The discussion revolves around a challenging equation encountered in fluid dynamics, with a potential connection to Gauss's Divergence Theorem. Participants suggest that the equation can be proven by analyzing each vector component and applying the divergence theorem, linking it to the conservation of mass. There is a request for clarification on the explanation provided, particularly regarding the term "etc." and a desire for a more explicit solution. The conversation highlights the complexity of fluid dynamics equations and the need for detailed understanding in proving them. Overall, the thread emphasizes collaboration in solving advanced mathematical problems in fluid dynamics.