If you've ever wondered what the Milky Way sounds like when it's spinning, a new musical composition has your answer. Mark Heyer, an astronomer and research professor at the University of Massachusetts Amherst, has developed an algorithm that transforms astronomical data on the movement of the galaxy into musical notes and composes galactic jazz. The song titled Milky Way Blues will be shown on the Astronomy Sound of the Month website within the next 30 days. The site shows different sounds created from real astronomy data and explores how sound complements the field of astronomy, which is by nature a visual science.
"This musical expression lets you" hear "the movements of our Milky Way," said Mark Heyer. "The notes primarily reflect the velocities of the gas revolving around the center of our galaxy."
The Milky Way is a barred spiral galaxy, a very common type of galaxy in the universe. It consists of several hundred billion stars and clouds of dust and gas, all of which interact by gravity. The interstellar gas forms an essential part of the visible matter in our galaxy. However, the distribution and movement of this gas is very complex, especially in the center of the galaxy. The gas, which is located in the space between the stars, comes in three forms: atomic, molecular and ionized. By assigning different tones and lengths of notes to the observed spectra of each gas, astronomers can express the movement of gases through the galaxy. It's something we can not find in astronomical imagery.
"Astronomers make amazing pictures, but they are a snapshot and therefore static." In fact, stars and interstellar gas are constantly moving through the galaxy, but this motion is not conveyed in these pictures. "The Milky Way and the universe are very dynamic "And translating that movement into music is one way to express that action," Heyer said. "I've stayed true to the data, I did not massage them to make them sound good, but by transforming what we actually observe with a radio telescope into a scale, it gives us familiar sounds that sound surprisingly like music  Heyer's two-minute composition is based on the 20 years of radio telescopes and focuses on molecular gas in the galaxy.The composition comprises four instruments: wood blocks and piano represent molecular gas while The pitch and length of the note vary with the speed and intensity of the gas.
To add a visual element to the piece, Heyer worked with another astronomer. Various colors and circles in the video represent the gas movement in the Milky Way.
"Every observation is through a line showing where the telescope was pointing and the positions of the circles along a line showing the positions of the gas in the galaxy responsible for the notes played, "explains Heyer. "To sum up, the variation in pitch that sounds in" Milky Way Blues "represents the movement of the gas around the center of our galaxy."