An infinitely long rigid body with gaussian mass distribution Are you joking You wrote that there s plenty of physicists who consider lines and planes of material points even in mechanics If there are so many then you have a lot to teach to those who are interested in this discussion Can you give some examples explaining what is the body and body property modeled with a line or plane and what is the purpose or application of the model That would be interesting And if you have an example in rigid body dynamics that would surprise me and make your contribution much more interesting Otherwise you will never convince me What you are trying to do is provided a model that might be used that s not enough to convince me