• Tar_Alcaran@sh.itjust.works
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    4 months ago

    Ooooh, i love this idiot! It overlaps my historical leather working hobby with my hatred of pseudohistorical bullshit.

    So, a 30m diameter sphere contains 14.000m3 of gas. Every liter of hydrogen lifts 1.14 grams, and for helium it’s 1.05 grams. So 14.000m3 = 14 million liters, or about 14 million grams, which is 14 tons. Sounds pretty decent until you realize that animal hide isn’t exactly weightless.

    A tanned cowhide, before it’s split, is over 4cm thick. Vegetable tanned cattlehide weighs something like 40 kg for a 5m2. But lets see how thick out balloon is. If it can lift 6 tons, it can only weigh some 8000kg itself. Our 30m sphere has a surface area of some 2800m2, so that means our animal hides can weigh, at most, 8000/2800=2.8kg per square meter. Those at home have probably noticed that 2.8 is a bit less than the 8kg you need to use cowhide.

    So, what kind of leather or hide were those balloons then? Well leather is usually sold in “ounces per square foot” (even in Europe), so we can just look it up. 2.8kg per square meter is about 9.2 ounce per square foot (says wolfram alpha), and a handy table I have printed says that’s around 3.6mm thick.

    So, we are too believe that the Egyptians made a 30m balloon, out of what is basically cheap-belt and saddlebag leather, somehow got that not just air-tight, while being ridiculously thin, and then used it to build massive structures.

    • ThisIsNotHim@sopuli.xyz
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      4 months ago

      Not just air-tight, lighter-than-air-tight. I’m not sure if it’s true for the whole set of lighter-than-air gasses, but helium is infamously difficult to keep from leaking, even with modern technology.

      Good at making gasses behave is a weird choice for ancient technologies we lost.

    • Tyfud@lemmy.world
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      4 months ago

      Do they need to do that before, or after they learn how to harness a tremendous amount of hydrogen? Which they conveniently forgot to mention anywhere.

      You also think that they would have made a few pictures of that happening, instead of the pictures they did make, which clearly show manual slave labor building the pyramids.

    • KillingTimeItself@lemmy.dbzer0.com
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      4 months ago

      i think they would likely be using intestines or cow stomachs as did the rigid airships of the time, as it was the only material that could hold back hydrogen, so that would’ve been an option. Especially with leather production, though someone would have to have thought about it first.

      I’m not sure either hydrogegn OR helium would’ve been accessible at the time, though if we’re tying to logically analyze this, its probably worth considering they would’ve alleviated like 80% the mass of the stone, and not all of it, as it’s a little redundant to make the thing float.

    • Valmond@lemmy.world
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      4 months ago

      Hah gain even more lifting power and also sidestep the whole need of creating helium by filling it with vacuum!

      \s if needed 🤷🏻‍♀️

  • Dizzy Devil Ducky@lemm.ee
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    4 months ago

    Gotta love how some people alive today cannot comprehend the fact humans have been able to build large structures long before we had things like crains and electricity.

    I imagine they are the same people who look at something like a castle in the UK built in the 12th century or the great wall of China and assume that it was impossible for humans to have built them because they believe humans were too dumb (ironically) to have figured out how to lift rocks using any other method than crains.

    • Flying Squid@lemmy.worldOP
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      4 months ago

      In case this is of interest to you, since 1997, a group of archaeologists and experts have been building a castle in France as accurately as they can in the way it was done in the 13th century. Apart from adding certain things for safety reasons, they try to be as authentic as possible. Of course, it’s taken decades and it’s still not done… but that’s because it’s a freakin’ castle. (Also, they don’t have a huge workforce, but that’s something else.)

      It’s even had a practical use. They were able to apply what they learned when reconstructing Notre Dame after the fire.

      https://en.wikipedia.org/wiki/Guédelon_Castle

      There was also a British documentary series about it with three archaeologists from Britain who go to contribute to the project and live in a Medieval style- https://www.youtube.com/watch?v=ydoRAbpWfCU&list=PL72jhKwankOiwI5zt6lC3eQtsQDxOaN_g

      • Tar_Alcaran@sh.itjust.works
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        4 months ago

        There are several recreations of old Age of Sail ships, made historically accurate via historical methods, and its been incredibly educational for historians worldwide.

        Reenactment like this is extremely useful in recreating information that was either a professional secret, or considered so blatantly obvious nobody ever had to write it down.

