arrow of time

The "arrow of time" refers to the one-way direction in which time flows, from the past to the future. It is most commonly associated with the second law of thermodynamics, which states that in an isolated system, disorder (or entropy) tends to increase over time. This means that processes are irreversible; for example, a broken glass does not spontaneously reassemble. The arrow of time helps us understand why events occur in a specific order and why we remember the past but not the future, reinforcing our perception of time as a linear progression.