‘Life in a planetary ring’ — public engagement with speculative astrophysics
On Saturday 13 April I led a team running a public engagement event on planetary rings in Lancaster town centre. This was part of a wider three-day, free ‘family-friendly festival’, Campus in the City 2024, designed to make Lancaster University’s research more accessible to the wider local community. Our own event an output of the interdisciplinary Ringmind project on self-organisation in planetary rings that I’ve led since 2019 with Lancaster co-investigators Chris Arridge (Physics) and Leandro Soriano Marcolino (Computing).
I plan to write a few more posts later this year explaining my interest and current thinking about planetary rings, but here’s a few bullets for now:
- we know from the NASA Cassini-Huygens probe to Saturn that ring systems, though made from the humblest matter (ice and rock) and forces (mainly gravity and collisions), nevertheless generate within themselves diverse complex patterns and phenomena (see composite image below — and for a summary this paper);
- there is little if any theorising about planetary rings in the humanities and social sciences: planetary social thought has generally focused on phenomena occurring on a planet’s solid surface or within its fluid compartments (such as ocean or atmosphere);
- planetary rings and other rotating, disc-like cosmic assemblages are pretty well understood by astrophysicists, in terms of the physics of their behaviour — but they are generally approached as residual categories, as if they were merely failed attempts to produce a spherical body such as a planet or moon;
- an orbiting ring — an ever-shifting swarm of myriad small objects, subject to orbital shear and tidal forces, and continually forming and dissolving structures on different scales — is a very distinctive context for matter’s powers of self-organisation that deserves to be investigated in its own right.
At the heart of the Ringmind project is a body of code (in the Processing coding environment, and available on request) that has been developed by a series of project members over the years, that generates and visually renders computer simulations of a range of planetary ring dynamics in real time. The real-time nature of the visualisations is important, as this makes possible direct user interaction and experimentation. The project so far has proceeded in three main modes — performances, speculative research, and public engagement (for more details, see the Ringmind website).
The event on 13 April was the latest and most ambitious Ringmind public engagement event so far. But I also wanted to use it as a showcase for all the work done by artists, students and interns over the last five years — and also as a spur to completing some developments of the code to make it ready for future new developments.
The ‘Sanctuary’ events room in Lancaster City Library was a superb venue. The library building, in the corner of the city’s central market square, was created in the 1930s from a former hotel, and this room upstairs was its dance hall (and still has the balcony where the small dance-band used to sit and play). As soon as I saw the room with Ringmind in mind, I could see its potential as an atmospheric space for a collective experiment in imagining ‘life in a planetary ring’.
I promoted the event in advance like this:
Building on what astrophysicists know about planetary rings and their complex dynamics, and using beautiful interactive computer simulations, we will be using our senses and our imagination to explore planetary rings known and unknown, real and imagined, possible and impossible.
In the three months leading up to the event, a superb team of students did the necessary coding work for preparing the different exhibits: Atiya Mahboob (who took overall responsibility for coding preparations as part of a University-funded internship), Ben Lowe (who I employed on an informal internship to work on some exhibits) and Ben Pilchard (who did his BSc Computing Final Year Project with Ringmind). And then on the day we had invaluable help in setting up and running the event from students Sam Stewart and Eoin Neale, and my co-investigator Leandro.
In the hallway just outside the room we put large posters explaining to visitors briefly what planetary rings are, what the Ringmind project is, and the layout and basic details of the eight exhibits that the visitors would encounter inside the room (also available as a handout). When they entered, they found themselves in a long, dark hall, with a number of bright colourful simulations evolving around the edge. The sense of being in an exotic space where strange things might happen and new thoughts arise was greatly enhanced by a rotating quadraphonic soundscape that spatial audio sound designer Tony Doyle developed for the project in 2019.
