May be it's not the right place for this, but I don't know the right definition of a strange attractor. Wikipedia states that "An attractor is informally described as strange if it has non-integer dimension or if the dynamics on it are chaotic." In the Tucker's paper about Lorenz system is written that "an attractor is called strange if for almost all pairs of different points in B( Λ_f ), their forward orbits eventually separate by at least a constant δ (depending only on Λ_f )." I feel that this definitions are not equivalent. I also would welcome links to useful literature.