Talk:Mass

Mass is defined in terms of either (a)"resistance to a force" and/ or (b)"the attractive force all objects in the universe have for each other". The definition does not try to explain how these two seemingly unrelated phenomena can be related by this singular characteristic - "mass". It also does not even begin to explain what mass is -- how is arrises from an object. Omitting the fact that these basic questions about this basic phenomina is "sketchy" is to overstate our thin understanding. Addressing what we don't know is just as, if not more important than addressing what we do. Doing so stimulates the creative mind.

Under GR, the fact that inertial and gravitational mass are the same can be reduced to the "principle of the universality of free fall" - basically a symmetry argument. As for declaring our lack of knowledge: well, we have a mathematical description of inertial and gravity which works in all but the most extreme situations (black holes and the big bang). Don't you think that counts for something? Our understanding of mass is on roughly the same footing as our understanding of the other three forces. With any scientific theory, someone can find a fundamental principle or assumption and say "but you don't know why that is the case". Theories which don't have such assumptions or principles are non-scientific. -- Tim