This features Stephen Hawking's vocals. It uses a sample of the British theoretical physicist's synthesized voice taken from a speech he made for a 1994 British Telecom commercial. (Hawking has suffered from a neuromuscular dystrophy since his early twenties that has left him almost completely paralyzed). Drummer Nick Mason told The Sun: "On one level, it's Stephen Hawking having a problem communicating and yet the sound of that voice is positively interstellar. He can communicate across galaxies with that sound."
This marks the second time Hawking has appeared on a Pink Floyd album. He previously lent his voice synthesizer to The Division Bell track "Keep Talking."
Until December 5, 1998, a song had to be issued as a single to make the Hot 100. Aaliyah's "Try Again" was the first tune to top the chart based on airplay alone, without any sales figures being included.