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.