When I place a needle near a clamped magnet and let it go, it moves towards the magnet. Since magnetic field cannot work on individual charge particles, we must conclude that the needle loses its overall internal energy and hence cools down! Is this true?
Yeah I think that's right, put spins in a magnetic field and they fall into the lower energy state, (with a time given by T1) it's the first step in magnetic cooling.
Edit: As Floris pointed out I got this backwards. As the spins go into a lower energy state the energy they had has to go somewhere.. into the lattice (or needle in this case.)