( ( ( ( ( ( A ( black ( body radiator ) ) ) ( is ( ( a ( theoretical object ) ) ( that ( is ( totally ( absorbent ( to ( ( all ( thermal energy ) ) ( that ( falls ( on it ) ) ) ) ) ) ) ) ) ) ) ) , ) thus ) ( it ( ( ( ( does not ) ( reflect ( ( any light ) ( so ( appears ( ( ( black . ) ( As ( it ( absorbs energy ) ) ) ) ( it ( heats up ) ) ) ) ) ) ) ) and ) ( ( re-radiates ( the energy ) ) ( as ( electromagnetic radiation ) ) ) ) ) ) . )
(ROOT (S (S (NP (DT A) (JJ black) (NN body) (NN radiator)) (VP (VBZ is) (NP (NP (DT a) (JJ theoretical) (NN object)) (SBAR (WHNP (WDT that)) (S (VP (VBZ is) (ADJP (RB totally) (JJ absorbent) (PP (TO to) (NP (NP (DT all) (JJ thermal) (NN energy)) (SBAR (WHNP (WDT that)) (S (VP (VBZ falls) (PP (IN on) (NP (PRP it))))))))))))))) (, ,) (RB thus) (S (NP (PRP it)) (VP (VP (VBZ does) (RB not) (VP (VB reflect) (SBAR (S (NP (DT any) (NN light)) (ADVP (RB so)) (VP (VBZ appears) (SBAR (S (SBAR (ADJP (JJ black) (. .)) (IN As) (S (NP (PRP it)) (VP (VBZ absorbs) (NP (NN energy))))) (NP (PRP it)) (VP (VBZ heats) (PRT (RP up)))))))))) (CC and) (VP (VBZ re-radiates) (NP (DT the) (NN energy)) (PP (IN as) (NP (JJ electromagnetic) (NN radiation)))))) (. .)))
A black body radiator is a theoretical object that is totally absorbent          to all thermal energy that falls on it, thus it does not reflect any light          so appears black. As it absorbs energy it heats up and re-radiates          the energy as electromagnetic radiation.
(ROOT (S (SBAR (WHADVP (WRB When)) (S (VP (VBN placed) (PP (IN in) (NP (JJ direct) (NN sunlight)))))) (, ,) (NP (DT a) (JJ black) (NN sweater)) (VP (MD will) (VP (VB absorb) (NP (DT the) (ADJP (RBS most) (JJ visible)) (NN light) (NN energy)))) (. .)))