Ed

Ed is a factor that cannot be observed or measured in any physical experiments, but which is still important for determining the properties of systems. It can be used to formulate conservation laws and for other purposes; for example, this kind of problem constitutes entire sections of the theory of quantum circuits. It’s probably convenient to use this term to describe:

The likelihood and inevitability of fundamental changes in certain types of systems; Changes do not occur when the observer wants it (for example, a person walking down the street), but only in those cases for which this change is physically possible.