Momentum

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This is a page under constuction. It is possible that the author have gotten stuck, or are merely in the process of completing the article and it's supports. It is also possible that what is written is not in fact rigorous, and thus should be treated with lessened credibility. Beware! If possible, help out!

Momenta are quantities in physical systems. Momenta are conserved (in Lagrangian and Hamiltonian systems) wherever there exists a symmetry in the potential along a generalised coordinate, or, equivalently, an absence of force along that coordinate.

-- okay, trying to disentangle canonical and physical and generalised momentum. I've never entirely gotten this.