Background signal detected with pulsars?
A few dozen gravitational-wave events from colliding black holes and neutron stars have been detected by laser interferometers. Completely different detectors - pulsar timing arrays - use a network of radio pulsars, whose extremely periodic blinking gets out of step due to gravitational waves. After years of searching, the NANOGrav project now reports an exciting find.
Gravitation waves are among the most spectacular predictions of Einstein's theory of relativity. The fact that moving masses not only warp the space-time surrounding them, but can also cause waves in it, goes far beyond our everyday experience. The phenomenon can be understood in analogy to water waves on the surface of a lake, which are triggered by falling stones.
And they really exist: For a few years now, gravitational waves have given us a completely new view of the universe that differs significantly from conventional astronomical observations. A characteristic feature of gravitational waves is that once they are generated, they propagate more or less undisturbed and hardly interact with the environment they pass through, due to the weakness of the gravitational force that describes their evolution over time. Gravitational waves are therefore truly cosmic messengers that can provide us with particularly clear insights into the high-energy processes that they create in the depths of space.
