**Conservation law of** | **Related symmetry** | **Explanation** |

momentum | translation symmetry in space | Executing an experiment 'here' gives the same result as executing it 'there', provided that the conditions are identical. |

energy | translation symmetry in de tijd | Executing an experiment 'earlier' gives the same result as executing it 'later', provided that the conditions are identical. |

electrical charge | translation symmetry along the potential-axis | Electrical voltage is a potential difference. The absolute value of the voltage cannot be measured, because in an electrical system, everything happens in the same way after adding a constant potential everywhere. (In an electrical circuit any point can be chosen to be connected with earth or ground, by definition the zero voltage.) |

mass | translation symmetry along the gravitational energy-axis | In a gravitational system (for example, in the planetary system) gravity energy is not defined. Only gravitational energy differences can be calculated. The planets would move identically if a constant energy is added to the gravitational energy formula.
In practice, in an infinitely distant point the gravitational energy is chosen to be zero by definition. |

angular momentum | rotation symmetry in space | |