Time is thought to be non-existent in the formalism of quantum mechanics. But time can also become unobservable and hidden in classical physics as well as in human consciousness. All physical or societal laws show timeless invariance, indicating that time-dependent movements can show timeless behavior. Therefore timeless behavior includes an unobservable form of underlying movements implying time. Movements in the present can be directly observed and necessarily show time coordinates, but movements accomplished in the past can no longer be directly observed and only leave traces of grouped movements, similar to animal tracks. Invariance of movements can only be stated when individual movements are grouped together in traces and already accomplished in the past. Then time can be estimated and, when necessary, associated with the traces. Time is no longer required, when different traces of movements are compared with each other. Nevertheless, invariant traces give evidence of underlying regular movements and therefore of time, even if time itself is no longer observable in the traces. In a similar way physical formalism includes the present, past and future of movements at a more highly concentrated information level. Since only the present is observable, information including past and future becomes unobservable, thereby hiding time. Time is also hidden in the digit codes of music on recorded CDs and becomes only observable again after reconversion by means of an appropriate device. The phenomenon of hidden time can be found in human consciousness and in classical physics, but becomes dominant in quantum mechanics.

hidden time, invariance, quantum mechanics, classical physics, consciousness