# Why is electric dipole moment represented by "p"?

I recently came across a text where the electric dipole moment was represented as "d" instead of the more commonly used "p". The reason behind using "d" here is probably that "dipole moment" begins with a "d". However, it also made me wonder why the most commonly used symbol of electric dipole moment is "p" and not "d". What is the reason behind using "p" to represent electric dipole moment?

Also, is there any historical reason for this?

• Maybe $p$ for “pole”? I have no idea why charge is $q$ either. Feb 1, 2019 at 3:36
• You should ask your question at the history of science and math SE - hsm.stackexchange.com Feb 1, 2019 at 6:51
• "p" as in Polarisation. Feb 1, 2019 at 8:03
• p as in pollos hermanos
– user65081
Feb 1, 2019 at 19:19
• @Avantgarde thanks for letting me know about the history of science and math SE. I will ask this there too.
– A B
Feb 1, 2019 at 21:11