Asked by: David Meyer, Crowborough
Not really – all movement is relative. To have absolute stillness you would need an absolute frame of reference. The (supposedly) fixed stars were once thought of as such a unique reference point, but now no such reference point is believed to exist. Ernst Mach (after whom the Mach number is named) argued that the concept of inertia would be meaningless in such a frame, and Einstein was stimulated by this to develop his General Theory of Relativity.