      • TachyonTele@lemm.ee
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        4 months ago

        I tend to think the difference is that the people building it today don’t need to build it, along with the lack of a work force. Necessity is a great motivator.

        • Tar_Alcaran@sh.itjust.works
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          4 months ago

          I also doubt they had hundreds and hundreds of workers doing manual labor as part of their taxes. And modern people had slightly different ideas of what acceptable labor is.

    • Artyom@lemm.ee
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      4 months ago

      I find that the general trend is that if they were white, people say “wow, people can do amazing things!” like with Stone Henge, but when they weren’t white, it would have been impossible and there is some missing fact like aliens or whatever.

    • Captain Aggravated@sh.itjust.works
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      4 months ago

      What’s amazing to me is that ancient people looked at what they were being asked to build, and the tools they were expected to build it wiht, and didn’t just say “No, go fuck your hat.”

    • Plopp@lemmy.world
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      4 months ago

      Gotta love how some people alive today cannot comprehend the fact humans have been able to build large structures long before we had things like crains and electricity.

      Yeah? You say that but like, uh… where’s your proof, man?

  • Wilzax@lemmy.world
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    4 months ago

    Because they definitely had a good supply of helium and/or hydrogen laying around to fill these balloons with, when levers and wheels were too advanced.

    Right.

    • IggyTheSmidge
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      4 months ago

      Clearly they used methane.

      Crowds of farm labourers during flood season, all lined up just waiting for their turn to fart into the balloon.

      • HonkyTonkWoman@lemm.ee
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        4 months ago

        It would be another age before they realized they could fill the balloons twice as fast using camel farts.

    • gmtom@lemmy.world
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      4 months ago

      You know you can make hydrogen out of water right? You just need high voltage electricity.

      • ivanafterall ☑️@lemmy.world
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        4 months ago

        Likewise, why would they bother with balloons, at all? We know they were highly advanced, it seems more likely they’d just skip to planes?

      • Cethin@lemmy.zip
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        4 months ago

        I’m assuming you subscribe to the Baghdad battery idea? Even that would produce only a tiny amount of electricity if it did at all. It definitely couldn’t be used for this or even the lighting idea some crazy people support. It may have produced a tiny jolt and have been used for religious purposes as they couldn’t explain the small shock.

  • wizardbeard@lemmy.dbzer0.com
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    4 months ago

    Nope, found my line. This is too absurd and well typed for me to believe this one isn’t just taking the piss.

    • Flying Squid@lemmy.worldOP
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      4 months ago

      You must not be familiar with Graham Hancock. That’s kind of his whole schtick- sounding like he knows what he’s talking about by sounding erudite but talking absolute garbage.

      • Captain Aggravated@sh.itjust.works
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        4 months ago

        I mean they weren’t on mute.

        Actually that puts a funny idea in my head. Several pyramids away from Giza, the stepped pyramid, the bent pyramid and the ruined pyramid were all built by Sneferu, Khufu’s father, and obviously only one or none of them could have been his tomb. What if he had some weird obsession that they had to be built in utter silence and gave up on one and made them start again if any of the men so much as grunted?

  • NegativeNull@lemmy.world
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    4 months ago

    Formula for surface area of a sphere: πD2
    Surface area of 30m diameter balloon: 2827.43 m2

    Average cow hide size: 4.6 m2 source

    For one balloon, you’d need 614 cows (approx)

  • mechoman444@lemmy.world
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    4 months ago

    Lol!

    And super dense helium hydrogen!

    (The size of the Hindenburg isn’t relative to how much it could lift it was relative to the amount of helium hydrogen gas required to lift things.)

      • mechoman444@lemmy.world
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        4 months ago

        You need a certain amount of hydrogen to create lift.

        The size of the Hindenburg would be relative to the amount of hydrogen needed to create such a lift.

        Therefore, the size of the Hindenburg isn’t relative to how much it can lift. The amount of hydrogen is the only thing that is relative.

        If you wanted to gain the same amount of lifting power in a smaller package, you would have to make the hydrogen denser which would turn it into a completely different element in and of itself which is why the statement in the post is funny and mine numbingly stupid.

  • Olhonestjim@lemmy.world
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    4 months ago

    If only. It’s funny to think, but hot air balloons could have been bronze age tech ( they almost certainly never were). All they would need is a giant sack made from fine thread, a source of heat, fuel, ballast, ropes, and a basket. Totally doable, but it’s another one of those things nobody thought of until very late.

  • Vivendi@lemmy.zip
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    4 months ago

    This is why you need to completely cut off your internet before you take a hit of that good shit