And so these phospholipids basically move with a greater velocity. And because they move with a greater velocity, those intermolecular bonds that are holding that rigid structure, the well defined and order structure, basically cannot maintain that rigidity any longer. And eventually, what happens is at a specific temperature called the melting temperature, there's a phase transition that takes place. And the collapse of that well defined and order structure basically leads into that fluid state. So as the temperature is increased, there's a sharp transition from the rigid state here to the fluid state here. And this temperature, the melting temperature, is the temperature at which this phase transition actually takes place.