Back in Newton's bailiwick of Cambridge, astronomers in the 1960s set
up a virtual forest of huge radio antennas on a soccer field and aimed them
upward, scanning the entire sky about every four days as the earth rotated.
Traditional astronomers needled radio astronomers for being interloping
technicians who did not even know the locations of stars, but the new researchers were interested only in galaxies; that's where provocative radio signals
seemed too emanate.
But what Cambridge research student Jocelyn Bell eventually heard from
the heavens in 1967 was as unforeseen as it was inexplicable: a repeated radio
signal as regular as a metronome. Was this the stellar imprint of an alien consciousness? Nature, in our world, offers no such unvarying, methodical pulsing.
Bell first noticed the bizarre object as a quarter-inch spike on the four
hundred-foot-long chart of the complete sky that the radio telescope took four
days to reel out. In later charts she returned again and again to this "funny, scruffy, messy, unclassifiable signal from the same bit of the sky." The signal was a string of pulses at regular intervals of one and one-third seconds. Logic dictated that the object had to be small, because it was fast, but in an apparent contradiction it was also large because the radio wave was so strong. In Bell's words, "Stars are great big things, like elephants, cumbersome, lumbering beasts, but this thing, whatever it was, was behaving like a flea, or some little jumpy insect. It was very nimble."