A magnet with a small top placed above it that has a dipole point opposite the magnetic field can hover in mid air for a little while. This avoids violating Earnshaws theorem because it is a dynamic system.

tex2html_wrap155 where S = spin angular momentum= tex2html_wrap156 . In this case tex2html_wrap157 = spin rate. tex2html_wrap158 typical oscillation frequency with respect to the equilibrium position. Then tex2html_wrap159 is an adiabatic invariant. tex2html_wrap160 does give a shallow minimum.

top stable for tex2html_wrap161 and tex2html_wrap162 . Then tex2html_wrap163 .

spindown time: tex2html_wrap164 . The torque is produced by the boundary layer around it. tex2html_wrap165 then tex2html_wrap166 Then tex2html_wrap167 . Then tex2html_wrap168 . Really interested in tex2html_wrap169 . This is tex2html_wrap170 minutes.


source psfile jl@crush.caltech.edu index