• Atomic@sh.itjust.works
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    17 hours ago

    That used to be true. But modern cars with modern engines have better thermal efficiency than humans.

    This is from a purely thermal efficiency standpoint. Not taking any environmental factors into play.

    • infinitesunrise@slrpnk.net
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      13 hours ago

      Right since as soon as you start looking into how that car was made and how the energy that ends up in those batteries is produced, the legs win again.

      • Atomic@sh.itjust.works
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        8 hours ago

        Look. I don’t know what you think you mean. But you’re clearly not talking about thermal efficiency.

        Thermal efficiency is a measurement of how much energy goes into work, and how much is wasted through heat.

        Muscles will never beat an engine. Combustion or otherwise.

        The fact that we “used to be” is a huge caviat, giving humans the best case scenario against the vehicles worst case. The moment we start to put in some effort to performing work, our thermal efficiency goes down, significantly.

        That’s ok… thermal efficiency isn’t what you should be worried about.

    • Arkthos@pawb.social
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      16 hours ago

      Couldn’t really find any sources, but honestly it sounds reasonable enough. Engines are way more specialized for their single mechanical task than our legs are.

      Of course you also move around way, way more weight most of the time. The mass/payload ratio is way worse with cars than with bikes so the comparable thermal efficiency would need to be greater to make up for that.

      Beyond being a curiosity it is a moot point anyways. Humans need exercise to be healthy, and as you said, there are other environmental factors like car construction, gas refinement, etc. That I imagine mostly favour bikes too.

      • Atomic@sh.itjust.works
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        9 hours ago

        Thermal efficiency is purely a measurement of how much of the energy you put in, goes to actual work, and how much is wasted through heat.

        Mass only plays a part in that thermal efficiency might change depending on the load the work is performed on.

        I can’t think of a single engine that have better thermal efficiency than an electric one. (Not taking into account how the electricity was produced)

        You’re right about it being a moot point. There are far more important aspects than simply thermal efficiency. I just wanted to set the record straight. Because saying humans have better thermal efficiency than cars is just not true. Not even close.

        We evolved sweat for a reason. Our thermal efficiency is so bad we had to develop external cooling or we would overheat.

    • da_cow (she/her)@feddit.org
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      16 hours ago

      While this is probably true (I have no idea, so I just gonna trust you on that one) its still pretty stupid if someone would bring that as an legitimate argument

      • Atomic@sh.itjust.works
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        9 hours ago

        It’s not a take. It’s factual. Thermal efficiency is a measurement of how much energy is wasted through heat rather than being used to perform work.

        Muscles are fantastic in many ways. But what they’re not. Is thermally efficient. That’s ok.

        • PlaidBaron@lemmy.world
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          2 hours ago

          Thats not my point. Its just not relevant to the overall efficiency of the bicycle compared to the car. Thermal efficiency isnt what we’re talking about here.

          • Atomic@sh.itjust.works
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            2 hours ago

            Thermal efficiency is exactly what the top comment was talking about. That’s where it started.

            • PlaidBaron@lemmy.world
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              2 hours ago

              Not really. Thats how youre interpreting it. When you consider the primary goal is to move a single person (in most cases), the bike wins out. You’re wasting energy moving a large amount of mass.