Why is momentum referred to as 'conjugate' in physics?

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The term 'conjugate momentum' in physics is defined as p_{i} = \frac{\partial L}{\partial \dot{q_{i}}}, where L represents the Lagrangian of the system. This terminology arises from the relationship between generalized momenta and generalized coordinates, highlighting their paired nature. The concept becomes particularly significant in Hamiltonian mechanics, where phase space coordinates (p, q) are recognized as conjugate pairs. Understanding this terminology is essential for grasping advanced topics in classical mechanics.

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snatchingthepi
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So I'm studying for my CM final and in looking over the section on ignorable coordinates and generalized momenta I come across the definition for conjugate momentum p_{i} = \frac{\partial L}{\partial \dot{q_{i}}}

My question is simple - why is it called 'conjugate'? I just never really thought to question to the name.
 
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You need a word to differentiate it from a physical momentum, I guess "generalized momentum" might also work, but the "conjugate" part comes into play more when you move to Hamilonian mechanics where your phase space coordinates are these (p,q) conjugate pairs.
 
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Thank you both.
 

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