Once in the room, visitors were encouraged to engage with the exhibits, which were organised into three progressively active modes of engagement: ‘watch’, ‘play’ and ‘imagine’. Over the four hours of the event, approximately 120 people came upstairs, entered the space and got involved with the different exhibits — most of these children of various ages in family groups.
Our first engagement mode was WATCH — allowing visitors to slowly get a sense of what they were seeing, in preparation for possible more active engagement.
Exhibit 1 was a show-reel projected on the large end wall created by Ben Lowe, loosely based on a similar exhibit that Thomas Cann and I had created for an earlier Ringmind public engagement event in the library in 2019 — it showed a programmed cycle of simulations and visualisations that were first developed for us in 2019 by artist Ashley James Brown. The first showed a spherical cloud of particles orbiting a planet, slowly flattening their orbits into a coplanar ring (in reality this takes a long time, as they collide and exchange momentum — in the simulation we cheat and accelerate the process). Next was a full ring system through which the camera flew on a pre-recorded path (see above). Finally, Ben’s show-reel switched to a ‘connected mode’ that Ashley created, speculatively connecting networks of particles as they formed into transient ‘murmurations’.
Exhibit 2 (above) showcased the work in 2022 of MSc student Aaron Patel. This used our simulation of a close-up of a section of ring to model the process where a moonlet orbiting in a ring gap (but held in the middle of the projection by moving the point of view along with the moonlet) produces wave-like ‘wakes’ in the nearby edges of the rings, as it gravitationally perturbs the orbits of the particles passing nearby (for an example from Saturn, see the moonlet Daphnis). We also showed a looping video explaining the rotating frame of reference used in this simulation (and in Exhibit 5).
Then came the second of the three engagement modes — PLAY — in which we encouraged visitors to get more hands on, exploring and manipulating planetary rings.
Exhibit 3 (above) was a simulation that shows what we might call a ‘metabolic’ exchange between rings and moons — how ring particles can sometimes coalesce into moons, and moons be broken up into particles (see this report of a new, short-lived moon of Saturn in 2012). It was coded by BSc Computing student Luigi Lin, in 2020, and then developed further by Computing student Alexandra Stanhope in 2021. I initially imagined that this exhibit would just run unattended for people to watch, but it turned out to be very popular, especially with the younger visitors, who loved to experiment with changing the parameters (number of particles, strength of gravity, proportions of ice and rock, etc.) to see how this altered the dynamic between moon formation and destruction. These curious budding speculative astrophysicists somehow managed to find combinations of parameters that produced ring dynamics that I had never seen before — sometimes managing to coax all the particles into wildly eccentric elliptical orbits, so that the image was often empty for prolonged periods, then the particles all rushed close to the planet, some smashing together into moons, then being broken up again.
Exhibit 4 (above) was a flight simulator coded for this event by MSc Physics student Ben Lowe. We based this loosely on the one developed by SpaceX simulating the controls and Heads-Up Display used by NASA astronauts to dock with the International Space Station. Using a rudder and throttle, and with realistic physics of moving in freefall, visitors learned how to pilot a spacecraft through a live-simulated ring system — if they got good at it, perhaps we would show them how to land on a moonlet! (We installed a few ‘cheat’ reset buttons, in case the craft overshot the system or spun wildly.)
Exhibit 5 (above) was coded by Computing and Maths student intern Atiya Mahboob, based on earlier work by graduate intern Chris Lawson in 2020, and incorporating code improvements from BSc Computing student Ben Pilcher. This, like E2, was a close-up of a ring section, in a rotating frame of reference, but like E3, was a hands-on interactive exhibit in which visitors could alter parameters, experiment, and in effect create their own ring system with structured disturbances (known as ‘propellers’) moving within it. They could add a moonlet and alter other parameters, and see how this affected the trajectory of particles , which were colour-coded into families of trajectories . Some particles manage to escape the moonlet, others collide with it and pile up in ‘Roche lobes’, others are sent ‘horseshoeing’ off back the way they came! (See this paper for more on these dynamics.)
