Reverse Turing test section. Since Turing test judges are sometimes presented with genuinely human subjects, as a control, it inevitably occurs that a small proportion of such control subjects are judged to be computers. This is considered humorous and often embarrassing for the subject. This situation may be described literally as the human "failing the Turing test", for a computer (the intended subject of the test) achieving the same result would be described in the same terms as having failed. The same situation may also be described as the human "failing the reverse Turing test" because to consider the human to be a
Characteristic class Characteristic class In mathematics, a characteristic class is a way of associating to each principal bundle "X" a cohomology class of "X". The cohomology class measures the extent the bundle is "twisted" — and whether it possesses sections. Characteristic classes are global invariants that measure the deviation of a local product structure from a global product structure. They are one of the unifying geometric concepts in algebraic topology, differential geometry, and algebraic geometry. The notion of characteristic class arose in 1935 in the work of Eduard Stiefel and Hassler Whitney about vector fields on manifolds. Let "G" be a topological