R_W: __In the references provided above, there a plenty of links to the calculation of the forces generated by radiation acting on rotating bodies of all sizes,-- from the dust grains that reach escape velocity to the constant push on the Earth's eveningside. These effects are known, starting in the 19st century. If you can refute that, bring on the arguments, details. Whether I am fantasising or not, leave that judgement to my psychiatrist. After all, of all the "light sails" in nature, most of them are spinning, we would not be here without them. It is subtle. so: to contribute, can we have comments further elucidating the subject matter?