Allen D I'll look at this tomorrow but in the meantime -- in one word (where that one word is a subset of 'yes/no') -- are the laws of physics the same at all points in the universe? Paul D PS I Googled "progressive radial oreintaion to a common point" and got zero hits. After correcting the spelling errors to get "progressive radial orientation to a common point" I got eight hits -- all at www.freelists.org/archives/geocentrism,the 'snippets' of which all exhibited spelling errors characteristic of Allen Daves. I believe that I am entitled to believe that this is a private definition of rotation held by Allen Daves. I then Googled "define:rotation". After rejecting references to tires on cars, conduct of card games, games of pool and agricultural practise etc, none of the definitions on offer agreed with that offered by Allen Daves. I am therefore forced to the conclusion that "progressive radial orientation to a common point" is not an agreed definition of 'rotation' and must therefore be deprecated. Start your day with Yahoo!7 and win a Sony Bravia TV. Enter now http://au.docs.yahoo.com/homepageset/?p1=other&p2=au&p3=tagline