David - just a thanks for all the effort and hard work put into this site.
I have to admit that for someone who knows absolutely nothing about the concepts (and was rubbish at physics at school), it's extremely hard-going but that isn't your fault at all... it's a complex subject. Ever thought of doing a "Complete Idiot's Guide"...
... you're going to tell me that this IS the complete idiot's guide aren't you?
I will persevere - I'm sure it'll all start to click in place eventually and I have already learnt much from it. Well done.