spinning sphere

Yep. he invented a motor.

w.

Why the odd angle for the windings, though?

As long as he's making an air bearing, he should dump all that electronics and make an air motor, too. They go to millions of RPMs.

You can levitate a golf ball and spin it really fast with just a compressed air nozzle. You point the nozzle upwards, and rest the ball on the air stream (it's quite stable). Then you slowly tilt the nozzle down a bit, and the ball starts to rotate more and more rapidly as gravity pushes it out of the centre of the stream and into the air velocity gradient at the edge.

Cheers

Phil Hobbs

I don't know the max speed anyone has spun a macroscopic object. NMR magic-angle spinning goes above 4 million RPM.

Jesse Beams was able to magnetically levitate a ball bearing, and in vacuum get it up to 1.5 MHz or so, 2500 mph surface speed and a billion g's of equatorial acceleration. The limit was strength of the rotor.

Quite a guy: his 1925 dissertation was on 10 ns time measurements.

Drat, I mis-copied the Jesse Beams reference

Parenthetically, that ultracentrifuge was operating in the 1960s and 1970s, and eventually he switched some of the controls to solid state, using the new uA741!

Your freon eye can top 2.5 million rpm if you spin it up gently so as not to tear loose the retina.