3 ms·

And dangerously. There is no redundancy.

Someone 6y ago
For insects, hummingbirds, and quadcopters of similar size, there’s no danger in dropping from the sky. J.S. Haldane in “on being the right size”: “You can drop a mouse down a thousand-yard mine shaft; and, on arriving at the bottom it gets a slight shock and walks away, provided that the ground is fairly soft. A rat is killed, a man is broken, a horse splashes. For the resistance presented to movement by the air is proportional to the surface of the moving object. Divide an animal’s length, breadth, and height each by ten; its weight is reduced to a thousandth, but its surface only a hundredth. So the resistance to falling in the case of the small animal is relatively ten times greater than the driving force. An insect, therefore, is not afraid of gravity; it can fall without danger, and can cling to the ceiling with remarkably little trouble.” (These wing suits are man-sized, so they would break their wearer on impact)
- dmurray 6y ago
  > A rat is killed, a man is broken, a horse splashes. I had thought that cats could fall from any height safely, but that's not quite true: observational studies suggest [0] they have a 50% or 90% survival rate from terminal-velocity height onto hard surfaces, but not without injury. Still, I'd expect a rat could also "walk away". It's quite a lot smaller than a cat, though it may lack other evolutionary adaptations for falling. And a rat is a mouse, taxonomically: we just informally call the bigger species of mice rats. [0] http://www.todayifoundout.com/index.php/2010/11/domestic-cats-can-fall-from-any-height-with-a-remarkable-survival-rate/ http://www.todayifoundout.com/index.php/2010/11/domestic-cat...
  - Kye 6y ago
    The dual taxonomy of so many animals is interesting. The line between a pigeon and a dove seems to be one of judgment, like with rats and mice. Or the slightly more distant mantis and roach.
    - dmd 6y ago
      Not quite. http://www.ratbehavior.org/RatsMice.htm http://www.ratbehavior.org/RatsMice.htm http://www.ratbehavior.org/RatMouseHybrid.htm http://www.ratbehavior.org/RatMouseHybrid.htm
  - stjohnswarts 6y ago
    a huge portion of that is that humans have a much worse weight to surface area ratio, cats hit at about 60mph and humans at 120 mph. very few humans survive falls in which they reached terminal velocity.
  - skykooler 6y ago
    Rats lack the long legs of cats that allow them to cushion their fall, though. Cats have a ton of adaptations that each help with some aspect of landing from a fall.

For insects, hummingbirds, and quadcopters of similar size, there’s no danger in dropping from the sky. J.S. Haldane in “on being the right size”: “You can drop a mouse down a thousand-yard mine shaft; and, on arriving at the bottom it gets a slight shock and walks away, provided that the ground is fairly soft. A rat is killed, a man is broken, a horse splashes. For the resistance presented to movement by the air is proportional to the surface of the moving object. Divide an animal’s length, breadth, and height each by ten; its weight is reduced to a thousandth, but its surface only a hundredth. So the resistance to falling in the case of the small animal is relatively ten times greater than the driving force. An insect, therefore, is not afraid of gravity; it can fall without danger, and can cling to the ceiling with remarkably little trouble.” (These wing suits are man-sized, so they would break their wearer on impact)

dmurray 6y ago
> A rat is killed, a man is broken, a horse splashes. I had thought that cats could fall from any height safely, but that's not quite true: observational studies suggest [0] they have a 50% or 90% survival rate from terminal-velocity height onto hard surfaces, but not without injury. Still, I'd expect a rat could also "walk away". It's quite a lot smaller than a cat, though it may lack other evolutionary adaptations for falling. And a rat is a mouse, taxonomically: we just informally call the bigger species of mice rats. [0] http://www.todayifoundout.com/index.php/2010/11/domestic-cats-can-fall-from-any-height-with-a-remarkable-survival-rate/ http://www.todayifoundout.com/index.php/2010/11/domestic-cat...
- Kye 6y ago
  The dual taxonomy of so many animals is interesting. The line between a pigeon and a dove seems to be one of judgment, like with rats and mice. Or the slightly more distant mantis and roach.
  - dmd 6y ago
    Not quite. http://www.ratbehavior.org/RatsMice.htm http://www.ratbehavior.org/RatsMice.htm http://www.ratbehavior.org/RatMouseHybrid.htm http://www.ratbehavior.org/RatMouseHybrid.htm
- stjohnswarts 6y ago
  a huge portion of that is that humans have a much worse weight to surface area ratio, cats hit at about 60mph and humans at 120 mph. very few humans survive falls in which they reached terminal velocity.
- skykooler 6y ago
  Rats lack the long legs of cats that allow them to cushion their fall, though. Cats have a ton of adaptations that each help with some aspect of landing from a fall.