Thanks for the replies folks, I never was much good a science at school, in fact we didn't even have science classes where I went to school. I think after reading the replies here which sounds a bit like the discussion on Darwin's theory, I will now have to cancel my subscription to the Flat Earth Society. Cheers. -- Michael J Campbell. michaeljcampbell63@gmail.com http://picasaweb.google.co.uk/michaelJcampbell63/ http://picasaweb.google.co.uk/michaelJcampbell63/…