One way to understand the mass hierarchy problem is to consider the behavior of neutrinos in the universe. Neutrinos are created in the cores of stars and in nuclear reactors, and they interact with matter through the weak nuclear force. However, their masses are still unknown, and this lack of knowledge has significant implications for our understanding of the universe.

For example, neutrinos are thought to play a crucial role in the formation and evolution of stars. The masses of neutrinos determine how they interact with matter, which in turn affects the way that stars form and evolve. However, without a complete understanding of the masses of neutrinos, we can't fully appreciate their role in the universe.