:: Some scalar values in Newtonian mechanics are conserved because there exist associated conservative fields (or more generally [[Noether's Theorem|symmetries of the Lagrangian]]). What is an example of a scalar value in the Newtonian mechanics that is not of this type, which makes this a conservative theory of motion while relativity is not? | :: Some scalar values in Newtonian mechanics are conserved because there exist associated conservative fields (or more generally [[Noether's Theorem|symmetries of the Lagrangian]]). What is an example of a scalar value in the Newtonian mechanics that is not of this type, which makes this a conservative theory of motion while relativity is not? |