Question: which instrument is used to measure the speed of light
[{'answer': 'Fizeau -- Foucault apparatus'}, {'provenance': [{'wikipedia_id': '148819', 'title': 'Fizeau–Foucault apparatus', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 393, 'bleu_score': 0.6820251393087231, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3140072895460644736}, 'section': 'Section::::Abstract.'}]}]