 There is no consensus regarding a precise definition of chaotic behavior among mathematicians and physicists, although physicists often prefer Chaos\(_{h}\) or Chaos\(_{\lambda}\). The latter definitions, however, are trivially false for finite uncertainties in real systems and of limited applicability for mathematical models. It also appears to be the case that there is no one “right” or “correct” definition, but that varying definitions have varying strengths and weaknesses regarding tradeoffs on generality, theorem-generation, calculation ease and so forth. The best candidates for necessary conditions for chaos still appear to be (1) WSD, which is rather weak, or (2) the presence of stretching and folding mechanisms (“pulls trajectories apart” in one dimension while “compressing them” in another). 