Lie great number of lies, depending on how the political wind blows." The question of whether lies can reliably be detected through nonverbal means is a subject of some controversy. Polygraph "lie detector" machines measure the physiological stress a subject endures in a number of measures while he/she gives statements or answers questions. Spikes in stress are purported to indicate lying. The accuracy of this method is widely disputed, and in several well-known cases it was proven to have been deceived. Nonetheless, it remains in use in many areas, primarily as a method for eliciting confessions or employment screening. Polygraph results
Sophus Lie them, and studying the corresponding generating vector fields (the so-called infinitesimal generators). The generators are subject to a linearized version of the group law, now called the commutator bracket, and have the structure of what is today called a Lie algebra. Hermann Weyl used Lie's work on group theory in his papers from 1922 and 1923, and Lie groups today play a role in quantum mechanics. However, the subject of Lie groups as it is studied today is vastly different from what the research by Sophus Lie was about and “among the 19th century masters, Lie's work is "in detail"