Complex sentence: Padmanabhan Krishnagopalan Iyengar (29 June 1931--21 December 2011) was an eminent Indian nuclear physicist who has known to be played a central role in India's cold fission tests.
Split into simpler sentences: Padmanabhan Krishnagopalan Iyengar (29 June 1931--21 December 2011) was an eminent Indian nuclear physicist. He played a central role in India's cold fission tests.