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This seems like a flawed argument. By the logic in this article, wouldn't horses or cows, which weigh multiple times what a human does, have to have stocky rath

This seems like a flawed argument. By the logic in this article, wouldn't horses or cows, which weigh multiple times what a human does, have to have stocky rather than slender legs?

ndr 2mo ago
1. They stand on 4 limbs, rather than 2. 2. That would be assuming that human legs are sized at the max capacity they can carry, which is not true.
- necovek 2mo ago
  Regarding 1, horses in particular are known to jump off two hind legs and land on their two forelegs, putting a lot more force on them than their stationary weight. On 2, I believe that's the GP's point too — human leg bones (or horses') can obviously take a lot more than their standing/walking/running weight.
  - ndr 2mo ago
    Agree re 1, but point 2 still stands. They can take more stress than standing, but the scaling law is still there. If you scale linearly height/section the max stress won't scale linearly because the weight will scale cubically.
    - necovek 2mo ago
      As I mentioned elsewhere, eg. femur can take at least 30x body weight, and we've got two to carry us. If a giant is 10x the size, and femur is just scaled linearly, even with 10x the relative weight, it can still take 3x giant's body weight. So perhaps no jumping on one leg anymore, but walking or light jogging should be fine. But, their bones could also have larger cross-section and a giant could be stockier yet still appear "human like".
maxerickson 2mo ago
How big is big? The practical limit for bipeds is probably ability to survive a fall to the ground. It's not super common, but enough people die simply from falling from standing.
- schoen 2mo ago
  On the other hand, people can learn to fall more safely (like in gymnastics and martial arts). Maybe some version of those skills could somehow become instinctual, as maybe the corresponding thing is in cats?
  - maxerickson 2mo ago
    I guess if there were resources that were much more available to these agile tall people that might happen.

This seems like a flawed argument. By the logic in this article, wouldn't horses or cows, which weigh multiple times what a human does, have to have stocky rather than slender legs?

ndr 2mo ago

1. They stand on 4 limbs, rather than 2. 2. That would be assuming that human legs are sized at the max capacity they can carry, which is not true.

necovek 2mo ago
Regarding 1, horses in particular are known to jump off two hind legs and land on their two forelegs, putting a lot more force on them than their stationary weight. On 2, I believe that's the GP's point too — human leg bones (or horses') can obviously take a lot more than their standing/walking/running weight.
- ndr 2mo ago
  Agree re 1, but point 2 still stands. They can take more stress than standing, but the scaling law is still there. If you scale linearly height/section the max stress won't scale linearly because the weight will scale cubically.
  - necovek 2mo ago
    As I mentioned elsewhere, eg. femur can take at least 30x body weight, and we've got two to carry us. If a giant is 10x the size, and femur is just scaled linearly, even with 10x the relative weight, it can still take 3x giant's body weight. So perhaps no jumping on one leg anymore, but walking or light jogging should be fine. But, their bones could also have larger cross-section and a giant could be stockier yet still appear "human like".

maxerickson 2mo ago

How big is big? The practical limit for bipeds is probably ability to survive a fall to the ground. It's not super common, but enough people die simply from falling from standing.

schoen 2mo ago
On the other hand, people can learn to fall more safely (like in gymnastics and martial arts). Maybe some version of those skills could somehow become instinctual, as maybe the corresponding thing is in cats?
- maxerickson 2mo ago
  I guess if there were resources that were much more available to these agile tall people that might happen.