Beat
n. one swing of the pendulum.
The beat of an interaction is the cyclical pulse that marks the successive moments of the happening. Beats are predictable, measured, and relative. They can speed-up, slow-down, present as pulses like a heartbeat or the buzz of a bee wing or the cycles of the sun.
Beats are felt as shifts of weight; moments of heaviness separated by moments of lightness. The beat of an interaction is relative to the actor (their literal size, their disposition, their past experiences), the environment, and the culture. It is possible that different actors may participate in the same event but experience different beat levels relative to themselves.
see Anacrusis–Crusis–Metacrusis, Attentional Hierarchy, In Time, Temporal Relativity, Shifts of Weight