Bitaw, this is how it is...
from The Physics of Giants and Dwarves: What we know about the existence and viability of drastically scaled creatures
By Julian G. Franco
Now let us see what happens when we expand our human to gigantic dimensions. If we augment the linear dimensions 10 times (i.e., our human giant’s height, fingers, nose and so on are ten times longer), the surface area of her skin will be 100 times larger and her bones 100 times thicker. Her volume will be 1,000 times larger, so that she will be supporting and moving around 1,000 times more weight than the original human.
Imagine that your neighbor Mary, who weighs 70 kg (154 lb), suddenly and magically becomes 10 times taller. Now you have 1,000 Mary's, her weight being now 70 tons! And you thought she was overweight before. That presents us with an insoluble situation. Her weight has increased 1,000 times, but her strength has increased only 100 times, as given by the corresponding increase in bone thickness. Therefore, if she could exist, she would feel like she was carrying nine extra people on top of her! If we were actually able to construct this giant human of flesh and bone with the exact same biology as ours, she wouldn’t survive, just on the basis of strength, her bones breaking, the doomed giant crushing under her own weight.
Evolutionarily speaking, this is one, among other drastic limitations, that prevent humans as a species, from growing much larger than its present overall size–short of changing their water/carbon-based biology, its shape, or both. Furthermore, since we all have a common origin and share the same biology, we can also study other animals that are closely related to each other and see what happens as size goes up and down. All mammals, for instance, are made pretty much of the same kind of flesh and bone and share many anatomical features.
Galileo was the first one to do exactly this. He compared the leg bones of a gazelle and a bison, both mammals of the deer family. He noticed that the bison’s leg bones were disproportionally thickened, as compared to the equivalent gazelle's bones. The bison cannot grow to be so heavy and at the same time keep the graceful figure of the gazelle. A glaring example of this needed disproportion is the stocky legs of an elephant.
Please note that it is not that human-like giants couldn’t exist, in principle, and up to a certain extent. It is simply that they would be completely different than the known human; i.e., same shape and proportions as ours, but bones of a superstrong, non-biological material; or same biology, but with a drastic change in proportions, becoming squatter and broader as the size increases. James Trefil, a noted American physicist and author, has pointed out for the sake of argument, that if we want to design a gravitationally viable, flesh, bone, and blood human giant, five times as tall as we are, it would weigh roughly twice as much as an elephant (12 tons), and look more like a Sherman tank than a person, 9-ft tall, 8-ft from front to back, and 16-ft wide!
More at:
http://knol.google.com/k/the-physics-of-giants-and-dwarves# Linkback:
https://tubagbohol.mikeligalig.com/index.php?topic=47514.0