Strange Attractors and You This site will explain what a strange attractor is and how to discover one yourself. All you need is a means of plotting a point. Graphing paper will do but a computer is preferred.

steps: given the following parametric equations: xn+1=a0+a1x+a2x2+a3y+a4y2+a5xyx_{n+1} = a_0 + a_1x + a_2x^2 + a_3y + a_4y^2 + a_5xy yn+1=a6+a7x+a8x2+a9y+a10y2+a11xyy_{n+1} = a_6 + a_7x + a_8x^2 + a_9y + a_{10}y^2 + a_{11}xy 1. Assign random values (from -1 to 1) to all values of aia_i it will look something like this: xn+1=0.30.5x0.9x2+0.9y+0.8y20.6xyx_{n+1} = -0.3 - 0.5x - 0.9x^2 + 0.9y + 0.8y^2 - 0.6xy yn+1=0.1+0.9x0.6x20.3y0.7y2+0.9xyy_{n+1} = -0.1 + 0.9x - 0.6x^2 - 0.3y - 0.7y^2 + 0.9xy We now have our attractor! ...But what do we actually do with it? 2. Pick an initial point, lets call it PP For simplicity we can start at (0,0)(0, 0), giving us P=(0,0)P = (0, 0) Using our xn+1x_{n+1} and yn+1y_{n+1} equations we can plug PP into them as many times as we wish, generating a new point Pn+1P_{n+1} using the equation Pn+1=(xn+1(Px,Py),yn+1(Px,Py))P_{n+1} = (x_{n+1}(P_x, P_y), y_{n+1}(P_x, P_y)) 3. Calculate Pn+1P_{n+1} and plot! 1 Use the slider to generate points 2 through 10 This is what we get after repeating step 3 nine times!

The result of our work is a little cool--at least to me--but it's really nothing "strange". Why then are they called "strange attractors" and what is an "attractor" anyways? Put simply, an attractor is a system that attracts points to certain positions in 2D space. In the example above, our point PP is being attracted to the point (-infinity, -infinity), which is called diverging. Since we randomly generated our example, there's an infinite number of other attractors! Some of which converge to a single point or certain paths. Okay... But what makes them strange? Well, 99% of the time an attractor will simply diverge to infinity, but the rest you will find act pretty strangely. That's really the only reason they're named that! I don't know about you, but I really find these beautiful. at least some of them. You can use the "generate new attractor" button if you're displeased. add dimension