( ( Since ( light ( ordinarily ( travels ( on ( a ( straight-line path ) ) ) ) ) ) ) ( , ( light ( ( ( follows ( a ( curved path ) ) ) ( if ( it ( passes ( through ( a ( strong ( gravitational field ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (IN Since) (S (NP (NN light)) (ADVP (RB ordinarily)) (VP (VBZ travels) (PP (IN on) (NP (DT a) (JJ straight-line) (NN path)))))) (, ,) (NP (NN light)) (VP (VBZ follows) (NP (DT a) (JJ curved) (NN path)) (SBAR (IN if) (S (NP (PRP it)) (VP (VBZ passes) (PP (IN through) (NP (DT a) (JJ strong) (JJ gravitational) (NN field))))))) (. .)))
Since light ordinarily travels on a straight-line path, light follows a curved path if it passes through a strong gravitational field.
(ROOT (S (NP (JJ Strong) (JJ gravitational) (NNS fields)) (VP (VBP are) (ADJP (JJ capable) (PP (IN of) (S (VP (VBG altering) (NP (NP (DT the) (NN rate)) (PP (IN of) (NP (NN time) (NN passing))))))))) (. .)))