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her physical body is able to act as a brace to a building that weighs over 5.51156 sextillion
</p><p>"But that's just a theory, a game theory!"
</p><p>What you fail to understand is that the Avatar universe, at least as far as bending is concerned, has only a light basis in our modern understanding of science. Obviously the muscle contraction and physical strain of bending was added purely to let the viewer feel the strain a character feels when bending - it doesn't entirely make sense. Pretty much, it looks cool.
However, since we <i>are</i> in the general disccussion board of the avatar forum, such an answer will not do. Thus, here is my proposal, listed as a number of points:
</p><p>1. Earthbenders do appear to use their physical strength very heavily when bending, and this is obvious throughout the series. However, and this is important, <i>one's earthbending does not become stronger if your body is stronger.</i> This seems to suggest that "earthbenders having to stay steadfast and strong" is more about the mindset, than the actual physical exertion. This is further backed because Aang manages to overcome his earthbending block by learning to think differently, rather than training at the gym.
</p><p>2. Yes, it is possible that the series was wrong, and this was indeed a plothole - this would be the case if internal consistency was ruined. However, as we see throughout the series, bending cannot be explained by applying modern physics and chemistry. Why can firebenders bend fire and lightning, but not other kinds of energy? If they can bend thermal energy, why can't they freeze someone/something by taking all of the heat out of it?
</p><p>3. The answer to that is simple. The Avatar universe is based on Eastern philosophy. Firebenders can bend fire and lightning because the <i>ideas</i> of fire and lightning are interlinked, and waterbenders can heal and get a power boost from the moon because it is a part of that philosophy. Healing in reality is not more linked to water than it is to air, however the concept of water in old Eastern philosophy reflects the way benders can use it.
</p><p>4. Finally, why can't Toph stop the drill? Even if she did the proper stance and everything, she would only be supported by the ground. The moving metal drill would simply push her over. She <i>was</i> able to slow it down by lifting it slightly off the ground with earth spikes, however even those it could get over quite easily.
The library, on the other hand, was made almost entirely of rock and - more importantly - it wasn't gravity that was pulling it down, it was more-so the will of the owl spirit. The spirit attempted to pull it back into the spirit world where it came from, however Toph's earthbending contested this power, and they existed in a relative equilibrium until the sandbenders distracted her.
</p><p>5. If she was indeed as strong as you said she was, she could've ripped open the metal cage like paper. If earthbenders had the ability to destroy anything as easily as they could obliterate a rock with a single kick, why didn't they do it? It's because these stances weren't the only thing at play here, and you cannot dumb the Avatar world down this way. It is much more complex than that, and establishes that complexity throughout the series - a complexity that is entirely it's own, not based in our world.
When an earthbenders kicks a rock and it explodes into dust, the action is really only a way to focus the mind to perform a bending action. We see several instances of benders using 'psychic' bending, bending without stances, and this appears to require far more focus and effort, because they cannot use the bending stances to help them focus.
</p><p>This may not be the most satisfying answer to someone who wants to break things down into easily calculatable formulas based on real-life research, but it is the case with the Avatar world. Yes, they have the same basic laws of physics, however bending itself defies a lot of them - it would be impossible for bending to exist without doing so. What is important is that it is very internally consistent, and this is what makes a good story, not accuracy to the real world
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