From: Bob Cook
I think I have a good science fair project for a grandson. A little high tech monitoring equipment is all that is necessary. Maybe NI would be interested in loaning the instruments. A transient change in the temperature of the ball and the surface upon which they spin would be nice to know to understand the issue of friction changes. An evacuated chamber would be warranted to eliminate the issue with loss of energy via stirring the air around the rotating balls. Yes, in a simple evacuated bell jar, it would be interesting to see if a pair of magnetized balls could be started and kept in rotation via an external laser beam, shining through the bell jar somewhat like a Crookes radiometer (which only works with a partial vacuum and not in the way commonly perceived.) However, in place of one side having a more absorbent coating, as in Crookes, we would be probably going for asymmetry in coherent photons causing tiny phase changes or spin coupling on one side or the other of the rotational vector. Does forward side irradiation help or hinder compared to trailing side? Lasers up to 10 watts are affordable but must be monitored with a grandson's science project. A 10 watt laser would possibly transfer 200 milliwatts through a bell jar - which should be more than enough. If the mirror is placed on top of a number of magnet configurations, then we have another possibility - does any kind of a magnetic field alignment help or hinder rotation. There could be a lesson or two here wrt any spin system, even at nanoscale.
