Hi all, I study Mathematics and Theoretical Physics at university. Next year, I'll have a choice between three modules; Thermodynamics and Statistical Physics Cosmology Fluid Mechanics My main interest is Condensed Matter Physics; therefore, thermodynamics and statistical physics is a given (it always was, as I'm not really convinced that studying physics can be done without a grounding in thermodynamics). Quantum mechanics is compulsory in my course and of course, I already have a grounding in Electromagnetism. So... that leaves Cosmology and Fluid Mechanics. I actually cannot, for the life of me, decide which to pick. Perhaps it's because from the small amount I know, they seem to be very similar; both require sophisticated mathematics and deal with vector calculus, which I like. I've been told that fluid mechanics is a lot more useful than cosmology, but that's not even a factor in my decision at the moment. Some further details: Fluid mechanics will be taught with much greater mathematical rigour than cosmology; that's great! However, the students I know who're studying cosmology say it's supposed to be more enjoyable. The lecturer for fluid mechanics is very demanding and apparently hard to deal with whilst the lecturer for cosmology is known to be excellent and easy to get along with. I've actually dealt with both before and I think they're both great; I actually like how brutal the fluid mechanics lecturer is. Both are experts in their fields. The modules are undergraduate level, but tensor calculus is used in both. Fluid mechanics is, according to more senior students, apparently much harder than cosmology, but everything is difficult for me and I get through it all the same. So, all you physicists and mathematicians on this great forum; would you be so kind as to sell me your favourite of two? What are the pros and cons of either? Thank you for reading!