( It ( ( is ( ( ( ( ( the power ) , ) ( ( the rate ) ( of ( ( energy release ) ( over time ) ) ) ) ) , ) ( that rules ) ) ) . ) )
(ROOT (S (NP (PRP It)) (VP (VBZ is) (NP (NP (DT the) (NN power)) (, ,) (NP (NP (DT the) (NN rate)) (PP (IN of) (NP (NP (NN energy) (NN release)) (PP (IN over) (NP (NN time)))))) (, ,) (SBAR (WHNP (WDT that)) (S (VP (VBZ rules)))))) (. .)))
It is the power, the rate of energy release over time, that rules.
(ROOT (S (NP (NP (DT The) (NN rate)) (SBAR (IN that) (S (NP (NN energy)) (VP (VBZ is) (VP (VBN released)))))) (VP (VBZ is) (VP (VBN known) (PP (IN as) (NP (NN power))))) (. .)))