- #1

James MC

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Is a (classical) physical object that is correctly described as a point mass (i.e. as a mass value M at a point x) a physically different object from a (classical) physical object that is correctly described as a mass density distribution distributed/defined over an infintesimal region?

If the answer is no, then are the point mass description and the infintesimal mass density distribution description just two ways of saying the same thing? In other words, if I am told that there exists a point mass is it trivial to immediately infer that there exists a mass density distributed over an infintesimal region?

If the answer is yes, what exactly is the difference, and is the idea of a 'dirac delta function' (which I don't yet understand) an attempt to apply formalism originally intended for densities, to point masses?

Thanks!