In quantum mechanics, how does the wave function relate to the measurement problem, particularly in terms of the collapse of the wave function upon measurement?

In quantum mechanics the wave function describes the probabilities of finding a particle in different places or states, and it evolves smoothly according to the Schrödinger equation. When we actually measure the particle, the wave function suddenly “collapses” to one specific outcome, which is the measurement problem because the theory does not explain why or how this collapse happens. This collapse means that the superposition of many possibilities becomes a single definite result, seemingly breaking the continuous evolution of the wave function. For example, if a photon is in a superposition of passing through two slits, before measurement it interferes with itself, but once we detect which slit it goes through, the wave function collapses to that slit and the interference pattern disappears.