The major unsolved problems in physics are either problematic with regards to theoretically considered scientific data, meaning that existing analysis and theory seem incapable of explaining certain observed phenomenon or experimental results, or problematic with regards to experimental design, meaning that there is a difficulty in creating an experiment to test a proposed theory or investigate a phenomenon in greater detail.
There are still some questions beyond the Standard Model of physics, such as the strong CP problem, neutrino mass, matter–antimatter asymmetry, and the nature of dark matter and dark energy. Another problem lies within the mathematical framework of the Standard Model itself—the Standard Model is inconsistent with that of general relativity, to the point that one or both theories break down under certain conditions (for example within known spacetime singularities like the Big Bang and the centres of black holes beyond the event horizon).