Scientific American digs into one of the most recognizable, most influential records (and cover images) – the astronomical story behind Joy Division’s Unknown Pleasures album art:
…[T]he cover is directly linked to a figure in The Cambridge Encyclopaedia of Astronomy (1977 edition)—a stacked plot of radio signals from a pulsar. My interest was piqued. I’m far from a music and album art expert but visualizing astronomical phenomena is part of my job description. Although I jotted down notes, my intention to look further into things faded.
Then, nearly two years later, when chatting with artist Philippe Decrauzat about his influences, my jaw hit the floor. His collection of favorite 1960s and 1970s Scientific American graphics included the stacked plot. It had been printed as a full-page figure in the January 1971 issue; white radio pulses on a field of cyan. My interest was piqued anew, to say the least.
When folks refer to the Unknown Pleasures cover, they generally just say that it shows a series of radio frequency periods from the first pulsar discovered. But what does that really mean? How does the physicality of a pulsar result in radio frequencies that translate into the famous stacked plot? What produced the data, how was it collected, who created the plot and what is its significance?
There’s a lot more at the link, including a video of cover designer Peter Saville discussing how he chose this pulsar data for this album, an interview with Arecibo radio astronomer Hal Craft and different stacked plots from the same pulsar, CP 1919.