In the real world, things have a limited number of degrees of freedom. Any chemical reaction that occurs in nature is a linear system that occurs because of a limited number of degrees of freedom and the superposition principle applies. The mathematical formalism of classical linear systems doesn't apply well to superposition because any two or more degree of freedom systems have combined system that doesn't have a total of all the degrees of freedom that were available in the individual systems. In other words, the superposition principle applies to physical systems that are nonlinear. The number of degrees of freedom is not always a good measure of the degree of nonlinearity. This is because a system can be completely linear and yet its equation of motion is nonlinear. Furthermore, we often don't know the exact degrees of freedom of a system. Even if we knew the exact degrees of freedom of a system, we often don't know all the possible combinations of all of its degree of freedom. For example, there are many possible combinations for a given number of degrees of freedom.
2560x1440 60fps mp4
0x3...799
