How theory first predicted gravitational waves 100 years ago
In early 2016, news broke that gravitational waves were detected for the very first time on 14 Sept 2015, and the Laser Interferometer Gravitational-Wave Observatory (LIGO) announced: ‘Gravitational Waves Detected 100 Years After Einstein's Prediction’. There was indirect evidence of gravitational waves since the 1970s, but this first direct detection was massive news! It brought a surge of excitement to this field — the number of gravitational wave detections is growing rapidly, new innovative detectors are being built, and we are already beginning to see first successes in multi-messenger astronomy. But have you ever wondered… why were we looking for them in the first place? How did theory predict gravitational waves 100 years ago? In this seminar, we’ll take a look at the first ideas that hinted towards the existence of gravitational waves in the general theory of relativity (General Relativity, GR). Together, we’ll go through a simple exercise that shows how gravitational waves naturally emerge from GR equations. The seminar will be accessible to all, even if you’ve not studied GR before or just aren’t a huge fan of tensors.