2 verifications about Energy Energy ×
“Energy can neither be created nor destroyed.”
The statement accurately expresses the standard conservation law: total energy in a closed system remains constant while changing form. Its unqualified wording is not fully universal, however, because general relativity may provide no well-defined globally conserved energy in dynamic curved spacetimes. Local energy-momentum conservation still applies.
“Energy cannot be created.”
The statement accurately expresses the conservation-of-energy principle used throughout ordinary physics: energy changes form rather than being created. It is not strictly universal, because an expanding general-relativistic universe may lack a well-defined globally conserved energy total. That limitation does not establish a conventional process that physically creates energy.