( ( ( ( thermal light ) , ) ( luminescence light ) ) . )
(ROOT (NP (NP (JJ thermal) (NN light)) (, ,) (NP (JJ luminescence) (NN light)) (. .)))
thermal light, luminescence light.
(ROOT (S (NP (NP (NNP Producing) (NN light)) (PP (IN without) (NP (NN heat)))) (VP (VBZ is) (VP (VBN called) (S (ADJP (JJ luminescence))))) (. .)))