Tom Service on the sound the universe makes

Come on Ridley, play that cosmic techno-flute

Aliens in the movies are often conjured into being, or communicated with, by music. Steven Spielberg's Close Encounters of the Third Kind, from 1977, is the classic example: a collection of five harmonious notes (D-E-C-C-G, since you ask, if we're in C major) become the bond that brings humans and aliens together. Those big bright UFOs just can't get enough of it: they spin and dance in the skies above Wyoming.

Ridley Scott does something similar in Prometheus. We see Michael Fassbender, as the robotoid character David, kick the spaceship containing the Engineers (humanity's all-too-imperfect progenitors) into action by playing a four-note major-key theme on what seems to be a cosmic techno-flute.

The point is: no music, no communication, no possibility of connection with our alien brethren. But is this all just the workings of Hollywood's febrile imagination? Not a bit of it. Nasa has recorded the "sounds" the planets make as they orbit; or at least it has turned the radiowaves they emit into an audible format – thus giving us a physical representation of "the music of the spheres", the celestial harmonies of proportion and geometry that the ancients believed held the universe together.

And they were right. When speaking to lay audiences, the American physicist Michio Kaku, uses a musical metaphor to explain string theory, which argues that vibrating strings are the basis of all matter in the universe. Think of these, says Kaku, as the strings of a violin or cello. "How many musical notes are there on a string?" he asks. "An infinite number."

Kaku goes further even than Scott does in Prometheus, making music reach back not just to our ancestors, but beyond – to the ultimate God-like creative force that may be responsible for the whole darn shooting match. Kaku puts it somewhat differently, of course. "The mind of God," he says, "would be cosmic music. Cosmic music resonating through 11-dimensional hyperspace." Well, I always knew it was important, but music as the mind of God? Truth, as ever, is stranger than the filmic fiction of Spielberg or Scott.