sentences:  To commemorate the International Year of Astronomy (IYA) 2009, he published (with J.V.Narlikar and Samir Dhurde) the IYA Astronomical Diary 2009 , which comprises 53 illustrated pages of astronomical information.In 2019, he co-authored with Vasanthi Padmanabhan the "Dawn of Science" (published by Springer).This is a lucid and captivating book which takes the reader back to the early history of all the sciences, starting from antiquity and ending roughly at the time of Newton.