almost last but not least a little excursion how to work scientifical - for our never want to learn it opinion-spamers: http://en.wikipedia.org/wiki/Empirical Empirical data are data produced by an observation or experiment. http://en.wikipedia.org/wiki/Heuristic http://en.wikipedia.org/wiki/Natural_deduction http://en.wikipedia.org/wiki/Scientific_method The first link is most important (and short to read) because any theoretical conclusion must be