Cybernetics Forrester at MIT in the 1950s, is a related field. Cybernetics has been defined in a variety of ways, by a variety of people, from a variety of disciplines. Cybernetician Stuart Umpleby reports some notable definitions: Other notable definitions include: The term "cybernetics" stems from κυβερνήτης ("cybernḗtēs") "steersman, governor, pilot, or rudder". As with the ancient Greek pilot, independence of thought is important in cybernetics. French physicist and mathematician André-Marie Ampère first coined the word "cybernetique" in his 1834 essay "Essai sur la philosophie des sciences" to describe the science of civil government. The term was borrowed by Norbert Wiener,
Complex number the theorem in 1797 but expressed his doubts at the time about "the true metaphysics of the square root of −1". It was not until 1831 that he overcame these doubts and published his treatise on complex numbers as points in the plane, largely establishing modern notation and terminology. In the beginning of the 19th century, other mathematicians discovered independently the geometrical representation of the complex numbers: Buée, Mourey, Warren, Français and his brother, Bellavitis. The English mathematician G.H. Hardy remarked that Gauss was the first mathematician to use complex numbers in 'a really confident and scientific way' although mathematicians