Classical mechanics

1. Inertial reference frames exist, and in any such frame the center of mass of a system that experiences no external interactions does not accelerate.

2. Spacetime is homogeneous and isotropic, i.e. laws of physics do not depend on absolute position in space or time, or orientation.

From these two postulates we derive mechanics.

• Conservation laws

• Constrained motion

• Kepler’s laws

• Noether’s theorem