So the second law of thermodynamics tells us that when given a chance to, energy will disperse to larger volume of space. So what that means is if we have localized energy that is closed in a very small localized region, and then we open up the space, that energy will disperse and spread out throughout the entire region of space. Now, because molecules carry energy, we can say the same thing about molecules. If we have molecules localized and trapped in a very small region of space, and then we open up that volume, those molecules will begin to move and disperse and spread out throughout that region of space. So what we see will happen is, over time, according to the second law of thermodynamics, those molecules that carry energy that can actually pass across these tiny pores in the membrane, will in fact pass across. And so that over time, this entire region of space that contains the water molecules also will contain these tiny red molecules, as shown in the following diagram.