Talk:Magnetic dipole–dipole interaction

Treatments of the magnetic dipole field

I have started a general discussion of the many treatments of the magnetic dipole field at Wikipedia talk:WikiProject Physics#Treatments of the magnetic dipole field. RockMagnetist (talk) 03:09, 3 August 2011 (UTC)

This note aims to clarify the origin of the magnetic dipole-dipole interaction between dipoles 1 and 2, which is usually given as -B₁(r₂)•m₂ or -B₂(r₁)•m₁, or the equivalent. The point of confusion is that each dipole feels the field of the other, so why isn't the interaction the sum of these terms? The answer is the following. The total energy of the two-dipole system is the energies of the dipoles plus magnetic field energy: U = U_1,0 - B₂(r₁)•m₁ + U_2,0 - B₁(r₂)•m₂ + ʃ dV B₁(r)•B₂(r)/μ₀. It happens that ʃ dV B₁(r)•B₂(r)/μ₀ = B₂(r₁)•m₁ = B₁(r₂)•m₂, hence the usual interaction energy. By the way, the total field energy is: ʃ dV [B₁(r)+B₂(r)]²/2μ₀, but the self-field energies of the two dipoles are implicit in the energies of the dipoles and therefore do not appear explicitly. This physics should appear at least in the Wikipedia section on the magnetic dipole-dipole interaction. TLemb11 (talk) 00:12, 3 January 2023 (UTC)

Mathias [Monday 12th of March]: I am not so sure that it is correct to have hbar^2 in the numerator. Often 1/hbar is inside the Gyromagnetic ratios. Please check this somebody:-) Thanks. — Preceding unsigned comment added by 150.244.101.168 (talk) 14:56, 12 March 2012 (UTC)

Am I correct to have changed the H on left-hand side of the first two equations to not be bold-faced? These are scalar quantities. Monsterman222 (talk) 22:57, 20 November 2012 (UTC)

Electron proton interaction?

Would be very interesting if someone added an example such as electron proton interaction. Thanks!   Daniel.Cardenas (talk) 17:54, 13 March 2024 (UTC)