I’ve been in Portsmouth this week at the RAS National Astronomy Meeting. The weather has been extremely pleasant – bagged lunches on the steps of the Guildhall were very pleasant, as Bob Nichol notes:
— Bob Nichol (@robertcnichol) June 26, 2014
I gave a quick 8 minute talk in the “IMF: Facts and Myths” session on the properties of brown dwarfs – those awkward objects that are too small to be stars, but too big to be planets. These in-betweeners turn out to be a very sensitive probe of planet formation theories, and observing the mass distribution of brown dwarfs should tell us whether they are more starlike than planetlike (more on that in a future post).
Alongside my usual conference activities, I took part in the first ever NAM hack day. Hack days are an opportunity for programmers and like-minded people to spend a day creating something useful or fun from scratch. “Hack” is the operative word here – throwing together something in a few hours is never that polished 🙂
My effort was inspired by Pythagoras’ musica universalis, or “music of the spheres”. Pythagoras, and others like him, were convinced that there was a deep relationship between mathematical concepts and music. Music theory depends heavily on mathematics, but Pythagoras believed that mathematics itself was inherently musical, and that the Universe moved to a deeply beautiful set of rhythms and harmonies. For example, he believed the motions of the planets produced a music that, if humans could hear it, they would not only consider it beautiful, but discover a deeper understanding of how the Universe worked.
So, I thought about the music in planetary systems. We have the benefit of knowing many more planets than Pythagoras did, orbiting stars other than our Sun. Even for a musical dunce like myself, it’s easy to create musical notes from the properties of planets. And that’s exactly what I did for my hack: I took exoplanet data from the Open Exoplanet Catalogue, and made repeating notes for each planet. The period of the planet’s orbit dictates how frequently a note is played. If a planet orbits its star once a year, then its note will play once per second. The pitch of the note is determined by the planet’s size – small planets play a high pitched tone, and large planets play a low pitched tone.
So here’s what the Solar System sounds like as a song (headphones recommended for the full bass experience):
The inner planets orbit the Sun quickly, and make a series of high pitched ringing sounds, with the giant planets beating out a slow, ponderous bass line.
The code I wrote to make this music is open-source on Github – you can find it here. It’s written in Python, and has a reasonable user interface (remember it’s a work in progress!). Happy music making!