For general information on Paris, Alistair Horne’s Seven Ages of Paris (Macmillan, 2002) proved very useful, as did Edmund White’s The Flâneur (Bloomsbury, 2001). The versions of the city presented in this book, however, are only loosely congruent with the real one. The Maigret novels of George Simenon also provided an obvious imaginative stimulus. Respect, Jules.
The search for gravitational radiation from cosmic sources continues to this day, with expectations of success at any time. For an outstanding and highly readable account of this fascinating and contentious story, from the late Joseph Weber’s pioneering work in the 1960s (mentioned by Maurya Skellsgard) to the latest ultra-sensitive schemes—such as the Leiden-based GRAIL programme, which is currently taking place only a few miles from where these words are being written—I recommend Einstein’s Unfinished Symphony by Marcia Bartusiak (National Academies Press, 2000). One of Weber’s students, incidentally, was the late Robert Forward, who went on to make a name for himself as a science fiction writer, and whose books contain much mind-stretching speculation about gravity and exotic physics.
The artificially engineered amusica virus is speculative, but the condition “amusica” is, unfortunately, a real one—the musical analogue to the language-impairing condition of aphasia. Subjects with amusica typically lose the ability both to make and appreciate music. I read about this condition in Harold L. Klawans’ fascinating book Toscanini’s Fumble (Headline, 1990). Like the case studies presented by Oliver Sacks, Klawans’ medical stories often seem more science fictional than any real SF, and are as addictive as any collection of short stories.
Simon Singh’s very readable The Code Book (Fourth Estate, 2000) provided much useful background on the history and workings of the Enigma machine.
For general information on the music of Floyd’s era (which isn’t quite the same as the music of our 1950s) I relied on Jazz: The Ultimate Guide by Ronald Atkins (Carlton, 1996), and the splendid five-CD supplement to Ken Burns’ Jazz: The Story of America’s Music (Sony, 2000). The Gitanes series of “Jazz in Paris” CDs also proved very useful.
For useful discussions, and general help with stupid questions, I am indebted to Tony Ballantyne, Barbara Bella, Bernd Hendel, Peter Hollo and Christopher Priest. Any mistakes, needless to say, are entirely my responsibility, not theirs.