this post was submitted on 28 Oct 2023
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Your body is burning energy because it's not good at holding a position continuously. An idling car is sitting there, burning fuel - but it's not actually doing any useful work, just getting hot. You get the same result by turning the engine off and putting on the handbrake, only without the heat.
Why do you think it takes work to suspend something using tension, but not to support something using compression - e.g., the same object resting on a desk?
Work is force times distance; that's proven to the n^th decimal place. If nothing moves, no work was done.
Battery-electric is a way to move power. You still need to generate power in the first place - and perpetual motion would be great for the grid, for ships, everything. It just doesn't work.
https://www.smbc-comics.com/?id=2305
I wasn't talking about perpetuum mobile, I was talking about the magnets actually spending their magnetic energy... you would have to magnetize them again from time to time.
Nice comic BWT, funny 😂.
If you genuinely use the magnets as a battery, they just don't store enough energy. Wikipedia lists Neodymium magnets as storing about 512kJ/m^3, and lead-acid batteries as about the same amount but per litre - so a thousand times more dense.
Remember that energy removed must equal energy added, so you need to find a way to pump those megawatt-hours into the battery.
In addition, energy storage mechanisms generally have to release that same amount of energy when destroyed. A fully charged lithium battery makes a serious fire, especially if it's a big one. A big tank of petrol makes a big fireball, when allowed to mix with air. A spring or a magnet mostly just goes 'bang'.