’scruff’

Abstract

Jocelyn Bell cycled out to the observatory as she had done many times before. Looking more like a vineyard than a radio telescope, the Interplanetary Scintillation Array — Hewish’s brain child to search for quasars — collected radio signals from space and recorded them as a series of squiggly lines on a paper chart. Among Bell’s jobs were feeding the recorder with paper and filling the ink wells for the recording pens. Her most important job, however, was to sift through the recordings looking for signs of quasars. Computers were around at the time, but it was thought a trained human was better at distinguishing between interference and quasar signals, at least until the astronomers became familiar with the behavior of the telescope. After analysing a hundred meters or so of the chart recordings, the 24-year-old Ph.D. student became rather good at her task. It was impractical to monitor and analyze the recordings in real time, and so Bell waded through the kilometers of paper chart recording after it had accumulated. Then one day in August 1967, she noticed what she would later describe as ‘scruff’ on the recording. Unlike any natural signal she had seen before, it didn’t look artificial either. Puzzling. Although it was probably nothing, she marked it with a question mark and went back to searching the recordings for quasars.