Speaker: Simon Barke Imagine, there is this huge data center but your user privileges allow you to access only 5% of the data. That is the exact same situation physicists face when trying to study the cosmos. 95% of our universe is made out of something that cannot be seen or touched. We generally call this unknown substance "dark matter" / "dark energy". The recent discovery of gravitational waves gives us a handle on the dark cosmos. We can now listen to invisible events in our universe. But there may also be other methods to shed light on the dark side. There is (much) more than meets the eye: 95% of everything there is in the universe does not interact with normal matter. It is completely transparent. Does not emit light. Reflects no light waves. Can be neither seen nor touched. The only reason we know it exists is the fact that this unknown substance curves spacetime: it interacts gravitationally. Hence gravitational wave astronomy can target the entire universe while conventional telescopes are fundamentally limited to only 5% of the cosmos. After the initial direct detection of gravitational waves by the Laser Interferometer Gravitational-Wave Observatory (LIGO) last year, many more observatories on ground and in space are under construction that will create a wideband gravitational wave detector network. We will be able to listen to stars falling into black holes, colliding galaxies, maybe even artificial sources of gravitational waves, and will find as yet completely unknown objects in the universe. But gravitational waves are not the only handle we have on the dark side of the cosmos. Many other research teams aim to directly detect dark matter. The Any Light Particle Search (ALPS) even tries to artificially generate dark matter particles in a controlled laboratory environment. It is under construction at the German Electron Synchrotron (DESY) in Hamburg, Germany. First results are expected as early as 2019. This lecture will give you a brief and fu