optical tuning range
81High-temperature superconductivity — Unsolved problems in physics What causes superconductivity at temperatures above 50 kelvin? High temperature superconductors (abbreviated high Tc or HTS) are materials that have a superconducting transition temperature (Tc) above 30 K… …
82Electronic amplifier — A practical amplifier circuit An electronic amplifier is a device for increasing the power of a signal. It does this by taking energy from a power supply and controlling the output to match the input signal shape but with a larger amplitude. In… …
83Gramophone record — A 12 inch (30 cm) 33⅓ rpm record (left), a 7 inch 45 rpm record (right), and a CD (above) A gramophone record, commonly known as a phonograph record (in American English), vinyl record (in reference to vinyl, the material most commonly used after …
84Norden bombsight — The Norden bombsight at the Computer History Museum in Mountain View, California. This example does not have the associated autopilot attached …
85artificial intelligence — the capacity of a computer to perform operations analogous to learning and decision making in humans, as by an expert system, a program for CAD or CAM, or a program for the perception and recognition of shapes in computer vision systems. Abbr.:… …
86Lyot filter — A Lyot filter, named for its inventor Bernard Lyot, is a type of optical filter that uses birefringence to produce a narrow passband of transmitted wavelengths. Lyot filters are often used in astronomy, particularly for solar astronomy.A Lyot… …
87High Frequency Active Auroral Research Program — HAARP is often confused with Project HARP, the High Altitude Research Project (a joint project of The Pentagon and the Canadian Department of National Defence).The High Frequency Active Auroral Research Program (HAARP) is an investigation project …
88Signals intelligence in modern history — This article is a subset article of the article Signals intelligence, which addresses the unifying conceptual and technical factors and common technologies in this intelligence discipline. This article deals with signals intelligence in the… …
89Seiko — Infobox Company company name = Seiko Holdings Corporation セイコーホールディングス株式会社 company type = Public tyo|8050 company company slogan = foundation = Chūō, Tokyo, Japan (1881) (Incorporated in 1917) location = Minato, Tokyo, Japan (Officially… …
90Dichroic filter — Dichroic filters A dichroic filter, thin film filter, or interference filter is a very accurate color filter used to selectively pass light of a small range of colors while reflecting other colors. By comparison, dichroic mirrors and dichroic… …
