On Tue, Nov 17, 2015 at 2:31 PM, <mix...@bigpond.com> wrote: It doesn't actually perform any *work* to keep it from happening, it > provides an > opposing *force*. Neither the magnet nor gravity do any work, since there > is no > component of the motion vector that is *parallel* to the force vector.
I do not deny your point. There's no work being performed, either up or down. The concept of work is narrower than the one we want here. If we were to replace the permanent magnet with a magnet that requires a current, we humans would have to expend a lot of energy (do work) to keep the system in stasis, even if the current were to circulate within a superconductor. In the case of gravity, we have a force that arises between massive objects. In the case of electrostatic attraction/repulsion, we have a force that arises between charged objects (e.g., electrons and protons). In the case we're considering here, we have angular momentum, somehow frozen into the permanent magnet, setting up a force between objects with intrinsic spin (electrons). This angular momentum does not decrease in the form of a transfer that results in an increase in potential energy to the object being held up as the force is applied, in the usual way that angular momentum can be harnessed to produce a force. That is amazing to me. Eric
