I have had a lifelong interest in physics and mathematics but life events have prevented me from pursuing the subjects I'm fascinated by. I'm most interested in theoretical physics (cosmology, astrophysics, quantum mechanics, relativity) and in the past pure mathematics was the subject I found myself most suited to.
I'm getting to an age (nearly 51) where any decision I make now is likely to be the last chance I get to at least gain a decent amount of knowledge to satisfy my curiosity. I realise that I'm not going to reach the pinnacle of understanding in any subject with the time I have left but would like to travel as far as possible in that direction, so any advice on topics or the direction to take would be gratefully received.
I do have A levels in the relevant areas and a little undergraduate study in pure mathematics (to certificate level). I'm considering an Open University degree in Maths and Physics Q77 but there are some elements of the course that either do not interest me or seem irrelevant for a study of theoretical physics.
One particular question I have is with regards to the type of mathematics most useful to theoretical physics. Do I go along the standard route which seems to include a lot of mathematical modeling and more applied mathematics or would I be better suited modifying the course to include more pure mathematics? I am able to go in either direction but straying from the standard path would probably lead to a BSc. STEM degree rather than a named BSc. Maths and Physics degree.
I'd also appreciate any advice re studying a higher degree considering these two degree options. I'm not expecting to be able to develop a career in this area considering my age so it's also important to me to study the areas that really interest me, but I don't want to preclude any options by making the wrong choice. One further point is that I really do not enjoy practical work and have little interest in chemistry, biology or earth sciences.
Essentially this comes down to choices of pure or applied mathematics and whether a named degree is particularly important or would the modules speak for themselves? Any advice would be greatly appreciated.