Question: when was the first episode of the big bang theory aired
[{'answer': 'September 24 , 2007', 'provenance': [{'wikipedia_id': '27382568', 'title': 'The Big Bang Theory (season 1)', 'start_paragraph_id': 32, 'start_character': 286, 'end_paragraph_id': 32, 'end_character': 305, 'bleu_score': 1.0, 'section': 'Section::::Production.\n'}]}, {'provenance': [{'wikipedia_id': '27382568', 'title': 'The Big Bang Theory (season 1)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 595, 'bleu_score': 0.981898582188057, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8027052636992491209}, 'section': 'Section::::Abstract.'}]}]