But the water molecules not shown can actually move across the semipermeable membrane. Now, from this discussion above, we know pure water has a potential, an osmotic potential of zero. But this water that contains the solute molecules has a smaller, a more negative osmotic potential. So we have a high osmotic potential, a low osmotic potential. And what that means is water will begin to naturally move down its osmotic potential gradient from the left side to the right side in the same analogous way that the marker will move down its gravitational potential gradient. So once again, suppose the left side only contains pure water while the right side contains water.