A Standing Problem

Scaling: Weighty Issues

There is an age-old physical dilemma that plagues structural engineers and scale modeling enthusiasts alike: strength to weight ratio.  As a kid I always wondering why a plastic scale model of an airplane is hopelessly unable to mimic the aerodynamic performance of the copied aircraft.  Conversely, a plastic car model can be dropped and exposed to scale-speed impacts with without so much as a dent.  Imagine a highway car wreck where vehicles bounce without damage!  Similarly, a model bridge made from popsicle sticks could not directly scale up to a size capable of supporting road traffic.

Strength to weight ratio (or Specific Strength) can have surprising consequences.  Weight is related to volume (third order) while strength is related to area of material cross-section (second order).  As a real life example, the strength to weight ratio of Balsa wood is greater than any metallic alloy.  This is great for building model rockets, yet it's clearly not possible to build an aircraft or rocket capable of carrying humans from Balsa.

Dino-Sized Concerns

Looking at living things, size has a big impact on abilities.  Ants are able to carry up to 20x their body weight and small lizards and frogs can climb window panes supported only by the attraction force of the glass.

Scaling the size of an animal up to the size of a dinosaur has led some paleontologists to postulate that sauropod (long necked) dinosaurs must have been aquatic instead of living on land.