Such entropic forces are macroscopic effects driven by the tendency to maximize entropy that don’t have any microscopic equivalent. Osmosis, for example, pulls liquids against the force of gravity through membranes in order to balance the concentrations of substances dissolved in these liquids. Now gravity, Verlinde proposed, may be an entropic force itself. Gravity can, according to Verlinde, “emerge from a microscopic description that doesn’t know about its existence.”
