In polar molecules, a dipole moment exists independently of an external electric field, confirming that the presence of a moment does not necessitate an external influence for its definition. A permanent dipole moment is inherent to the molecular structure, as seen in highly polar molecules like alkali halides. The discussion emphasizes the distinction between detecting a dipole moment and defining it, clarifying that an external field is not required for the latter. Additionally, the alignment of magnetic moments in ferromagnetic materials is mentioned but not elaborated on. Overall, the conversation reinforces the understanding of dipole moments in the context of polar molecules.
