump.
fnordpiglet 4y ago
I think it’s the same but different rates of propagation. It’s about potential force and gradient descent in the end. It’s also interchangeable. The water moves a physical object which induces a moving magnetic field which induces current in a conductor which moves through the circuit and can induce a magnetic field in a conductor which can move a magnetic which can move water.
deleted 4y ago
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derefr 4y ago

> suppose if you could throw a switch and turn gravity on or off it would be a closer analogy I mean, you could, insofar as you can mechanically control the height difference between the start and end of the maze. I think the real problem with the analogy was just that the hydrodynamic version wasn't a circuit in the sense that the electrical version was. The water just falls out of the system, so of course you can't control the pressure difference :) The exit of the hydrodynamic version should have been a (sealed) pipe that flows into an (open) buffer-chamber thatis after the maze; from which a pump operating on a control system then brings pumps water back to the (open) buffer-chamber that sits before the maze. Additionally, said pump's speed should be determined by the water-level imbalance between the two buffer-chambers, such that it's always trying to bring the two chambers into water-pressure equilibrium. (This pump is then a proper hydrodynamic analogue of a generator: two terminals with a constant height [voltage] differential between them, that pumps faster or slower [= varies current] to maintain the same potential difference in the system, whether the system is loaded or unloaded.) Then "turning off gravity" would just mean moving everything (the input buffer, maze, output buffer, and pump) from being in a vertically descending sequence (where the pump would be doing constant work to maintain the potential difference despite the "load"), to being on a flat plane (where everything would reach potential equilibrium, and the pump would then turn off.) And you could then represent AC flow, by just alternatingly raising and lowering the two chambers, and using a bidirectional pump.

fnordpiglet 4y ago

I think it’s the same but different rates of propagation. It’s about potential force and gradient descent in the end. It’s also interchangeable. The water moves a physical object which induces a moving magnetic field which induces current in a conductor which moves through the circuit and can induce a magnetic field in a conductor which can move a magnetic which can move water.

deleted 4y ago

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