Question: who introduced the term photon to represent a packet of light energy
[{'answer': 'Leonard T. Troland', 'provenance': [{'wikipedia_id': '23535', 'title': 'Photon', 'start_paragraph_id': 7, 'start_character': 354, 'end_paragraph_id': 7, 'end_character': 372, 'bleu_score': 1.0, 'section': 'Section::::Nomenclature.\n'}]}, {'provenance': [{'wikipedia_id': '23535', 'title': 'Photon', 'start_paragraph_id': 7, 'start_character': 0, 'end_paragraph_id': 7, 'end_character': 882, 'bleu_score': 0.5039699931524221, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11105179485366120006}, 'section': 'Section::::Nomenclature.\n'}]}]