If you have previously taken a physics course then you have probably noticed that a rather odd symbol is used for momentum, namely \(\Pi\), rather than the more commonly employed p. The reason for thi...If you have previously taken a physics course then you have probably noticed that a rather odd symbol is used for momentum, namely \(\Pi\), rather than the more commonly employed p. The reason for this peculiar usage is that there are actually two kinds of momentum, kinetic momentum and total momentum (or canonical momentum), just as there are two kinds of energy, kinetic and total. As a general rule, the total momentum is related to a particle’s wave vector via the de Broglie relation,
