( Never ( ( mind ( that ( motion ( ( has always ) ( been ( ( defined ( as ( ( a change ) ( in position ) ) ) ) ( in ( a ( coordinate system ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (ADVP (RB Never)) (VP (VB mind) (SBAR (IN that) (S (NP (NN motion)) (VP (VBZ has) (ADVP (RB always)) (VP (VBN been) (VP (VBN defined) (PP (IN as) (NP (NP (DT a) (NN change)) (PP (IN in) (NP (NN position))))) (PP (IN in) (NP (DT a) (JJ coordinate) (NN system))))))))) (. .)))
Never mind that motion has always been defined as a change in position in a coordinate system.
(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))))))) (. .)))