Listen to our galaxy’s rotation as cosmic jazz

Thomas McMullan Read more May 4, 2018

A research professor at the University of Massachusetts Amherst has translated the movement of the Milky Way into a particularly jazzy musical composition.

Astronomer Mark Heyer developed an algorithm that takes data about astronomical gases, and then expresses this as notes on a pentatonic scale. The result is a piece of music he calls Milky Way Blues.

“This musical expression lets you ‘hear’ the motions of our Milky Way galaxy,” he claims. “The notes primarily reflect the velocities of the gas rotating around the centre of our galaxy.”

To make the music, Heyer assigned notes to the atomic, molecular and ionised gases that exist between stars in the galaxy, doling out different tones, pitches and note lengths to the spectra and velocity of each gas phase. Atomic gases were assigned an acoustic bass, molecular gas was given woodblocks and piano, and ionised gas was expressed as notes on a saxophone.

For Heyer, the reason behind the project is to try and find a way to communicate the galaxy’s motion. “Astronomers make amazing pictures, but they’re a snapshot in time and therefore static,” he says. “In fact, stars and interstellar gas are constantly moving through the galaxy but this motion is not conveyed in those images. The Milky Way galaxy and the universe are very dynamic, and putting that motion to music is one way to express that action.”

Heyer says he has been true to the data, which he amasses from 20 years of radio telescope observations. In the above video, the astronomer worked with Greg Salvesen of the University of California, Santa Barbara, to visualise where each note was coming from in the galaxy. “Each observation is represented by a line showing where the telescope was pointing and the positions of the circles along a line show the locations of the gas in the galaxy responsible for the played notes,” says Heyer.

This is far from the first effort to turn cosmic movements into music. The whole concept of the Music of the Spheres is an ancient notion that connects the movement of celestial bodies to mathematical harmony. Thinkers from Pythagoras to Johannes Kepler have based ideas on this line of thought.

Modern physicists also have a penchant for turning data into music. In 2016 the Quantizer project translated events from the ATLAS detector into different compositions. The results ranged from prog-rock soundscapes to music that sounded like the opening of a cop drama.

Last year, we chatted to Marcus du Sautoy about a collaboration with the composer Emily Howard to create compositions based on different types of mathematical proof. He spoke about the appeal of understanding patterns, whether that’s an abstract proof or the movement of galactic gases, in terms of music:

“I think the aesthetic in maths is similar to the aesthetic in music, perhaps more so than any of the other artistic disciplines,” he said at the time. “Because I think it’s very much based on the brain enjoying connection and transformation. It enjoys seeing how one thing is connected to a previous thing, but has changed and is developing.”