( ( ( The lines ) ( in ( ( the spectrum ) ( of ( ( a ( luminous body ) ) ( such ( as ( a star ) ) ) ) ) ) ) ) ( ( ( are similarly ) ( shifted ( ( ( toward ( ( the violet ) ( if ( ( ( the distance ) ( between ( ( ( the star ) and ) ( the earth ) ) ) ) ( is decreasing ) ) ) ) ) and ) ( toward ( ( the red ) ( if ( ( the distance ) ( is increasing ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NNS lines)) (PP (IN in) (NP (NP (DT the) (NN spectrum)) (PP (IN of) (NP (NP (DT a) (JJ luminous) (NN body)) (PP (JJ such) (IN as) (NP (DT a) (NN star)))))))) (VP (VBP are) (ADVP (RB similarly)) (VP (VBN shifted) (PP (PP (IN toward) (NP (NP (DT the) (NN violet)) (SBAR (IN if) (S (NP (NP (DT the) (NN distance)) (PP (IN between) (NP (NP (DT the) (NN star)) (CC and) (NP (DT the) (NN earth))))) (VP (VBZ is) (VP (VBG decreasing))))))) (CC and) (PP (IN toward) (NP (NP (DT the) (NN red)) (SBAR (IN if) (S (NP (DT the) (NN distance)) (VP (VBZ is) (VP (VBG increasing)))))))))) (. .)))
The lines in the spectrum of a luminous body such as a star are similarly shifted toward the violet if the distance between the star and the earth is decreasing and toward the red if the distance is increasing.
(ROOT (S (NP (NNP Red-shift)) (VP (VBZ refers) (PP (TO to) (NP (NP (DT a) (NN shift)) (PP (IN toward) (NP (NN red))))) (PP (IN in) (NP (NP (DT the) (NN spectrum)) (PP (IN from) (NP (NNS stars)))))) (. .)))