> For what they want to study, it doesn't matter if they model the human as a sphere or as a real-life model with limbs and so on. It won't affect the grand pic

> For what they want to study, it doesn't matter if they model the human as a sphere or as a real-life model with limbs and so on. It won't affect the grand picture. The exact claim is that such modeling, eg, fails to find avalanche dangers that truly exist in the world of skiers moving their body on physical skies, due to their shifting and localized weight, which is missing in the spherical skier model. Your post does nothing to address this. The simplifications you call out are all cases of decreased accuracy in exchange for easier computations: that is, for less accurate results that are “good enough”. But the intersection of many such simplified models may fail to accurately model reality.