LETTERS; The Illimitable Universe
Published: April 1, 2008
To the Editor:
Re ''A Boy's Life, Guided by the Voice of Cosmic Wonder'' (March 25): Dennis Overbye writes: ''When Clarke died, one of his few disappointments was that we had not yet heard from any extraterrestrial intelligence, although anybody within 50 light-years sufficiently advanced could easily tell we are here.'' Unfortunately for Sir Arthur C. Clarke, the operative hindrance is ''50 light-years.''
Any number of immensely distant civilizations could have developed and ultimately perished, while flooding the cosmos with signals that have long since passed or will never arrive so as to intersect with our woefully narrow listening window of mere decades (so far). Contact would seem to require an almost infinitely improbable convergence of the timely evolution of civilizations, appropriate distances and the speed of light.
DRAWING (DRAWING BY JOHN HERSEY)