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'''Conservation law''' is a [[physical law]] that says that some physical quantity is conserved, which means ''never changes''. Examples of ''conserved quantities'' in physics are energy and momentum along 3 axies. So we have at least 4 independent conservation laws of momentum around axis 1, momentum around axis 2, momentum around axis 3, and energy, that is considered axis 4 by some autors or axis 0 by others. Usually mathematicians use diferent convention for numbering axes than physicists, who number axes starting from 0 for ''energy'', and so on for other axes (e.g. t, x, y, z where t denotes time, and the rest relate to ''space'').

'''Conservation law''' is a [[physical law]] that says that some physical quantity is conserved, which means ''never changes''. Examples of ''conserved quantities'' in physics are:

*[[Angular momentum]]

 

There are various quantities that are conserved in certain situations, but are not conserved in general.