I decided to expand my knowledge on Physics a little from what I was taught at school, which was mostly classical/Newtonian stuff. I am planning on learning both Quantum Mechanics & Relativity. Which one should I learn first, so that the knowlege from that first subject would help me learn the other? Why is that? (I'm interested in looking out for some of those connections) My education in Physics stopped at A-level...otherwise known as Year 12. After that, in the engineering degree I was in, you stick mostly to Newtonian stuff, apart from a little relativity in Celestial Mechanics. From what I know, the E3's (Electrical & Electronic Engineers) did QM. The Physics subject in the A-level examination board I sat for (Cambridge's) did not touch Relativity at all. As for QM, it was very introductory, mostly thermionic emission from ZnO (IIRC) and how various experiments concluded that light had wave-particle duality and delivered its energy in distinct packets, instead of being purely a wave. The syllabus stopped at saying "there is more than meets the eye for light." Literally.