Exhibit 6 (above) used the full-3D virtual reality simulation of a ring-and-moon system developed in 2019 by graduate interns Thomas Cann and Sam Hinson, and artists Ashley James Brown and Tony Doyle, using the Unity game development engine. This is now a free downloadable app that runs on any Android phone, placed in a Google Cardboard viewer (which cost about £10). The app runs a simulation on the phone itself, so is simplified in its dynamics. But its full-3D VR presentation of rings and moons circling around a central planet — and the facility to use the button on the viewer to select a moon or planet and fly to it , plus Tony’s spatial audio soundscape— gives a really nice, immersive way to explore a ring-and-moon system. (Personally, I like to fly out to a moonlet orbiting within an outer ring and sit there watching the particles drift by, as if floating along a lazy river.)
The third and final mode of engagement was IMAGINE — for which we had two exhibits designed to encourage people to develop and share their own ideas about what it might be like for humans — or other beings — to live in a planetary ring.
Exhibit 7 (above) was a wall on which people could write their own questions, prompted by a few ideas of our own and encouraged to be as wild and imaginative as they liked.
Finally, Exhibit 8 (above) was a little pod that could accommodate four people at once, in which they could draw their own ideas about what life might be like in a planetary ring. If humans lived there, how might they adapt to or take advantage of how rings behave? What forms of alien life might evolve there?
imagine a speculative astrophysics club and planetary makerspace
Overall, I was delighted with how the event went. Thanks to weeks of superb, collaborative coding from Atiya, Ben and Ben — and quite a few hurried fixes of last-minute technical glitches — all the exhibits worked really well. The visual and sonic elements of the event combined to make a striking atmosphere in the room, completed by the engagement of the visitors, which seemed to be a nice mix of wonder, curiosity, experimentation, reflection and imagination.
It was only after the event that one of its achievements became clear to me. Rather than simply showing them images of distant planetary rings like those of Saturn, we helped people start to imagine what it would be like to actually be in a ring system, and what might happen there. And, even in the short time that most of them were in the room, at least some of the visitors seemed to want to move beyond just learning ‘facts’ about planetary rings and how they behave, and instead to explore with us the ‘outer limits’ of what planetary rings, somewhere in the cosmos, might be able to do — or come to be able to do.
Some of the visitors, especially children, came more than once during the afternoon — some even asking if they could ‘come back tomorrow’ to continue their experimentation, and were disappointed to find out that ours was a one-off event. And that got me doing my own imagining over the following days.
- Imagine if we developed each of the exhibits further, so that they even more carefully facilitated users developing their own, deep, embodied understanding of planetary rings as an environment.
- Imagine if we expanded the event into something more long-term— maybe created a weekly ‘speculative astrophysics club and planetary makerspace’.
- Imagine if this resulted in a few years’ time in a cohort of young people with a deep understanding of the peculiar geometry of orbital space with its different ‘zones’ and ‘points’ generated by three-body gravitational interaction; of the laws of motion in the void and how to use them to move around a gravity well; of how order and structure emerges out of the interaction of populations of orbiting particles exchanging energy and momentum.
- And imagine a group of people confident in designing their own exoplanetary ring systems, of using their understanding of ring dynamics to imagine ring systems with very different physical properties, capable of even greater feats of self-organisation and structure-formation than are observed in our own solar system.
That would be quite an outcome.
ACKNOWLEDGEMENTS
As well as those thanked above, many thanks are also due to Jess Shaw and the rest of the Campus in the City team at Lancaster University; Amelia Webster and Dave Webster at Lancaster Central Library for being so helpful, and tolerating all my visits, questions and requests leading up to the event; Lancaster University’s Careers & Employability Service and Faculty of Science and Technology for internship funding, and the Information Systems Services and Mobslab for equipment loan; and Lilka Szerszynska for creating the ‘rotating frame of reference’ video.
