Strong-field gravity with the Double Pulsar and in the future

The Double Pulsar system is a unique physical and astrophysical laboratory, containing two active and observable pulsars. It is not only useful for studying the functioning of pulsars and the evolution of massive stars and binary pulsars, but the Double Pulsar is also the most relativistic system ever found. It allows us to observe a plethora of relativistic effects simultaneously in single system. Together with the ratio of the pulsar masses, only accessible because both pulsars can be timed, the system provides new and unique tests of theories of gravity, resulting in the best strong-field test of general relativity ever.