Matter turns out to be highly packed energy, transformable into other forms of energy; and therefore something in the nature of a process, since it can be converted into other processes, such as light and, of course, motion and heat. Thus one may say that the results of modern physics suggest that we should give up the idea of a substance or essence. They suggest that there is no self-identical entity persisting during all changes in time … The universe now appears to be not a collection of things, but an interacting set of events or processes
Karl Popper writes:
