# Conserved Charges

If we are studying a physical system which has some symmetries, why do we calculate conserved charges? What do the conserved charges tell about the system that the symmetries do not?

• What do you mean by calculating conserved charges? Are you asking about how $\frac{d\rho}{dt}+\vec\nabla \cdot \vec J=0$? – Aaron Stevens Sep 21 '18 at 13:09