So we have gone for a "not really hard engineering degree so I can p!ss about" to Physics?
I don't know your background and perhaps you do have the brains to be the next Lucassian Professor of Mathematics at Cambridge but judging by your post, you seem to just want to do the standard thing which is to go to University - not necessarily for a P!ss up but to further yourself. Many people do it and take courses like Environmental Management, and Art, or Human Geography. Good luck to them.
But Physics is completely different. Physics isn't something you just fancy doing. Most of my colleagues are MSc Pure Maths or Physics graduates, min IQ's of 140 and the type of people that got A's in A Level Further Maths without even thinking about it. Yet in Uni, they were in their books every waking hour just to get a 2.2 for the Bachelors.
Physics is probably the second hardest degree course to take. Hardest is probably Philosophy and Physics in Cambridge - when I looked in 2001 at the prospectus, it required 30 UCAS points (three A's- max intake 24 students).
You still haven't elaborated as to whether your question is pertaining to a future career in aviation - pilot, mechanic, engineer?
If not, then this isn't really the forum where you should ask those questions. Its like a A-level chemistry student coming here and asking if its best to study Medicine at Kings College or Cambridge....