Engine in thrust. Particularly notable kinds of engines include: Engine An engine or motor is a machine designed to convert one form of energy into mechanical energy. Heat engines burn a fuel to create heat which is then used to do work. Internal combustion engines are heat engines that burn fuel in a combustion chamber to extract work from the pressure of expanding gases. Electric motors convert electrical energy into mechanical motion; pneumatic motors use compressed air; and clockwork motors in wind-up toys use elastic energy. In biological systems, molecular motors, like myosins in muscles, use chemical energy to create forces
The Work of Art in the Age of Mechanical Reproduction free", for lacking the "aura" of the original work of art. The Work of Art in the Age of Mechanical Reproduction The Work of Art in the Age of Mechanical Reproduction (1935, "Das Kunstwerk im Zeitalter seiner technischen Reproduzierbarkeit"), by Walter Benjamin, is an essay of cultural criticism which proposes that the "aura" of a work of art is devalued by mechanical reproduction. The subject and themes of the essay have much influenced the fields of art history and architectural theory, and of cultural studies and media theory. During the Nazi régime (1933–1945) in Germany, Benjamin wrote the essay to