How Gravitational Waves Let Us Hear the Sound of Space

For centuries we’ve only possessed one sense to explore space: our eyes. Everything we know about the universe is based on things we observed gazing at the stars. Using powerful telescopes and ever-more sophisticated technology, we have managed to map our galaxy and were able to peek into others as well. But most of the universe remains dark and full of mysteries and scientists need to find other ways of exploration. A combination of a large scale observatory and a massive international research enterprise, the LIGO experiment was brought into play to detect cosmic gravitational waves – much like an ear tuned to faint sound waves in the environment. Einstein predicted the existence of gravitational waves in 1916 as a consequence of his theory of general relativity, but for a century, science was unable to prove him right. The uncertainty ended in September of 2015, when LIGO detected gravitational waves from the collision of two black holes which took place about 1.3 billion years ago. Karsten Danzmann, a world-leading expert on the subject, and his colleagues at the Max Planck Institute for Gravitational Physics in Hannover made crucial contributions to this major breakthrough that has been likened to finding the Higgs particle or determining the structure of DNA. It has also launched numerous efforts to use the new technology in order to explore parts of the universe that previously had been out of our reach, going back as far as the Big Bang. At Falling Walls, Karsten explains how listening closely to the sound of the universe might help us understand its very beginnings.