Complex dynamics can display emergence. There may be simple (e.g. physics-based) microrules that describe how individual states interact and evolve, but collectively, at the level of many states, complicated macrophenomena may emerge. It is typically these macrophenomena that are observable and/or affect our daily lives. Macrophenomena can often be characterised as large collections of individual states that evolve as a group for a substantial time duration. To access these macrophenomena, we will use linear operators induced by the nonlinear microdynamics. More specifically, we develop Laplace-type operators with their own dynamic isoperimetric theory specialised to dynamics, to identify (possibly transient) coherent objects in complex dynamics. The techniques will be illustrated on Rayleigh-Bénard convection and oceanic atmospheric flows using models and observations.