English: Photographed during the opening function of the exhibition titled 'Light Matters' on the occasion of the ‘International Year of Light and Light-based Technologies, 2015’ (IYL 2015), an United Nations observance on Wednesday, 23rd December 2015, that was opened by Professor Santanu Bhattacharya, Director, Indian Association for the Cultivation of Science (IACS) at the Birla Industrial & Technological Museum (BITM), Kolkata. It was developed by the National Council of Science Museum (NCSM) under the Ministry of Culture, Govt. of India.