The Shoulders Of Giants by Robert J. Sawyer

From ESCAPE POD - Read by Stephen Eley - November 2, 2006 - The Pioneer Spirit was a colonization ship; it wasn’t intended as a diplomatic vessel. When it had left Earth, it had seemed important to get at least some humans off the mother world. Two small-scale nuclear wars—Nuke I and Nuke II, as the media had dubbed them—had already been fought, one in southern Asia, the other in South America. It appeared to be only a matter of time before Nuke III, and that one might be the big one.SETI had detected nothing from Tau Ceti, at least not by 2051. But Earth itself had only been broadcasting for a century and a half at that point; Tau Ceti might have had a thriving civilization then that hadn’t yet started using radio. But now it was twelve hundred years later. Who knew how advanced the Tau Cetians might be?