I think we have to be careful with such concepts.Rahula wrote:Not everything changes.
Energy is constant. Nobody could ever observe energy being created or destroyed.
http://en.wikipedia.org/wiki/Conservation_of_energy" onclick="window.open(this.href);return false;
But the appearances of this energy change.
"Energy" is a concept, developed only for the purpose to explain certain phenomena within experience. There is no energy to be experienced, only phenomena which can be described with the concept of energy. Same applies for "electrons" or "protons" and so on. They're just fictional concepts whose validity will be accepted as long as they are useful to describe phenomena in experience with tolerably accuracy. Those concepts change in the same way like everything else.
best wishes, acinteyyo