A Standing Problem
Scaling: Weighty Issues
There is an age-old physical dilemma that plagues structural engineers and scale modelers alike: strength to weight ratio. As a kid, I wondering why the plastic scale model of an airplane was hopelessly unable to mimic the performance of the copied aircraft. Conversely, a plastic car model could 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 ability. 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 an animal up to the massive size of a dinosaur has led some paleontologists to postulate that sauropods (long necked dinosaurs) must have been aquatic, instead of land animals. But this is in conflict with the evidence. DinosaursIn fact, dinosaurs do have a serious scale problem, as well explained by Ted Holden:
Dinosaurs ...and the Gravity Problem
How could a dinosaur stand and walk, given their overwhelmingly massive weight and available muscle mass? Specifically, how can dino tracks in apparently soft ground be only a few inches deep? How deep would a house sink in mud if it was supported on four pillars the size of dino feet? Yet, the majority of the volume of a house is mainly empty air, while a similar sized sauropod is solid!
Have physics changed? Has gravity always remained constant? If the Electric Universe theory holds weight, gravity today could be different than it was in the past: