A330ismylittlebaby,
As the author of the post that sparked your concern, I feel an obligation to echo the wise words of
Rivet gun in stating that an airline pilot need not be familiar with the fairly complex mathematics and physics of manometry.
What is necessary, is to possess a good understanding of the relationships between CAS / EAS / Mach Number / TAS / TAT etc., and to be able to make day to day conventional conversions between them using conventional means such as Pilot Computers and/or tables.
As an ATPL student, a practicing airline pilot, an ATPL instructor, and in preparing ATPL examination papers, not once did I ever see the need for discussion of or examination upon the 'deeper' mathematics and physics involved. In studying Aeronautical Engineering and in lecturing to University students on the subject, much emphasis was made upon these aspects.
It's only necessary to be practical, understand the relationships, and be proficient in the day to day conventional application of the conversions involved.
Some people understand the 'why' better if they understand the 'how', which is why I sometimes go a bit to excess with the physics and mathematics involved. I, for one, cannot accept anything unless I understand HOW, but that's only me.
Regards,
Old Smokey