“Behind every man now alive stand thirty ghosts, for that is the ratio by which the dead outnumber the living. Since the dawn of time, roughly a hundred billion human beings have walked the planet Earth, which is an interesting number, for by a curious coincidence there are approximately a hundred billion stars in our local universe, the Milky Way. So for every man who has ever lived, in this universe there shines a star.
“This data release is a tremendous milestone for the Breakthrough Listen team,” said Dr. Danny Price of the search “pipeline” that scans through billions of radio channels, looking for signals of radio-transmitting extraterrestrial civilizations in our Galactic neighborhood that are too narrow and well-defined to result from natural processes.
Two mind-boggling conjectures about the existence of advanced alien civilizations have been made by Harvard’s chief astronomer and the director of Columbia University’s Astrobiology Center.