• 0x4E4F
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    1 year ago

    Or use a Perendev magnet motor… should be more efficient anyway.

    • Five@slrpnk.netOP
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      1 year ago

      Liquid air motors don’t violate the laws of thermodynamics. It runs on energy stored as cooled air, similar to a compressed air cartridge.

      If the motor design doesn’t account for entropy, it won’t work. Perendev magnet motors, like all permanent magnet perpetual motion machines, don’t work.

      • 0x4E4F
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        1 year ago

        I’ve seen tons of other videos that disprove this one… which one is right? IDK, I guess I’ll have to build one and see.

        And it’s not free energy, the magnets become demagnetized with time, which is logical, they push or pull on one another. On a long enough time scale, yes, they do become less magnetized.

        • Five@slrpnk.netOP
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          1 year ago

          Building one might be an interesting project, but don’t be too hard on yourself if it doesn’t work. Your workmanship will not be at fault, it is the physics that are flawed.

          This is not a machine that creates energy by demagnetizing magnets. But if it were, then the amount of energy the motor could produce would be proportional to the amount to which the magnet was demagnetized, and the total amount of energy the motor could release over its lifetime is bounded by the minimum amount of energy required to magnetize the magnets in the first place. If you’re curious how much energy that is … not much.

          • 0x4E4F
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            1 year ago

            See this is what bugs me about the last answer.

            This issue is that it doesn’t take any work to hold a weight at fixed height. If you set the weight on a table, does the table need some energy source to hold it up? Does a car need to burn fuel to keep from sliding down if it’s parked on a slight slope? The energy just stays fixed, with no flow.

            I’m sure the person that asked those questions meant it as holding 50kg suspended in air, via a rope or something. People have done these tests for a while now, and I’m sure there is more to the story, cuz, let’s face it, holding something suspended in air, via a rope or whatever, with nothing like a nail or a screw screwed to the ceiling, is doing work (the latter examples have the power of friction on their side, that’s how they work, which is not the case with a pair of magnets). It’s like you holding that same thing suspended in air for a year. You must put in work to do that, right?

            I’m sure that even physicists are missing something here… either that, or no one knows how to explain things like this person asked in plain language.

            I’m an egineer BTW, but permanent magnets were never really well layed out in uni. But then you stumble upon things like the Perendev motor and wonder why no physicist will try and tackle this issue, dispoving it in practice, instead of just dismissing it as a perpetu mobile.

            What I’m definitely saying is that there is no free energy, that’s ridiculous… or maybe in a form we still have’t disovered, who knows. But, using trapped energy in a magnet… that could actually work. The concept might sound weird to a scientist, but we all know that most of the time, egineers are the ones that “break the rules” in conventional science and that most revolutionary discoveries are done by them, not suits with Phds. And Perendev was a legit engineer, a smart one as well. So this leads me to at least consider this idea as a sustainable scenario, thus leading me to try and make one of my own.

            • Five@slrpnk.netOP
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              1 year ago

              Teach yourself the fundamentals of physics whatever manner works best for you. But until you’ve built a working Perendev motor and had the design and device peer-reviewed, please don’t advertise it as a real alternative to solutions that don’t break the laws of thermodynamics.

              • 0x4E4F
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                1 year ago

                Hey, i could say the same about your link 🤷. Doesn’t break the rules, but let’s face it, it’s not a viable alternative. I really can’t imagine someone doing this in the age of electric cars.

            • SomeoneSomewhere@lemmy.nz
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              1 year ago

              It’s like you holding that same thing suspended in air for a year. You must put in work to do that, right?

              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.

              I really can’t imagine someone doing this in the age of electric cars.

              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

              • 0x4E4F
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                1 year ago

                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.

                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 😂.

                • SomeoneSomewhere@lemmy.nz
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                  1 year ago

                  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’.