Perpetuum mobile – Indistinguishable from Magic :)

I was in Bristol yesterday opening the Star Vistas Exhibition at the Photo Gallery on Baldwin Street.  Just round the corner, up a flight of stone steps, is THE most amazing market I have been to in a very long time.  John Morris owns a fantastic Mineral, Rocks and Fossils stall which has some of the most superb specimens I have ever seen – and believe me I have been to a lot of places, all over the planet, buying this stuff.  You can see John’s web site here.  At another stall I purchased the fascinating toy you can see in the video below.  A Celestial sphere rotating within a plastic globe and powered by Sunlight.  What’s the real mechanism behind this?  There is some blurb on the instructions which is clearly almost complete nonsense – anyone out there know how this thing really works??