Degree choice -- Math or physics I realize that it is of bad form to cross-post. However, on this matter I very much hope to hear arguments from all sides...
I hope to become a physicist focusing mainly on the theoretical side in the future. I am trying to decide whether to go for a physics or math undergrad course.
Assuming that I am capable of doing either, what are the pros and cons of either route?
I know that mathematics is essential to doing physics, and in most math courses, there are applied math modules that are very much related to physics. Also that many research physicists have math degrees. But surely there are reasons for people to choose the physics course over the math course and vice versa? In particular, what are the possible advantages of a physics degree over a math one, given that a math degree could lead to PhD in physics and possibly open more possibilities in say the financial world (though that is not my interest)?
Thank you.
 A: I don't know if this is an option for you, but I would suggest you do both. At my university (Utrecht University in the Netherlands) there is a combined mathematics/physics course. Because it is heavier than the separate mathematics and physics courses, it is a good preparation for a Ph.D. scholarship in either discipline. Moreover, when you realize that mathematics is the superior discipline, you can always drop physics ;-)
A: My 2 cents on this:


*

*If you are mainly interested in being a theoretical physicist, going for Math may better, given that theoretical physics requires a very high level understanding of the more abstract mathematics. I would advise you to at least take some basic physics courses so that you may try to find out which topic excites you the most. 

*If you are looking to keep as many potential career paths open (as interests may change over time), Physics is definitely not a bad choice. It exposes you to math, basic engineering, material science, statistics, some programming. Not to mention that experiments in physics form a backbone for basic understanding of several physical concepts (After all, seeing is believing). You do not require too much infrastructure for learning maths; but that University Physics lab is vital for supplementing your knowledge in physics. As an after-thought, many of the current financial products and theories have been developed by engineers and physicists too. So Finance will not be a forbidden sector if you take Physics.


Hope this helps.
A: And here are mine - 
I choose Physics with Astrophysics as my degree course, I had similar interests to you (I think, regardless of the fact that you haven't listed them) and had in the back of my mind the drive to complete a PhD when my undergrad was all done.
I knew I was more interested in the theoretical side rather than the experimental and as such after one year of studying Physics with a LOT of time spent in the lab I converted my degree to Mathematics with Physics. the best choice I made. I studied only mathematics and theoretical physics modules and then in my 3rd year (at a UK institution) I choose as many Mathematical physics modules as I could $wrt$ the $120$ credits on offered per academic year. This allowed me to study Quantum Field theory, General Relativity and String Theory, along with electives from the Physics department on Condensed Matter Theory and Astro-particle Physics.
I thoroughly enjoyed my undergrad and long for lost days getting red-faced in anger at Green's functions for Feynmann diagram propagators. Really, for me, the combined course had it all.
It then prepared me for a PhD in Cosmology (Inflation & Superstrings) and the abstract mathematical modules I studied in my Master's year really became invaluable.
In short, a combination might be useful for you, but do remember that you gain just as much as you lose by Studying one or the other.
A: Take a math undergraduate degree.  You must understand the math before you can understand the physics.  If you do not understand the math then you will spend most of your time learning the math while taking the physics courses.  This will make you less competitive.  The top students in theoretical physics always know more math than the other students.  
