Radio Astronomy and the Transient Sky (Public Talk)

For human beings, the natural way to observe the sky is by just looking up. The invention of the telescope led to discoveries such as the moons of planets, and the zoo of galaxies. All of these discoveries were made using observations in a very narrow range of electromagnetic waves, viz. light waves. Celestial objects however emit many kinds of electromagnetic waves. In particular there are a class of objects that either emit mainly radio waves or are easiest observed from earth using radio waves. These objects began to be discovered and studied about a hundred years ago, with the invention of the radio telescope. In this talk I will briefly discuss how radio telescopes work, in the particular context of the Giant Metrewave Radio Telescope (GMRT). The GMRT, built and operated by NCRA-TIFR, is located between Pune and Nashik, and is one of the most sensitive radio telescopes in the world at its wavelengths of operation. I will also discuss the ongoing development of major new instrumentation at the GMRT aimed at enabling it to efficiently detect brief transient flashes of cosmic radio waves.