UltrasoundUltrasound is sound with frequencies greater than 20 kilohertz. This frequency is the approximate upper audible limit of human hearing in healthy young adults. The physical principles of acoustic waves apply to any frequency range, including ultrasound. Ultrasonic devices operate with frequencies from 20 kHz up to several gigahertz. Ultrasound is used in many different fields. Ultrasonic devices are used to detect objects and measure distances. Ultrasound imaging or sonography is often used in medicine.
Hydraulic empireA hydraulic empire, also known as a hydraulic despotism, hydraulic society, hydraulic civilization, or water monopoly empire, is a social or government structure which maintains power and control through exclusive control over access to water. It arises through the need for flood control and irrigation, which requires central coordination and a specialized bureaucracy. Often associated with these terms and concepts is the notion of a water dynasty.
Blade RunnerBlade Runner is a 1982 science fiction film directed by Ridley Scott, and written by Hampton Fancher and David Peoples. Starring Harrison Ford, Rutger Hauer, Sean Young, and Edward James Olmos, it is an adaptation of Philip K. Dick's 1968 novel Do Androids Dream of Electric Sheep? The film is set in a dystopian future Los Angeles of 2019, in which synthetic humans known as replicants are bio-engineered by the powerful Tyrell Corporation to work on space colonies.
Blade Runner 2049Blade Runner 2049 is a 2017 American epic neo-noir science fiction film directed by Denis Villeneuve and written by Hampton Fancher and Michael Green. A sequel to the 1982 film Blade Runner, the film stars Ryan Gosling and Harrison Ford, with Ana de Armas, Sylvia Hoeks, Robin Wright, Mackenzie Davis, Dave Bautista, and Jared Leto in supporting roles. Ford and Edward James Olmos reprise their roles from the original film. Gosling plays K, a Nexus-9 replicant "blade runner" who uncovers a secret that threatens to destabilize society and the course of civilization.
