Solar Equation

Relational Architecture 16

"Solar Equation" is a large-scale public art installation that consists of a faithful simulation of the Sun, 100 million times smaller than the real thing. Commissioned by the Light in Winter Festival in Melbourne, the piece features the world’s largest spherical balloon, custom-manufactured for the project, which is tethered over Federation Square and animated using five projectors. The solar animation on the balloon is generated by live mathematical equations that simulate the turbulence, flares and sunspots that can be seen on the surface of the Sun. This produces a constantly changing display that never repeats itself, giving viewers a glimpse of the majestic phenomena that are observable at the solar surface and that only relatively recent advances in astronomy have discovered. The project uses the latest SOHO and SDO solar observatory imaging available from NASA, overlaid with live animations derived from Navier-Stokes, reaction diffusion, perlin, particle systems and fractal flame equations.

Using an iPhone, iPod touch or iPad, people may disturb the animations in real-time and select different fluid dynamic visualizations. You can download the free app from here.

While pertinent environmental questions of global warming, drought, or UV radiation might arise from the contemplation of this piece, Solar Equation intends to likewise evoke romantic environments of ephemerality, mystery and paradox, such as those from Blake or Goethe. Every culture has a unique set of solar mythologies and this project seeks to be a platform for both the expression of traditional symbolism and the emergence of new stories. Just like the installation depends on the world’s brightest projectors to exist, conceptually the piece is open for the public to make their own symbolic projection and interpretation. Some might experience the work as a traditional son-et-lumiere spectacle, other as a didactic visualization of natural forces, while others as a call to action to harness the sustainability of solar power. Coincidentally, the sun’s generates its own energy by nuclear fusion of hydrogen nuclei into helium, the inert gas that is used to fly the maquette.

Download a pdf file with detailed information on the project including historical precedents, technical and practical details.

General info

Spanish name:
Ecuación Solar
Year of creation:
spherical captive balloon, helium, tethers and winches, 5 HD projectors, 7 computers with custom-made software, wifi network, iOS app
aerostat has 14 meters diameter



  • Concept, Direction and Visuals: Rafael Lozano-Hemmer
  • Programming: Conroy Badger
  • Production Assistance: David Lemieux, Karine Charbonneau, Stephan Schulz, Guillaume Tremblay, Natalie Bouchard, Gideon May, Susie Ramsay, Ben Duffield, Andrew Emond
  • Artistic Director, The Light in Winter: Robyn Archer (Artistic Director), Matt Jones (Program Manager)
  • CEO, Fed Square Pty Ltd: Kate Brennan
  • Commissioned by: the Light in Winter Festival, Federation Square, Melbourne, with Major Partners the City of Melbourne, Microhire, Air Canada, Sofitel, Technical Direction Company, Ikon.
  • Custom balloon by: Airstar Lighting
  • Acknowledgements: friends at Fed Square Pty Ltd, Fed Square Pty Ltd'sBoard, friends at Microhire (particularly Adam Halliday, Aaron Pendergast and Shaun Donsen), friends at Airstar (Benoit Beylier, Pascal Petitjean, Alexis Coudurier and Simon Lee), Victor Friedberg, Paul Bourke, Emily Bates, Nina Miall, friends at NASA (Bert Ulrich, Madhulika Guhathakurta, Steele Hill, Bernhard Fleck, Bob Stein)