Chaos Lab vs Deltarium

Chaos Lab puts the beauty of chaos in your hands. With a tilt of your device, you control the parameters of beautiful mathematical objects called strange attractors, the reaction rates of a chemical oscillator, the position of two stars in a 3-body chaos simulation, and the shape of the Julian fractal. Now you can be an experimentalist and an artist. Using real-time integration of over 6,000 points for the attractors whose parameters are tied to your motion, over 7,000 data points for a fractal which morphs at your command, ten "asteroids" demonstrating chaotic sensitivity to initial conditions in a jittering twin-star system where the stars move with your tilt (can you keep them from escaping?), and a real-time BZ-reaction simulation which you control by both tilt and touch, this is chaos as you've never seen it before. Chaos Lab comes loaded with four of the most stunning attractors in chaos theory. The Rössler and Lorenz attractors are well known, but the Thomas and Newton-Leipnik attractors are relatively new and quite amazing! This work has been supported in part by grant PHY-0754081 from the U.S. National Science Foundation, the Nonlinear Dynamics Research Group at Drexel University (directed by Dr. Robert Gilmore), and the Department of Physics at Drexel University. Please note, some of these experiments will run slower on the older models of iPhones and iPod touch devices. Find the beauty in the chaos!

Deltarium is a place to walk among worlds, the way a planetarium is a place to walk among stars. Each world is a living system of change. You move a few sliders, press play, and watch what the mathematics does: rabbits and foxes chase each other in cycles, a chaotic attractor traces its butterfly wings, a rocket bends time on its way to another star. Built for kids and curious people first, and for scientists too. There is nothing to sign into, nothing to buy, and no ads. The app runs entirely on your phone and collects nothing. THE 8 WORLDS PREDATOR AND PREY. The classic hare-and-lynx cycle. Set the birth, hunting, and dying rates and watch the populations chase each other around a loop. A guided tour walks through this world one step at a time. THE BUTTERFLY. The Lorenz attractor in 3D, spun with a finger. Turn on the twin path, which starts a hair away from the first, and watch the two separate. The butterfly effect you can see. ESTUARY. A coastal model of nutrients and life that blooms and crashes with the seasons. THE DANCE. Three stars pulling on each other, including the famous figure-eight where they chase one another forever. PARKING IN SPACE. The 5 Lagrange points, the spots where a small craft can hold its place relative to the Earth and Moon. Give all 5 a shared kick and see which ones stay parked and which wander off. RADIOACTIVITY. How a radioactive source fades over time, following the real decay chain from a parent down through its daughters. TIME DILATION. A rocket that holds a steady 1 gravity of thrust all the way to a distant star, flipping over at the midpoint to slow down. The clock on the ship and the clock back on Earth pull apart. BUILD YOUR OWN. Write your own equations, add sliders for the parts you want to tune, and watch the system run. UNDER THE HOOD Every world is a real system of ordinary differential equations, solved on your phone by the same numerical method scientists use. Each screen carries a science card naming the model, its author, and a reference you can look up. The phone's engine is checked against a published Python reference, and all the source code is public at github.com/evanleeturner/deltarium-iphone.