Here is something for people to get their teeth into. I attach my paper on the possibility of gaining thrust from the Earth's magnetic field. This paper looks at inertia induced electromagnetically, starting with the accepted wisdom that electric charge in the vicinity of other charges exhibits an inertia that behaves like mass inertia except that it can be either positive (like mass inertia) or negative (unlike mass unless there is ever such a thing as negative mass). Some old text books have referred to this as electrostatic mass whereas I think it should be called electrodynamic mass since it will only show up under dynamic conditions. Unfortunately the values of induced mass-like inertia are too small to be of any practical use.
From the oft used analogy between electric and magnetic effects I then posit that a magnetic pole should also exhibit inertia in the presence of other magnetic poles. This boils down to a simple equation where the other poles are represented by their combined magnetostatic scalar potential. Since magnetic poles do not exist in isolation the induced inertia is then calculated for a magnetic dipole which is rotating and the result is a dynamical unbalance. For practical dipoles (magnets) that are physically rotating the unbalance is too small to be of any significance. But we have the ability of creating a solid-state rotating dipole within a disc or sphere of ferromagnetic material by simply having two coils at right angles driven in phase quadrature, and we can achieve enormous rotation speeds. Then in the presence of the scalar magnetic potential of the Earth's magnetic field (something that is hardly ever mentioned but is huge at the poles) we should achieve a measurable dynamic unbalance. If that proves to be the case then it may be possible to modulate the driving waveforms to "rectify" the unbalance so as to achieve thrust in a given direction. But not at the equator where the potential is zero. So if ever this was used for launching into space the launch sites would be best placed at the Earth's poles where the potential is maximum.
Enjoy!