In what could be said a breakthrough in the world of astronomy scientists said that they have finally detected gravitational waves, the ripples in the fabric of space-time that Einstein predicted a century ago. The phenomenon detected was the collision of two black holes. Indian scientists played a crucial role, including in data analysis, in the path-breaking project. In a tweet PM Modi also congratulated Indian scientist. PM tweeted "Immensely proud that Indian scientists played an important role in this challenging quest."