Dust is a minor component of the interstellar medium but plays a major role in the evolution of the universe and on our capability to observe it. Despite recent advances, some aspects of the physics of cosmic dust are still poorly understood. This leads, for example, to theoretical predictions of dust yields from supernova explosions that are two orders of magnitude larger than observed. In this talk I will use dust formation in core-collapse supernovae as a case study to discuss the current status and recent advances on our understanding of the physical and chemical mechanisms at the base of the gas-solid phase transition. I will discuss different approaches to the problem and compare their outcomes to available observations. I will conclude by highlighting some interesting parallels between astrophysical dust condensation and aggregation and other areas of active research, such as condensation nuclei and the role of aerosols in climate.