🚀 go-pugleaf

> John Roberts writes:
>
> I've read that small children often survive long falls with surprisingly
> little injury. It was speculated that they may be more likely to relax
> than adults.
>


        I think that the main cause of differences in the ability of
different creatures to survive falls is our old friend, the square cube law:

        Count a child as having half the linear dimensions of an adult.
Relative to an adult, the "squash room" available for deacceleration is
related to the linear dimension (1/2 of an adult).  If children had the same
body plan as adults, a "half adult size" child would have a mass proportional
to her volume, which is proportional to the cube of her linear dimensions ---
the child would have a mass of 1/2*1/2*1/2 = 1/8 of the adult (real kids hare
probably heavier than this due to the relatively larger sizes of their heads
in the overall body plan).

        Stored energy in a falling body is proportional to mass.  The child
thus has 1/2 the distance for deacceleration, but 1/8 the energy to get rid
of by deformation etc.

        Mice do quite well when dropped a few meters. Dropping an elephant
the same distance would probably create an insurance writeoff.  The
difference is related to body size, not the special body defences that cats
have in addition to their natural size protection (I wouldn't want to drop my
pet lion from the balcony of a 10th story apartment).






--
Bruce Dunn    Vancouver, Canada   Bruce_Dunn@mindlink.bc.ca