• Reddfugee42@lemmy.world
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    3 days ago

    This is (fortunately) why there’s a maximum size on insects. The environment is less oxygen rich today than in the eras of giant insects in the past. They reach a size where oxygen can’t penetrate deeply enough onto their bodies.

    • excral@feddit.org
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      2 days ago

      It’s all based on a very fundamental mathematical law: if you increase the size of something, the volume increases with the third power while the surface area increases with the second power. An insect twice as large would be 8x as heavy and need 8x as much oxygen but 4x as much surface area.

      That’s also the reason why insects are as strong as they are. The strength of a muscle scales primarily with the cross section area of it, which again scales with the second power. So if you’d increase the weight of an ant by a factor 10,000,000 (e.g. 5mg to 50kg), the expected strength would increase by 10,000,000^(2/3) ≈ 46,400. If it could lift 10x it’s weight at the original size, it could now only lift about 4.6% of it’s weight

      • Sauerkraut@discuss.tchncs.de
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        2 days ago

        Reminds me of how the damage to roads scales with the weight of the vehicle to the 4th power, so someone driving a 6000lb pickup does 16x more damage to roads than a 3000lb sedan

        • EddoWagt@feddit.nl
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          2 days ago

          How does double the mass increase the damage 16 fold? I understand surface area vs volume, but that doesn’t seem relevant when working with mass

          • MDCCCLV@lemmy.ca
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            2 days ago

            It’s more about a minimum of weight or pressure that affects it. So the higher the pressure the more likely it is to flex the road where a small vehicle with light pressure might not make it flex at all. The heavier it is the more the weight will flex the subsurface and cause more damage.

            https://www.forbes.com/sites/lauriewinkless/2023/08/30/how-roads-fail-and-why-theyre-set-to-get-worse/

            “To give you an example of that impact, let’s do a quick calculation. Here in New Zealand, the heaviest vehicle allowed on (some of) our roads is the 50MAX truck. It has nine axles and a total weight of 50 tonnes, so the load-per-axle is 5.55 tonnes. The best-selling car in NZ in 2022 was the Mitsubishi Outlander. It weighs 1.76 tonnes, so its load-per axle is 0.88 tonnes. The fourth-power law says that to calculate the relative stress that these two vehicles apply to a road, you take the ratio of their loads-per-axle and raise the result to the fourth power. In this case, (5.55 / 0.88)4 = 1582. In practical terms, it means that a 50MAX truck applies as much stress to a road as 1,582 cars (or quite literally billions of bicycles)”

    • Anomalocaris@lemm.ee
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      3 days ago

      maybe once I have money for hobbies, but I really want to make oxygen rich terrariums, and selectively breed tarantulas to see if I can make them larger.