Could it be that human existence depends on gravitational waves? Some key elements in our biological makeup may come from astrophysical events that occur because gravitational waves exist, a research team headed by John R. Ellis of Kings College London suggests.
With Newtonian physics if you have two neutron stars orbiting each other they would just continue orbiting forever. With general relativity, the orbiting neutron stars shed energy by sending out gravitational waves. Losing energy they get closer and closer and then merge.