( Motion ( ( ( is simply ) ( change ( of ( position ( in space ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Motion)) (VP (VBZ is) (ADVP (RB simply)) (NP (NP (NN change)) (PP (IN of) (NP (NP (NN position)) (PP (IN in) (NP (NN space))))))) (. .)))
Motion is simply change of position in space.
(ROOT (S (PP (IN In) (NP (NN science))) (, ,) (NP (NN motion)) (VP (VBZ is) (VP (VBN defined) (PP (IN as) (NP (NP (DT a) (NN change)) (PP (IN in) (NP (NN position))))))) (. .)))