Astronomy and Astrophysics - An Introductory Survey, A lecture series by Prof. G. Srinivasan - Lecture 14 - Special Theory of Relativity

The one-sided relativistic jets of radio galaxies, as seen in Cygnus-A, was predicted through the application of relativistic Doppler boosting. Interestingly, the `Principle of Relativity was first considered by Newton. However, the world had to wait for more than two centuries for Einstein to generalize this principle and give us the modern `Theory of Relativity. ABOUT THE LECTURE In 1687, Newton published his Principia, considered the greatest intellectual achievement by mankind. In that, he stated his Laws of Motion. He also stated a Principle of Relativity. More than two centuries later, Einstein felt that this principle needed to be ‘generalized’ to include all laws of physics, and not just the laws of motion. But he faced a serious difficulty in accommodating the great discovery by Maxwell that the velocity of light is absolute. In order to accommodate this, he had to abandon two key assumptions of classical physics, namely, the absoluteness of space and time. And when he abandoned the concept of the absoluteness of space and time, several consequences emerged which were truly revolutionary. After a brief introduction, this lecture explains a few dramatic consequences of Einstein’s Special Theory of Relativity in astronomical contexts. ABOUT THE LECTURE SERIES This lecture series is organized by the Astronomical Society of India as a part of its Golden Jubilee celebrations. Aimed at undergraduate and graduate students, this series of talks by renowned astrophysicist and teacher, Prof G. Srinivasan, starts from the first principles of Physics and builds up the subject rigorously to the present state of our understanding. Series website: https://astron-soc.in/srini-ana The website hosts a question bank as well as a list of suggested reading for each lecture (prepared by Dr. Sushan Konar) ABOUT THE SPEAKER Professor G. Srinivasan In a research career spanning more than five decades, his interests have spanned many aspects of physics and astrophysics. He is a passionate teacher and has authored two outstanding Astronomy texts titled ‘What Are The Stars?’ and ‘Can Stars Find Peace?’ He is a Past President of the Astronomical Society of India, and a Past President of the Division on Space and High Energy Astrophysics of the International Astronomical Union. In his distinguished career he has worked at the University of Chicago, USA; the IBM Research Laboratory in Zurich, Switzerland; Chalmers University of Technology, Goteborg, Sweden; the Cavendish Laboratory, University of Cambridge, England and the Raman Research Institute, Bengaluru Follow us on social media at https://twitter.com/asipoec https://www.facebook.com/asi.poec/ This series is also supported by the IAU OAE Centre in India https://twitter.com/astro4edu_India https://www.facebook.com/OAE-Center-India-105698322030674