Contact - Carl Sagan [17]
In the scant few decades in which humans have pursued radio astronomy, there has never been a real signal from the depths of space, something manufactured, something artificial, something contrived by an alien mind. There have been false alarms. The regular time variation of the radio emission from quasars and, especially, pulsars had at first been thought, tentatively, tremulously, to be a kind of announcement signal from someone else, or perhaps a radio navigation beacon for exotic ship that plied the spaces between the stars. But they had turned out to be something else-equally exotic, perhaps, as a signal from beings in the night sky. Quasars seemed to be stupendous sources of energy, perhaps connected with massive black holes at the centers of galaxies, many of them observed more than halfway back in time to the origin of the universe. Pulsars are rapidly spinning atomic nuclei the size of a city. And there had been other rich and mysterious messages that had turned out to be intelligent after a fashion but not very extraterrestrial. The skies were now peppered with secret military radar systems and radio communication satellites that were beyond the entreaty of a few civilian radio astronomers. Sometimes they were real outlaws, ignoring international telecommunications agreements. There were no recourses and no penalties. Occasionally, all nations denied responsibility. But there had never been a clear-cut alien signal.
And yet the origin of life now seemed to be so easy-and there were so many planetary systems, so many worlds and so many billions of years available for biological evolution-that it was hard to believe the Galaxy was not teeming with life and intelligence. Project Argus was the largest facility in the world dedicated to the radio search for extraterrestrial intelligence. Radio waves traveled with the speed of light, faster than which nothing, it seemed, could go. They were easy to generate and easy to detect. Even very backward technological civilizations, like that on Earth, would stumble on radio early in their exploration of the physical world. Even with the rudimentary radio technology available-now, only a few decades after the invention of the radio telescope-it was nearly possible to communicate with an identical civilization at the center of the Galaxy. But there were so many places in the sky to examine, and so many frequencies on which an alien civilization might be broadcasting, that it required a systematic and patent observing program. Argus had been in full operation for more than four years. There had been glitches, bogeys, intimations, false alarms. But no message.
* * *
"Afternoon, Dr. Arroway."
The lone engineer smiled pleasantly at her, and she nodded back. All 131 telescopes of Project Argus were controlled by computers. The system slowly scanned the sky on its own, checking that there were no mechanical or electronic breakdowns, comparing the data from different elements of the array of telescopes. She glanced at the billion-channel analyzer, a bank of electronics covering a whole wall, and at the visual display of the spectrometer.
There was not really very much for the astronomers and technicians to do as the telescope array over the years slowly scanned the sky. If it detected something of interest, it would automatically sound an alarm, altering project scientists in their beds at night if need be. Then Arroway would go into high gear to determine if this one was an instrumental failure or some American or Soviet space bogey. Together with the engineering staff, she