Why are non-living things considered semipermeable

The one-sided diffusion of a substance (usually water) through a semipermeable membrane is called osmosis (Greek osmos = penetration). A semipermeable (semi-permeable) membrane is characterized by the fact that it is only permeable to certain substances. Water can always pass through the membrane, but the substances dissolved in it, such as sugar or salts, cannot.
Osmosis is based on the effort of the particles to create a concentration balance between the interior and exterior of the membrane. That is why the water always flows from the location of the higher water potential (fewer dissolved particles) in the direction of the lower water potential (more dissolved particles). Osmotic pressure exists until the concentrations on both sides of the membrane are equalized. From this point on, the same amount of water flows in both directions (isotonic state).

Cherries are ideal for illustrating the process of osmosis, because their outer skin functions as a semipermeable membrane. In late summer, when the cherries ripen, the sugar content inside the cells is highest. A rain shower can then make the cherries burst. It works like this: water droplets on the cherry flow into the interior of the cherry because the concentration of dissolved sugar particles is much higher on the inside than on the outside. A balance of the concentration can only be achieved by inflowing water (to a certain extent by diluting the cell sap with water), because the sugar molecules are too large to be able to leave the semipermeable membrane to the outside. As a result, the cherry sucks itself full of water (osmotic pressure) until the concentration is equalized (the same number of dissolved particles inside and outside the membrane). However, since the cells of the cherry cannot expand as much as desired, the cherry will burst at some point.

Incidentally, osmosis is also responsible for wrinkled skin when bathing. The concentration of dissolved salt particles is much higher in the skin cells than in bath water. Then water flows into the cells and causes the skin to swell.