Chronology Of The Beep

1955: John Martels born.
1985: an accident in a radio telescope.
20-?:  Adolph Haertel revolutionizes physics.
2060: Thor Wald born.
2090: final test of Wald's Dirac communicator, using a Haertel overdrive ship.
2091: Earth Security Service begins to extract messages from the Dirac "beep."
209?: discovery of Fortean tunnels to solar and alternate-solar planets.
2---?: Service defeats an armada from the Black Horse nebula.
2973: in NGC 2287, the Service protects a cub who will take over from them when he grows up.
3022: coded Dirac message describing a mass evacuation.
3480: the President of the Milky Way announces federation with the Magellanic Clouds.
6000: High Earth and Traitors' Guild.
8704: destination of a world-line cruiser on Hathshepa, NGC 4725, 11 million light years away.
88-?: Dirac distress call from the world-line cruiser.
8873: departure point of the world-line cruiser.
          Rebirth II civilization destroyed by worldwide glaciation. 
          Rebirth III, a tightly organized, high-energy, low population culture.
          Rebirth IV tribesmen in a tropical phase.
25,000: Martels time-projected from 1985.
25,100: Rebirth V civilization begins.

Sources: The Quincunx Of Time; Midsummer Century.