I have to disagree both in the case of animals and the volcano example. With animals, there are real underlying physics principles that dictate the strength-to

I have to disagree both in the case of animals and the volcano example. With animals, there are real underlying physics principles that dictate the strength-to-weight ratios at various scales that lead to smaller animals being able to move more quickly (muscle strength is proportional to cross section, while mass is proportional to volume). In the case of the avalanche, the force at work is the same (gravity) it's just that we are zooming way out and so crossing the same distance takes much more time.